THERMOCHEMICAL PROCESSING OF ANIMAL FAT AND MEAT AND BONE MEAL TO HYDROCARBON BASED FUELS

The results of the study at hand may have implications for treatment of grease, lipid fractions, free fatty acids (FFA) and salts of FFA extracted from wastes of food industry, bio-refineries or sewage sludge as well as contaminated lipid containing forage. The goal of the study is, to prevent such contaminated wastes from entering the food chain. The following ways of treatment are proposed. Thermal conversion of waste fats from rendering plants or lipids in the presence of aluminosilicates of the zeolite family produce hydrocarbons with net calorific values in the range of 40 - 42 MJ/kg. NMR studies show aliphatic hydrocarbons as main product at T = 400 degrees C. The spectrum of products is shifted to alkyl benzenes at T = 550 degrees C. In case of sodium carbonate conversion is achieved in the presence of 5% water at T = 430 +/- 20 degrees C yielding mainly a liquid bio-crude with a low acid index, a mixture of non condensable gases and minor amounts of coke. Rectification of bio-crude from animal fat produces 65.8% of hydrocarbon based bio-diesel and 13.3% of gasoline type hydrocarbons. Distillation curve for bio-diesel is in accordance with DIN EN 490. However, the gasoline fraction lacks low boiling hydrocarbons indicating the necessity for technical improvements of condensers. Sodium carbonate is found to be effective as well as being relatively inexpensive compared to zeolite catalysts. Finally, successful conversion of meat and bone meal to biochar is proved by solid-state C-13-NMR.