This presentation has been prepared strictly for personal and educational use.

1. ProcessProcess
IntensificationIntensification
- A Way to Revolutionize Chemical Engineering Processes

2. HistoryHistory
• In 16th
century a famous book by Georgius Agricola explained a process
on retrieving gold from gold ores. Then it was all related to stirrers. This gave
the world the vision for process of and for chemical industry.
• What happened in 16th
century was not really intensification. The philosophy
of process intensification followed later as the modifications in existing and
newer processes developed.
• Process Intensification this pair words got recognition in 1995 at first
International Conference on Process Intensification in the Chemical
Industry.
• Ramshaw, a pioneer in the field, presented the world with defining process
intensification and stamped the beginning of renaissance in Chemical Process
Industry.

3. ConceptConcept
Process Intensification is a philosophy which will efficiently guide
the onward journey of Chemical Process Industry. Various stalwarts has
made many attempts in defining Process Intensification. It was quite difficult
to confine exact concept in precise words. Process Intensification has
various aspects, following are the attempts made by geniuses to convey the
concept of Process Intensification (PI).
• “Physical miniaturization of process equipment while retaining throughput and
performance”.
• PI mainly deals with engineering methods and equipments. It does not vouch
for new chemical routes or change in composition of catalyst, no matter how
dramatic the improvements the bring to the technology.
Ramshaw (1983)[1] devising exceedingly compact plant
which reduces both the ‘main plant item’
and the installations costs.
Cross and Ramshaw (1986)[2] strategy of reducing the size of chemical
plant needed to achieve a given
production objective.

4. Stankiewicz and Moulijn (2000)
[3]
development of innovative apparatuses and
techniques that offer drastic improvements in
chemical manufacturing and processing,
substantially decreasing equipment volume,
energy consumption, or waste formation, and
ultimately leading to cheaper, safer, sustainable
technologies.
Tsouris and Porcelli (2003)[4] refers to technologies that replace large,
expensive, energy-intensive equipment or
process with ones that are smaller, less costly,
more efficient or that combine multiple
operations into fewer devices
(or a single apparatus).
ERPI (2008)[5] provides radically innovative principles
(‘paradigm shift’) in process and equipment
design which can benefit (often with more than
a factor two) process and chain efficiency,
capital and operating expenses, quality, wastes,
process safety and more.
Bech (2009)[6] stands for an integrated approach for process
and product innovation in chemical research
anddevelopment, and chemical engineering in
order to sustain profitability even in the
presence of increasing uncertainties.

5. Principles of PIPrinciples of PI
1) Maximize the Effectiveness of Intra and Intermolecular Events:[7]
This principle deals with changing the kinetics of the process.
According to collision theory factors responsible for effectiveness include
frequency of collision, geometry of approach, orientation of molecules in the
moment of collision. P I covers the engineering of the methods to control these
factors.
2) Uniform Treatment for Every Single Molecule in the Process:[7]
Process where every single molecule goes under same process conditions. This
delivers ideally uniform products with minimum waste. Mainly focuses on
macroscopic RTD, dead zones. Meso and micro mixing and temperature gradient
plays an important role. A plug-flow reactor with gradient less, volumetric heating
(e.g., by means of microwaves) will obviously be much closer to the ideal described
by the above principle than a stirred-tank reactor with jacket heating.

6. 3) Optimize the Driving forces at Every Scale and Maximize the Specific Surface Area to
which these Forces Apply:[7]
This principle is about transport rates across the interfaces. Optimization is not
always maximization of driving force (e.g. concentration difference) required. The
output needs to be maximized. This can be done by maximizing interfacial area. Transfer
areas can be increased by using millimeter sized channel diameters.
4) Maximize the Synergistic Effects from the Partial Process:[7]
Synergistic effects must be utilized and at all possible scales. This effect is
used maximum in multifunctionality on macroscale. For example in reactive separation
units the reaction equilibrium is shifted by removing the products in situ from the
reaction environment. Synergistic effect can also be seen on molecular and meso
scales.

7. ClassificationClassification
1) Process Intensifying Equipment :
 Novel reactors.
Process intensification tools, such as the capillary reactor, offer several
benefits to the chemical process industries due to the well-defined high specific
interfacial area available for heat and mass transfer, which increases the transfer
rates, and due to low inventories, they also enhance the safety of the process. This
has provided motivation to investigate three such tools, namely the capillary
micro reactor, spinning disc and rotating tube reactors.
 Intensive mixing.
Intensive mixing and intensive mixers have replaced the traditional ring
through mixer and planetary mixing (1924). Intensive mixing separates the
transportation of the mix from the actual mixing process. The mixing can be
arranged either horizontally or at optimized angle of inclination, as suitable for the
process.

8.  Heat transfer devices.
Chemical reactions in the process industry are temperature dependent. Many
traditional designs such as stirred tank reactors incorporate heat transfer in the process
(double jacket, external or internal coil, etc.). The aim of thermal intensification is to reduce
this distance by supplying or removing the heat almost as rapidly as it is absorbed or
generated by the reaction, i.e. combining the reaction and heat transfer into a single piece of
equipment: using for instance a heat exchanger as a chemical reactor, the so-called HEX
reactor. As a result this technology may offer better safety (through better thermal control of
the reaction), improved selectivity (through more isothermal operation) and by-products
reduction.
 Mass transfer devices.
An intensified mass-transfer device is the rotating liquid–liquid extractor. The
conventional design of liquid–liquid extractors was based on using the density difference between the
liquids to drive a counter-current flow, by putting the denser fluid at the top of the column and the
lighter at the bottom. Heat and mass transfer are interrelated. If one is enhanced the other also gets
enhanced.

9. 2) Process Intensifying Methods:
• New or hybrid separations.
• Heat exchange
• Phase transition (multifunctional reactors)
• Techniques using alternative energy sources (light,
ultrasound, etc.)
• New process control methods (intentional unsteady state
operation)

11. Intensification TechniquesIntensification Techniques
• Enhanced Transport Processes [8]
• Integrating Process Steps [8]

12. Enhanced Transport ProcessesEnhanced Transport Processes
Mainly fluid dynamics controls the heat and mass transport rates. This directly
affects heat and mass transfer coefficients and the available area on which transfer of
energy and or mass can occur. So processes can be intensified by enhancing the turbulence
in the system and/or by increasing the transfer surface area. This can be achieved by
providing the reaction environment with external force field such as : Electric, centrifugal
and ultrasonic fields.
 Alternative Force Fields :
Alternative force fields commonly employed to intensify processes include
Ultrasound, Electric fields and Energy of Electro-magnetic radiations, whose
applications in chemical and biochemical processes in the context of PI have been
reviewed by Stankiewicz.

13. Centrifugal Force field : Surface rotation technique is used as intensification.
In 1950 Hickman’s research in two phase heat transfer on spinning disc resulted in first
centrifugal evaporator which is used in sea water desalination.
• The HT, MT and mixing rates are intensified due to formation of very thin films
because of extremely high gravity field.
• Short path lengths and high surface area per unit volume results in rapid molecular
diffusion and enhanced heat transfer.
• Rotating devices allows us to handle fluids containing solids which tends to foul
conventional devices. Rotating action itself acts as ‘self cleaning’ mechanism.
• Very short and controllable residence time, enables heat sensitive material to be process
with minimal risk of degradation.
Unit operations include distillation, extraction, boiling, condensation,
crystallization, precipitation and gas-liquid reactions.
Rotating Pack Bed (RPB) is well known example of centrifugal field processing equipment.

14. Centrifugal Adsorber [9]
Schematic of Spinning Disc Reactor [9]

15. Ultrasonic Fields : [8]

16. Ultrasound means sound waves beyond audible range of Human ear.
• Frequency – 20KHz to 500MHz. Frequency used in chemical processes are <2MHz
• Ultrasound is propagated through liquid medium in alternating cycles of
compressions and rarefactions.
• Induces an effect known as cavitation. Micro bubbles are generated and destroyed
in successive compression cycles, releasing large amount of heat and pressure energy
in local environment.
• The local temperature and pressure can be as high as 5000°C and 2000 atm
respectively, depending upon power input.
• Waves generate intense mixing conditions and enhances transport rates throughout
the bulk of the liquid medium in homogeneous systems and at liquid/liquid or at
liquid/solid interfaces in heterogeneous systems, this influences chemical reactions.
• Sonolysis.
• Increases in both reaction speed and yield in an extensive range of heterogeneous
and homogeneous systems, as explained by Thompson and Doraiswamy.
• Waste minimization through increased selectivity.
• Changes in and simplification of reaction pathways which may lead into milder
process conditions and higher energy efficiency.
• Use of environmentally benign reactants or solvents while retaining or enhancing
the reaction rate under ultrasonication.

17.  Electric Field : High intensity electrical fields have destabilizing effect on dispersed
systems containing polar molecules (water) and to enhance MT processes via promoted
coalescence of dispersed phase.
The essential features of the mechanism involved in electrostatic separations
are:
• Charging of liquid droplet. A) By polarization B) Direct contact of DC charged
electrode.
• Aggregation, coalescence, and settling under gravity of electrically charged droplets.
The large interfacial areas formed due to small droplet formation in electric
fields can be effectively applied to enhance overall rates of reaction in immiscible liquid
systems, higher degree of stable emulsification is achieved.
e.g: The enzymatic hydrolysis of triglyceride esters to yield free fatty acids and glycerol.
They are used to intensify dispersion of aqueous phase into oil substrate by
creating large interfacial areas between the reacting species.

18.  Electromagnetic Fields : The electromagnetic spectrum covers wide range of
energy fields, microwaves, light, X-rays and γ-rays. For chemical process
intensification microwaves and light energy is considered.
 Microwaves:
• Form of electromagnetic energy with frequency range of 300MHz to
300GHz
• Commonly used frequency in chemical processing is 2.45GHz.
• Microwave heating is different from conventional heating. Dipole interactions
or ionic conductions come into picture, depending upon chemical species.
• Heat is generated through molecular collision and friction. Light Energy:
• The very thought of changing physical property of a specie by keeping its
chemical properties intact was born by very observation in 1845 by Blyth and
Hoffman where they saw liquid styrene being converted to solid glassy
substance by sunlight.
• Photoinitiation is alternative to thermal activation.
•Cleaner process. Highly targeted towards desired product; thus reduces
byproducts and cost for downstream separation processing.

19. Enhanced Surface Configuration
Well defined structures or enhanced surface configuration increases the
efficiency of chemical processes. E.g. : Molecular scale structure such as zeolite
supports, known as molecular reactors influences chemical transformation at molecular
scale. The meso and macroscale structures such as channel reactors, monoliths, foams
and static mixers all improves process performances like yield and selectivity.
 Micro/millichannel reactors:
• 10-100μm and 0.5-2.0mm reaction spaces in the form of channels in
different shapes; allows more control of diffusion, heat exchange,
residence/ retention time and flow patterns in chemical reactions.
• Flow is laminar still effective MT can be achieved by short diffusion path
lengths.
Characteristic diffusion time is given by tD = (l2
/ D1).
• Still it is slow for efficient micro mixing. Solution for this is suggested by
Hasel through “passive” techniques.
• Passive techniques include use of miniaturized static inert, this
continuously split and recombine the flow streams.
• Near plug flow behavior which controls RTD can be achieved by
introducing segmented flow via second phase in flowing systems.
• High surface area to volume ratios of up to 5000m2
/m3
is possible in
comparison to conventional stirred tank reactor geometrics.

20. A micro reactor made up of glass. [8]

21.  Monolithic structures:[9]
• A type of structured packing unit consisting of large
number of parallel, straight capillary channels,
separated from each other by walls.
• Honeycomb channels comes in various size and
shapes; rectangular channels being widely used.
• Made up of ceramic or metallic materials, used as
catalyst support in treatment of NOx and CO emissions
in automotive industry.
• Useful in multiphase catalytic reactors.
• Flow in channels is uniformly distributed, with
relatively low pressure drops.
• Provides good contact in gas/liquid phase and catalyst.
• The large contact areas between reacting phases and
the catalyst, gives rise to intense mass transfer to and
from the catalyst.

22.  Static Mixers: [9]
• Motionless pipeline inserts designed to promote
mixing.
• Applied to viscous materials and laminar or turbulent
mixing in single phase liquids or multiphase systems.
• For Laminar mixing the mixer elements are designed
to repeatedly split the incoming flow into many layers,
which are redistributed around the mixer structure in
transverse direction relative to the net flow.
• This uniformly distributes the component across the
flow cross section of the pipe and increased interfacial
area for enhanced diffusion.
• For Turbulent mixing enhances the formation of
turbulent eddies in the flow stream.
• Other benefits are homogeneous mixing, narrow RTD,
low cost and low maintenance, due to absence of
moving part.
• They have limitation in handling very high viscous
material. Also problem of blockages can arise by
suspended solids.
• Static mixers are applicable in gas-liquid dispersion
and liquid-liquid extraction for enhanced mass transfer.
• They are also used as in-line mixer in multifunctional
heat exchanger reactors.

23. Mass and Heat Transfer Performance of several intensified units. [8]

24. Integrating Process StepsIntegrating Process Steps
• Most important strategy is combining process steps, thereby reducing overall number in a process.
 Reduction in capital cost.
 Reduction in running cost.
 Reduction in duty of downstream unit operations.
The most familiar integrations is between reactions and separations.
1) Membrane Reactors: Membranes are
permeable to only one of the products are used
to remove this product in situ. Thereby
overcoming equilibrium constraints. This helps
in bringing equilibrium reactions to completion
• Hydrogen Membrane Reformer (H2MR) is an
innovative, significantly reduces cost and energy
consumption upto 25%.
• Used for large scale hydrogen production
( ammonia or methanol production and refinery
applications). Decarbonisation of fossil fuels by
CO2 capture.
• Separation and reaction has been integrated. By
removing the hydrogen from reaction zone we
can drive the reaction almost to completion
without going to extreme temperature as in
conventional reformers.

25. 2) Reactive Extraction: Separation process in which reaction is used to cause a product
to move into a different phase. This is between two liquid phases, normally organic
and aqueous , although it can be between solids and liquids.

26. 3) Reactive Distillation: Distillation function also acts as reactor, which removes reactor
from the flow sheet. This not only reduces the number of unit operations but also
overcomes the equilibrium limitations of a reactions, by removing product through
distillation.
MeOH
H2SO4
AcOH
To impurity removal
columns
Return form impurity
removal columns
MeOAc
H2O
1
2
3
4
AcOH
MeOH
H2SO4
MeoAc
Heavies
Water
Water + H2SO4 Reactive Distillation for Methyl acetate
Methanol + acetic acid methyl acetate + water

27. 4) Super critical Operation: Separation of solvent (CO2) from reaction mixture is easy
and does not require a separate unit operation. The only requirement is of
appropriate pressure release upto necessary degree for the reaction mixture to come
out.
Supercritical Water
Cooled Reactor
• SCWR is typically designed as a direct-cycle,
where steam or hot supercritical water from the core
is used directly in a steam turbine.
• This makes the design simple, like a Boiling
Water Reactor (BWR) is simpler than a Pressurized
Water Reactor (PWR). An SCWR is a lot simpler
and more compact than BWRs.
• There are no steam separators, steam dryers,
internal recirculation pumps, and recirculation flow
inside the pressure vessel.
• The design is a once-through, direct-cycle, the
simplest type of cycle possible. The stored energy
in the containment is also a lot lower than PWRs
and PWRs.[3]
• Water is liquid at room temperature, cheap, non-
toxic and transparent, simplifying inspection and
repair (compared to liquid metal cooled reactors.)
• A fast SCWR can be a breeder reactor, and can
burn the long-lived actinide isotopes
A heavy-water SCWR can breed fuel from thorium (4x
more abundant than uranium), with increased proliferation
resistance over plutonium breeders

28. Algorithm for Process IntensificationAlgorithm for Process Intensification [10][10]

29. Barriers for Process IntensificationBarriers for Process Intensification [11][11]
1) R&D effort in chemical companies is primarily focused on the new products than
focusing on new methods to synthesize. Chemical manufacturers are not interested in
developing novel equipments or processing techniques. On the other hand equipment
manufacturers and engineering companies are not keen on process intensification.
2) Many novel apparatus and methods are not yet proven on industrial scale. Every plant
manager avoid to take risk involved in the application of the equipment or processing
method that has not yet been tested on the full scale elsewhere.
3) Chemical engineers in industries are not familiar with process intensification and are
not aware with emerging novel types of equipments and processing methods. Process
intensification is not taught in chemical engineering curricula, which is based on unit
operations, onionskin methodology(first reactor then separation/purification then heat
integration followed by process control and safety.) for process development.
4) Standard tools for modern process development from the laboratory to commercial
scale are often missing. Any chemist developing new fine chemical will stick to
standard available method. We do not have highly efficient continuous reactors as
standard laboratory equipment.

30. 5) Many of the novel equipments and processing methods are of radically different
nature, and there is lack of simulation and process scale up capability. Also there is a
lack of early screening methods to qualify these novel technologies.

31. Merits of Process IntensificationMerits of Process Intensification [8][8]

32.  Business:
• Miniaturization of plant
• Reduction in operating cost
• Reduction in capital cost
• Distributed product manufacturing
• Faster Introduction of Product into market
 Process:
• Higher selectivity/ product purity
• Higher reaction rates
• Improved product properties
• Improved process safety
• Wider processing conditions
 Environment :
• Less Energy Consumption
• Reduced Waste
• Reduced Solvent Use
• Smaller Plants, Optimize use of lands.

33. ConclusionConclusion
Process Intensification has gained a momentum as a revolutionary approach to
chemical process, in around last two decades. PI has been described as “ the key to
survival of the fittest in international competition”. With much emphasis on sustainable
development nowadays, PI can come handy and make chemical and pharmaceutical
processes much greener. Chemical Process and industry fraternity is looking towards PI
as new paradigm in to lead chemical process industries. It took over transport
phenomena.
The potential for PI remains largely untapped, but the economic rewards for
those companies that do introduce PI are likely to be substantial and this will have
environmental benefits for a more sustainable future for generations to come.

34. ReferencesReferences
1) Ramshaw, C. Higee distillation-an example of process intensification. Chem. Eng. London
1983, 389, 13.
2) Cross, W. T.; Ramshaw, C. Process Intensification - laminar-flow heat-transfer. Chem. Eng.
Res. Des. 1986, 64, 293.
3) Stankiewicz, A.; Moulijn, J. A. Process intensification: transforming chemical engineering.
Chem. Eng. Progr. 2000, 96 (1), 22.
4) Tsouris, C.; Porcelli, J. V. Process Intensification - Has its time finally come? Chem. Eng.
Progr. 2003, 99 (10), 50.
5) ERPI. European Roadmap for Process Intensification. Creative Energy - Energy Transition.
www.creative-energy.org (accessed September 2, 2008).
6) Becht, S.; Franke, R.; Geisselman, A.; Hahn, H. An industrial view on process intensification.
Chem. Eng. Process.: Process Intens., available online April 26,
2008,http://dx.doi.org/10.1016/j.cep.2008.04.012.
7) Tom Van Greven, Andrzej Stankiewicz – Structure, Energy, Synergy, Time- The fundamentals
of Process Intensification. Ind. Eng. Chem. Res. 2009, 48, 2465-2474.
8) Kamelia Boodhoo and Adam Harvey – Process Intensification: An Overview of Principles and
Practice. School of Chemical Engineering and Advanced Materials Newcastle University,UK.
9) Andrzej Stankiewicz and Jacob A Mouljin, - Process Intensification: Transforming Chemical
Engineering, January 2000 Chemical Engineering Progress.
10) Philip Lutze, Rafiqul Gani, John M Woodley – Process Intensification: A perspective on
process synthesis. Chemical Engineering and Processing 49(2010) 547-558.
11) Process Intensification. Ind. Eng. Chem. Res. 2002, 41, 1920-1924.
12) www.wikipedia.org.in