Transformation of bioethanol to aromatic hydrocarbons using two consecutive beds of MgHPO4-droped gamma-Al2O3/Modified H-ZSM-5 catalysts

Abstract

Currently, bioethanol produced from biomass can be used as a petrochemical feedstock to produce hydrocarbon compounds. Aromatics are one of the most interesting products. Consequently, the transformation of bioethanol to aromatic hydrocarbons was studied in the system of two consecutive catalytic beds that were independently controlled at two different temperatures. A 0.5 wt% MgHPO4-added alumina was the only catalyst packed on the first catalytic bed, aiming to convert ethanol to ethylene, whereas various HZSM-5 based catalysts (ZnO-, Ga2O3-supported H-ZSM-5, and ZnO-Al2O3 mixed with HZSM-5) were packed in the second bed, aiming to further convert ethylene to aromatics. It was found that the gallium oxide-loaded HZSM-5 in the second be was the best catalyst that gave the highest amount of liquid hydrocarbons and also aromatic yields. Approximately 23% total oil yield was obtained, which was composed of 96.3 wt% aromatics. In addition, the economic pre-feasibility evaluation of bioethanol-based aromatic manufacturing plant based on the aromatic production using the best pair of catalysts was also investigated. However, the results revealed that all profitability indicators (NPV, Payback period, and profitability index) were a negative value. IRR cannot be evaluated (no IRR). It can be suggested that the bioethanol-based aromatic production plant using a dual-bed reactor was not commercially feasible due to the negative revenue.