synthesis gas”, Co and Os catalysts. Fischer and Tropsch report about the preparation of hydrocarbons over an Fe catalyst, the catalyst deactivates rapidly.  The catalyst used for Fischer Tropsch reaction is 20% DMAA / Clay,  H. Schulz, J.H. Cronjé, Fischer–Tropsch-Synthese, in: Ullmanns. Fischer-Tropsch synthesis. Biosyngas gas rich in H2 and CO obtained by gasification of biomass. Syngas comparable to biosyngas, but from.
|Published (Last):||27 July 2007|
|PDF File Size:||15.37 Mb|
|ePub File Size:||17.35 Mb|
|Price:||Free* [*Free Regsitration Required]|
The Fischer—Tropsch process or Fischer—Tropsch Synthesis or F-T is a set of chemical reactions that changes a mixture of carbon monoxide gas and hydrogen gas into liquid hydrocarbons like gasoline or kerosene.
The Fischer—Tropsch process involves many kinds syntyese reactions, which lead to both wanted and unwanted results.
Fischer–Tropsch process – Wikipedia
The desirable reactions create chemicals called alkanes. Sometimes the gas methane natural gas tischer produced, which is generally undesirable. Sometimes, different kinds of alcohol are produced in small amounts. Many steps are required to make the gases needed for the F-T process.
For example, all chemicals entering the reactor must have all sulfur removed.
For factories that start out with methane and want to make a liquid hydrocarbon like keroseneanother important reaction is “steam reforming”, which turns the methane into CO carbon monoxide and H 2 hydrogen gas. This is the chemical equation for how steam reforming works. The reaction above describes one molecule of H 2 O steam plus one molecule of CH 4 methane converts into one molecule of CO carbon monoxide and three molecules of H 2 hydrogen gas.
A catalyst is a substance added to change the rate of a chemical reaction, generally to make it faster. Many different catalysts can be used for the Fischer—Tropsch process. The most common catalysts are the metals cobalt, iron, and ruthenium.
These metals are all transition metals. The metal nickel can also be used, but generally with unwanted results. A nickel catalyst in the reaction usually produces a lot of methane, which is undesirable. Cobalt seems to be the most active catalyst it has the greatest and fastest effect on the process.
When the input is a natural gas, cobalt catalysts are very good for the Fischer-Tropsch process. Iron catalysts are better when the input gas is of lower quality less pure such as coal or biomass.
Most metals used for this process like cobalt, nickel, and ruthenium remain in their metal form when added to the process. However, iron catalysts behave very differently. Often, iron catalysts change form and chemical phase, like converting into various oxides and carbides during the reaction.
It is important to control all of the iron reactions during the process, or else the process may not work correctly. Fischer-Tropsch catalysts are famous for being extremely sensitive to the addition of sulfur. Even a tiny amount of sulfur can have an undesirable impact on the reaction. Cobalt catalysis is more sensitive to sulfur than iron.
HTFT uses an iron-based catalyst. Some F-T factories use coal, biomass or other solid compounds as a starting point. Before these factories can begin the F-T process, they must turn the solids into gases such as CO, H 2and fischwr. Changing solid chemical compounds into gas is called gasification. This ratio can be adjusted from 0. Gasification is a dirty and expensive process.
Coal-based Fischer—Tropsch factories start out with coal, gasify the syhthese, and then use the resulting gas as feed stock for the Fischer-Tropsch process.
These factories can produce large volumes of CO 2 in this way. One of the main reasons for this approach is the large amounts of energy required for a coal-based gasification process.
Since then, many improvements have been made. The term “Fischer-Tropsch” now is used for many similar processes. Fischer and Tropsch hropsch several patentslike US patent no. Germany had an abundance of coal but very little petroleum. The F-T process enables the conversion of coal into gasoline, which is important for gasoline-based transport like cars, airplanes, and trucks.
The F-T process has been used by many syntyese companies, however the process is unpopular for many reasons. F-T factory equipment is expensive, and has high operating and maintenance costs.
Also, petroleum, which competes with F-T products, synhhese very unpredictable prices. Usually, factories are only profitable when ttropsch have access to “stranded gas”. If the natural symthese could be pumped to these cities and sold directly to consumers, it would be much more profitable. Therefore, several companies are developing processes to enable practical exploitation of so-called stranded gas reserves.
South Africa is a country with large coal reserves but not enough oil to meet demand. Germany is in a similar situation. Sasol employs coal and natural gas in the F-T Process.
They produce many different substitutes for oil products, and produce most of the country’s diesel fuel. One of the largest uses of F-T technology is in Bintulu, Malaysia. This Shell factory turns natural gas into low-sulfur diesel fuels and food-grade wax. It said that it will do this along with the manufacturing processes at its European paper and pulp plants.
It will use waste biomass from paper and pulp manufacturing as raw material for biodiesel. Inchemists working for the U. Navy studied Fischer-Tropsch for making fuels with hydrogen from electrolyzed seawater. With the usually optimal cobalt catalyst, this study produced mostly methane gas.
Further refining of the hydrocarbons produced could lead to the creation of kerosene-based jet fuel. The abundance of CO2 makes seawater look like a good alternative fuel source.