Analysis of the work of a renewable methanol production installation based ON H2 from electrolysis and CO2 from power plants

This article presents a thermodynamic analysis of a system for producing renewable methanol from H-2 generated from electrolysis, fed by surplus energy from a 40 MW wind farm WF during the night valleys and from CO2 captured from a power plant's flue gas. A methodology determining the energy efficiency of the entire methanol production and purification installation was developed, as well as a methodology for determining the efficiency of its components, i.e. the hydrogen generator HG (eta(HG)) and the methanol generator MG (eta(MG)). A number of effective ways to improve these efficiencies were proposed and analyzed. To evaluate the cooperation of the HG with a WF, a number of indicators were introduced: an indicator of the maximum working time utilization, a rated power index for the generator, an energy storage indicator, and an indicator for the working time with nominal power. The listed efficiency and indices were determined as a function of the nominal power of the HG in relation to the nominal power of the WF (in a range from 1 to 45%). The energy efficiency of the entire system under study, eta, ranged from 45.5% to 52.9% with a MG efficiency of 69%-69.64%. The use of heat from compressed gases increased the efficiency eta by 0.98 p. p. Relative to the best variant, while the use of compressed gas heat, waste heat from the methanol production and purification installations, and the use of the chemical energy of residual gases gave a possibility of achieving an efficiency exceeding 60% (60.4%). (c) 2020 Elsevier Ltd. All rights reserved.

Automated summary

This study presents a thermodynamic analysis of a system for producing renewable methanol from H2 generated from a wind farm and CO2 captured from a power plant's flue gas. Various methods to improve system efficiency were proposed and analyzed, with the introduction of indicators to evaluate the cooperation between components. The energy efficiency of the system ranged from 45.5% to 52.9%, with potential for exceeding 60% efficiency with certain additional measures.