Process for the purification of crude gas from solids gasification

Abstract

A process and device is provided for the generation and purification of a crude gas for synthesis gas generation from a solid carbon-containing fuel by a coal gasification reaction. The fuel is mixed with a quenching medium directly after generation to dissipate the internal energy and is then brought into contact with a compound or a sorbent in the mixing chamber or downstream of the mixing chamber such that the acidic or basic or sulphur-containing or halogen-containing constituents contained in the crude gas and originating from the gasification reaction are absorbed. A solids-separating device removes the solid or solidified constituents from the system. The sorbent can be regenerated and returned to the process such that an energy-intensive cooling of the crude gas is not required for its purification and the synthesis gas thus purified can be used in a subsequent process without any further heating.

Description

CROSS SECTION TO RELATED APPLICATIONS[0001]This application is a divisional application of U.S. Ser. No. 12 / 733,910, filed Aug. 12, 2010. U.S. Ser. No. 12 / 733,910 was pending as of the filing date of the present application. U.S. Ser. No. 12 / 733,910 is a US National Phase application of PCT EP2008 / 008194 filed Sep. 26, 2008.BACKGROUND OF THE INVENTION[0002]The invention relates to a process for the purification of a dust-containing gas generated in a gasification reaction from solid carbon-containing materials by conversion with an oxygen-containing or water vapour-containing and oxygen-containing gas at an increased temperature, in which a crude gas is generated which mainly consists of carbon monoxide and hydrogen and the actual purification step is carried out by the addition of a solid sorbent to the hot gas stream immediately after production. The purified gas obtained is a synthesis gas which is used for chemical syntheses, for the recovery of hydrogen and the production of me...

AI Technical Summary

Benefits of technology

[0017]during or after the addition of the colder gas or the evaporated liquid the dust-containing crude gas is mixed for purification with a solid sorbent which is entrained and conveyed with the crude gas in gas flow direction and reacts within a short period of time with the acidic or basic or sulphur-containing or halogen-containing substances and converts these substances to a solid and bound form.

[0053]The invention facilitates an efficient and quick purification of a synthesis gas or generator gas from a coal gasification process by adding a solid sorbent directly after the coal gasification reaction. By a quick reaction of the admixed sorbent with the crude gases containing acidic or sulphur-containing or halogen-containing substances or a combination of the latter, it is possible to remove these interfering substances from the crude gas. Consequently, it is not necessary to carry out the energy-intensive and time-consuming scrubbing process connected with cooling and the subsequent gas re-heating. The obtained sorbent may be re-used or regenerated at low cost.

Problems solved by technology

Many of these pollutants are of a basic or acidic nature and are of corrosive effect.

As the pollutants interfere with many purposes of further use, they must be removed from the generated crude gas.

In the production of chemicals the corrosive constituents may affect plant sections or react with the chemicals such that the desired processes are impeded or suppressed.

For many purposes the presence of sulphur-containing foreign substances is also problematic since these may enter into undesired chemical reactions.

Thus in the production of iron by the direct reduction process, for example, a sulphur content of the synthesis gas is of great disadvantage since the sulphur impairs the reduction process and sulphides may form or remain in the pig iron.

However, this is very energy-intensive and involves high investment and current costs especially if the synthesis gas must be reheated for the subsequent application.

When performing the coal gasification reaction at temperatures of more than 1200° C. there is the problem that the halogen and sulphur compounds decompose and react with hydrogen and carbon monoxide.

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