Using disulfide oil as coke inhibitor to reduce environmental hazards in olefin heaters

Abstract

This paper describes the feasibility of replacing a sulfur-based additive with the waste by-product disulfide oil (DSO) in steam cracking for the production of olefin. The objective of adding this substance is to reduce coke formation, and consequently, prevent its formation on the inner walls of the reactor and heat exchanger. It is reported that dimethyl sulfide (DMDS) is a source of hydrogen sulfide, and it is hydrogen sulfide that minimizes coke formation, even though the mechanism is not clear. Disulfide oil is a waste material in gas refineries and a source for hydrogen sulfide production; therefore, it makes sense to evaluate its efficacy in minimizing CO production and coke formation during olefin production. Therefore, pilot plant runs were performed to evaluate its feasibility. By using disulfide oil, the total sulfur content of the pyrolysis gasoline will change and be equal to 26.89 mg/L for the unit with a capacity production of 18000 kg/hr. This action not only provides a low-price resource that inhibits coke deposition in olefin plants but also curtails the emission of hydrogen sulfide into the environment.