Energy Efficiency of Pretreatment of Digester Synthetic Substrate in a Vortex Layer Apparatus

Abstract

Introduction. Processing organic waste to reduce the anthropogenic impact on the environment remains an urgent task, one of the ways to solve which is the use of methods for bioconversion of organic matter of organic waste to produce gaseous energy carrier and high-quality organic fertilizers. One of the most important stages of anaerobic processing of organic waste in bioreactors is the stage of preliminary preparation of waste for fermentation, which can be carried out by a number of methods. However, the technical literature does not pay enough attention to the use of devices with a vortex layer for the preliminary processing of substrates. The aim of the work is to determine the energy efficiency of the organic waste pretreatment process in the vortex layer apparatus before anaerobic digestion. Materials and Methods. An experimental installation was developed to study the process of organic waste pretreatment. A mixture of organic fraction of municipal solid waste and tap water in the ratio of 300 g/l served as a substrate for treatment in the vortex layer apparatus. Results. The calculations confirmed that the condition for energy efficiency of processing substrate pretreatment of methane is met, despite the additional cost of electrical energy during the integration of this stage in the system of anaerobic processing. Discussion and Conclusion. Integration of the process of organic waste pretreatment in the vortex layer apparatus before fermentation in anaerobic bioreactors into the system of anaerobic treatment of organic waste can improve both the energy efficiency of the system and the level of anaerobic decomposition of organic matter of waste. The specific amount of biogas energy produced in the digestion process in an anaerobic bioreactor with pretreatment of the substrate in the apparatus of the vortex layer fully compensates the energy cost of pre-treatment of the substrate in the vortex layer apparatus. The practical significance of the work is confirmed by an increase in the specific yield of commercial energy by 70% compared to anaerobic treatment in traditional methane tanks.

Heat Recovery of Low-Grade Energy Sources in the System of Preparation of Biogas Plant Substrates

“…Efficient energy production at a biogas plant, according to (Kovalev et al, 2020c) is possible only when the total energy of the produced biogas will significantly exceed the energy consumption for its production, ie. the condition must be met…”

Cavitation Reactor for Pretreatment of Liquid Agricultural Waste

“…• those with moving parts, such as a rotor-stator [18][19][20][21]; • without moving parts, for example, a vortex-based device [22][23][24][25], swirling jet [26], venturi tube [27,28], hydrosonic pump [12], and orifice plate [29,30]. Of particular interest among innovative methods is the generation of cavitation, when vapor microbubbles in a liquid medium collapse due to sharp drops in local pressure, and a large amount of energy is released, as well as intense local heating (about 5000 • C) and high pressure (about 50 MPa) [12].…”

“…• those with moving parts, such as a rotor-stator [18][19][20][21]; • without moving parts, for example, a vortex-based device [22][23][24][25], swirling jet [26], venturi tube [27,28], hydrosonic pump [12], and orifice plate [29,30].…”