DD139595A1 - PROCESS FOR OBTAINING LIQUID COAL FUELS - Google Patents

Abstract

The invention relates to the recovery of liquid fuels from coal by combining the Bergius and the Fisctier-Tropsch process and a further improvement thereto. The aim of the invention is the vjirtschaftliche design of both methods. The method thus relates to the 'extraction of liquid fuels, characterized in that one subjects the after removal of gaseous and liquid hydrocarbons remaining ash and oil-containing residue hydrogenation of a gasification in the presence of oxygen under elevated pressure, the gas mixture contained partially zn hydrogen , partially hydrogen and carbon monoxide-containing synthesis gas works, the hydrogen is used in the hydrogenation, produced from it synthesis gas, catalytically under elevated pressure methanol and / or Dime thy lather and. converts them catalytically into liquid hydrocarbons

Description

718

Process for the production of liquid fuels from coal

The invention relates to a method for the production of. liquid fuels from coal using high-pressure hydrogenation of coal and the recovery of lower-boiling hydrocarbon mixtures from the high-boiling hydrogenation residues »

Well-known technical solutions

In view of the expected shortage of crude oil, which up to now has been used mainly as a basis for the production of liquid fuels, there are increasing efforts in recent years to use coal as raw material for the production of the named products instead of crude oil the hydrogenation of coal slurried in a heavy oil according to the aera Bergius process, in which hydrogen is added to the carbonaceous substance under high pressure to produce liquid hydrocarbon mixtures. * Another known process is the. tion of the carbon monoxide obtained by the gasification of coal and. Hydrogen-containing synthesis gas according to the Pischer-Tropsch-Verfahx-sn, wherein in addition to Koh «lenwaßsörstoffgeiaisoheri in general also larger Meh

~ 2 - 31. 1 * 1979

54 214 12

be obtained on oxygenated compounds. Both procedures are not viable because of the current market situation. It was therefore considered how the economic efficiency of the process can be increased. "It has recently been proposed to combine the coal hydrogenation and the Piseher-Sropsch synthesis" This coal is to be reacted with hydrogen at elevated pressure "The oily residues of this hydrogenation should be supplied as far as possible removal of the oil components in a vacuum distillation of a gasification with partial oxidation to obtain gas, which is partially worked up to hydrogen for the hydrogenation, partly to the required for the .Pischer-Tropsch synthesis gas in the usual manner However, the proposed method also increases the economics of producing coal fuels, but there are significant technical problems which reduce the value of the process. These are due to the accumulation of undesirable products, in particular the Piseher-Tropsch -Synthe se, in the distillative work-up of the residues from the coal hydrogenation and in the conversion of 'the distillation residue into the desired gases.'

The object of the invention is to easily circumvent the difficulties mentioned above and to make the process even more economical by introducing other process steps.

7 ί § ~ 3 - 31. 1. 1979

54 214 12

We8en of the invention

The invention relates to a process for obtaining liquid fuels from coal by hydrogenation of carbonaceous material under elevated pressure, gasification of carbonaceous products in the presence of oxygen to obtain hydrogen and a synthesis gas containing hydrogen and carbon monoxide, and recovery of hydrocarbon mixtures from the Hydrogenation and the synthesis gas, characterized in that subjecting after removal of gaseous and liquid hydrocarbons ash and oil-containing residue of the hydrogenation of a gasification in the presence of oxygen under elevated pressure j the gas mixture partially to hydrogen, partly to a hydrogen and carbon monoxide containing synthesis gas, the hydrogen is used in the hydrogenation, produced from the synthesis gas catalytically under elevated pressure methanol and / or dimethyl ether and these catalytically in liquid hydrocarbons converts "

Both lignite and hard coal can be used in the process. The hydrogenation is carried out under elevated pressure, for. B, at 20ΟΊ000 bar, and elevated temperature, z. B. 3OO-6OO ^U C, in known per se,. advantageous in the presence of a catalyst, for. B, iron oxide, performed.

The carbonaceous material is suitably slurried after appropriate preparation by drying and grinding in a heavy oil obtained in the hydrogenation and in this .Form in the Kydrierreaktoren

- 4 - 31. T. 1979 54 214 12

The liquefaction of coal by high-pressure hydrogenation, for example, by the Bergius process, in contrast to the method previously used, can not be achieved with a view to maximizing the accumulation of liquid hydrocarbons in the gasoline boiling range but with the aim of achieving high yields Yield of liquid hydrocarbons higher boiling ranges are operated, which can then be worked up with the known methods of refinery technology. The separation of the liquid hydrocarbon mixtures can be carried out by distillation, for example _. whereby a vacuum distillation can also be switched on in order to obtain the highest possible oil content from the hydrogenation residue. This is at about 75O ~ 1400 ⁰ C subjected to gasification in the presence of oxygen and water vapor and / or carbon dioxide as a gasifying agent, wherein z. B _{e is} the known pressure gasification method by partial oxidation of the feedstock used v / can ground. Depending on the desired ratio of hydrogen to synthesis gas, the gas mixture obtained in the gasification plant is worked up, with Ze B "a conversion, for example over an iron oxide" catalyst, for the reaction of carbon monoxide at z _e B "400-55O ° C. The hydrogen thus obtained is fed to the coal hydrogenation. From the synthesis gas, after appropriate adjustment of the ratio of carbon monoxide to hydrogen in a known manner, z * B * by the high-pressure or low-pressure method, catalytic methanol and / or or dimethyl ether are synthesized. These products are then catalytically, ζ · B *, over synthetic zeolites of low alumina and high silica content, at elevated temperatures up to about 500 ° C., optionally

2f% £ 1 Tf 4 \ 't & f 1

- 5 - 54 214 12

also increased pressures, au predominantly liquid hydrocarbon mixtures of the gasoline boiling range implemented. It succeeds so as to increase the accumulation of the desired products over the known method and to reduce the investment required because of the elimination of expensive separation apparatuses.

For example, the coking processes which use periodically operating reaction vessels for coke formation and coke removal can be used with particular advantage. The resulting gaseous and liquid hydrocarbons are a workup, the coke is fed to the gasification with partial oxidation.

Of course, it is possible to recover from coal by conventional gasification further amounts of hydrogen or synthesis gas. Also in this Pail one will work in the presence of oxygen with the partial oxidation of the carbon to obtain the heat required in the gasification. The coal may optionally be fed to the coking plant or gasified together with the coke from the coking plant. In this case, the pre-ekene for gasification coal first in a known manner at temperatures of about 300-700 ⁰ C world and the Schwelrückstand be brought to gasification.

The processing of the recovered gaseous and liquid products to the desired products can in the usual manner, as used in the refinery technology, eg. B ₄ . with the Hydrokrackverfahrenj the Kaffinations = · * and finishing process, are available, wherein if desired, liquid or gaseous. hydrocarbons

- 6 - 31. 1 «1979 54 214 12

can be obtained, which are suitable as fuels or as raw materials for petrochemical productions.

By way of example, a possibility for carrying out the method according to the invention is described in the FIGURE, the reproduction of keying devices being omitted for the sake of simplicity.

In the high-pressure hydrogenation unit I lignite is introduced and there at 350 bar and approximately «500 ⁰ C with the addition of Y / on Hydrogen unreacted after substantial removal of gaseous and liquid hydrocarbons formed is the residue remaining a cokers conditioning ΪΙ eye leads, in the in Coke reactors that are switched on periodically coke formation takes place with the simultaneous occurrence of further gaseous and liquid hydrocarbons. "The coke enters the gasification plant III". Here he is with the addition of oxygen and water · ™ steam as a gasifying agent at about 1350 - gassed 1,400 ⁰ C * "The gas mixture is purified in a conventional manner (not shown) and then partially with a catalytic conversion IV of the carbon monoxide with water vapor , about 450 ^° C. to hydrogen and carbon dioxide. In Appendix V, the carbon dioxide is washed out of the gas. The remaining gaseous mixture of mainly carbon monoxide and hydrogen is transferred into the scrubber VI in which the carbon monoxide is washed out. This is added as required to conversion IV or to unit VII. The remaining hydrogen is transferred to the hydrogenation unit. The other part of the gas mixture is discharged into the methanol synthesis plant VII. Carbon monoxide and hydrogen are passed. Copper-containing catalysts are present at about 80-100 bar

- 7 - 31. 1. 1979 54 214 12

the synthesis of methanol. If you work in Appendix VII at higher pressures, z. B. 300 - 330 bar, in the presence z, B _{e of} a zinc oxide chromium oxide catalyst, obtained in the synthesis and smaller proportions of dimethyl ether · methanol and optionally the dimethyl ether v / earth in Appendix VIII at temperatures up to about 500 ⁰ C. passed through a zeolite catalyst with low Al ^ O-2 ~ content, wherein in addition to small amounts of gaseous hydrocarbons liquid hydrocarbons arise predominantly in the gasoline boiling range *

Claims (1)

- 8 - 31. 1. 1979 54 214 12 invention claim A process for recovering liquid fuels from coal by hydrogenating carbonaceous material under elevated pressure, gasifying carbonaceous products in the presence of oxygen to yield hydrogen and a hydrogen and carbon monoxide containing synthesis gas, and recovering hydrocarbon from the hydrogenation and synthesis gas characterized _s that the after separation of gaseous and liquid hydrocarbons remaining ash and oil-containing residue to the hydrogenation of a gasification in the presence of oxygen under elevated pressure by subjecting the gas mixture contained partially worked up bearing synthesis gas to hydrogen, in part, to a hydrogen and carbon monoxide, uses hydrogen in the hydrogenation, from which synthesis gas catalytically generates methanol and / or dimethyl ether under elevated pressure and converts it catalytically into liquid hydrocarbons. « 2e method according to item 1 *, characterized in that subjecting the residue from the hydrogenation a coking «process with periodically to emptying switchable coking chambers and the coke thus obtained used in gasification; 3> Process according to point 1 and 2 _S characterized in that in addition su your residue from the hydrogenation or * the coke derived from it still coal fed to the gasification * Klerxu // Ropes Zefehn-ang