The research of technological circuits of biomethane from biogas production with the use of the most widespread amine and water absorption processes of carbon dioxide and hydrogen sulfide removal from biogas is carried out. With the use of software modeling for the amine process, an effective absorbent MDEA_mod — an aqueous solution of methyldiethanolamine and monoethanolamine is proposed. This absorbent can be effectively applied to a wide range of biogas and for a range of pressure practically from atmospheric to 0.28 MPa. At the same time, the heat load of desorber reboiler is less in 1.5–4 times compared with the use of monoethanolamine solutions.Comparison of energy costs for the production of biomethane using amine and water technology shows that taking into account the greater yield of biomethane in the amine process by 8–15 % than in water absorption (loss of CH₄ due to dissolution in H₂O), and the use of this difference to heat the amine desorber reboiler these costs are comparative. In the case of the need to produce carbon dioxide as a commodity product, the amine process has an advantage, since the CO₂ achieved in this process has a concentration of 98 % versus 80 % when using water absorption. The obtained results of simulation of СО₂ and H₂S removal process by amine and water absorption can be used in technologies of biogas refining and production of biomethane - an analogue of natural gas, as well as carbon dioxide as a commercial product. Bibl. 24, Fig. 6, Tab. 4.

The production of biomethane from biogas energy costsfor the most widely used amine and water processes for extracting carbon dioxide from biogas were analyzed using computer simulation. Combined water-amine absorption method of biogas purification from CO₂ wasincluded in the comparative analysis. For the CO₂ content of the biogas from 32 to 42 %, the specific energy costs when using water absorption to extract carbon dioxide from biogas are, on average, in ~ 2.5 times lower than amine absorption, but the loss of CH₄ by water absorption was 7.1–7.6 % due to its watersolubility with practically zero CH₄ loss when using amine absorption and insignificant loss (0.17–2.8 %) using water-amine technology. Using preliminary water absorption of CO₂ saved CH₄ can compensate the power consumption of the biogas compressor or the heatcosts of saturated amine absorbent regenerating. This will allowto reduce energy consumption to almost equal to water absorptionone. The results of simulation of carbon dioxide extraction from biogas can be used to optimize technological absorption schemes for the production of biomethane — an analogueof natural gas. Bibl. 13, Fig. 5, Tab. 6.

The EU countries are implementing biomethane production projects from biogas, supplying it to the natural gas distribution grid, or using it as motor fuel. It is also extremely relevant for Ukraine, supposing the problems with gas import due to Russian aggression. Biogas production from landfills, agriculture waste, and sewage is already implemented in Ukraine, so the next step must be biomethane production on an industrial scale and the selection of biogas separation technology is important. Using 11 years of industrial experience in biogas production from landfills, wide experience of the different methane-containing gases separations, and small companies’ industrial possibilities, the most applicable separation technologies for Ukraine were selected: amine, water, and combined water amine carbon dioxide separation. These technologies had compared using computer simulation with real landfill biogas flow rate debt. Results of a software simulation of the most applicable water-amine absorption technology were verified using a laboratory setup. For carbon dioxide concentration in biogas at 32–42 % vol., the specific energy consumption when using water absorption is on average 2 times less compared to amine absorption, but at the same time, the loss of methane due to its solubility in water during water absorption amounted to 7.1–7.6 %, with practically no losses in amine absorption, and minor losses at 0.17–2.8 % in combined water-amine technology. The energy consumption of combined water-amine absorption is comparable to that of water absorption due to: a) reduction of heat losses for the regeneration process of saturated amine absorbent, as part of carbon dioxide has already been removed with water technology; b) using the methane excess to compensate power consumption of the biogas compressor during the preliminary water absorption of carbon dioxide and/or to compensate heat costs of the saturated amine absorbent regeneration

The article presents the results of the development of the modernization of the complex gas preparation installation, namely the modeling of the processes of removing heavy hydrocarbons at the stage of preparing natural gas for transportation. Heavy hydrocarbons, which are removed at this stage, become a separate commodity product in the process of processing. With the use of software systems for computer simulation of technological processes of GazCondNafta and HYSYS, a variant of the modernization of the existing installation of complex gas preparation of the gas condensate field was developed. Options for modeling technological schemes for obtaining target fractions of methane, ethane, propane, butane from natural gas, gas synthesis and pyrolysis gas are given. Bibl. 9, Fig. 5, Tab. 8.

The presence of carbon dioxyl as a non-combustible admixture in the landfill biogas of solid household waste and the absorption of ambient air into the layer of landfill waste, and therefore its entry into the landfill gas, significantly reduces the concentration of methane in it, which affects the efficient operation of the gas piston engine of the power plant and the reduction of volumes electricity generation. With the use of computer modeling for the composition of biogas with an increased content of N2 and a reduced concentration of CH4 £ 32 %, calculations were made on the enrichment of biogas to concentrations of CH4 in it of 36–44 % due to the use of CO2 amine absorption technologies, in which the costs for the regeneration of the absorbent are compensated by the produced thermal energy of the gas piston engine of the power plant. The removal of carbon dioxide from biogas makes it possible to simultaneously increase the concentration of methane in it at the input to the heat engine, which contributes to the stable and efficient operation of the gas piston engine of the power plant and the increase in the amount of electricity generation as a result of energy utilization of landfill gas. The use of complex biogas utilization technology in the cogeneration mode allows obtaining not only electricity, but also heat, which can be used in absorption amine technologies for CO2 extraction from biogas and thus reducing carbon dioxide emissions into the atmosphere. Bibl. 17, Fig. 9, Tab. 3.