Catalytic conversion of ethanol into light olefins using SAPO-34 catalyst in a commercial plant and a pre-feasibility study

Abstract

Light olefins (both ethylene and propylene) are important intermediates widely used in the petrochemical industry. With the shortage of natural resource and the growing demand for light olefins, the production of light olefins from renewable resources such as bio-ethanol has received wide attention. In this work, light olefins production from bio-ethanol was investigated using a silicoaluminophosphate zeolite (SAPO-34) catalyst through the catalytic dehydration process. The effects of operating conditions were studied in terms of catalytic activity. The reaction temperature, liquid hourly space velocity (LHSV), and time on stream (ToS) were varied in the range of 350C to 500C, 0.2 h-1 to 1.0 h-1, and 45 minutes to 180 minutes, respectively. The results revealed that the reaction temperature, LHSV, and ToS had the influences on catalytic activity. The reaction temperature of 400C and the LHSV of 0.5 h-1 were found to be the suitable conditions for a high production of propylene. The reaction temperature and the LHSV also affected to the coke formation on the catalyst. The amount of coke increased with the increase of reaction temperature and the decrease of LHSV. Moreover, the pre-feasibility of the bio-ethanol to light olefins plant was studied as well. It was found that the bio-ethanol to light olefins plant modified from Chematur was not commercially viable due to the high raw material price and high total capital cost. Moreover, the sensitivity analysis revealed that ethanol price and the product prices were the sensitive parameters mainly affecting to the feasibility of this project.