Determining impact of difference in price of liquid manure and degestate on production costs of biomethane and electricity

Abstract

Assessment of production costs to get biomethane and electric power on its basis in agriculture is impossible without assessing the impact on this indicator of the price of digestate. In Ukraine, where chernozem soils are the basis of agricultural production, the issue of restoring their fertility is an urgent problem. The production of biomethane should take into account the costs of manure before fermentation and the sales revenue of digestate after fermentation using it as organic fertilizers. The article suggests a methodology for economic assessing of production costs to get biomethane and electric power on its basis provided that the costs for the production of biomethane include production costs with taking into account the difference in prices of the biomass of liquid manure before fermentation in the digester and digestate after fermentation in the digester. The technique is based on the calculation of such indicators as a requirement in biomass to receive one m3 of biomethane and to get one kW hour of electricity. These values for liquid manure in accordance are 93.3 kg·m-3 and 23.9 kg·kWh-1. The zero production costs of biomethane and biomethane-based electricity production will be when the price of digestate will be more than the price of liquid manure before fermentation in the range from 1.1 to 2.0 EUR·t-1. The zero-profit of biomethane production will be when the price of digestate will be less than the price of liquid manure before fermentation in the range from 1.3 to 2.1 EUR·t-1. The zero-profit of electricity production will be when the price of digestate will be less than the price of liquid manure before fermentation in the range from 4.1 to 6.6 EUR·t-1. The suggested methodology may be useful for the assessment of production costs when carrying out measures for the utilization of digestate and in the training process of biotechnologists.