Professional paper
Alkaline hydrolisis slaughterhouse waste
Sanja Kalambura
Tajana Krička
Željko Jurić
Neven Voća
Dejan Kalambura
Abstract
Slaughterhouse waste was processed in rendering houses and meat bone meal was used as a component in animal meals before the appearance of bovine spongiform encephalopathy. However, the emergence of mad cow disease resulted in prohibition of meat bone meal use in animal nutrition. The rendering houses have remained functional for taking care of carcasses and slaughterhouse waste using incarceration as the only proper method prescribed for final sanitation of meat bone meal. However, slaughterhouse waste is a highly valuable raw material for anaerobic digestion, and this work is placing emphasis on alkaline hydrolysis, a method applied as a pre-treatment in production of biogas for the first and second category of slaughterhouse waste. In the process of alkaline hydrolysis slaughterhouse waste is mixed with alkali NaOH/KOH and boiled for 3-6 hours at the temperature of 150 °C and pressure of 4 Bars. The chemical bonds of the large protein molecules, nucleic acids (DNA and RNA), lipids, viruses and prions break into smaller molecules which react with NaOH/KOH and form Na/K-salts, and fatty acids with alkalis form soaps. The resulting chemical compound is a neutral or partially alkaline solution of organic substances suitable for anaerobe microbiological decomposition, or a valuable raw material for anaerobic digestion.
Keywords
alkaline digestion; slaughterhouse waste; NaOH/KOH
Hrčak ID:
2166
URI
Publication date:
3.5.2005.
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