Evaluation of blue hydrogen production from Japanese light crude oil gasification reactions using Ca(OH)2 and NiO particles

• Mineral additives enhance crude oil gasification and hydrogen-rich gas yield. • NiO promotes catalytic reforming, increasing H 2 production efficiency. • Ca(OH) 2 reduces CO 2 emissions via in situ carbonation during gasification. • Energy recovery ratio improves with temperature and mineral loading. • Process enables low-carbon fuel gas recovery and blue hydrogen generation. Blue hydrogen gas production is a popular clean energy alternative to fossil fuels. However, the blue hydrogen production process presents several operational difficulties. Hence, a novel fuel gas recovery process was developed to recover crude oil as fuel gas via in situ combustion and the addition of minerals to enhance gasification. This study investigated the influence of temperature and mineral species on the gasification characteristics of Japanese crude oil using a laboratory gasification system. Above 400°C, process gas was obtained experimentally, and above 600 °C, oil gasification was sufficiently advanced, increasing CH 4 production. Further temperature increases promoted water vapor reformation, enhancing hydrogen production. Under NiO addition, exothermic reactions from oxygen desorption increased the system temperature, while the catalytic effects of Ni accelerated reforming. Under Ca(OH) 2 addition, the hydrogen accounted for 42 % of the total gas, which was 9 % higher than that without Ca(OH) 2 . The CO 2 concentration decreased by 2 %, while CO 2 produced by reforming was mineralized and fixed by the Ca(OH) 2 carbonation reaction. The energy recovery ratio (low heating value (LHV) of oil to LHV of gas obtained with H 2 and CH 4 ) increased with increasing temperature. Under NiO and Ca(OH) 2 addition, the carbon intensity (CO 2 per unit gas volume) decreased and increased, respectively. However, higher Ca(OH) 2 loading improved the enhanced oil recovery (EOR) and reduced the carbon intensity compared to standard conditions. The mineral content also had a significant effect on these values. Therefore, feeding Ca(OH) 2 for EOR before gasification can facilitate efficient fuel conversion and blue hydrogen production.