CN1187383A

CN1187383A - Synthesis clean gas

Info

Publication number: CN1187383A
Application number: CN97125259A
Authority: CN
Inventors: G·H·基斯
Original assignee: Thermoselect AG
Current assignee: Thermoselect AG
Priority date: 1996-10-29
Filing date: 1997-10-29
Publication date: 1998-07-15

Abstract

Method for total material emission-free utilisation of the synthesis clean gas obtained during high-temperature recycling of waste of all types, in which method the synthesis clean gas is continuously converted in a catalytic process into carbon dioxide and hydrogen, at least partially.

Description

Synthetic cleaning gas

All known thermal processes for waste treatment are characterized by the production of effluents in gaseous form and the leaving of residual material to be dumped.

A thermal process for waste utilization is described in german patent DE4130416C1, which has substantial ecological, economic and technical advantages compared with all known processes in industrial production. The resulting particulate inorganic material is absolutely inert; ferrous metals may be used metallurgically. Claim 11 of this method proposes that the purified synthesis gas should be thermally utilized or used as an energy source; in doing so, it is inevitable that harmful substances are generated by the combustion process, which at least partly pollute the atmosphere. Heavy metals contained in the synthesis gas are separated from chlorides and fluorides and in addition sulfide and hydroxide residues of heavy metals are produced which have to be dumped.

Although this method produces only small concentrations of harmful substances, well below all regulations and standards, and the amount of dross to be dumped is less than 1% relative to the feed amount, it is neither emission-free nor dross-free.

The object of the present invention is to develop a process in which synthesis gas is the fully utilized substance and no emissions are produced.

This object is achieved according to the invention with the features cited in the characterizing portion of claim 1.

Further advantageous developments and embodiments of this object are the result of the dependent claims.

According to the invention, it is proposed that the synthesis clean gas can be converted at least partially into CO₂And hydrogen, the synthesis cleaning gas preferably originating from a process as described, for example, in german patent DE4130416C 1. It should be particularly emphasized that the residual gases which remain can be fed back into the high-temperature reactor without emissions when the process is carried out. The converted component may thereafter be used for further purposes.

A preferred form of embodiment provides a synthesis clean gas consisting essentially of hydrogen, carbon monoxide and carbon dioxide, which is subjected to the action of steam in a catalytic process to completely convert the carbon monoxide contained in the synthesis gas into hydrogen and carbon dioxide: ( ). The two gas components, hydrogen and carbon dioxide, can be separated by generally known methods (such as pressure swing adsorption equipment) and used commercially.

The carbon dioxide may be condensed, cooled and used as dry ice.

Hydrogen can be used as an energy source and/or as a material. Hydrogen is an absolutely emission-free energy carrierif it is used as a general or engine fuel, because water is produced when hydrogen is used as an energy source ( )。

If hydrogen is used instead of fossil fuel, environmental damage that inevitably occurs when fossil fuel is used can be avoided. These resources can be used more rationally due to the limited mineral feedstock from which fossil fuels are derived.

Furthermore, hydrogen can be used in fuel cells as an energy source for generating electricity. Not only do fuel cells have substantially higher efficiency than conventional power stations, they do not produce any harmful substances in the process of generating electricity.

Hydrogen can be used as a substance in, for example, hydrogenation reactions and synthesis processes. In organic hydrogenation reactions, organic molecules are subjected to hydrogen enrichment with hydrogen gas under pressure and at a certain temperature.

In inorganic hydrogenation reactions, metal oxides are reduced to metals with hydrogen (e.g. by hydrogenation) )。

"Ammonia" can be synthetically produced from hydrogen and nitrogen. It should be particularly emphasized that the oxygen required for the gasification of the waste is obtained with an air separation unit; nitrogen is also produced from this air separation unit and can be used on a large scale for ammonia synthesis. It is particularly advantageous if an air separation unit is already present as an integral part of the process.

If hydrogen is used to make methanol, the carbon dioxide present in the synthesis gas is converted to hydrogen and carbon by adding steam to the synthesis gas such that the hydrogen and carbon monoxide are present in the synthesis gas in a ratio of 2: 1 (partial conversion) lost.

Next, carbon dioxide is separated by generally known methods, and hydrogen and carbon monoxide are sent to synthesis, thereby producing methanol.

By using hydrogen as a material, a chemical raw material that can be stored and transported and can be used in many ways can be obtained.

Claims

1. Method for emission-free utilization of all materials of a synthesis clean gas obtained during high-temperature repeated cycles of all types of waste, characterized in that: the synthesis clean gas thus obtained is treated with steam in a catalytic process in order to convert the carbon monoxide contained in the synthesis gas at least partially into carbon dioxide and hydrogen, the remaining residual gas is fed back into the high-temperature reactor and the resulting main product comprising hydrogen, carbon monoxide and carbon dioxide is separated into the hydrogen component and/or carbon monoxide and/or carbon dioxide using known separation methods, such as "pressure swing absorption apparatus", and used as such.

2. The process according to claim 1, characterized in that the synthesis clean gas thus obtained is continuously subjected to partial conversion until the hydrogen and carbon monoxide reach the volume ratio necessary for the synthesis of methanol; the carbon dioxide is then separated by conventional known methods, and the remaining hydrogen-carbon monoxide mixture can be used to synthesize methanol: ( )。

3. A method according to claim 1, characterized in that the synthesis clean gas thus obtained is completely converted into carbon dioxide and hydrogen, and the substances thus obtained are used separately.

4. A method according to claim 3, characterized in that hydrogen is used together with nitrogen for the synthesis of ammonia, the nitrogen being obtained during the high-temperature gasification in which oxygen is produced from the separation of air.

5. A method according to claim 3, characterized in that hydrogen is used, preferably as a fuel, for driving a truck equipped with the heat treatment unit.

6. A method according to claim 3, characterized in that hydrogen is used in a fuel cell for the production of electricity.