CaO and isopropanol transesterify and crack triglycerides to isopropyl esters and green diesel

Fatty acid methyl esters (biodiesel) synthesized by transesterifying vegetable oil and fats with methanol are unsuitable for northern climates and alpine regions. Isopropyl esters derived from oil and isopropanol have superior cold flow properties and lower cloud point but reaction rates are slow in batch liquid phase processes. To accelerate the reaction rates by several orders of magnitude, we atomize mixtures of canola oil and isopropanol into a fluidized bed of CaO/Al2O3 operating at 450 degrees C. Coke, CO, CO2, isopropyl esters and hydrocarbons in the C-5-C-19 range form at contact times less than 1 s. A solenoid valve cycles the feed composition between oil/isopropanol and air, which maximizes the reaction rates and maintains a constant level of coke. The dwell time of the catalyst in oilfisopropanol and air is 2 min. The coke yield ranges from 3.5% to 34% and the isopropyl esters yield varies from 2% to 31% for isopropanol:triglycerides molar ratios equal to 28, 35 and 51. The coke yield decreases with isopropanol:triglycerides molar ratios and 02 flow during the regeneration step while the isopropyl esters yield increases. The highest hydrocarbons yield was 42%. (C) 2017 Elsevier Ltd. All rights reserved.