Energy and Economic Balance between Manure Stored and Used as a Substrate for Biogas Production

Abstract

The aim of the study is to draw attention to the fact that reducing methane and nitrous oxide emissions as a result of traditional manure storage for several months in a pile is not only a non-ecological solution, but also unprofitable. A solution that combines both aspects—environmental and financial—is the use of manure as a substrate for a biogas plant, but immediately—directly after its removal from the dairy barn. As part of the case study, the energy and economic balance of a model farm with dairy farming for the scenario without biogas plant and with a biogas plant using manure as the main substrate in methane fermentation processes was also performed. Research data on the average emission of ammonia and nitrous oxide from 1 Mg of stored manure as well as the results of laboratory tests on the yield of biogas from dairy cows manure were obtained on the basis of samples taken from the farm being a case study. The use of a biogas installation would allow the emission of carbon dioxide equivalent to be reduced by up to 100 Mg per year. In addition, it has been shown that the estimated payback period for biogas installations is less than 5 years, and with the current trend of increasing energy prices, it may be even shorter—up to 4 years.

Analysis of the overall potential for electricity production from farm animals manure in Bulgaria

“…Only the manure that could be gathered is used for the further calculations. Both results of about 14 million tons produced manure per year in Bulgaria and for about 10 million tons manure of it that could be gathered are roughly comparable with similar results of 180 million tons from Canada for year 2006 and of above 112 million tons from Poland per year [2], [8]. This indicates that the calculated results are realistic.…”

“…Animal husbandry is responsible for about 14,5% to 16,5% from the anthropogenic greenhouse gases emissions and 20% of them or 3% of all anthropogenic greenhouse emissions are from the dairy industry. [2] The main reason and source of these greenhouse gases emissions is the traditional way of storing and treatment of the manure from the farm animals and other organic waste. The traditional way involves gathering all the manure and other organic waste into big heaps and leaving it that way till the natural digestion process ends with a solid residue as a result which could be used as an organic fertilizer for plants due to its high nutritional value.…”

“…The traditional way involves gathering all the manure and other organic waste into big heaps and leaving it that way till the natural digestion process ends with a solid residue as a result which could be used as an organic fertilizer for plants due to its high nutritional value. But gathering the manure into heaps leads to digestion in anaerobic environment due to fast deplete of the available oxygen and no additional access to oxygen except for a thin surface layer [2]. The result of the anaerobic fermentation is generation of biogas which contains 50% to 65% CH4, 30% to 50% СО2 and up to 10% other gases and H2O.…”

“…The result of the anaerobic fermentation is generation of biogas which contains 50% to 65% CH4, 30% to 50% СО2 and up to 10% other gases and H2O. CH4 and СО2 are greenhouse gases and CH4 has 21 to 28 times higher global warming potential from СО2 [2]. The most important element in the solid residue is the nitrogen which is important as a fertilizer for plants but the nitrogen not used by plants is transformed by a bacteria into N2O which is a greenhouse gas with global warming potential 265 to 298 times higher than СО2 [3].…”

Economic Conditions of Using Biodegradable Waste for Biogas Production, Using the Example of Poland and Germany

“…Renewable fuels include organic products [5] whose mass is formed by photosynthesis from water and carbon dioxide absorbed from the atmosphere, and whose combustion does not increase the concentration of CO 2 particles in the atmosphere. The management of animal waste is very important for managing this type of waste and applying sustainable development in agriculture [6]. A characteristic feature of renewable sources is that they are renewable.…”