The effect of variable operating parameters for hydrocarbon fuel formation from CO2 by molten salts electrolysis

Ossama Al-Juboori, Farooq Sher, Abu Hazafa, Muhammad Kashif Khan, George Zheng Chen

Research output: Journal PublicationArticlepeer-review

51 Citations (Scopus)
4 Downloads (Pure)

Abstract

The emission of CO2 has been increasing day by day by growing world population, which resulted in the atmospheric and environmental destruction. Conventionally different strategies; including nuclear power and geothermal energy have been adopted to convert atmospheric CO2 to hydrocarbon fuels. However, these methods are very complicated due to large amount of radioactive waste from the reprocessing plant. The present study investigated the effect of various parameters like temperature (200–500 oC), applied voltage (1.5–3.0 V), and feed gas (CO2/H2O) composition of 1, 9.2, and 15.6 in hydrocarbon fuel formation in molten carbonate (Li2CO3-Na2CO3-K2CO3; 43.5:31.5:25 mol%) and hydroxide (LiOH-NaOH; 27:73 and KOH-NaOH; 50:50 mol%) salts. The GC results reported that CH4 was the predominant hydrocarbon product with a lower CO2/H2O ratio (9.2) at 275 oC under 3 V in molten hydroxide (LiOH-NaOH). The results also showed that by increasing electrolysis temperature from 425 to 500 oC, the number of carbon atoms in hydrocarbon species rose to 7 (C7H16) with a production rate of 1.5 μmol/h cm2 at CO2/H2O ratio of 9.2. Moreover, the electrolysis to produce hydrocarbons in molten carbonates was more feasible at 1.5 V than 2 V due to the prospective carbon formation. While in molten hydroxide, the CH4 production rate (0.80–20.40 µmol/h cm2) increased by increasing the applied voltage from 2.0–3.0 V despite the reduced current efficiencies (2.30 to 0.05%). The maximum current efficiency (99.5%) was achieved for H2 as a by-product in molten hydroxide (LiOH-NaOH; 27:73 mol%) at 275 oC, under 2 V and CO2/H2O ratio of 1. Resultantly, the practice of molten salts could be a promising and encouraging technology for further fundamental investigation for hydrocarbon fuel formation due to its fast-electrolytic conversion rate and no utilization of catalyst.
Original languageEnglish
Pages (from-to)101193
JournalJournal of CO2 Utilization
Volume40
Early online date10 Jun 2020
DOIs
Publication statusPublished Online - 10 Jun 2020

Keywords

  • Applied voltage
  • CO2/H2O
  • Electrochemical conversion and Carbon dioxide capture
  • Molten salt electrolysis
  • Renewable energy
  • hydrocarbon fuels

Fingerprint

Dive into the research topics of 'The effect of variable operating parameters for hydrocarbon fuel formation from CO2 by molten salts electrolysis'. Together they form a unique fingerprint.

Cite this