【Frontiers of HaiChuan Chemical Technology】Coal-based fuel cells: Chinese electrochemical systems convert coal into electrical energy without any direct carbon emissions

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Chinese researchers have developed a coal-based fuel cell that generates electricity through an electrochemical process rather than combustion. Traditional coal-fired power generation is usually associated with high pollution, significant carbon emissions, and relatively low efficiency. However, a completely new coal-based power generation method is challenging this entrenched perception by eliminating the burning process altogether. Instead of burning coal, this system converts its chemical energy directly into electrical energy, thereby avoiding carbon dioxide emissions that typically determine its environmental impact. This breakthrough came from a research team led by Xie Heping, an academician of the Chinese Academy of Sciences at Shenzhen University, who developed what is known as zero-carbon direct coal fuel cells (ZC-DCFC). This concept effectively redefines coal as an electrochemical energy source rather than a fuel that requires combustion, opening up a potential new pathway for the cleaner utilization of fossil resources. Coal fuel cells do not require a steam cycle or combustion. It is reported that the coal in this system is not burned, but rather undergoes multiple preprocessing steps before being used to generate electricity. It is first ground into a fine powder, then dried and purified, and surface-treated to optimize its reactivity. The treated coal is then fed into the anode chamber of the fuel cell, while oxygen is supplied to the cathode side. Inside the battery, coal particles are directly oxidized by an oxide film, triggering an electrochemical reaction that generates electrical energy on the spot. It is crucial that this method no longer requires the power generation processes that are central to traditional power plants, such as steam production and mechanical turbines. At the anode outlet, the carbon dioxide produced by the reaction is captured on-site and then converted catalytically into useful chemical feedstocks such as syngas, or chemically stabilized into compounds such as sodium bicarbonate. This closed-loop carbon treatment method makes the entire process appear quiet and clean. In contrast, traditional coal-fired power plants rely on combustion to generate heat, which is then used to produce steam that drives turbine generators through a multi-stage energy conversion chain. This indirect path is fundamentally constrained by thermodynamic limits, particularly the upper limit on Carnot efficiency associated with heat engines, which limits the proportion of fuel energy that can be converted into usable electrical energy. Breaking through the limits on durability and power output: Xie Heping said that the traditional coal-fired power generation process is constrained by the Carnot cycle, with an upper limit for thermal efficiency of around 40%. He believes that the zero-carbon direct coal fuel cell (ZC-DCFC) avoids the energy losses associated with combustion and heat engine systems, thus possessing a significantly higher theoretical efficiency. Since 2018, Xie Heping’s research team has been advancing this technology through multiple rounds of technical iterations, overcoming long-standing challenges in materials science, battery durability, fuel processing, and maintaining a continuous supply of coal. Early versions of direct carbon fuel cells were limited by low power density and short operational lifespan, while the latest designs aim to overcome these issues through continuous engineering optimizations. According to the research team, the latest version of the fuel cell offers improvements in stack scalability, long-term stability, carbon conversion efficiency, and overall system integration. Xie Heping also pointed out that this concept can be applied to deep coal seams located about 1.2 miles (around 1.9 kilometers) underground. There is no need to extract and transport coal to the surface—a costly and complex process—since this system can convert coal into electricity directly underground, transmitting only electricity to the surface. In this way, as shallow coal reserves gradually deplete, this method will help alleviate supply pressures.