WO1987005620A1

WO1987005620A1 - Process for liquefying carbonaceous materials

Info

Publication number: WO1987005620A1
Application number: PCT/AT1986/000023
Authority: WO
Inventors: Hermann Jauk
Original assignee: Hermann Jauk
Priority date: 1986-03-19
Filing date: 1986-03-19
Publication date: 1987-09-24
Also published as: EP0266339A1

Abstract

Process for producing liquid hydrocarbons by the reaction of solid carbon-containing materials with a gaseous hydrogen-containing substance. The solid carbon-containing material used may be in the form of graphite, wood, charcoal, carbon, coke, etc. in particle form which is applied in combination with a gaseous hydrocarbon providing free hydrogen, such as methane, propane, butane, ethylene, etc. In this way it is not necessary to produce hydrogen by synthesis, which required the use of a substantial part of the carbon used for the carbonaceous material production of water gas.

Description

Coal liquefaction

The invention relates to a method for producing liquid hydrocarbon compounds from gaseous substances and carbon present in solid form. In particular, the invention relates to a process for the production of liquid hydrocarbons from gaseous hydrocarbons such as methane, propane, butane, ethylene and the like, and from carbon which is in solid form such as graphite, wood, charcoal, coal, coke. In particular, the invention aims to show a new, technically and economically advantageous way of liquefying coal.

The processes known for liquefying the coal can be divided into three groups. One group is formed by the well-known Fischer-Tropsch synthesis and its variants. In these processes, a synthesis gas containing carbon monoxide and hydrogen is first formed from the coal, and the liquid products are produced therefrom by means of contact catalysis.

In the second group of processes, the coal is hydrogenated to liquid products (Chem.Ing.Techn. 46, 925 [1974]). The third group is formed by those processes in which the liquid products are extracted from the coal with solvents, advantageously with solvents having a high hydrogen content. This extraction process is also used in combination with coal hydrogenation (NIMDOK Fachinformation der Chemieindustrie, Budapest, 1975/1).

The known methods have numerous disadvantages in terms of industrial feasibility. The processes based on the extraction of the coal operate with low yield, their specific energy requirement (based on a unit of liquid process product) is extremely high, and the regeneration of the extractant makes the process even more expensive. For Fischer-Tropsch synthesis and for carbohydrate hydrogenation are extraordinary expensive devices and a lot of energy are consumed, and the thermal efficiency of the processes is unsatisfactory. Another disadvantage is that the methods mentioned work under high pressure, which requires more expensive devices and also the compliance with certain safety measures.

In addition, the majority of the hydrogen required in the known process for the recovery of liquid hydrocarbons is obtained from water gas and the remaining requirement for hydrogen comes from the volatile constituents of the coal, which are obtained in coal gasification. In order to reduce the hydrogen requirement in the conventional process, coal with a high proportion of volatile constituents is preferred, not least because the production of hydrogen represents the greatest cost factor in all previously known processes. In all the processes known to date, the hydrogen is obtained either electrolytically or from water gas.

Water gas is obtained when steam is passed over red-hot coal, corresponding to the following reactions:

The reaction according to equation 2 is preferably carried out under the influence of catalysts (e.g. iron, chromium) at around 400 ° C.

A common feature of all previously known processes, regardless of whether they are based on the basic processes from BERGIUS, HABER-BOSCH or FISCHER-TROPSCH, is the production of hydrogen from synthesis gas, whereby a substantial part of the coal is already used to produce water gas.

The aim of the present invention is to provide a process with which liquid hydrocarbon compounds, in particular from coal, can be obtained much more easily than is the case with the known processes. To achieve this goal, the invention proposes, in a process for the synthesis of liquid hydrocarbons, a C / H ratio of 1: 1 (eg C ₆ H ₆ ) to approximately 1: 2.1 (eg C ₁₂ H ₂₆ ) and above (eg heavy oils and liquid hydrocarbons with multiple bonds) have, from solid carbon and a hydrogen carrier the hydrogen requirement from gaseous hydrocarbons, eg methane, propane, butane and the like. Like. To cover. The gaseous hydrocarbons do not occur as intermediates in the synthesis process, rather they are fed into the process as raw materials together with solid carbon particles.

The free hydrogen can be obtained from the gaseous hydrocarbons by thermal dissociation with or without a catalyst at normal pressure or else at elevated pressure.

For example, it is known from the literature that pure CH ₄ at 600 ° C. and 1 bar pressure consists of approximately 75% H ₂ molecules and C molecules, whereas only around 25% are present in the form of CH ₄ .

Since the original H / C ratio of 4/1 can be shifted in any manner by adding solid carbon particles, there are those ratios which are characteristic of the formation of liquid hydrocarbons with or without the presence of catalysts or at normal pressure, positive pressure or negative pressure are.

The reactions follow the generalized formula

Since the reaction is exothermic to the right, cooling is required during the reaction process. The dissipated heat can be used to heat or preheat the starting products (gases + solid carbon particles). The further process is based on known processes for the fractional condensation of liquid hydrocarbons.

The process according to the invention not only enables the coal to be made fully usable for the actual coal liquefaction, it also permits the sensible use of amounts of gaseous hydrocarbons, for example natural gas, which are often available in excess or are available, and which often have to be flared due to the lack of further processing options.

Claims

Claims:

1. A process for the production of liquid hydrocarbons by reaction of solid carbon with a gaseous hydrogen carrier, characterized in that gaseous hydrocarbons covering the hydrogen requirement are fed together with solid carbon particles to the synthesis process.

2. The method according to claim 1, characterized in that the gaseous hydrocarbons used are methane, propane, butane, ethylene or the like. Gases.

3. The method according to claim 1, characterized in that one obtains the free hydrogen required for the synthesis by thermal dissociation, optionally in the presence of catalysts and / or using excess pressure, of the gaseous hydrocarbons used.