Decreasing the hydrogen-rich gas circulation ratio and service life extension of the C9-C14 alkanes dehydrogenation catalyst

This article describes the method of reducing the supply of hydrogen into the reaction zone of the dehydrogenation process for C9-C14 hydrocarbons. Coke suppression method is proposed, based on changing the flow of demineralized water into the reactor as water is involved in the oxidation of coke structures. Calculation of water amount is based on the mathematical model that authors have developed for the dehydrogenation process. Results of the model calculations show that the reduction of hydrogen gas supply can be compensated with increasing the water supply into the reactor, proven with a test at the actual industrial plant. It can be compensated partially with increasing the water flow into the reactor up to 13-14 l/h instead of normal 9-10 l/h at the end of the operation cycle. Reducing the service life of the catalyst to 270-290 days even at an increased water flow is still a factor, determined by the intensity of the coking reactions. However, the economic feasibility of operating under such conditions causes a considerable increase in the linear alkylbenzenes (LABs) production, up to 181-186 tons per day.