High-efficiency carbon dioxide reduction using catalytic nonthermal plasma desorption

Abstract

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%.