Synthetic fuel can be produced through methods like polymerization, Fischer-Tropsch process, and Bergius process, with polymerization involving combining smaller hydrocarbon molecules, Fischer-Tropsch converting carbon monoxide and hydrogen into liquid hydrocarbons using catalysts, and Bergius process directly liquefying coal through hydrogenation at high pressures and temperatures. These methods allow the production of synthetic gasoline and other fuels from sources like coal, natural gas, and biomass as alternatives to petroleum-derived fuels.

1. Fuel and Combustion
By A Nirala
Assistant Professor
Galgotias University
niralaiitk@gmail.com

7. SYNTHETIC FUEL

8. (A) Introduction
(B)Methods of producing
(a) Polymerisation
(b) Fischer– Tropsch process
(c) Bergius Process

9. Synthetic fuel or synfuel is a liquid fuel obtained
from coal, natural gas, oil shale, or biomass.
It may also refer to fuels derived from other solids such
as plastics or rubber waste. It may also (less often) refer
to gaseous fuels produced in a similar way.
Common use of the term "synthetic fuel" is to describe
fuels manufactured via Fischer Tropsch
conversion, methanol to gasoline conversion, or
direct coal liquefaction.

10. Methods of producing synthetic petrol:
• Polymerisation
• Fischer- Tropsch method
• Bergius process
Polymerisation:
In this method, smaller molecules of hydrocarbons are
combined to form heavier molecule resembling gasoline.
It is of two type:
(a)Thermal polymerisation
(b)Catalytic polymerisation

11. (a)THERMAL POLYMERISATION:
Thermal polymerisation is carried out at
temperature about500-600 oC and pressure
about 70-350 kg/cm.cm
(b)CATAIYTIC POLYMERISATION:
It is carried out at a lower temperature of 150-200 C ,in a
low pressure and in presence of catalyst like posphoric
acid. The rate of reaction is increased. The gasoline
obtained is of improved quality and
possess high antiknock properties than the gasoline
obtained from thermal polymerisation process.

12. The Fischer– Tropsch process (or Fischer– Tropsch synthesis) is a
collection of chemical reactions that converts a mixture of carbon
monoxide and hydrogen into liquid hydrocarbons. The process, a
key component of gas to liquids technology, produces a synthetic
lubrication oil and synthetic fuel, typically from coal, natural gas,
or biomass. The F–T process has received intermittent attention as
a source of low-sulfur diesel fuel and to address the supply or cost
of petroleum-derived hydrocarbons.

13. Fischer- Tropsch process
The water gas is varied with hydrogen and the combination is purified by
transitory from side to side Fe2O3 and then into a mixture of Fe2O3+Na2CO3.
The cleanse gas is dense to 5 to 25 atm and then led from side to side a
converter, which is preserve at a temperature of 200 – 300oC.
The converter is provided with a catalyst bed consisting of a mixture
of 100 parts cobalt, 5 parts thoria, 8 parts magnesia and 200 parts
keiselghur earth.
The outcoming gaseous mixture is led to a condenser, where the
liquid crude oil is obtained. The crude oil is fractionated to yield gasoline
and heavy oil. The heavy oil is used for cracking to get more gasoline.

15. :Bergius process
One of the main methods of direct conversion of coal to
liquids by hydrogenation process is the Bergius process.
In this process, coal is liquefied by mixing it with hydrogen
gas and heating the system (hydrogenation). Dry coal is
mixed with heavy oil recycled from the process. Catalyst is
typically added to the mixture. The reaction occurs at
between 400 °C (752 °F) to 5,000 °C (9,030 °F)and 20 to
70 MPa hydrogen pressure. The reaction can be summarized
as follows:

16. Bergius Process - Synthetic Petrol:
In this process, the finely powdered coal is completed keen on a paste through
heavy oil and a catalyst powder (tin or nickel oleate) is mixed with it. The paste is
pumped along with hydrogen gas into the converter, where the synthetic paste is heated
to 400 - 450°C under a pressure of 200 - 250 atm.
During this process hydrogen combines with coal to form saturated higher
hydrocarbons, which experience additional decay at superior temperature to acquiesce
combination of lesser hydrocarbons. The mix is led to a condenser, where the crude oil
is attained. The crude oil is then fractionated to yield:
(a)Gasoline (b)Middle oil (c)Heavy oil