fischer tropes

1. M e t h o d s o f s o l i d w a s t e t r e a t m e n t

2. 1
Huzaifa Rashid FA19-CHE-058
Abdul Hanan Wali FA19-CHE-042
Group Members
Syed Taqqi Haider FA19-CHE-100
2
3

3. Solid Waste: A
Growing Problem
Solid waste is a major problem in many countries, including Pakistan. The amount of solid waste
generated is increasing every year, and it is becoming increasingly difficult to find suitable
disposal sites.
There are several different methods for treating solid waste, each with its own advantages and
disadvantages.

4. Solid Waste: A Growing Problem
•Landfilling
•Incineration
•Composting
•Anaerobic
digestion
•Gasification

5. LANDFILLING
Landfilling is the most common method of solid waste disposal. Waste
is buried in layers, covered with soil, and compacted.
Landfills can be a source of methane, a greenhouse gas, and leachate, a liquid that can contain
harmful pollutants.

7. ADVANTAGES AND DISADVANTAGES
× Landfills can be a source of methane, a greenhouse
gas that is more potent than carbon dioxide.
 Landfilling is a relatively inexpensive
method of waste disposal.
 Landfills can be used to dispose of a wide
variety of waste materials.
 Landfilling can help to reduce the amount of
waste that is sent to incinerators, which can
produce harmful pollutants
× Landfills can also be a source of leachate, a
liquid that can contain harmful pollutants.
× Landfills can take up a lot of space.

8. 1
Preparation: The site is
prepared by grading,
installing drainage
systems, and installing a
liner.
Waste disposal: Waste is
brought to the site and is
disposed of in layers.
Landfilling process can be divided into the following
steps:
2

9. 1
Compaction: The waste
is compacted to reduce
the amount of space it
takes up.
Covering: The waste is covered with
soil or other materials to help
prevent the growth of pests and to
reduce the spread of odors.
3
4

10. Incineration:
Incineration is a process of burning solid waste at
high temperatures. This process can reduce the
volume of waste by up to 90% and can also generate
heat or electricity. However, incineration can also
produce harmful pollutants, such as dioxins and
furans.

12. Step 1 Step 2 Step 3 Step 4 Step 5
Loading waste into
the furnace
Burning waste at
high temperatures
Turning the steam
into electricity
Incineration
Generating steam
from the heat of
combustion
Disposing of ash
and other residues
safely

13. 1 Reduces landfill waste by up
to 90%.
2 Generates electricity.
3 Destroys hazardous
waste
3
Produces hazardous ash
1
Releases air
pollutants.
2
May not be cost-effective.
Advantages and Disadvantages

14. Gasification Gasification is a waste treatment process that
converts solid waste into a gas that can be used
to generate electricity or heat. The gasification
process involves heating the waste in a low-
oxygen environment, which breaks it down into
its basic components, including carbon
monoxide, hydrogen, and methane. However,
gasification is also a relatively new technology.

15. ADVANTAGES AND DISADVANTAGES
× High cost.
 Reduces landfill waste by up to 90%
 Can be used to produce syngas, which can be
used to produce a variety of products, such as
synfuels, fertilizers, and chemicals.
 Generates electricity or heat.
× Specialized equipment required.
× Not all waste materials are suitable for
gasification.
× Gasification plants can be complex and require
careful operation and maintenance.

16. Pressure gasification can be done with fine coal in suspension and in fluidized beds.
𝐶𝑂2 + 𝐶 → 2𝐶𝑂 ∆𝐻 = +39,460 𝑐𝑎𝑙(1500𝐾)
Process
(General Reaction)
The partial combustion can be carried out at pressure of 400-450 psi to obtain synthesis gas.

17. Pulverized coal is gasified with oxygen and steam, the gases leave the combustion zone at a high
temperature.
Process
This process employs a noncaking type of coal in a pressurized fixed bed.

18. This is done by water washing the gas in packed or spray towers, cooling as well as cleaning the gas.
Purification Process
The raw synthesis gas must be purified to remove solids such as unburned carbon and fine ash.
Hydrogen sulfide and organic sulfur are catalyst poisons and must be
removed to an extremely low value. Carbon dioxide is harmful to the catalyst in high concentrations

19. Acidic constituents of raw synthesis gas, C𝑂2 and H sulfide can be removed either by water or by an
alkaline wash such as mono ethanol amine, diethanolamine.
Process
In water washing3-5 per cent of the carbon monoxide and hydrogenis lost by solution in water.
Water scrubbing depends upon physical solubility of carbon dioxide and hydrogen sulfide in water.

20. Rectisol process is another method of purification and based on the physical solubility of impurities in a
methanol solution at - 40 to - 60°C.
1 2
Iron oxide boxes are usually added
in the purification train, Iron oxide
impregnated on wood shavings
effectively reduces the
concentration of hydrogen sulfide.
A small amount of methanol is
thoroughly regenerated by
heating for the final purification
Process

21. Fischer-Tropsch Process
The principal catalysts, operating conditions, and products of tt syntheses and similar data on the Fischer-
Tropsch process.
Three processes, the Oxo, Synol, and Isosynthe are related to the Fischer-Tropsch process in that
hydrocarbons or oxygenated chemicals are produced from mixtures of hydrogen and carbon monoxide.

22. Temperature and Pressure
Effect
Usually low-molecular-weight olefins react at lower temperatures and more rapidly than do the higher-
molecular-weight olefins.
Temperatures of hydro formylation range from 110-190° depending upon the catalyst activity and the nature
of the olefins.

23. 1 Oxo Process
This reaction of an olefin with
hydrogen and carbon
monoxide in the presence of
a cobalt catalyst.
2 Synol Process
The Synol process is a
technical process for the
production of primary
alcohols from synthesis gas .
The process was carried out
from around 1940 as a
modification of the Fischer-
Tropsch synthesis.
3
Isosynthesis'' referred to
catalytic hydrogenation of
carbon monoxide in which a
proper choice of reaction
conditions and catalyst led to
production.
Fischer-Tropsch Process
Isosynthe Process

24. Catalysts that are commonly used for the Fischer Tropsch synthesis are:
 Nickel
 Cobalt
 Iron
Catalysts
Catalysts can be used for making a gaseous and liquid products from coal.

25. Nickel as a catalyst can be used for making a gas from coal comparable in heating value to natural gas.
Nickel Catalyst
Nickel catalysts have been prepared by precipitation from nitrate solution with the potassium carbonate in the
presence of thoria and kieselguhr.
It is not desirable to employ nickel catalysts at low temperatures and elevated pressures because the
formation of nickel carbonyl is excessive.

26. 1
2
3
Nickel catalysts does not employ
on low temperatures and elevated
pressure.
As the temperature increased to 300-
350c and the pressure increased to
the 300-400 psi nickel only produce
methane.
Nickel as a catalyst is costly to
use and also required high
temperatureto work efficiently.
Nickel Catalyst

27. Cobalt Catalyst
1
2
3
Cobalt catalysts are preferable to
nickel when greater yields of
liquid products are desired.
The catalyst was used at atmospheric
pressure or at 7-10 atm and at 180-200
c.
Because of the expense and
scarcity of cobalt ,emphasis has
shifted to the use of iron.

28. Iron Catalyst
1
2
3
Iron catalyst prepared by the
precipitation from solution , from
magnetite ore, or from magnetite
obtained by fusion of iron oxides,
or by oxidation of metallic iron
with steam.
The catalyst used for ammonia
synthesis performs quite well in the
fisher tropch synthesis.
Iron catalysts operate over a
considerable wider temperature
range ,200-300c than do cobalt
catalysts.

29. Iron Catalyst
The space velocity of operation is almost directly proportional to the pressure
However pressure above 450 psi are not used for prolonged operation because of the danger of
forming iron carbonyl, resulting in deterioration of catalyst.

30. Brownsville Plant
Catalyst
The reactor used for F-T process have been used either commercially or in large-scale pilot
plants.
Fluid Bed
Modern Ruhrchemie Fixed-bed Reactor
Sasol Plant.

31. For F-t reaction reactor are made according to the removal of heat produced in reaction.
The chief difference between these reactors is the method provided for removing the large quantity of
heat generated in the reaction.
Reactor

32. A commercial Fischer-Tropsch plant using coal as raw material was put on stream late in 1955 at Sasolburg
in South Africa.! Large quantities of coal are located in the area
Coal consumption is 5,000 tons per day, of which 1,800 tons is for the power plant and 3,200 tons for
gasification.
Sasol Reactor

33. Raw coal is crushed and classified
into three sizes. The finest portion
is used in the power plant, which
has four boilers, each having a
capacity of 160 tons of steam per
hour. Synthesis is conducted at
about 220°C and about 25 atm. Iron
is used as Catalyst.
Sasol Reactor

34. 1
2
3
A commercial Fischer-Tropsch
plant using coal as raw material
was put on stream in South Africa
The cost of the mined coal being
about $1.00 per ton.
Raw coal is crushed and classified
into three sizes. The finest portion
is used in the power plant.
Sasol Plant

35. 4
5
6
There are five fixed-bed reactors.
The has 10 ft diameter and 40 ft
height.
60% conversion is achieved.
Each reactor is supplied with
700,000 cu ft per hr of synthesis
gas
Sasol Plant

37. Gasoline, 70OC
Diesel 550 oF
Liquefied petroleum
gas, -490F to 340F
Sasol Plant Production
1
2
3
Fuel oil, 100 °F
Pitch and Tar road 570
OF
Paraffin waxes, 170-
310°F
4
5
6

38. Ethanol
Acetone
Butanol
Chemicals Produced
1
2
3
Benzene
Xylene
Toulene
6
5
4

39. The first American synthetic-fuels plant was
constructed at Brownsville, Tex., by the Carthage
Hydrocol Company in 1951. Reactor design was
based or. a fixed fluidized bed of iron catalyst to
convert hydrogen-rich synthesis gas, produced from
natural gas, to liquid hydrocarbons and chemicals.
Brownsville Plant

40. Commercial Operation
In 1939 there were 14 commercial Fischer-Tropsch plants operating throughout the world
Most of the German plants were destroyed during World War II
About three-fourths of the total annual output of synthetic fuels came from Germany

41. Commercial Operation
Operation has been resumed at only two plants in West Germany
The first American synthetic-fuels plant was constructed at Brownsville reactor design was based on a
fixed fluidized bed of iron catalyst to convert hydrogen-rich synthesis gas
Since the economics of producing liquid fuels are unfavorable, principally waxes and high-boiling aliphatic
alcohols are produced, the latter for use in detergents and fatty acids

42. After two years experimentation, it was concluded that under prevailing domestic conditions the
process could not produce gasoline and chemicals as cheaply as competitive processes.
About 64 million cu ft per day of natural gas is required, including that used as fuel for processing the
products.
Commercial Operation

43. An oxygen plant supplies about 1,800 tons per day to the gas generator in accordance with the
following equation
𝐶𝐻 + 0.61 𝑂2 → 0.96𝐶𝑂 + 1.82 𝐻2 + 0.04𝐶𝑂 + 0.18 𝐻2𝑂
Approximately 180 million cu ft per day of synthesis gas is produced.
Commercial Operation

44. The cost of a 27,000-bbl-per-day synthetic liquid-fuels plant using coal-steam-oxygen pressure gasification was
estimated at 290 million dollars, not including the costs for a coal mine, royalties, start-up expense and working
capital.
With these items included, the total investment cost amounted to 380-400 million dollars, which is equivalent to
about $14,500 per daily barrel of oil.
The cost of manufacturing synthetic gasoline has been estimated at slightly more than 17 cents per gallon
Economics of Fischer-Tropsch
Improvements in technology should result in reduction of the costs.

45. METHANATION
High-Btu gas consisting principally of methane can be produced by conversion of synthesis gas over nickel
or iron catalysts; nickel is more active
Methanation
Four volumes of synthesis gas is consumed per volume of methane formed. A feed gas of 3H2 : 1CO ratio is
desirable in accordance with the reaction
CO + 3H2 → CH + H20

46. Methane was first synthesized by Saba tier and Senderens more than fifty years ago.
For many years little work was done on developing methanation.
Methanation is highly exothermic
1
2
3
Methanation Process

47. This reaction of an olefin with hydrogen and carbon monoxide in the presence of a cobalt catalyst to produce
aldehydes, containing one carbon atom more than that of the hydrocarbon in the feed, may be written as
R-CH=CH + CO + H → R-(CH2)2-CHO
Reaction

48. METHANATION
The Oxo Process
When ethylene was added to water gas in the presence of cobalt catalyst at
200-225°C and atmospheric pressure.
Pressures of 1O-200 atm, all liquid products from the reaction of ethylene and water gas were
oxygenated.

49. METHANATION
Raw Materials
Synthesis gas and an olefin are the reactants of the Oxo process. The ratio of H2 : CO is usually 1:1
Synthesis gas and an olefin are the reactants of the Oxo process. The ratio of H2 : CO is usually 1:1

50. Raw Materials
The reaction of carbon monoxide and water vapor to form carbon dioxide and hydrogen. An important
step in the industrial production of hydrogen.
CO + H 2O → CO2 + H2

51. Oxo process Catalyst
Dicobalt octacarbonyl is formed according to the equation
2CoCO3 + 2H2 + 8CO → Co2(CO)8 + 2H2O + 2CO2
Cobalt catalysts are universally used for the Oxo reaction. dicobalt octacarbonyl from cobalt carbonate and
synthesis gas has been described by Wender.

52. Temperature and Pressure
Effect
Usually low-molecular-weight olefins react at lower temperatures and more rapidly than do the higher-
molecular-weight olefins.
Temperatures of hydro formylation range from 110-190° depending upon the catalyst activity and the nature
of the olefins.

53. Kinetics and Mechanism
Also synthesis gas is independent of the total pressure between 100 and 400 atm3
Kinetic data from batch autoclave experiments indicate that the rate of the hydro formylation reaction when
using IH2 :1CO

54. 1 Reduces landfill waste by up
to 90%.
2 Generates electricity.
3 Destroys hazardous
waste
3
Produces hazardous ash
1
Releases air
pollutants.
2
May not be cost-effective.
Advantages and Disadvantages

55. Word of Thought
‫ہے‬ ‫بھی‬ ‫یہ‬ ‫اصول‬ ‫غیبی‬ ‫ایک‬
‫چیز‬ ‫جو‬ ‫کہ‬
‫تقسیم‬
‫گی۔‬ ‫جائے‬ ‫ہو‬ ‫فراوانی‬ ‫پاس‬ ‫تمہارے‬ ‫کی‬ ‫چیز‬ ‫اسی‬ ‫گے‬ ‫کرو‬
‫وہ‬ ‫چاہے‬
‫دولت‬
،‫ہو‬
‫عزت‬
،‫ہو‬
‫علم‬
،‫ہو‬
‫محبت‬
‫ہو‬
‫درگزر‬ ،
،‫ہو‬
‫کھانا‬
‫یا‬ ‫ہو‬
‫آسانیاں‬
‫۔‬
(‫زاویہ‬)