Protecting the Environment by Managing and Processing Animal Manures: The Effect of Raw Material (Cow and Chicken Manure) and Reactor Type for Improving and Maximizing Biogas Production

Abstract

Abstract Biomass energy is a type of renewable energy and animal waste is one of the main resources for its production. Anaerobic digestion is a method for biological treatment of organic waste, which nowadays plays an important role in refining and reusing wet and degradable waste materials due to the production of environmentally friendly materials and energy recovery. The process of anaerobic digestion takes place in oxygen-free conditions inside reactors called anaerobic digesters and produces a substance called biogas. The purpose of this study is to investigate the effect of raw material type (cow and chicken manure) and the type of reactor (digester) on the biogas produced by measuring the amount of methane in the product. Three types of digester (metal, simple PVC and PVC with leachate rotation) with the same volume (10 Liter) were prepared. Equipment was installed on the digesters to measure the pH and volume of produced gas. The experiments were carried out in controlled temperature conditions (28–30 ºC) and in two stages. The first experiment was to load the digesters with cow excrement and the second experiment was to load the digesters with chicken excrement. In both experiments, the digesters were fed with 1.5 kg of animal manure and water with a ratio of 1:1. During a period of 60 days, the volume of biogas and methane produced was measured and recorded. The results showed that the amount of biogas produced from chicken waste is more than the amount obtained from cow waste. However, the amount of methane produced using cow excrement was more than that of chicken excrement. Also, the performance of PVC digester with leachate rotation was better than the other two digesters, which could be due to the mixing of raw materials in this type of digester.