Catalytic conversion of de-pitched tall oil to fuels and chemicals over H-ZSM-5: Single and dual reactor system

Abstract

The catalytic conversion of de-pitched tall oil to fuels and chemicals was studies over H-ZSM-5 in a fixed bed microreactor operated at atmospheric pressure and in a temperature range of 350–500°C. The effect of co-feeding steam on the product distribution was investigated also. In addition, experiments were carried out using a dual reactor system where two reactors, with different temperature levels, were used in series. The conversion of tall oil in the single reactor system was between 65–93 wt.-% and decreased by 10–15 wt.-% upon steam addition. The amount of organic distillate product was between 24 and 52 wt.-% of feed, which contained up to 65 wt.-% of aromatic hydrocarbons and 20 wt.-% of heavy fraction. The conversion to gaseous hydrocarbons increased from 9 wt.-% at 350°C to 40 wt.-% at 500°C. With the addition of steam, the coke formation decreased, especially at lower temperatures. When the dual reactor system was used, the concentration of heavy fraction in the organic distillate decreased to 6–8 wt.-%. Based on these results, a reaction scheme was postulated.