A novel hybrid approach to pink and turquoise hydrogen production via oxy-fuel combustion

Hydrogen has been considered a clean energy source essential for net zero by 2050. However, the current green hydrogen production process is not economically feasible compared to the existing hydrogen production pathways. Therefore, this study proposes a hybrid operation of pink and turquoise hydrogen as a stepping-stone until the maturity of green hydrogen. Pink and turquoise hydrogen have their disadvantages: pink hydrogen requires an electric heater (EH) with high power load, and turquoise hydrogen faces economic drawbacks due to the high cost of air separation units (ASU). The proposed hybrid operation can mitigate these weaknesses: (1) by using low-grade waste heat from turquoise hydrogen to reduce the EH power load, and (2) eliminating the ASU process by utilizing high-purity oxygen produced from pink hydrogen for oxy-fuel combustion. We conducted energy, environment, techno-economic, sensitivity, and scenario-based cost analysis for the independent and hybrid operations. With the hybrid operation, total energy and specific energy consumption decreased by 11.5 % and 11.7 %, respectively, compared to independent operation. The environmental assessment showed the CO2 eq. flow of the hybrid operation decreased by 200 % compared to the independent operation, and the total expense and levelized cost of hydrogen (LCOH) decreased by 10.7 % and 10.7 %, respectively. Finally, the analysis revealed the hybrid operation can alleviate uncertainties about cost fluctuations of feedstocks and utilities, as well as the volatility of by-product costs. Therefore, the hybrid operation integrating pink and turquoise hydrogen is expected to serve as a stepping-stone to the transition to green hydrogen.