Study On The Coking Behavior Of Flare Gas And Its Preventive Measure And Application

Flare gas is a flammable gas generated in petrochemical processes, which contains a lot of energy and useful components, so the recovery of flare gas is a great measure to save energy. However, flare gas will coke at high temperatures, which makes the compressor sprue and the pipeline blocked and the recovery efficiency reduced. Therefore, prevention of coking is a key solution to realize efficient recovery of flare gas.This paper was based on the background of the recovery of flare gas and prevention of coking, and the causes and the mechanisms of polymerization and coking were investigated in detail. Coking experiments under different conditions were carried out to find out the principal causes for coking and those key components during coking process. From the experimental results, reaction kinetic models were also studied to discuss the characters of coking reactions in flare gas. On the basis of the above work, the effective measures was proposed and introduced to the practical process to solve the coking problem in flare gas.The main studies and results in this paper were as follows.1. Kinetics experiments for coking reaction were carried out under different reaction temperatures, reaction pressures or reaction times, and the results showed that coking reaction was influenced mainly by reaction temperature with little effect by pressure. During a given time range with the temperature higher than 100℃, there was obvious coking reaction in flare gas, and it reach to a stable state with the temperature keeping on going up. During a given pressure range, the coking reaction in flare gas could be described by a linear reaction kinetic model, of which the reaction rate constant with temperature could be fitted as k = 8.82*10~5 exp (-6.46/T).2. The reason for coking was studied and discussed, and the experimental results proved that olefins polymerization, which accorded with the radical solicitation mechanism. It was found that if there was enough energy, the radical would form from...