POTENTIAL OF PRODUCING VARIOUS HYDROCARBONS FROM CANOLA OIL BY CATALYTIC TREATMENT OVER Pt-ZSM-5

摘要

Canola oil conversion was studied at atmospheric pressure over Pt-ZSM-5 catalyst (0.5 wt% Pt) in a fixed bed micro-reactor. The operating conditions were; temperature rangeof 400-500°C, weight hourly space velocity (WHSV) of 1.8 and 3.6 h~(-1) and steam/oil ratio of 4:1. The products were coke, gas, an organic liquid product (OLP) and residue. The gas and OLP consisted mainly of hydrocarbons. The objective of this study was to maximize the amount of gasoline range hydrocarbons in the OLP and the selectivity to isohydrocarbons in the gas. The . gas yields varied between 22-65 wt% and were higher in the presence of steam compared to the operation without steam. Also, the gas fraction decreased with increase in space velocity. The olefin/paraffin ratio of C_2-C_4 hydrocarbon gases varied between 0.31-0.79. The amount of isohydrocarbons relative to n-hydrocarbons were higher with Pt-ZSM-5 (1.6-4.8) compared to pure HZSM-5 catalyst (0.2-0.3). The OLP yields with Pt-ZSM-5 (20-55wt% of canola oil) were slightly lower compared to HZSM-5 (40-63wt% of canola oil) under similar conditions. The major components of OLP were aliphatic and aromatic hydrocarbons. The main aromatic hydrocarbons were benzene, toluene, xylenes and trimethylbenzenes. Alkylated pentane and hexane were the main aliphatic hydrocarbons. In the presence of steam, Pt-ZSM-5 gave higher yields of liquid hydrocarbons within the gasoline boiling range than HZSM-5.