Production and treatment of synthesis gas, by generating synthesis gas by gasification, where synthesis gas contains hydrogen, carbon monoxide, carbon dioxide, methane, water and impurities and purifying acidic impurities washing in column

摘要

The process comprises generating synthesis gas by gasification, where the synthesis gas contains hydrogen, carbon monoxide, carbon dioxide (CO 2), methane, water and impurities including sulfur compounds, and purifying all or part of the acidic impurities including CO 2and sulfur compounds by washing in a column using an acid gas solvent, where the purification step comprises prewashing a lower part of a gas column to eliminate impurities of hydrogen sulfide and carbonyl sulfide with a fraction of CO 2solvent and to recovery of the lower part of the column of the solvent to CO 2. The process comprises generating synthesis gas by gasification, where the synthesis gas contains hydrogen, carbon monoxide, carbon dioxide (CO 2), methane, water and impurities including sulfur compounds, and purifying all or part of the acidic impurities including CO 2and sulfur compounds by washing in a column using an acid gas solvent, where the purification step comprises prewashing a lower part of a gas column to eliminate impurities of hydrogen sulfide and carbonyl sulfide with a fraction of CO 2solvent and to recovery of the lower part of the column of the solvent to CO 2and sulfur compounds, washing an upper part of the gas column by an acid gas solvent for absorption of CO 2contained in the gas to be purified and for recovery synthesis gas in the upper part of the column and CO 2solvent in the middle of the column, regenerating the solvent produced by a gas expansion at an average pressure and then regenerating the solvent produced by the gas expansion at low pressure of 3 bar, recycling flash gas in the synthesis gas through single recycle compressor after compression, and cryogenic separating the remaining constituents in the synthesis gas with a production of flash gas of the cold box. The flash gas of the cold box is sent in the compressor for recycling the flash gas and the synthesis gas. The purification step is a step of extraction via a physical solvent of type Rectisol(RTM: Acid gas removal process)/ Selexol(RTM: Acid gas removal solvent) using methanol. The cryogenic separating step is immediately preceded by a purification step. All or part of flash gas from the cold box is used as regeneration gas in the purification step before the flash gas sent to the recycle compressor. An independent claim is included for an installation for production and treatment of synthesis gas.