Dynamický model absorpce surového benzolu z koksárenského plynu

Abstract

BTX (benzene, toluene, xylenes) is an important and valuable component of coke oven gas (COG). COG is obtained as a by-product of metallurgical coke production. The recovery of BTX from coke oven gas is achieved by absorption into the washing oil. Washing oil is a complex mixture of polycyclic aromatic hydrocarbons with higher boiling point. Absorption is carried out in counter-current scrubbing column. The rich wash oil from bottom of the column is heated and transported to the stripping column for regeneration. In the experimental part, BTX recovery dynamic model is developed in Aspen Plus Dynamics. Various simulations were performed with different process operating conditions. The change in physical properties and composition of the wash oil, the BTX concentration in the purified COG and the yield and quality of the BTX product were observed. Based on the results, The feed temperature of coke oven gas is a key parameter controlling the absorption process. Inlet temperature increase results in benzol yield decrease and higher concetration of BTX in purified gas. Another important variable is a distillation column head temperature. Head temperature rise causes faster wash oil degradation, which leads to lower yield and higher BTX amount in the gas.