Coal is the predominant energy resource used as primary fuel for power generation and supplied over one-third of global electricity production in 2020. Its widespread use can be undermined by incomplete fuel combustion and concomitant formation of toxic gases, pointing to the need for more effective and environmentally friendly coal thermal conversion technologies. Researchers in Russia have improved coal-burning efficiency with the use of catalytically active agents to intensify the combustion process.

Copper salts were tested as activating additives to improve reactivity of high-ash coal fuels, such as anthracite, and semicoke. These fuels are characterized by high minimum ignition and combustion temperatures and low combustion intensity. Copper nitrates, acetates and sulfates were added to fuel Tests were conducted in a combustion chamber at heating medium temperatures of 500° C to 700° C. Source: Sergey Gnuskov/NUST MISISsamples by the incipient wetness procedure, and ignition and combustion experiments were conducted in a combustion chamber at heating medium temperatures of 500° C to 700° C.

The introduction of copper salts intensified the combustion process and reduced temperature and was demonstrated to improve reactivity and increase the burn rate of fuel samples. The concentration of unburned carbon in the ash residue of treated samples was significantly lower than that in reference samples.

The use of oxide-based additives more commonly applied to enhance coal combustion requires dynamic contact between the fuel and the additive. Such contact is not a requirement for the use of salts as a catalyzing agent, making this coal modification approach more widely applicable in the energy industry. By increasing fuel efficiency in energy production, these salt-based additives also offer scope to minimize energy use for preheating power generating equipment and reduce carbon emissions from coal-fired power plants.

A paper on the research conducted by scientists from National Research Tomsk Polytechnic University, National University of Science and Technology (NUST MISIS) and Boreskov Institute of Catalysis SB RAS is published in Fuel Processing Technology.