Abstract:
Fusel oil is a by-product of bioethanol production. It is considered a renewable feedstock as well as an environmentally friendly material. However, due to the limitation of its application, the market is not able to absorb the demand for fuel oil, which results in a relatively low price. As a consequence, fusel oil is an interesting new renewable source to convert into value-added products via a high-efficiency bioenergy conversion process. In the present work, the catalytic cracking of fusel oil to light olefins (ethylene, propylene, and butylene) was investigated in a fixed bed reactor using zeolites as catalysts. The physicochemical properties of fusel oil were also examined. The three well-known zeolites; ZSM-5, HY, and H-beta were selected to study the effect of the topology of zeolite on this reaction. Under the same condition, the results found that HZSM-5 gave the highest carbon in light olefins yield because of its suitable pore structure. As a result, HZSM-5 zeolite was chosen for further study to achieve the highest catalytic performance. The effect of operating parameters such as reaction temperature and fusel oil feed flowrate on gas carbon yields was studied. The operating reactions play a vital role in gas product and distribution in order to control the side reactions (i.e., H-transfer, aromatization, isomerization) which produce undesired hydrocarbons. With the consideration of light olefins, the optimum condition was at 550oC with 0.04 ml/min fusel oil feed flow rate with 0.2 g catalyst. Moreover, the effect of co-feeding water and reactants were also studied. The results exhibited the significant role of the ratio of co-fed water and the role of reactants in catalytic cracking reaction over HZSM-5 catalyst. The stability of HZSM-5 on catalytic cracking of fusel oil was also examined. There was a slight drop in light olefins yield over 20 h of time on stream on HZSM-5. Thus, HZSM-5 showed good merit to develop stability and catalytic performance in the novel way to produce light olefins via catalytic cracking of fusel oil in future work.
