Blue Hydrogen Production in Pilot and Demo-Scale Plants through Pet-Coke Slurry Gasification, WGS, and PSA Units

Syngas from gasification is converted into hydrogen and CO2 through the water-gas shift (WGS) reaction, and the subsequent pressure swing adsorption (PSA) separation produces high-purity hydrogen while capturing high-concentration of CO2. The collected CO2 can be utilized, at least as a feedstock for dry ice, which is in short supply in many countries. There are still many under-utilized low-grade feedstocks, such as pet-coke, biomass, and waste. These feedstocks can serve as good starting materials for producing economically feasible hydrogen for fuel cell power generation and hydrogen-fueled automobiles. Gasification technology is effective at breaking down low-grade feedstocks into syngas (CO + H2). However, in pet-coke gasification, there is an additional challenge due to its high sulfur content, which necessitates extensive desulfurization. Specifically, to use hydrogen in fuel cells, the residual sulfur concentration in hydrogen must be reduced to below 0.1 ppm. Over the last 3 years, a 2-ton/day pilot plant has been operated to produce high-purity hydrogen from pet-coke, using gasification, desulfurization, WGS, and PSA units. Based on the results from the pilot plant, a scaled-up 20-ton/day demonstration plant was constructed, yielding preliminary results toward the ultimate goal of producing blue hydrogen. Operation results show that sulfur containing impurities can be reduced to less than 0.1 ppm, and hydrogen of 99.9% purity can be obtained after WGS and PSA units. Several business models were proposed to utilize the developing process by module approach.