Determination of the Chemical Oxygen Demand (COD) of Hydrothermal Pretreated Hay Samples

Abstract

Energy production is one of the significant challenges our world will face in the future. The utilization of fuels originating from plants as an alternative energy source will impact fossil fuel utilization and energy production. This research focuses on the hydrothermal treatment of hay biomass by analyzing the chemical oxygen demand (COD), which is a commonly used testing method to determine the amount of organic pollutants found in drinking or wastewater. The test indicates the mass of oxygen consumed per liter of solution, expressed in milligrams per liter (mg/L), also referred to as ppm. In this paper, COD tests were used to indirectly determine whether the yield of biogas in a biogas plant could be increased by pretreating the biomass (hay) with heat and/or decreasing the particle size. It was assumed that the potential space-time-yield of biogas in biomass is directly linked to the amount of its accessible organic compounds. Hence the COD of filtrates of different hydrothermal pretreated hay samples was measured in order to determine if there is a relation to temperature and particle size.