Parametervariation of a temperature swing adsorption for BTXN removal

Abstract

The gasification of biogenic residual material is an important contribution to the non-fossil production of chemicals. During gasification, beside the product gas, dust, higher hydrocarbons (tars) and sulphur compounds which must be removed before usage in a synthesis plant, are generated. To remove tars to synthesis gas standard efficiently, two-stage gas cleaning has been developed. In the first step, high-molecular tar components are separated in a scrubber. In the second step, low-molecular tar components (e.g. benzene, toluene, xylene) are adsorbed in an adsorption plant on activated carbon. As a result, a high purified synthesis gas originates which can be used for various synthesis applications. To operate this gas cleaning efficiently, the activated carbon must be regenerated. In a laboratory scale unit model tars are adsorbed and desorbed on activated carbon. Due to parameter variation of desorption temperature, desorption time and amount of flushing gas the process is optimised. Furthermore, possible displacement effects of the separate tar components are investigated.