Development of a Linear Optimization Model for Biogas Generation of Electrical Energy using Pig Dung

Abstract

Biogas is a renewable energy source produced by the breakdown of organic matter in the absence of oxygen. It can be produced from raw materials such as agricultural wastes, manure, municipal wastes, plant materials, sewage, green wastes or food wastes. However, the production of biogas has not been commercialized and people are still depending on natural gas which is non renewable and depleting fast. This study develops a linear optimization model to optimally control pig dung for full-scale biogas power generation using computer simulation. The biogas digestion processes were simulated and a linear state space model was generated. The linear optimization model was implemented and validated by calculating the volume of digester, the volume of biogas and the daily energy generated by biogas. A linear optimization model with a coefficient term of 0.68 and a constant term of 0.77 was developed. The result showed that after retention time of 23 hours, the value of biogas electrical power output with linear optimization increased by 0.12 kWh which is 1.45% increase after optimization. The results show the applicability of the optimization model potential which can be exploited using optimal control scheme. The model developed forms a basis for optimal control of real full-scale biogas production.

Keywords: Biogas, Computer Simulation, Renewable Energy, Linear Optimization, State State Model, Pig Dung.