In April 2024, a Chinese large cement plant successfully launched a demonstration project for purifying 200,000 tons of CO2 per year using oxy-fuel combustion. As of now, the system has been operating continuously and stably with excellent results. The project is currently the largest carbon capture and utilization initiative in the Chinese cement industry and is set to become a benchmark project for oxy-fuel combustion coupled with low-energy carbon capture technology globally.
The feasible CO2 capture and purification technologies in the cement industry are mainly divided into 2 types. The first type targets the capture and purification of CO2 from flue gases with low-concentration CO2, which incurs relatively high costs. The second achieves CO2 self-enrichment during the combustion process to capture it, which is represented by oxy-fuel combustion coupled with carbon capture technology. It is employed in the CO2 capture project at the cement plant.
The main engineering components of the project include the oxygen generation system, the CO2 self-enrichment system, and the CO2 capture and purification system. The oxygen generation system uses VPSA (vacuum pressure swing adsorption) technology; the CO2 self-enrichment system employs oxy-fuel combustion technology, and the CO2 capture and purification system adopts a combined technology scheme of VPSA + adsorption & distillation for purification.
PKU Pioneer provided an efficient and economical VPSA oxygen plant (9,700Nm3/h, 80%) for the project, supplying stable oxygen to the CO2 self-enrichment system to help increase the CO2 concentration in the flue gas, effectively reducing the operating cost of the carbon capture and purification system and achieving preliminary purification of carbon dioxide. According to the project manager, the oxy-fuel combustion technology can increase the concentration of CO2 in the exhaust gas from the conventional 20%-30% to 75%-80%. The energy consumption per unit of CO2 produced using oxy-fuel combustion technology is 1.5-1.7GJ/ton of CO2. Compared to conventional post-capture technology, the energy consumption and operating cost per unit of CO2 can be reduced by more than 25%.
The captured CO2 from this project will be utilized for industrial enhanced oil recovery (EOR) to increase oil production and can also be applied in carbon-rich agriculture to enhance photosynthesis and boost crop growth. It is of great significance towards achieving China's "carbon peak and carbon neutrality" strategic goals, and of great importance for advancing carbon reduction in the cement industry both in China and globally.
For PKU Pioneer, this project represents the opening of a new application scenario for VPSA oxygen generation technology. It signifies that PKU Pioneer can not only provide oxygen-enriched air for oxygen-enhanced combustion in cement kilns, helping to improve combustion efficiency, reduce fuel consumption, and increase cement production, but also supply oxygen to the oxy-fuel combustion system for CO2 capture in cement flue gas, helping cement clients reduce carbon emissions and achieve high-quality sustainable development.
In 2022, PKU Pioneer constructed a VPSA oxygen generation unit for South Korea's largest cement plant, significantly reducing the user’s natural gas costs and uplifting economic benefits. As a world-leading supplier of VPSA/PSA oxygen generation units, PKU Pioneer has provided oxygen generation solutions to over 300 customers globally, covering more than 20 industrial sectors including steel, non-ferrous metals, cement, glass, waste treatment, new energy, and chemistry, making it the preferred supplier for industrial oxygen globally.
