Mathematical model for dynamic simulation of codigestion of manure and industrial waste

 In the model the substrate is described by its composition of basic organic component, i.e., carbohydrates, lipids and proteins, as well as intermediates, and important inorganic components, i.e., ammonia, phosphate, cations and anions. Consenquently dynamic changes of the process during a shift of substrate composition can be simulated by changing the input substrate difinition. The model includes two enzymatic hydrolytic steps, eight bacterial steps and involves 19 chemical compounds. The model also includes a detailed description of pH and temperature characteristics. Free ammonia, acetate, volatile fatty acids (VFA) and long-chain fatty acids (LCFA) constitute the primary modulating factors in the model. The model has been with success used to simulate cases of codigestion of manure with glycerol trioleate or manure with gelatin in laboratory scale reactors. Finally the model was validated with results from a full scale biogas plant codigesting manure together with a proteinous waste water and bentonite bound oil