1. ENHANCEMENTOF
SYNGASPRODUCTION
USINGAGRI-WASTE
TECHNOLOGY
PLANT DESIGN
PROJECT REPORT
Tug of War:
Fossil Fuels against
Renewables
LEAD DESIGNERS:
SAM TZE MUN (920720075054);
LEE REN JIE (930405085243); LIM SHIH CHIANG (921203135201);
MONG IRENE (930323145708); SHERON LIM GEK JOO (930330136084)
YEAR OF STUDY: 4TH YEAR (FINAL YEAR)
CONTACT:+6012-4159110 | 7E1B8965@STUDENT.CURTIN.EDU.MY

2. I
ACKNOWLEDGEMENT
First and foremost, we would like to express our deepest appreciation to the Faculty of
Chemical Engineering of Curtin University Sarawak Campus for giving us the opportunity to
participate in the National Chemical Engineering Symposium (NACES) Process Plant Design
Competition in our final year.
Next, we would like to express our gratitude to our supervisor, Dr. Jibrail Kansedo for all the
sincere help from providing insight in various aspects to recommending useful and reliable
resources with clear explanation. He is very approachable and welcomes any enquiries in the
form of email and face-to-face discussion. We definitely will not be able to commence the
design without his advices.
Lastly we would like to express our indebted gratitude to Dr Bridgid Chin Lai Fui, the
advisor for this category in providing relevant information and advices that are proved useful
in research and report writing. We would not be able to complete this report smoothly
without her sincere guidance.

3. II
TABLE OF CONTENTS
Page
1.0 INTRODUCTION ..........................................................................................................1
1.1 Design Background.....................................................................................................1
1.2 Market Survey.............................................................................................................2
1.2.1 World energy consumption and supply ...............................................................2
1.2.2 Hydrogen Economy .............................................................................................3
1.2.3 Global agri-waste production...............................................................................3
1.2.4 Sub-bituminous coal supply.................................................................................4
1.2.5 Syngas market......................................................................................................5
1.3 Raw Materials .............................................................................................................7
1.4 Process Screening........................................................................................................7
1.5 Site Selection...............................................................................................................9
1.6 Problem Statement ....................................................................................................10
1.7 Proposed Solution .....................................................................................................10
2.0 DESIGN METHODOLOGY........................................................................................11
2.1 Design Process Description.......................................................................................11
2.1.1 Basis of design ...................................................................................................11
2.1.2 Process overview................................................................................................11
2.2 Material and Energy Balance ....................................................................................14
2.3 Heat Integration.........................................................................................................14
2.4 Process Optimization.................................................................................................15
2.5 Process Control .........................................................................................................16
3.0 PROFITABILITY ANALYSIS ....................................................................................17
3.1 Capital and Operating Cost Investment ....................................................................17
3.2 Economic Scenario Analysis: Base, Best and Worst Case .......................................17
4.0 RISK ASSESSMENT...................................................................................................18
4.1 Economic Aspect.......................................................................................................18
4.2 Safety Aspect and HAZOP Assessment....................................................................18
4.3 Environmental Aspect...............................................................................................19
5.0 CONCLUSION.............................................................................................................20
REFERENCES ........................................................................................................................21
APPENDICES .........................................................................................................................28
Appendix A: Product, Raw Materials and Process Technology Evaluation........................28
Appendix B: Process Plant Site Selection............................................................................34
Appendix C: Process Simulation Basis of Design ...............................................................36

4. III
Appendix D: Process Flow Diagram, Stream Table, Utilities, Mass and Energy Balance
(Before Optimization) ..........................................................................................................41
Appendix E: Heat Integration ..............................................................................................60
Appendix F: Optimization Parameters, Stream Table and Process Flow Diagram (After
Optimization) .......................................................................................................................66
Appendix G: Piping and Instrumentation Diagram (PID) ...................................................74
Appendix H: Equipment Schedule and Pipe Sizing Specifications .....................................77
Appendix I: Equipment Costing and Methodology .............................................................80
Appendix J: Economic Assumptions and Capital Cost Calculation....................................98
Appendix K: Layout Plan and Safety Features .................... Error! Bookmark not defined.
Appendix L: Key Issues for Plant Commissioning, Start-up and Shutdown.....................111
Appendix M: Environmental Risk Assessment .................................................................113

5. IV
LIST OF FIGURES
Figure1.1. World primary energy supply (Botha 2012) ............................................................2
Figure 1.2. Global rice husk production (Bronzeoak 2003) ......................................................4
Figure 1.3. Estimated world coal production from 1985 to 2100 (Hook et al. 2010)................5
Figure 1.4. World primary energy demand (Energy Security n.d.) ...........................................6
Figure 1.5. Syngas Usages (Syngas 2015).................................................................................6
Figure 1.6. Proposed site area for plant design (Score 2015) ....................................................9
Figure 2.1. Process flow diagram of co-gasification of coal and biomass plant design ..........12
Figure 2.2. Flowchart for energy integration workflow ..........................................................14
Figure 2.3. Composite Curves .................................................................................................60
Figure 2.4. Process flow diagram after optimization...............................................................16
Figure D. Process flow diagram before optimization ..............................................................41
Figure F. Process flow diagram after optimization..................................................................67
Figure G. PID for process plant ...............................................................................................74

6. V
LIST OF TABLES
Table 1.1: Raw materials and product specification................ Error! Bookmark not defined.
Table 2.1. Total Flowrate of Utilities....................................... Error! Bookmark not defined.
Table 2.2. Energy saving from hot and cold utilities ...............................................................15
Table 2.3. Total utilities cost before and after process optimization .......................................66
Table A.1. Fractional atom economy calculation ....................................................................28
Table A.2. Calculation of raw materials gasification process economy..................................29
Table A.3. Summary of comparison between various types of gasifiers.................................30
Table A.4. Summary of different type of fluidized bed gasification processes.......................31
Table A.5. Evaluation on various desulphurization process technologies...............................32
Table A.6. Summary of similar operating plant with CFB technology ...................................33
Table B. Comparison for Site Selection ..................................................................................34
Table C.1. Property method, model and general assumptions for simulation thermodynamics
..................................................................................................................................................36
Table C.2. Ultimate analysis (% wt) of coal and rice husk by dry ash free basis....................36
Table C.3. Proximate analysis (% wt) of coal and rice husk ...................................................36
Table C.4. Sulphur analysis (% wt) of coal with 1.97% sulphur in ultimate analysis.............36
Table C.5. Key equipments, feeds and process stream specifications for design basis input .37
Table D.1. Base case flowsheet ...............................................................................................41
Table D.2. Heating and cooling utilities ..................................................................................48
Table E.1. Data Extracted from Aspen Energy Analyzer and Shifted Temperature ...............60
Table E.2. Sub-Networks and Cascading Process ...................................................................63
Table E.3. Cascade Diagram....................................................................................................64
Table F.1. Flowsheet optimization...........................................................................................66
Table F.2. Optimized case flowsheet....................................... Error! Bookmark not defined.
Table G. Process control philosophies for each equipments ...................................................75

7. VI
EXECUTIVE SUMMARY
Following the recent focus in biomass gasification as alternative feed to fossil fuels for its
minimal environmental impact, the co-gasification of coal and renewable carbon-based
biomass has become a new area of research and attractive design approach due to its ability to
reduce greenhouse gas emissions and improve energy efficiency. A plant design is proposed
at Samalaju Industrial Park, Sarawak, Malaysia with the highlight of co-gasification
technology using sub-bituminous coal and rice husk at 1:1 ratio to achieve high gas yield, low
tar and char yield, as well as high thermal efficiency with effective HRSG and
desulphurization gas cleaning technology that promotes sustainable development in
environmental, economics, safety and resources aspects. A promising alternative to the
conventional processes is provided with significant focus in process safety for which risk
assessment, HAZOP, contingency plan and start-up and commissioning procedures are
readily available. Material and energy balance calculation performed has proved the design
feasibility followed by heat integration and process optimization with the optimized process
flow diagram shown in Appendix F (page 69).The proposed plant design is capable of
producing 50 kilo-tonnes of hydrogen-rich syngas annually with TAC of RM
3,527,888,385.34 and a payback period of 0.55 years with energy saving of 82.7%.
KEYWORD: Plant Design, Co-Gasification, Rice Husk, Sub-Bituminous Coal, HRSG, Heat
Recovery Steam Generator, Desulphurization

8. 1
1.0 INTRODUCTION
The global demand for energy and biofuels is experiencing a rising trend with the growth of
the world population and economic development in recent years. The background of the
proposed design, market survey, process screening, proposed site and solution are covered to
introduce an alternative plant design using agri-waste technology to meet energy demand.
1.1 DesignBackground
The well-established gasification technology is commonly used to transform fossil fuels such
as coal or biomass respectively into synthesis gas, often abbreviated as syngas, for
subsequent refining or utilization as combustible gas or industrial feedstock. The highlight of
this plant is the design of co-gasification process using coal and agricultural biomass waste,
rice husks as fuel to produce approximately 50 kilo-tonnes per year of syngas, with a high
target yield of hydrogen rich syngas. The gasifier is fed with rice husk and coal at a ratio of
1:1 with steam in order to achieve high gas yield, low tar yield, low char yield and high
thermal efficiency (Krerkkaiwan et al. 2013). Co-generation is defined as the production of
electricity (mechanical power) and heat such as high temperature liquid and steam to provide
a more efficient energy system which maximizes the utilization of waste heat from electricity
production (Cogeneration 2012). By introducing the co-generation system, the raw product
gas is processed through a Heat Recovery Steam Generator (HRSG) to meet the required
temperature for subsequent wet scrubbing as well as generation of mechanical power.
As further gas cleaning and treatment is required to meet pollutant emission limits and
environment policy, the crucial gas cleaning steps involved desulphurization where gaseous
contaminants such as H2S is removed before it is processed in the water gas shift reactor for a
higher hydrogen rich syngas yield (Sciubba 2009). The desulphurization technology focuses
in the regeneration of the metal absorbent used in sulphidation and it produces sulphur as one
of the by-product. Hence, the proposed green plant design using co-gasification and
desulphurization technology aims to give a promising alternative to the conventional
processes with potential all year round profitability by meeting market requirement and
operational sustainability in terms of resource utilization, social responsibility and
environmental commitment.

9. 2
1.2 Market Survey
The price trend of the raw materials and the current demand trend of the product are
investigated. In order to meet customers’ needs and expectations, marketing research is
crucial in allocating the readily available products and services to them. (Market Research
2010). The primary research is to gather data from analyzing current sales and the
effectiveness of current practices.
1.2.1 World energy consumption and supply
Following the increase in global population, industrialization development is expected to
double up the world primary energy requirements, reaching 3.2% increment annually by 2050
(Botha 2012). As mentioned by the International Energy Agency Report, fossil fuels
undeniably contributed 81.4% to the world energy supply, for which 68% of it is used in
electricity generation. However a high percentage of the world primary energy supply is from
the gas sector as shown in Figure 1.1.
Figure1.1. World primary energy supply (Botha 2012)
Greenhouse gases are generated from burning activities of fossil fuels, where the primary
components consists of carbon dioxide (CO2), water and methane. The carbon dioxide itself
is capable of absorbing solar heat radiation, fabricating an insulation layer around the earth
by preventing heat radiation to escape inside out and ultimately increasing surrounding
temperature. According to Elder and Allen (2009), the concentration of CO2 has increased
tremendously (35%) from year 1750 to 2005, events including glacial retreat that caused sea
level to rise and the extinction of natural habitats and catastrophic physical consequences
began to occur with the alarming rate of global warming. According to Botha (2012), this
global warming phenomenon had led to heavy investigation for a more efficient way to
reduce the production of greenhouse gases. A few initiative steps had been taken by the
United Nations Framework Convention on Climate Change (UNFCCC) in reference to the
21%
6%
2%
10%
26%
34%
1% Gas
Nuclear
Hydro
Biomass
Coal/peat
Oil
Others

10. 3
Kyoto Protocol by enforcing laws throughout different continentals. As with the fact that
fossil fuel is still dominating the energy supply industry, it is necessary to develop a more
innovative technology pathway to ensure a sustainable future for the coming generations.
1.2.2 Hydrogen Economy
Hydrogen is envisioned as a clean energy carrier which has the potential to replace fossil fuel
in the future (Hui Liu 2012). As hydrogen is highlighted as a high energy content producer
with zero pollution in the combustion phase, it can be the alternative energy resource to
reduce greenhouse gas emissions. Hydrogen is commonly used in fuel cells for electricity
production where recently, hydrogen market price spur significantly with introduction of the
newly Integrated Gasification Combined Cycle (IGCC) technology (Long et. al 2011).
Scientists found out that the fuel cells are capable of producing electricity up to an efficiency
of 50%. Moreover, hydrogen can be utilized to produce synthetic petroleum from coal in
Fischer Tropsch process (Botha 2012).
Hydrogen rich gas can be produced from fossil fuels such as coal and water while the current
conventional supplies are from steam reforming or thermal cracking using natural gas.
Ironically, the down-side of using fossil fuel is the large amount of greenhouse gases emitted,
which defeated the purpose of producing hydrogen as it is considered as a clean fuel.
Meanwhile, hydrogen can also be produced by splitting water, through a CO2 free process, or
even High Temperature Electrolysis, nevertheless this required a relatively high temperature
environment (Botha 2012). The process of producing hydrogen using water is usually more
expensive than using steam gasification of coal or biomass. In comparison, more benefits are
provided in terms of carbon dioxide emissions, environmental implications, primary energy
availability and hydrogen production costs using co-gasification, which will be discussed in
the upcoming section.
1.2.3 Global agri-waste production
Rice from the agricultural industry are cultivated around the globe, it is the primary source of
food for billions of people. Rice production in China is the highest followed by India, the
Asia region. According to Bronzeoak (2003), the global rice production is increasing at a rate
of 10% from year 1992 to 2002. Part of the rice, rice husk which is not eaten is claimed to be
an agri-waste where in reality, rice husks are listed as one of the largest readily available but
most under-utilized biomass resources, being classified as an ideal fuel for electricity
generation. The calorific value is different on rice variety, bran and moisture content but

11. 4
usually in a range of 8 to 10% moisture content and 15MJ/kg of calorific value (Bronzeoak
2003). To combat energy crisis, rice husk is selected as a resource for energy production for
those countries that primarily depend on imported oil resources (Ajay et. al 2012). About 770
million tonnes of rice husks is produced in Asia yearly (Santiaguel 2015). According to
TIFAC (2014), the rice husks price ranged from 20- 50 MYR/tonne with respect to
industrialized states and regions. A tremendous increase from 2 million tonnes rice is
exported in the early 1990s to 14 million tonnes in 2013 as observed for South Asia country
(Mohanty 2014). The production of rice husks produced globally is observed in Figure 1.2.
Figure 1.2. Global rice husks production (Bronzeoak 2003)
Thus rice husk is selected as the preferable biomass feedstock as it does not require any pre-
treatment process throughout the gasification process. The ash content of 20% is present at
minimal level in rice husk compared to other biomass source. The ash is high in silica (SiO2)
content range, highly porous and light in characteristic, with wide outer surface area (Ajay et.
al 2012). The ash of rice husk is statistically proven useful to many industrial applications
especially in insulating properties, which is the absorbent (Bronzeoak 2003). With the
revenue generated from selling the rice husk ash this would benefits the plant in term of the
pay-back period for the capital investment to establish the process plant. Other by-products
and their re-utilization proposal are tabulated in Table A.1 (Appendix A).
1.2.4 Sub-bituminous coal supply
A significant role is played by coal in power generation with 39% supply in the world’s
electricity and it is expected this trend will continue within the coming next 30 more years
(The Coal Resource n.d.). The expected growth in coal industry has shown China as one of
the largest producer and importer of coal with a total amount of 341 million tonnes of coal in
2013 with expected rise to 471Mt in 2019, consuming more than 50% of the global coal
demand (Sadamori 2014). The sub-bituminous coal is generally used for electricity
generation, although it has the second lowest energy content, large quantities are found in
China
31%
Indonesia
9%
Bangladesh
7%
Vietnam
5%
Thailand
5%
Myanmar
4%
Philippines
2%
Japan
2%
Others
14%

12. 5
thick beds near the surface, resulting in low mining cost and correspondingly, lower prices in
70-80 USD/tonne (EIA 2011).
Currently, over 4050 million tonnes of coal is consumed globally. It is used in various sectors
including the power generation plant, iron and steel production, cement manufacturing and
liquid fuel production (The Coal Resource n.d.). According to Sadamori (2014), with a
growing rate of 2.1% on average annually, the demand of coal will eventually surpass the 9
billion tonnes threshold in 2050 as one of the highly demanded fossil fuel where the top five
producers of coal are China, USA, India, Australia, and South Africa. It is reported that the
steam coal production is projected to reach around 5.2 billion tonnes; coking coal 624 million
tonnes; and brown coal 1.2 billon tonnes (The Coal Resource n.d.). The global coal
production is shown in Figure 1.3 as follows.
Figure 1.3. Estimated world coal production from 1985 to 2100 (Hook et al. 2010)
1.2.5 Syngas market
Syngas is an extremely flammable transparent and odourless gas with major composition of
CO followed by CO2, water, CH4 and H2 (Syngas Mix 2015). Generally, syngas is used to
generate power or further refined as feedstock for petrochemical industry. It can be further
upgraded to meet specific demands since it is a crucial intermediate resource for hydrogen,
ammonia, methanol, and synthetic hydrocarbon fuels production. The composition of H2 to
CO2 in syngas can be adjusted with respect to the demand for the syngas mixture (Brar et al.
2012). A number of liquid fuels can be created from syngas, including gasoline, diesel,
methanol and other synthetic oils which has been widely used in South Africa (Syngas 2015).
It is also used as intermediate for chemical synthesis such as methanol, ethanol, ammonia and
methene production which formed a basis for fertilizers, pharmaceutical products and other
commercial products. High hydrogen percentage syngas can be chemically converted and

13. 6
separated into a pure hydrogen stream via the shift reaction. This is summarized in Figure
1.4 below.
Figure 1.4. Syngas Usages (Syngas 2015)
It is estimated that the syngas compound annual growth rate (CAGR) will surge up to 9.5%
between 2015 to 2020 where a total amount of 116,600 MWth of syngas is produced in 2014
and is expected to hit 213,100MWth in 2020 (Rohan 2015). The end use of syngas are
classified into a few major application, including chemicals, liquid fuels, gaseous fuels, and
power generation. It can be further refined to yield products like methanol, ammonia, oxo-
chemical, hydrogen, N-butane, and Dimethyl ether (DME) which have better market price
than the revenue generated from syngas sale (Rohan n.d.). Syngas price varied from 100-300
USD/m3 with the capability of generating 3.6 MWh of electricity and 3.5 Gcalh of heat
(Syntes 2015). The world primary energy demand of natural gas and oil will eventually spike
up to 3000 to 5500 million tonnes in the coming 30 years (Energy Security n.d.). This trend
can be observed in Figure 1.5.
Figure 1.5. World primary energy demand (Energy Security n.d.)
Hence with this preliminary economic anaylsis, the proposed project is achievable with
positive price trend and high demand for the product gas. The process plant aimed to produce

14. 7
syngas at a rate of 0.316 m3/s, for which this 60 % H2 composition in syngas can provide
higher efficiency in electricity generation or to further refining steps.
1.3 Raw Materials
Sub-bituminous coal and rice husk are chosen as the raw material for co-gasification as they
are both readily available in Asia and rice husk is the energy source in thermochemical
conversion process such as gasification and combustion directly without processing
(Makwana et al. 2015). Rice husk is chosen with consideration of various aspects as shown in
Table A.1 (Appendix A). Rice husk particles varied in the range of 0.21 to 0.85 mm which is
a suitable size for Circulating Fluidized Bed technology (Gómez-Barea and Leckner 2010). It
is also the major by-products from rice milling process and constitutes about 20 % and is not
utilized to any significant extent and has great potential as an energy source (BioEnergy
Consult 2015). Furthermore, rice husk ash produced from gasification and combustion
processes can be used further as supplementary material in cement and ceramic
manufacturing process while the biochar produced can be used as soil amendment (Makwana
et al. 2015). The use of fossil fuel, coal is reduced by half compared to a typical gasification
plant, where the syngas achieved higher carbon conversion which is complimented by coal
and rice husk to produce sufficient carbon content in syngas (Mundi n.d. 2015). The storage
condition of the raw materials is available in Table A.2 (Appendix A).
1.4 Process Screening
The main processes for this plant are gasification and desulphurization, which consists of
several alternative technologies. The process screening flowchart is summarized in Figure
1.6 below.
Figure1.6. Process screening flowchart
For gasification, 4 types of gasifiers, namely the fixed bed updraft, fixed bed downdraft,
fluidized bed and entrained bed technologies are compared with respect to their fractional
atom process economy, cost, advantages, limitations and various factors as shown in Table
Select
feed
Select
gasification
technologies
Identify type
of gasifier
design
Select
desulphurization
technologies
Select
sorbent
Validate real
plant
application
1 2 3 4
2
5 6

15. 8
A.4 and Table A.5 (Appendix A). The fluidized bed and fixed bed are the most common
type of gasifiers used for co-gasification. Fixed bed updraft gasifier is able to handle high
moisture and high organic content of biomass while product from fixed bed downdraft
gasifier contains low tar and ash content (Bhavanam and Sastry 2011). However, both
designs are not feasible for up-scale production (Gasification Status and Technology 2012).
Whereas, entrained bed gasifier produce nearly tar-free and low methane syngas but it is not
suitable for biomass feed due to its high moisture content (Basu 2013). For fluidised bed
gasifier, it excels in mixing of coal and biomass feed, which is applicable to co-gasification
plant. Agglomeration of ash by-product on the bed particles might lower the process
efficiency (Kern 2012), yet this only causes less impact to entire plant. Therefore, fluidized
bed gasifier is selected and the summary is available in Table A.6 (Appendix A).
Focusing on the selected technology, there are three types of fluidized bed gasifier that can be
designed, namely bubbling fluidized bed (BFB), circulating fluidized bed (CFB) and dual
fluidized bed (DFB). BFB and CFB are operated in similar system where the difference is
CFB has an extra cyclone which is used to separate syngas and particles and allow the
materials will return to the bottom of the gasifier after separation (Makwana et al. 2015).
DFB is eliminated due to its complex construction and operation as well as it is relatively
more expensive (Puig-Arnavat 2015). CFB is the extension of BFB with cyclones and
separators to capture recycle solids to extend solid residence time (Li et al. 2004). This
increase the carbon conversion and rate of reaction in the chamber which increase the
production of syngas (Gómez-Barea and Leckner 2010). As a result, Circulating Fluidized
Bed (CFB) is chosen as shown in Table A.7 (Appendix A) for its high carbon conversion,
capability for constant temperature in reactor, compatibility for biomass-coal mixing as well
as the minimal ash and slag content in product gas for cost effective and feasible design
For gas clean-up technology, desulphurizer is designed to remove sulphur content in raw
syngas, in the form of H2S or COS. The sulphur removal is proved to be more effective by
applying adsorption process. Adsorption is a surface process, the accumulation of a gas or
liquid on a liquid or solid (Chromatography 2014). Table A.8 (Appendix A) demonstrated
the comparison of adsorption by solid sorbents and solvents, based on its advantages and
limitations. Due to its greater process efficiency and high energy saving, solid sorbent is
eventually chosen to undertake the adsorption process (Ke Liu 2010).

16. 9
Lastly, the comparison of worldwide similar operating plants, based on its development status
and product syngas characteristics is shown in Table A.9 (Appendix A). Both Foster
Wheeler and Fraunhofer Umsicht plant are using Air-Blown Gasification Cycle, with directed
heat under atmospheric pressure, while Uhde uses High Temperature Wrinkler (HTW)
gasifier, which is heated under pressurized condition, with high carbon conversion of 98%.
Based on the product characteristics, Uhde possessed the greatest potential to produce
hydrogen rich syngas, with composition of 30.1% H2 (Renzenbrink 1998).
1.5 Site Selection
For this design project, three sites have been considered. They are Samalaju Industrial Park,
Sarawak, Malaysia; Jababeka, Cikarang, West Java, Indonesia; and Zhengzhou High Tech
Industrial Development Zone, Henan, China. Samalaju Industrial Park is chosen as the
proposed plant location after comparison since various infrastructures and utilities are well
established in this industrial park and the economical aspect is also favourable as
demonstrated in Appendix B. The proposed plant site is illustrated in Figure 1.7 below.
Figure 1.7. Proposed site area for plant design (Score 2015)
Acceptable utilities cost, availability of proper waste water management, and the presence of
various governmental incentives are also some promising factors in choosing Samalaju
Industrial Park. By comparing the land price, it is found that the Samalaju Industrial Park is
far cheaper compared to the other two and a lower capital cost for the start-up of the plant is
possible. Besides that, vicinity of Samalaju Port and other transportation also ease the import
and export processes of raw materials and products, especially from China as presented in the
earlier market survey. The demand for syngas for power generation and petrochemical
Proposed Site
Location

17. 10
industries from industries in Samalauju Industrial Park is also observed in SCORE. It should
be noted that although the sub-bituminous reserve is reported to be more in China, the
weather in China varies all year round and in extreme winter, that would mean extra cost
needed for the heating system in the plant. Since Malaysia is least prone to natural disaster
such as earthquake, volcano eruption, typhoon and many more, extra advantages to build the
plant in Malaysia itself is preferred.
1.6 Problem Statement
In order to solve the alarming issue of rising greenhouse gas emission and to meet the
increasing global energy demand for renewable energy of high energy efficiency and minimal
environmental impact, the present work critically examines literature on co-gasification of
coal and biomass from pre-processing of feedstock to product utilization, and this knowledge
is applied in the proposed syngas production plant design.
1.7 Proposed Solution
The proposed plant design aimed to decrease greenhouse gas emission with the use of
recycled agricultural waste, rice husk as the fuel to co-gasification with coal and steam using
the proposed circulating fluidized bed process technology to promote efficiency in a green
field site called Samalaju Industrial Park, Sarawak, Malaysia. Moreover, the proposed plant
design emphasized on clean gas product utilization with the removal of H2S, tar and ammonia
in a recirculating desulphurization loop prior being stored or supplied to other industries.
Thus the objectives of this project are to meet market demands by producing approximately
50kT of hydrogen rich syngas annually; to reduce environmental impact and operational risks;
and lastly to ensure profit and sustainability of the plant. A sustainable environmental
development plant is proposed such that waste such as absorbents, catalyst and char are
reutilized (Appendix A) and utilities are co-generated within the plant to generate electricity
for renewable energy and ultimately to achieve high energy saving with the use of biomass.
The main constraint is the feedstock properties where the source and storage condition of raw
materials has to be constant in order to achieve the required product specifications. Another
constraint is present in the production rate for which the amount of waste produced per
annum is limited with respect to government acts and strict waste management requirement.
Lastly, the accessibility, land and safety of the plant provide challenge in plant capacity and
growth where natural disaster can impose certain risks to the plant.

18. 11
2.0 DESIGN METHODOLOGY
The basis of design, assumptions, simulation specifications and, the mass and energy balance
is presented to design the process plant. The process flow diagram and simulation flowsheet
are then developed in this section.
2.1 DesignProcess Description
The design criteria of the process plant are highly significant for the development of the
simulation, hence the input data and specifications are developed based on critical literature
review with a few assumptions applied with proper justifications.
2.1.1 Basis of design
The process is simulated using Aspen Plus instead of Aspen HYSYS due to the capability of
Aspen Plus to simulate solid feed and later on liquid-vapour phase streams with accurate
result. The operating period of the plant is 330 days per year in consideration of time taken
for maintenance or start-up work. The property methods, models and general thermodynamic
assumptions used in Aspen Plus is tabulated and justified in Table C.1 (Appendix C).
For the feedstock of the process design, pre-treatment will not be simulated and the
composition of coal and rice husk varies with negligible amount of sulphur for rice husk. The
ultimate analysis, proximate analysis and sulphur analysis of coal and rice husk is required as
basis for the simulation design in feed specifications as shown in Table C.2 to Table C.4
(Appendix C). Other feeds such as steam, water and oxygen as well as the key input data for
major equipments and streams are presented in flowsheet sequence as summarized in Table
C.5 (Appendix C).
There are a few reactions involved in the process plant, for which these reactions occurred in
the gasifier, pyrolysis reactor, desulphurizer, two absorbent regenerators and lastly the water
gas shift reactor. The pyrolysis and water gas shift reaction involved catalysts, and some
reactions in each reactor happened simultaneously as side reactions. These chemical reaction
mechanisms are shown respectively in Appendix C.
2.1.2 Process overview
The proposed process flow diagram developed from critical literature review and experts
input is shown in Figure 2.1 below with respect to the design basis and assumptions made in

19. 12
the previous section. A more detailed process flow diagram and the simulation stream table
are illustrated in Figure D and Table D.1 respectively, in Appendix D.
Figure 2.1. Process flow diagram of co-gasification of coal and biomass plant design
Based on the above illustration, the plant consists of four major sections, which are the
gasification process, gas cooling or Heat Recovery Steam Generator (HRSG) section, the gas
cleaning process, and lastly the water gas shift process. The feed includes rice husks, coal,
water, steam and oxygen in different sections whereas the products of the plant are mainly the
hydrogen rich syngas and a considerably small amount of sulphur as by-product.
Prior the gasification process, the pre-treated uniform sized raw materials (rice husks and coal)
are mixed and fed to a dryer (D-100) by using conveyors (CV-100 and CV-101) which are
mounted and installed to transport the solid feeds. At the gasifier (G-100), both feeds are co-
gasified at temperature of 700ᴼC and pressure of 32.04 bar with continuous steam input
generated from the following HRSG section. The gasification process utilized steam only as
the gasifying agent because the use of air in gasification could result in undesired nitrogen
dilution thus lowering its value (Boharapi, Kale and Mahadwad 2015). Hence the proposed
gasification without air or oxygen input has the advantage of higher hydrogen element yield,
higher product value and improved resource utilization in the form of steam used in the
cooling sections. A primary tar cracking process is involved in the gasifier where one of the
gasifying product, char is accumulated on the bed in a porous form to reduce the tar level in
the presence of steam (Fjellerup et al. 2005). The raw syngas exit from the gasifier and it is
fed into a cyclone (CY-100) to remove ash and the remaining char components, in illustration
of a full fluidized bed gasifier system where the residue remains are removed from the
bottom of an actual gasifier (Boharapi 2015). The solid-free raw syngas then entered the
cooling section.

20. 13
The HRSG, which covers the cooling section, features a quencher, a superheater heat
exchanger, a medium pressure (MP) and a high pressure (HP) steam cooler respectively,
compressor, a series of heaters and a steam turbine. The raw syngas flowed through a
quencher (Q-200), a superheater (HX-100), C-200 and C-201 coolers before half of this
mixture is recycled and compressed back to Q-200 to quench the gas and maintain the
temperature difference between hot and cold stream prior entering the wet scrubber. The
recirculation of the raw gas enables heat to be recovered where mechanical work is produced
in the gas compressor (CO-200). The processed, pure water feed is utilized for the generation
of power from the steam turbine (STUR-400) and heater series where steam is formed for
gasification process. The utilities are summarized in Appendix D with detailed calculation.
At the subsequent gas cleaning process, the raw syngas is mixed with deaerated water in the
water scrubber (SC-200) at 144ᴼC and 26 bar in order to limit tar, ammonia and the steam
flow rate from the total product composition (Botha 2012). The wet scrubber scrubbed
secondary tars to a pyrolysis reactor (R-200) at the condition of 120ᴼC and 20 bar where tar
cracking reaction occur in the absence of oxygen and it is assumed that the secondary tars are
fully converted to raw syngas.
As desulphurization requires high cost and complex design to cool the syngas to certain
temperature, the HRSG has benefitted the plant such that the power generated from STUR-
400 and CO-200 have driven a heat-integrated system in preparation for gas cleaning
treatment (Gupta et al. 2001). Desulphurization (R-300) took place at 450ᴼC and at the
pressure of 26 bar using absorbent (Fe2O3) generated from the regenerators (R-301 and R-302)
in a recirculation loop. Molten sulphur is condensed out continuously in the SO2 regenerator
(R-301) from recirculating SO2 gas stream generated from the O2 regenerator (R-302). The
sulphided absorbent is fed into the multistage reactors and it is heated (H-300) to 600ᴼC to
form the regenerated sorbent, where subsequently this partially regenerated sorbent is passed
into R-302 and oxygen is added to the regeneration gas for maximum conversion before it is
cooled (C-300) and fed back into R-300. The recirculation loop allows clean syngas to be
recovered using a condensing separator (S-300) and this clean gas with hydrogen 50 vol%
proceeds to its last cleaning step. The catalyst packed reactor (R-400) is operated at
temperature 200ᴼC and pressure 15 bar where the water gas shift reaction occurred to
produce more hydrogen, which is a final greener and cleaner syngas product with 60 vol%, in
accordance with customers demand.

21. 14
2.2 Material and Energy Balance
Mass and energy balances are performed in order to compare the result from theoretical
methodology with the result obtained from Aspen Plus simulation. The methodology of the
material and mass balance is in Table D.6 (Appendix D) whereas for energy balance is in
Table D.8 to Table D.14 (Appendix D) for respective equipment. For mass balance, the
small error percentage between the result from simulation and manual calculation is due to
difference in some properties used in simulation and manual calculation whereas for energy
balance case, it is due to a few thermodynamic assumptions made shown in previous section.
A summary of result for comparison of material and heat balance between manual and also
Aspen Plus calculation is shown in Table D.7, Table D.3 to Table D.5 (Appendix D).
2.3 Heat Integration
Heat integration, also known as energy integration or pinch analysis is a technique used for
minimizes energy consumption and maximizes heat recovery in the plant. Heat energy
network (HEN) is used to indicate the calculation of minimum heating and cooling
requirements which reveal significant energy savings. A more detailed step-by-step approach
is shown in detailed in Appendix E. The methodology is summarized in a flowchart in
Figure 2.2 below.
Figure 2.2. Flowchart for energy integration workflow
The main objective to perform energy integration is to improve the energy efficiency of the
co-gasification plant which includes heat exchanges, heaters as well as coolers to heat and
cool the process streams to specific desired temperatures. Reactor such as pyrolysis reactor,
Aspen Energy Analyzeris
used to obtain the
composite curve and
recomendedHEN design.
The inlet andoutlet
temperature, enthalpy, and
heat capacityflowrate
(MCp) are obtained.
Shiftedtemperatureis
calculatedby using
∆𝑇 𝑚𝑖𝑛 = 10℃
Utilities in streams is
calculatedby using∆𝐻 =
𝐶𝑃𝐻 − 𝐶𝑃𝐶 × ∆𝑇
Heat cascade is performed
via the temperature
interval.
Program table algorithm
(PTA)is carriedout.
The pinchtemperature is
obtainedby indicatethe
largest heat deficit,which
in this case is 600.18℃.
Total minimum heating
requirement, 𝑄 𝐻𝑚𝑖𝑛 and
minimum cooling
requirement, 𝑄 𝐶𝑚𝑖𝑛 is
obtained.
Above pinch temperature
andbelow pinch
temperature is cauculated.
Heat exchanger network
design (HEN) is carried
out.

22. 15
desulphurizer and water gas shift reactor which require duty are taken into consideration. The
total heat required before and after heat integration is compared in Table 2.1.
Table 2.1. Energy saving from hot and cold utilities
Detail Cold Utilities (MW) Hot Utilities (MW)
Before Heat Integration: 241.87 44.54
After Heat Integration: 123.05 44.54
Total Heat Reduced: 118.82 0.00
Total Saving (%): 49.13 0.00
The energy saving are 49.13 % and 0 % for hot and cold stream respectively. As the cooling
water used to cold down the ash is recycled repeatedly which brings to only small amount of
water is required with small duty (SOLEX 2015), which is insignificant when compared to
the hot utilities to heat up the water in order to generate the steam for gasifier. Hence, this
indicated the 0 % of energy saving in hot utilities.
2.4 Process Optimization
The process optimization is carried out with the aim of reducing utilities cost as the capital
cost is assumed to be constant since the equipment sizing remain unchanged. The outcome
from the heat integration from previous sub-section is applied. The utilities cost is tabulated
in Table F.1 (Appendix F) indicating the total cost of utilities before and after process
optimization where it is shown that the total utilities cost is reduces from RM 296
million/year to RM 51 million/year, indicating a saving up to 82.7 %.
Another objective function of this process optimization is the syngas product hydrogen, H2
yield as it is an important factor to achieve a higher H2 yield in relation to the reduction in
utlities cost from heat integration.The variables that are manipulated includes equipment with
possible exergy losses such as mixer, gasifier, reactors, heat exchangers and heaters or
coolers, for which their parameters are adjusted , including flow ratio, exit temperature,
operating pressure feed ratio and fractional coversion of reactions. The minimum approach of
heat exchangers can only be reduced to a certain range for an efficient and feasible design,
whereas the H2/CO ratio is also increased subsequently, due to the unavoidable increase in H2
and reduction in CO. Again, this ratio specification is based on the customer demand on the
type of syngas for different industries. Lastly, the safety parameters such as flammability
point and storage pressure of the product is also maintained at specific range. The optimized
parameters are shown in Table F.2 (Appendix F) with respect to the objective, manipulated
variable and constraints.

23. 16
Thus a cost saving of 82.7% is achieved, with an increase in hydrogen yield of 12.9% from
82.3% of base case to 92.9%. The optimized flowsheet after heat integration and flowsheet
optimization is obtained as shown in Figure 2.4 below. A detailed PFD of the optimized case
simulation diagram and its flowsheet is available in Figure F.1, Figure F.2 and Table F.3
respectively (Appendix F).
Figure 2.4. Process flow diagram after optimization
2.5 Process Control
The proposed process control and instrumentation system aims to reduce variability, increase
efficiency and ensure safety (Rangajah, 2012) while meeting the product specifications and
policies. Instruments and valves are installed for reliability and robustness, for which the
process control philosophy is established based on Luyben’s Top Down approach (Luyben
and Luyben 1997), following the steps below:
- Define operational objectives
- Identify degree of freedom and operating condition
- Identify and select primary controlled variables
- Select the location of Top-down Production Management, TPM
The H2/CO ratio and syngas yield are maintained using flow, ratio and composition
controllers so that a hydrogen-rich syngas product is processed at an approximate rate of 162
tonne per day. Moreover, instruments such as alarms and indicators are useful when a failure
is registered within a specific safety margin where technicians are called in for action. Lastly,
majority of the plant equipment and vessels pressure and temperature are regulated with
pneumatic signal transmission for effective and immediate response, where in overall a total
of 39 control valves are installed. The piping and instrumentation diagram and the plant wide
control philosophy are shown in Figure G and Table G respectively (Appendix G).

24. 17
3.0 PROFITABILITY ANALYSIS
To investigate the profitability viability, the equipment schedule and pipe specifications are
first specified as shown in Appendix H followed by calculation for equipment sizing and
costing (Appendix I) which covers each equipment methodology with assumptions made in
Appendix J. From calculation, the total capital investment for the gasification plant is
estimated to be RM 2,282,298,569.24 as shown in Table J.1 (Appendix J). The capital and
operating cost are then calculated and three economic scenarios are developed for analysis.
3.1 Capital and Operating Cost Investment
The Chemical Engineering Plant Cost Index of 2015, often abbreviated as CEPCI, is utilized
to estimate the cost index for capital investment of the co-gasification plant. According to
Timmerhaus et. al (2003), the direct and indirect costs of the overall plant including the
investment costs of land, site development, battery-limit facilities, and auxiliary facilities is
part of the capital cost. It is found that the direct cost, which covered purchased equipment,
installation, piping, instrumentation, controls, electrical system, building and service facilities
cost around RM 1,370,286,616.13 whereas the indirect cost, which is the summation of
engineering and supervision, construction, contractor and contingency fees of this plant is
RM 571,708,985.54. The cost summary and calculation of the direct and indirect production
cost of syngas calculation is in Table J.2 (Appendix J).
3.2 Economic Scenario Analysis: Base, Best and Worst Case
The profitability analysis of the syngas production plant is investigated in three case
scenarios which are the base, best and worst case to determine impact of the fluctuation of
raw material cost to the overall profit of the plant. From Appendix J, the operating cost for a
yearly basis are RM 1,101,767,028.21 (best), RM 1,236,355,282.89 (base), RM
1,525,383,537.57 (worst), as shown in Table J.3. The cumulative discounted cash flow in
Figure J.1 is derived from the sensitivity study of the discounted cash flow rate shown in
Table J.4 to Table J.6 for each of the scenario within a lifespan of 25 years. The bank loan
payment schedule for each scenario is tabulated in Table J.7 to Table J.9 and illustrated in
Figure J.2 to Figure J.4 respectively. The total annualized cost for the best, base and worst
scenarios are RM 3,527,888,385.34, RM 3,668,196,640.85, and RM 3,969,508,596.35
respectively where the best case scenario gives the most economic advantages among the
others as shown in net profit analysis (Figure J.5). The payback period for base, best and
worst case is calculated as 0.55, 0.93 and 3.12 years respectively with the shortest profit
generation duration and highest revenue for best case shown in Figure J.6 and Figure J.7.

25. 18
4.0 RISK ASSESSMENT
The vulnerability of the plant is assessed in this section in terms of economic, safety and
environmental aspects. A hazard and operability study (HAZOP), and SWOT analysis are
presented in this section as well.
4.1 Economic Aspect
The profit of the plant is dependent on the market and customer demand where the best,
worst and base case scenarios can be referred such that thorough case study can be done to
prepare strategies for worst scenarios. Meanwhile, the impact of risk, hazards or catastrophe
events is highly interrelated to the business operation where regulations and proper planning
of the plant operation are important to keep the reputation and prevent financial loss. Thus, a
complete hazard identification, vulnerability assessment and impact analysis is important to
reduce or mitigate potential risk with effective strategy at high priority. This is further
discussed in the following section.
4.2 Safety Aspect and HAZOP Assessment
Proper plant layout is important for the prevention of the occurrence of catastrophic event.
Proposed plant layout was divided into three zones (safe, moderate and dangerous) according
to safety level as presented in Appendix K.
By referring to the plant layout, green zone is the administrative area, bottom yellow zone is
for storage tanks, top yellow zone is the waste water treatment plant and utilities system and
lastly red zone is the process plant and flare gas system area. Area allocation is based on
prevailing wind direction and the safety distance of 3.5 m between each equipment is planned
to prevent terrific loss and enable ease of control when severe accident occurs. Moreover,
administrative zone which consists of offices and canteens in which most personnel will be
working at will be situated furthest away from the production and storage area, where in the
case of control room it is designed with special barriers. This is to ensure that in any case of
incidents such as toxic gas release, explosion or pressure burst at red zone area it will have
minimal impact to the personnel (Health and Safety Executive 2015).
Various safety features are included in the design of the building such as proper emergency
exit plan, multiple exit doors for heavy flow area, fire resistant materials for room
construction, fire detection alarm, operational links between operators, proper temperature
and airflow control. Sprinkler store room, water tanks are also situated near the production

26. 19
area for ease of fire extinguishing in case of any emergency while assembly points are
available at emergency evacuation.
Operation-wise, it is crucial that proper commissioning is done follow by start-up process
where all the installed equipment in a plant is thoroughly checked to ensure the equipment
can work properly prior to plant operation (Integrated Service Solutions 2015). Various
functional checks will be done on the equipment and any defects are to be recorded and
resolved. Once all the commissioning activities are done, commissioning team will have to
issue RFSU (Ready for Start-Up) certificate so that start-up activities can be initiated.
To ensure the integrity of the equipment and the efficiency of whole operations, maintenance
has to be done regularly during the shutdown. This phase will comprised of proper inspection
on equipment and repair of any faulty equipment as well as control system. All of these
phases are important throughout the whole life cycle of the co-gasification plant to ensure
effective operations, continuous production of syngas, prevent any incident, and for the
occupational health and safety of all the personnel. The detailed activities involved in each
phase are further elaborated in Appendix L.
4.3 Environmental Aspect
Preliminary environmental impact assessment is crucial in determining the possible activities
that could cause harms to the environment, safety, social aspects as well as the company’s
benefits. Throughout the lifecycle of the plant, various activities might have caused adverse
impact on the environment such as pollution or potentially harm the surrounding community.
Thus, a preliminary environment impact analysis as shown in Table M.1 (Appendix M) is
developed to identify possible accidents and their impacts with suitable mitigation measures
while a plant contingency plan with safety measures during emergency and safe handling
plan for hazardous materials is presented in Table M.2 and Table M.3 (Appendix M)
respectively.
A HAZOP study is presented in Table M.4 (Appendix M) where any possible deviations of
parameters such as temperature, pressure, flow, level and many more from normal conditions
are identified before a well-planned safeguard and recommendation actions are prepared.
These considerations can make a big difference during operation as it is crucial that all the
equipment are equipped with safety features and undergone scheduled maintenance to reduce
or eliminate any potential risks.

27. 20
5.0 CONCLUSION
The implementation of biomass gasification as alternative feed to substitute fossil fuels usage
in energy generation is applicable. Based on the results generated, it is proven that the
gasifying biomass with coal will raise the efficiency of the propose gasification plant, and
reducing the greenhouse gases emissions. Utilizing both the feedstocks, sub-bituminous coal
and rice husk at 1:1 ratio to achieve high gas yield, low tar and char yield, as well as high
thermal efficiency with effective HRSG and desulphurization gas cleaning technology that
promotes sustainable development in environmental, economics, safety and resources aspects
is achievable. The increase in energy saving after optimization are mainly a result of
reduction of substances that require energy to be removed from the syngas, especially those
with sulphur content. It is also observed that the water scrubber play an crucial role in gas
clean-up system, increasing the levels of biomass with less fly ash as well as slag output.
Material and energy balance calculation performed had proved the design feasibility followed
by heat integration and process optimization with the optimized process flow diagram shown
in Appendix F (page 69). The results of the sensitivity analysis demonstrate that feedstock
cost was the most sensitive cost factor on unit costs manipulating the economic analysis of
the overall process plant for the best, base, worst case scenarios.
In summary, the proposed plant design is capable of producing 50 kilo-tonnes of hydrogen-
rich syngas annually with total annualised cost (TAC) of RM 3,527,888,385.34 and a
payback period of 0.55 years with energy saving up to 82.7%.
Recommendation
Despite much research is being conducted in this field, the co-gasification of rice husk and
coal has not yet been fully explored. The tar evolution profile from the co-gasification of rice
husk and coal requires further investigation to customize the operating system and removal
system. Along with this, the catalyst used can also be a research opportunity for the future as
it affect the production rate of the syngas, as well as the efficiency of the overall process plant.
More economic analysis methods can be conducted for results comparison with the propose
method, the purpose is to further validate the values obtained with proper justification for the
method chosen.

28. 21
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35. 28
APPENDICES
Appendix A: Product, Raw Materials and Process Technology Evaluation
Prior process screening, the type of agri-waste used for gasification is considered carefully.
Table A.1 is developed as shown below with respect to palm oil kernel shell, sugarcane and
rice husks.
Table A.1. Comparison of different biomass resources
Type of
biomass
Rice Husk Palm Oil Kernel Shell Sugarcane Straw
Physical
Properties
- 1 ton Rice Husk is
equivalent to 410- 570
kWh electricity
- Calorific value = 3000
kcal/kg
- Moisture content = 5 –
12%
- Heat Energy/ Calorific
Value: > 4.000 kcal/Kg
- Inherent Moisture: < 20 %
- Ash content:< 15%
- Size: 4-20mm
- Foreign materials (By
visual): < 2%
- Gross heat = 18.870
kcal/kg
- Fiber content = 65 %
- Pith cells = 25 %
- Water soluble = 10 %
- Ash content = 2.4 %
- Size = 1.5-2 mm
Chemical
Properties
- C: 45.8 %; O: 47.9 %; H:
6.0 %; S: 0.0 %
N: 0.3 %
- C: 63.02 %; O: 36.04 %;
Al: 0.43 %; Si: 0.17 %; P:
0.17 %; K: 0.17 %
- C: 51.71 %; H: 5.32 %; O:
42.64 %; N: 0.33 %
Advantages - Can be directly used in
gasification.
- Low moisture content
- Inexpensive (waste from
rice mill)
- -Asia has the highest rice
husk production
- Can be stored at open
space
- Blends well with coal dust
- Inexpensive inner logistics
- Non-absorbility
- Inexpensive (waste from
sugarmill)
- Suitable for fluidized bed
processing.
Limitations - Large amount of rice husk
is required.
- Resistance for crushing
- Need to be processed
before being used for
gasification
- Limited supply as
sugarcane only produced
for 6 months of the year.
- Need to be processed
before being used for
gasification
Reference Mundi n.d. (2015);
Vélez et al. (2009);
BioEnergy Consult (2015)
Biofuel Resources (2015);
BMC (2015); Dagwa,
Builders and Achebo (2012)
Ripoli (2000); Hassuani
(2005)
The re-utilization or disposal of the ash, char and tar by-products is shown in Table A.2. Ash
can be encapsulated, which is added or bounded into concrete to enhance concrete in terms of
workability and durability (Business Recycling 2015). It can be used to fill abandoned mine
and unpaved roads as well. Char can be recycled into biomass pyrolysis process as well as
reused as absorbents and carbon supported catalysts, providing additional value added
products from the bio refinery (Kastner2015). On the other hand, Tar Steam Reforming (TSR)
process can convert high molecular weight hydrocarbon of tar into smaller gas products
including CO2 and H2 (Vivanpatarakji 2014). It can be recycled to tar cracking process as
well, for further treatment into reusable products.

36. 29
Table A.2. Utilization of by-product
Residues Ash Char Tar
Reutilization
/ Disposal
- As a partialreplacement for the
sand, limestone and cement
content in concrete.
- Structural fill for abandoned
mines
- Top layer for unpaved roads
- Recycled in biomass
pyrolysis process
- Can be reused as tailored
absorbents and carbon
supported catalysts
- Sent to Tar Steam Reforming
(TSR) to form smaller gas products
- Recycled into tar cracking process
to form reusable products
References Southeast Coal Ash Waste (2013),
EPA (2015), Business Recycling
(2015)
Kastner (2015), James
(2013)
Rabou (2009), Vivanpatarakij (2014)
Table A.3. Storage and transportation for feedstock and products
Aspects Sub-BituminousCoal Rice Husk Syngas
Storage - Covered storage yards
- Continuous water sprinkling
systemon the roof
- Covered with permanent
weather shed roofing and side
walls
- Covered storage yards
- Fixed water pipenetwork
system
- Store in syngas storage tank with
international standards such as
ASMESection VIII Div 1, 2, PD
5500, AD Merkblatter and Codap
2000
- Store in temperatureless than 52
0
C equipped
- Storage tank is safety valves, level
gauge, pressureand temperature
gauges and other safety
accessories
- Storage tank is located away from
heat source and open flames.
Transportation - Tarpaulin cover before loading
the coal onto the track
manually
- Cover using nylon shed to
avoid spilling
- Loaded into trucks
manually using shovels
- Cover using nylon shed
to avoid spilling
- Delivered using stainless steel
pipeline with weatherproofed
coating
Reference G. Okten (2015); Mehrishi (2012) G. Okten (2015); Mehrishi
(2012)
Corporation (2000); Tanks (2015)
Table A.4. Fractional atom economy calculation
i
Sum
vik
Mi viMi
viMi*SF
(ton/day)
Price ($/ton)
Price*viMi*S
F ($/day)
C -4 12.01 -48.04 -39.21 80.17 (Vélez et al. 2009) -3143.47
H2O -2 18.02 -36.04 -29.42 0.41 (Baliga 2014) -12.06
CH4 -5 16.04 -80.20 -65.46 139.3 (C.H. Wong et al. 2011) -9118.58
O2 -5 16.00 -80.00 -65.30 35 (Muller 2007) -2276.05
CO 6 28.01 168.06 137.17 600 (Clean Technica 2014) 82302.00
H2 12 1.01 12.12 9.89
1200 (ManitobaEnergy
Development Initiative 2003)
11868.00
CO2 3 44.01 132.03 107.76 10.15 (Lucklow et al. 2013) 1093.76
Fractional Atom Economy
=
168.06+ 12.12
−(−48.04 − 36.04 − 80.20− 80)
= 0.7376
Sum with CO2 ($/day)
80713.61
Scale Factor, S =
50000
𝑡𝑜𝑛𝑛𝑒𝑠
𝑦𝑒𝑎𝑟
×
𝑦𝑒𝑎𝑟
340 𝑑𝑎𝑦𝑠
168.06 + 12.12
= 0.8162
Sum without CO2 ($/day)
79619.84
Table A.5. Calculation of raw materials gasification process economy
Feedstock Carbon (C)
Composition
Average Price (MYR) Average Price × Carbon
Composition
Sub-bituminous
coal
0.824 (
472 − 285
2
) + 285 = 378.50
0.824 × 378.50 = 311.88
(Vélez et al. 2009)
Biomass
(rice husks)
0.458 (
50 − 20
2
)+ 20 = 35
0.458 × 35 = 16.03
(Vélez et al. 2009)
Total Price for C/tonne
311.88+ 16.0 = 327.91 𝑀𝑌𝑅
≈ $ 80.17

37. 30
Table A.6. Summary of comparison between various types of gasifiers
Criteria Fixed bed updraft
gasifier
Fixed bed
downdraft gasifier
Fluidized bed gasifier Entrained bed
gasifier
Process
Description
- Also known as
counter-current or
counter-flow
gasification
- Feed is
introduced at the
top of gasifier
while air is
injected at the
bottom
- The product
syngas leaves at
the top
- Divided into
drying, pyrolysis,
gasification and
oxidation zones
- Heat from
oxidation and
gasification
provides energy
for drying and
pyrolysis
- Also known as co-
current
gasification
- The fuel (biomass
and coal mixture)
travel down by
gravity and exit at
the bottomwith
air injected at the
body
- The fuel beds are
divided on various
grates for different
processes.
- Process includes
drying, pyrolysis,
oxidation and
reduction with air
feed.
- A bed of dry, solid
feedstockwhich
comprise of coal and
biomass mixture is
seeped with gasifying
agent such as steam or
air through the pores at
the bed where solid
will be suspended in
the fluid for the
gasification reaction
- Main processes fast
pyrolysis, reactions of
volatile matters and
gasification of char
with steam and 𝐶𝑂2
- Powdered coal and
biomass mixture fed
with gasifying agent
from the top.
- Combustion will be
carried out at the top
with the turbulent
flame burning
mixture with very
high temperature
and provide the
condition for fast
coal conversion to
produce high quality
syngas.
- The ash from
combustion will
melt at the gasifier
walls and be
discharged as
molten slag.
Operating
conditions
- 600 ºC to 1000
ºC
- Approximate 0.1
MPa
- Gasifying agent:
air
- Capacity of 20 to
2000 kW
- Gasifying agent:
air
- 800 ºC to 1000 ºC
- Operate at vary coal
ratio
- 0.10 ≤ biomass percent
≤ 0.50
- The existing co-
gasification plant used
maximum 10%
biomass in industrial
scale.
- Gasifying agent: steam
or air
- More than 1000 0C.
- Endothermic
gasification reaction
will reduce the
temperature to about
800 0C.
- Gasifying agent:
oxygen
Cost Low cost with
simple design
Low cost with
simple design
Expensive unit and
expensive to operate as
high temperature is
required
Expensive unit and
expensive to operate
as high temperature is
required
Advantages - Able to handle
high moisture and
high organic
content of
biomass
- High thermal
efficiency
- Small pressure
drop
- Product gas has
acceptable
calorific value
with low tar and
ash content
- Simple and proven
scheme
- Suitable for
biomass with low
moisture
- High overall
carbon conversion
- Uniform temperature
throughout reactor
- Excellent mixing of
coal and biomass
- Insensitive to size of
feed solid
- Loss of carbon due to
fine chars escaping
with product
- Formation of slag is
minimal and can
remove stray ash easily
- Suitable for up-scaling
- Suitable for most
coal types
- Can destroy tar
easily and produce
nearly tar-free and
low methane syngas
- Almost 100 %
carbon conversion
- Ash is produced as
slag

38. 31
Table A.6. Summary of comparison between various type of gasifiers (continued)
Criteria Fixed bed updraft
gasifier
Fixed bed
downdraft gasifier
Fluidized bed
gasifier
Entrained bed gasifier
Limitation - Consists high level
of tar: 10 to 20% by
weight in product
syngas
- Extensive gas clean-
up required to
remove impurities
- Poor reaction
capability with
heavy gas load
- Not suitable for up-
scaling
- Low carbon
conversion when
uneven gas
distribution occur
- High exit gas
temperature with
lower product
efficiency
- High residence
time of solids with
low gas velocity
- Restricted scale up
potential due to
250 kW capacity
limit
- Low ash melting
point of biomass
result in
agglomeration
and stick to bed
particle
- Not suitable for
small scale.
- Complicated to
operate.
- Not suitable for
biomass due to its
high moisture content
- Alkali compound in
biomass can corrode
the gasifier refractory
or metal lining
- Require fine fuel due
to short residence time
where biomass
pulverized slower
- Require large amount
of O2
- Require high
temperature
References Bhavanam and Sastry
(2011); Gasification
Status and Technology
(2012)
Gasification Status
and Technology
(2012); Bhavanam
and Sastry (2011)
Long (2011); F.
Velez (2008);
Chapter 8;
Fermoso; Kern
(2012)
Basu (2013); Ogi et al.
(2013)
Table A.7. Summary of different type of fluidized bed gasification processes
Criteria Bubbling Fluidized Bed
(BFB)
Circulating Fluidized Bed
(CFB)
Dual Fluidized Bed (DFB)
Operating
system
- Oxygen or steamis blown
upwards through the fine
inert material bed at the
bottomof the gasifier with a
high velocity which enough
to agitate the material.
- Biomass that is fed from the
side of the gasifier will be
mixed, combusted and
formed syngas which will
leave from the top of the
gasifier
- Air, oxygen or streamis
blown upwards with
relatively high velocity to
suspend the material
throughout the gasifier.
- Biomass that is fed from
the side of the gasifier will
be suspended,combusted
or reacted to form syngas..
- A cyclone is used to
separate syngas and
particles. The materials will
return to the bottomof the
gasifier after separation.
- Biomass is fed into the
BFB/CFB gasifier and be
converted into nitrogen-free
syngas charby using steam.
- Air is fed into the combustor
and combustion of char and
accompanying bed particles
is carried out.
- The hot bed particles are
then fed back into the
gasifier and act as the source
of indirect reaction heat.
- Cyclone in CFB chamber
will separate the syngas
Operation
conditions
- Operates with lower velocity
(0.5-2 m/s) to maintain
fuel:fluidization gas ratio
- Operates below 900 0C to
prevent ash melting and
sticking
- Can be pressurized.
- Operates with higher
velocity (2-5 m/s).
- Has higher fuel flow rate.
- Operates below 900 0C to
prevent ash melting and
sticking.
- Can be pressurized.
- Operates below 900 0C to
prevent ash melting and
sticking.
- Can be pressurized.
Advantages - No clinker formation
- Low electric power
consumption.
- High fuel flexibility.
- Good scale-up potential,
mixing, gas-solid contact.
- Product gas with low tar
content.
- Low feedstockinventory.
- High fuel flexibility
- Allow in-bed catalytic
process
- High carbon conversion
and rate of reaction
- Ease of operation
- Good temperature control
- Can operate when loads are
lower than design load.
- Allow in-bed catalytic
process
- Good gas-solid contact and
mixing
- Suitable for high specific
capacities (>1 MW)
- Good scale-up potential.

39. 32
Table A.7. Summary of different type of fluidized bed gasification processes (continued)
Criteria Bubbling Fluidized Bed
(BFB)
Circulating Fluidized Bed
(CFB)
Dual Fluidized Bed (DFB)
Limits - Carbon loss with ash
- Product gas has high
particulates content.
- Product gas has moderate
tar content and high
particulates content.
- Complex construction and
operation.
- Pre-cleaning of gas is
required.
- Product gas with moderate
tar level.
- Low efficiency.
References Makwana et al. (2015);
Gómez-Barea and Leckner
(2010); E4 Tech (2009);
Gómez-Barea and Leckner
(2010); Puig-Arnavat, Bruno
and Coronas (2010); E4 Tech
(2009);
Puig-Arnavat, Bruno and
Coronas (2010); E4 Tech
(2009);
Table A.8. Evaluation on various desulphurization process technologies
Criteria Adsorption by solvents Adsorption by solid sorbents
Descriptions
Required solvents characteristics:
- Sufficient sulphursolubility or absorption capacity
- Higher selectivity for sulphur
- Able to be regenerated or recycled
- Stable, low corrosion and low reaction heat
- Simple recovery of absorbed sulphur
- Conventional cold gas clean-
ups’temperature reduction is
not energy efficient
- Hot gas clean-up is
developed as an alternative
method which operating
under high temperature
- Major sorbents are metal
oxides
Solvents /
Sorbents
Chemical solvent
- Methyldiethanolamine
(MDEA)
Physical solvent
- Selexo
Sorbent
- Zinc Oxide (ZnO)
Advantages
- Higher selectivity for H2S
and CO2
- Higher solution capacity
- Less corrosive
- Thermally and chemically
stable
- Sparingly miscible with
hydrocarbons
- High selectivity for H2S and
COS over CO2.
- Also remove other
contaminants such as CS2,
HCN and more.
- no chemical reaction and
degradation.
- Higher thermal and
chemical stability than
chemical solvents
- Low vapourpressure
resulting in low solvent
losses.
- Thermally and chemically
stable.
- Higher process efficiency
achievable without syngas
cooling and removal of
water from the syngas
- Sour water treating is not
necessary
- Elimination of “black mud”
(ash – char – water mixture)
produced in quenching or
scrubbing process
- Solid sorbents are usually
less toxic and corrosive
Limitations
- Selectively removes H2S
resulting in much CO2
unabsorbed
- Proprietary additives are
required in MDEA solution
to enhance the capability of
CO2 removal
- More expensive than other
amine solvents
- Losses of hydrocarbons due
to coabsorption
- Refrigeration sometimes
required, resulting in
additional cost and
complexity
- Absorption at high pressure
is preferable for high
absorption capacity
- Removal of mercury in
syngas becomes difficult
due to temperature rise
- Presence of H2O is proven to
have negative effect on
sorption performance of
ZnO sorbent
- Removal of other
contaminants such as HCN
is difficult using current
developed sorbents
- Degradation of sorbents
during the regeneration
process
References Kothandaraman (2005) Olov Öhrman (2010) Ke Liu (2010)

40. 33
Table A.9. Summary of similar operating plant with CFB technology
Criteria Foster Wheeler Uhde Fraunhofer Umsicht
Technology
description
- Air-Blown Gasification
Cycle (ABGC)
- Direct heated CFB under
atmospheric pressure
- Circulating-bed solids are
combusted and supply
heat for mostly
endothermic reactions
- High Temperature
Wrinkler (HTW) gasifier
- Direct heated CFB under
pressurized condition (10
or 25 bar)
- Air/Oxygen and steam
blown
- Carbon conversion >98%
- Air-Blown Gasification
Cycle (ABGC) with
catalytic gas treatment
- Direct heated CFB under
atmospheric pressure
- As gasifier in Biomass
Heat & Power Plant
(BHPP)
- 26-29% of electrical
efficiency
Development
status
- 4 commercial gasifiers
were built in1980s
- Coal power plant in Lahti,
Finland uses similar
gasifier since 1998
- A similar plant was built
in Belgium which the
moisture of feedstocks
can vary between 20-60%
- Proven to be technically
feasible after the testing on
several demonstration
plants in 1980s
- 30 bar HTW gasifier are
available for IGCC plant of
either 600MWe
(oxygen/steam) or 400
MWe (air)
- A 400 MWe HTW plant
was built in Vresova,
Czech Republic in 2002
- Pilot plant was
commissioned in 2002 and
succeeded under
uninterrupted operation,
producing almost tar-free
gas
- Demonstration plant with
thermal capacity of 5 MW
was planned in late 2002,
yet failed to establish
because certain conditions
were unfulfilled
Syngas
characteristics
- 5-17 vol% of H2; 21-22
vol% of CO; H2/CO ratio
= 0.74; 10-11 vol% of
CO2; 46-47 vol% of N2
- No syngas cleaning
required
- 30.1% H2; 33.1% CO;
H2/CO ratio = 0.91; 0.03%
of H2S; 0.4% of N2, 90
ppm NH3; 770 ppm of
C6H6; 5.7% methane
- Syngas cleaning by warm
gas filtering
- 18 vol% of CO; 14 vol% of
H2; H2/CO ratio = 0.78; 16
vol% of CO2; 10 vol% of
H2O; 39 vol% of N2; 3
vol% of methane
- Less than 50mg/Nm3 of tar
- Syngas cleaning by hot gas
catalytic tar reforming and
fabric filtering
References
Amec foster wheeler (2015);
Horst Hack (2013)
Renzenbrink (1998); E4 Tech
(2009)
Harasek (n.d); E4 Tech
(2009)

41. 34
Appendix B: Process Plant Site Selection
Table B. Comparison for Site Selection
Factors Site 1: Samalaju, SCORE, Malaysia Site 2: Jababeka, Cikarang, West Java,
Indonesia
Site 3: Zhengzhou High Tech Industrial
Development Zone, Henan, China
Size of
Industrial
Area
More than 50 ha of land, approximately 62km
from Bintulu city (SCORE 2015)
40ha of land area (Jababeka 2014) 60ha
Land price USD 15/𝑚2
(MIA 2009) USD 196.57/𝑚2
(Deutsche Bank 2015) USD 54/𝑚2
Climate
/Weather
Year-round hot, humid and wet weather. No
major extreme weather. (World Guides 2015)
Moist tropical climate with abundant rain and high
temperatures (Global Rice Science Partnership
2012).
Risk of earthquake and volcano eruption (News
Track India 2015)
Monsoon climate with a hot summer and a
cool winter (Global Rice Science Partnership
2012)
Availability
and supply
of raw
materials
Sub-bituminous coal: obtained from Merit-Pila
mine at upper reaches of Rajang River
(Pui 2008)
Rice husks:Paddy residues Bernas Bintulu
(Bernas 2015)
Sub-bituminous coal: Coal supply from Cigading
International Bulk Terminal
Rice husks: Paddy plantation from West Java and
import from Thailand (Global Rice Science
Partnership 2012)
Sub-bituminous coal: Henan Energy and
Chemical Industry Group Co. Ltd.
Rice husks: Rice production in Henan.
(Global Rice Science Partnership 2012) Else,
the rice can be obtained via ZhengZhou
Commodity Exchange.
Demand of
product
-Electricity generation to supply in Sarawak.
-Bintulu LNG Complex to be further refined as
feedstock.
The syngas produced can be used to power
electricity in Java. (Rawlins 2014)
The syngas can be further refined to generate
electricity to be supplied in factories in
ZhengZhou such as Honour Trust Co Ltd and
Henan Anfei Electronic Glass Co.Ltd.
(KPMG 2008)
Transport
facilities
-Trans-Borneo Highway (2,083 km)
- Samalaju port (SCORE 2015)
-Easy access to Bekasi-Cikampek toll-road.
-Cikarang Dry Port is located in Jababeka Industrial
Estate. It is the extension of Tanjung Priok
International Seaport for import and export
purposes.(Jababeka 2014)
Railway: Beijing-Guangzhou Railway and
Lianyungang China Lanzhou Railway
Port: Lianyungang pPort, Yangshan Port,
Shanghai Port
(Hong Kong Trade Development Council
2015)
Availability
of labour
Cheap labour available Minimum wage of RM
800 monthly.
USCORE Project develop human capital for
SCORE (Chemsain Konsultant Sdn. Bhd 2010)
Cheap labour available. Minimum wage of Rp 2
700 000 monthly (Wage Indicator 2015)
Cheap labour but lacks high-tech talent (Hong
Kong Trade Development Council 2015)

42. 35
Table B. Comparison for Site Selection (continued)
Factors Site 1: Samalaju, SCORE, Malaysia Site 2: Jababeka, Cikarang, West Java,
Indonesia
Site 3: Zhengzhou High Tech Industrial
Development Zone, Henan, China
Utilities and
Services
Inexpensive electricity supply from Bintulu
CCGT, Sarawak Energy (Sarawak Energy
2015)
130MW power supply by PT Bekasi Power
(Jababeka 2014)
1000MW power supply from Henan
ZhengZhou Power Supply at price of USD
0.1/kWh, Water resources from Yellow River.
(Hong Kong Trade Development Council
2015)
Waste
Disposal
Samalaju Water Treatment Equipped with two water treatment plant and two
waste water treatment plant. (Jababeka 2014)
Treatment available for sewage and solid
waste. (KPMG 2008)
Geographica
l condition
Located strategically south of the booming
North Asian markets, Japan, South Korea,
Australia and India. (SCORE 2015)
Biggest industrial estate in Southeast Asia with
investments from various foreign companies
Lies in the middle and lower reaches of
Yellow River and thus suitable for various
industries. (KPMG 2008)
Incentives /
Government
Support
1. RECODA to offer free support and independent
advice as well as incentive programmes such as,
pioneer status, discount on industrial land, tax
exemption to foreign companies looking to
invest or locate in SCORE. (SCORE 2015)
Various financial incentives from government such
as CTF Investment Plan to support renewable
energy (Damuri and Atje 2012)
Various benefits such as tax exemption, free
rental for investment more than USD 500000,
education, healthcare, housing , travel and
social welfare for foreign investor(KPMG
2008)

43. 36
Appendix C: Process Simulation Basis of Design
Table C.1. Property method, model and general assumptions for simulation thermodynamics
Aspects Descriptions
Process type Common
Base method SOLIDS
- Solids are involved and this package is recommended for coal processing
according to the property method selection assistant in Aspen Plus. The
simulation of heat and mass balances of a solids process required for the
physical property model is suitable for solid components (AspenTech 2000).
- Hence, the models that specialized in physical property for solid components
are required. For instance,accurate data of solids particle size distribution can
be expected for solid equipment such as cyclones.
Stream class MIXCINC
Free-water method Steam-TA
General assumptions - Gasification process is at steady state and isothermal
- No heat loss from the reactors throughout the whole process
- All reactions reached chemical equilibrium
- Specific heat (cP) of species is independent of operating pressure at which
reaction takes place.
- Specific heat (cP) of species stay constant at the average of the reactor feed
temperature and calculated equilibrium (or reactor outlet) temperature.
Table C.2. Ultimate analysis (% wt) of coal and rice husk by dry ash free basis
Ultimate Analysis C
(%)
H
(%)
O
(%)
N
(%)
S
(%)
Reference
Coal 78.03 5.06 5.66 1.69 1.97 Boharapi, Kale and
Mahadwad (2015)Rice Husk 36.1 1.94 37.8 4.8 -
Table C.3. Proximate analysis (% wt) of coal and rice husk
Proximate Analysis Moisture
(% )
Fixed
Component (% )
Volatile
Matter (% )
Ash (% ) Reference
Coal 9.07 55.44 36.97 7.59 Hoffman (2003)
Rice Husk 8.44 9.3 71.4 19.3 Panda (2012)
Table C.4. Sulphur analysis (% wt) of coal with 1.97% sulphur in ultimate analysis
Sulphur Analysis Pyritic Sulphate Organic Reference
Coal 0.91 0.15 0.91 Hoffman (2003)