A novel methanol production process utilizing carbon black from turquoise hydrogen: Integration with chemical looping hydrogen generation

Turquoise hydrogen production is an environmentally sustainable and economically viable method that generates carbon black as a byproduct. This study presents a novel approach for incorporating carbon black into chemical looping hydrogen generation (CLHG). Previous research has primarily evaluated the economic feasibility of turquoise hydrogen production based on revenue from selling carbon black. However, as turquoise hydrogen gains broader commercialization, the surplus of carbon black could saturate the market. Therefore, it is essential to explore alternative strategies for carbon black use to maintain the economic viability of the process without relying solely on its sale. This study proposes a process that integrates turquoise hydrogen production with CLHG, using carbon black from the production process as feedstock for the CLHG. This integrated process doubles the hydrogen production compared to turquoise hydrogen production alone. The generated hydrogen is then used for methanol (MeOH) synthesis, along with the carbon dioxide (CO2) produced during the reaction. Comprehensive energy, environmental, techno-economic, and sensitivity analyses were conducted for the proposed process. The energy analysis revealed a total energy efficiency of 66.21 %. Environmental analysis revealed that the specific direct CO2 equivalent (eq.) emissions and specific total CO2 eq. emissions were 0.11 t/t MeOH and 0.975 t/t MeOH, respectively. The levelized cost of methanol was $188.02/t without a carbon tax and $216.75/t with a carbon tax, reflecting a 43.04 %–45.69 % reduction compared with the conventional methanol production process. Integrating turquoise hydrogen production with the CLHG process and using carbon black as a feedstock presents a promising, economically, and environmentally sustainable solution for future methanol production.