Integrating solid oxide electrolysis cells and H2-O2 combustion for low-emission high-temperature heating with heat pump in the chemical industry

• SOEC uses 7.76 MW of external heat to reduce power consumption. • Prove the effectiveness of new integration through ethylene cracking case study. • The steam supply requires a heat pump with 63% of energy saving. • Reduce carbon emission by 84.28% via PV power. Low-emission high-temperature heating could be achieved by exploiting electrical heating, clean fuel, or carbon capture. However, it is difficult to replace current coal or natural gas furnaces in some places because the high-temperature thermal demand needs combustion. In the present work, the green hydrogen production process by solid oxide electrolysis cells (SOEC) and H 2 -O 2 combustion is integrated into ethylene production. The working conditions of electrolyzer and furnace are analyzed. The SOEC should work over 800°C to keep endothermic state no matter the current density. To produce the hydrogen of 80 MW heat value, the electric consumption is at least 69.4 MW. With the high-temperature waste heat of 7.76 MW, an additional 3 MW power is required for water electrolysis. The heat released during condensation of combustion products is 30.52 MW, much higher than 13.19 MW from SOEC products. Therefore, the heat pump is necessary to recycle the waste heat of water condensation and generate steam as the electrolysis ingredient and cooling medium, which saves 63 % of energy. Although the total energy consumption increases by 11.23 % from 80.23 MW to 89.24 MW, the CO 2 emission drops by 84.28 %.