DE102010011076A1 - Method and device for optimizing a target yield in a Fischer-Tropsch synthesis, comprise separating the sections to short-chain hydrocarbons and long-chain hydrocarbons and then feeding back to an inlet of a synthesis chamber - Google Patents

Abstract

The method and device for optimizing a target yield in a Fischer-Tropsch synthesis, comprise separating the sections to short-chain hydrocarbons and long-chain hydrocarbons and then feeding back to an inlet of a synthesis chamber, and feeding back the long-chain condensed portion to a hot portion of the gas preparation using a temperature-controlled pump (17) and then again evaporating, where the remaining gaseous portion is fed to the inlet of the synthesis chamber and the feeding back steps take place over the temperature-controlled pump. The method and device for optimizing a target yield in a Fischer-Tropsch synthesis, comprise separating the sections to short-chain hydrocarbons and long-chain hydrocarbons and then feeding back to an inlet of a synthesis chamber, and feeding back the long-chain condensed portion to a hot portion of the gas preparation using a temperature-controlled pump (17) and then again evaporating, where the remaining gaseous portion is fed to the inlet of the synthesis chamber and the feeding back steps take place over the temperature-controlled pump. Several return lines are equipped with outlet valves to remove the accumulating excess amounts. The separation of the unwanted sections occurs over a cooler, whose cooling temperatures are freely adjustable.

Description

State of the art

In 1925, the researchers Fischer and Tropsch developed the process named after them for the production of long-chain hydrocarbon molecules from the gas combination CO (carbon monoxide) and H2 (hydrogen gas).

In the emergency times of Germany during World War II, this process was used on an industrial scale to supply the country with fuel.

Due to the low oil price of US $ 3.00 / bbl (159 ltr) after World War II and almost unchanged until 1973, all fishery-tropical-synthesis activities soon faltered. This in particular with a coal price of US $ 12 / short ton (907 kg) corresponding to US $ 13.2 / t, to which is added the energy expenditure for the FT procedure.

On a larger scale, this process came into play again at the end of the 70s, when in 1979 after the revolution in Persia the supply of the then "apartheid state" South Africa with oil by Chomeini was stopped.

Soon, the already begun synthesis productions with the works Sasol 1 to 3 were expanded enormously, so that very soon a large part of the fuel was produced in the country.

In Europe, the Fischer-Tropsch process was completely forgotten and only when the oil price in March 2008 exceeded the one hundred dollar mark, considerations began to use this procedure again.

This was combined with the idea of winning fuel as renewable energy and then became more concrete in the large-scale project "Choren" in Freiberg, which was to go into production in 2009 with a great deal of press work.

For whatever reason, you can not hear it anymore. In any case, a significant production of BtL fuels has not yet been produced.

issues

A problem of the Fischer-Tropsch synthesis is that by means of the setting parameters temperature, catalyst design, pressure and gas velocity, a maximum of the desired hydrocarbon chain is always achieved, but even after a distribution curve both short-chain and longer-chain products are achieved.

Although this equilibrium reaction can be constricted by optimizing the process, it can not stop it. Biodiesel also produces small quantities of LPG, more gasoline and, on the other hand, paraffins. For this reason, the yield is only about 50-70% depending on the target product. The other parts must then be used differently or the high-boiling parts should be cracked again.

Troubleshooting

Optimal would of course be a Fischer-Tropsch synthesis in each of which the target product is produced and thus the refining would be superfluous or at least no other refining products remain.

This is especially useful, even necessary when dealing with relatively small, decentralized stations. Here, a very special fuel to be produced and for the typical by-products there is neither a purchase nor another use on site.

Method and apparatus for optimizing the target yield in a Fischer-Tropsch synthesis

With the method according to the invention, the yield, based on the target fuel to be optimized.

This happens because the forming equilibrium reaction is used by the areas which are outside the target material are separated by appropriate columns or coolers and then fed back to the input gas.

This is quite simple with the remaining gas or the gas phase left over at the corresponding temperature. This line should be tempered.

In the case of the high-boiling fraction, it precipitates as liquid at the corresponding temperature. This must then be pumped back. Both the pump and the line must be heated and the recirculation takes place in the high temperature range of the Fischer-Tropsch cooler for immediate gasification.

Thus, the hydrocarbon chains of the surrounding sections are already available in the Fischer Tropsch reactor, thus suppressing their production in the sense of equilibrium. As a result, the desired type of fuel is then predominantly generated.

description

Based on 1 and 2 the procedure should be clarified.

1 shows an assumed distribution of hydrocarbon chain length as a typical distribution curve 1 , In the short-chain area 2 the yield of liquid gases can be seen, with the underlying methane and ethane. This is followed by the area 3 , of Bezin, followed by the widest area 4 , which makes up the diesel fuel. Then follow as the long-chain section 5 the paraffins.

2 now shows a possible expression of an apparatus for performing the method according to the invention.

The gas for the Fischer-Tropsch process arrives 6 in the gas preparation 7 such as pre-cooling and cleaning. After that, the appropriately prepared gas arrives 8th in the catalyst chamber 9 , There learns its chaining and joins 24 out, then into the first cooling chamber 10 to flow. Here, the longest-chain areas are condensed out and liquefied. Via a tempered pipe, the liquids obtained pass through the pump 17 back in the hot area 18 the gas preparation.

The still gaseous parts come over the line 11 in the second cooling chamber. Here the working area is condensed out and flows over the line 14 in the tank 15 , Here, the residual water collects in the lower area 19 and can be deducted there.

The remaining gas flows over the tempered pipe 13 back into the catalyst chamber 9 ,

In order to be able to deduct a surplus that accumulates, there are the valves 20 with the withdrawal line 21 and valve 22 with the withdrawal line 23 ,

Claims (6)

Method and apparatus for optimizing the target yield in a Fischer-Tropsch synthesis, characterized in that the regions are separated with short-chain and / or long-chain hydrocarbons and then fed back to the input synthesis chamber. A method and apparatus according to claim 1, characterized in that the long-chain and condensed part is returned to the hot part of the gas preparation by means of a tempered pump and is evaporated again. Method and device according to one of claims 1 to 2, characterized in that the remaining gaseous part is supplied to the entrance of the synthesis chamber. Method and device according to one of claims 1 to 3, characterized in that the returns take place via tempered lines. Method and device according to one of claims 1 to 4, characterized in that the return lines are equipped with drain valves, so that excess quantities that have accumulated, can be deducted. Method and device according to one of claims 1 to 2, characterized in that the separations of the unwanted areas via cooler happens, the cooling temperatures are freely adjustable.

Images