CaO and isopropanol transesterify and crack triglycerides to isopropyl esters and green diesel
2017; Elsevier BV; Volume: 139; Linguagem: Inglês
10.1016/j.enconman.2017.02.008
ISSN1879-2227
AutoresDaria C. Boffito, Federico Galli, Carlo Pirola, Gregory S. Patience,
Tópico(s)Thermochemical Biomass Conversion Processes
ResumoFatty 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 °C. Coke, CO, CO2, isopropyl esters and hydrocarbons in the C5-C19 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 oil/isopropanol 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 O2 flow during the regeneration step while the isopropyl esters yield increases. The highest hydrocarbons yield was 42%.
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