Industrial-scale hydrogen combined heat and power (CHP) systems represent a transformative approach to decarbonizing high-temperature process heat in energy-intensive industries. These systems simultaneously generate electricity and useful thermal energy from hydrogen combustion or electrochemical conversion in fuel cells, offering a pathway to reduce reliance on fossil fuels while maintaining operational efficiency. Sectors such as chemical manufacturing, food processing, and metallurgy stand to benefit significantly due to their substantial heat demands, often exceeding 300°C.
System configurations for hydrogen CHP vary based on the primary energy conversion technology. Gas turbine-based systems modified for hydrogen combustion can achieve thermal outputs suitable for industrial furnaces and kilns. These turbines are often integrated with heat recovery steam generators (HRSGs) to maximize energy extraction. Alternatively, solid oxide fuel cells (SOFCs) operating at high temperatures (600–1,000°C) provide both electricity and high-grade waste heat, making them ideal for processes like steam reforming or metal annealing. Hybrid systems combining fuel cells with hydrogen boilers offer flexibility, ensuring consistent heat supply during variable demand cycles.
Efficiency gains are a key advantage of hydrogen CHP. Traditional separate heat and power systems typically operate at 40–50% efficiency, whereas hydrogen CHP can reach 70–90% total energy utilization. For example, a gas turbine CHP system burning hydrogen may achieve 35–40% electrical efficiency and 40–50% thermal efficiency, while SOFC-based systems can exceed 50% electrical efficiency with 30–40% thermal recovery. These figures translate to direct fuel savings and lower operational costs over time.
Carbon reduction potential is substantial. Replacing natural gas with green hydrogen in a 10 MW CHP system can eliminate up to 20,000 tons of CO2 annually, assuming continuous operation. In metallurgy, hydrogen-fueled rotary kilns can reduce emissions by 85–100% compared to coke-based processes. The chemical industry, particularly ammonia and methanol production, can leverage hydrogen CHP to decarbonize steam methane reforming by integrating electrolysis-powered systems.
However, challenges persist in hydrogen storage and handling. Industrial CHP systems require large-scale storage solutions, often necessitating compressed gas or liquid hydrogen tanks with capacities exceeding 50 tons. Metal hydrides and liquid organic hydrogen carriers (LOHCs) are emerging as compact alternatives but face cost and cycle-life limitations. Combustion modifications are also critical; hydrogen’s high flame speed and low ignition energy demand burner redesigns to prevent flashback and NOx formation. Retrofitting existing gas turbines or boilers involves material upgrades to mitigate hydrogen embrittlement in pipelines and valves.
Retrofitting infrastructure presents economic and technical hurdles. Many industrial facilities rely on legacy equipment designed for natural gas, requiring significant capital expenditure for conversion. For instance, modifying a conventional gas turbine for 100% hydrogen combustion may cost $5–10 million per unit, though blending up to 30% hydrogen often requires minimal adjustments. Pipeline networks must be assessed for compatibility, as hydrogen can degrade polyethylene pipes and welds over time.
Case studies highlight successful implementations. A German chemical plant integrated a 1.4 MW SOFC-CHP system with hydrogen derived from chlor-alkali byproducts, achieving 85% total efficiency and cutting natural gas use by 70%. In Sweden, a steel pilot facility employed hydrogen CHP to power electric arc furnaces, reducing CO2 emissions by 1,500 tons per year. Japan’s ENE-FARM project demonstrated residential SOFC-CHP units running on hydrogen, though scalability for industrial use remains under evaluation.
Economic feasibility hinges on hydrogen cost and policy support. Current levelized costs for hydrogen CHP range from $80–150/MWh, heavily dependent on electrolyzer electricity prices. At hydrogen prices below $3/kg, CHP systems become competitive with natural gas in regions with carbon pricing above $50/ton. Government incentives, such as the U.S. Inflation Reduction Act’s 45V tax credit, improve project returns by offsetting capital costs.
In conclusion, industrial hydrogen CHP systems offer a viable route to decarbonize high-temperature process heat, with demonstrated efficiency and emissions benefits. Technical challenges in storage, combustion, and retrofitting must be addressed through continued research and pilot deployments. As hydrogen production scales and costs decline, these systems will play a pivotal role in achieving net-zero industrial operations.