Fischer-Tropsch and Bergius processes for synthetic fuel production

Synthetic Fuels are liquid or gaseous fuels that are used as an excellent alternative to gasoline and natural gas. They are derived from a variety of sources like coal, tar, biomass etc. As the demand for fuel is increasing there is more extraction from the natural sources and consequently faster depletion of the same. Synthetic fuels offer to be an excellent solution for this problem of depleting energy resources. Some of the important synthetic fuels that are industrially produced are Methanol, ethanol, hydrazine, synthetic Hydrogen, etc. Let us look into two main methods of producing synthetic fuels before discussing their advantages and disadvantages.

Fischer- Tropsh Method

One of the important laboratory methods of producing synthetic fuel is the Fischer- Tropsh method. This method is actually a reduction of carbon monoxide. Two German scientists named Franz Fischer and Hans Tropsch developed this method. This process essentially involves a mixture of hydrogen and carbon monoxide reacting in the presence of cobalt catalyst at high temperature and 5-10 atmospheric pressure. The product is a mixture containing liquid hydrocarbons. By means of fractional distillation the synthetic petrol is separated from the other products.

Bergius Process

Another well-known method is the Bergius Process found out by Dr. Friedrich Bergius. In this method finely powdered brown coal or lignite is reacted with hydrogen gas at high pressure and temperature. (450 degrees). This hydrogenation process yields alkanes and the final condensation of the vapors yields synthetic petroleum or what is known as crude oil. This upon fractional distillation yields synthetic petrol and other oils. [B.S.Bahl]

Hydrogen Gas

Synthetic Hydrogen offers an environmental solution to the energy crisis faced by the world. Cost effective production of hydrogen has always been a major hurdle. However scientists are the looking at a novel way of tackling this problem. The new technique is to isolate the hydrogen producing enzymes from micro-organisms and study their structure and to duplicate their actions. Researchers are already working on this new possibility. [James E. Kloeppel]

Disadvantages

The main drawback with synthetic fuels is their exorbitant costs. This is mainly attributed to the huge production costs in the form of the capital investment. The cost incurred in the infrastructural setup and the logistics (transport of Raw materials) adds on to the production cost. Also the cost keeps on changing along with the cost of the raw materials. (Coal, biomass, etc.). Some synthetic fuels like methanol and ethanol have high levels of aldehyde emissions causing potential health hazards Only when synthetic fuels fall below or at least equal the cost of production of natural fuels it is viable for them to replace conventional fuels. In future we can expect that synthetic fuels may be a technically and economically feasible alternative to the conventional fuels.