Mechanical Engineering Journal (Mar 2023)

High-efficiency carbon dioxide reduction using catalytic nonthermal plasma desorption

  • Hiroyuki WAKIMOTO,
  • Haruhiko YAMASAKI,
  • Tomoyuki KUROKI,
  • Masaaki OKUBO

DOI
https://doi.org/10.1299/mej.22-00191
Journal volume & issue
Vol. 10, no. 2
pp. 22-00191 – 22-00191

Abstract

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To sustainably reduce carbon dioxide (CO2) emissions at ambient temperature and atmospheric pressure, CO2 is reduced to carbon monoxide (CO) using nonthermal plasma (NTP) flow and a catalyst. In a liquefied natural gas (LNG) gas-turbine combined power generation plant with high power generation efficiency, CO2 zero-emission can be achieved for the power plant if the energy efficiency of CO2 reduction by NTP is at least 49%. In this study, CO2 reduction performance is evaluated for a two-step process using different gas mixtures. First, CO2 is adsorbed from a gas flow mixture of nitrogen (N2) and CO2 (~10% concentration) by an adsorbent; second, CO2 is desorbed and concentrated by NTP flow to a higher concentration from 19% to 25% and reduced by N2 NTP flow and a catalyst under all experimental conditions. γ-alumina, copper, and copper doped alumina are used as catalysts, and the results are compared with those of a previous study where zeolite was used. The energy efficiency increases with the elapsed time and can reach 9−11%. When using copper doped alumina, plasma-catalysis promotes CO2 reduction even in low-temperature environments at ~80 ℃, resulting in a higher CO concentration relative to the CO2 concentration and the highest efficiency of all tested catalysts: conversion efficiency is 18% and energy efficiency is 11%.

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