Experimental evaluation of main emissions during coal processing waste combustion

Area of Science:

• Environmental Science
• Chemical Engineering
• Energy Technology

Background:

• Coal processing generates millions of tons of filter cake waste annually in Russia, China, and India.
• Filter cakes are the largest volume coal processing waste, with potential for use in coal-water slurries (CWS) and coal-water slurries containing petrochemicals (CWSP).
• Previous studies have explored CWSP combustion, but direct measurement of CO and CO2 emissions from filter cake combustion is novel.

Purpose of the Study:

• To quantify carbon monoxide (CO) and carbon dioxide (CO2) emissions from the combustion of coal processing filter cakes.
• To evaluate the impact of combustion temperature on hazardous emissions.
• To determine optimal combustion conditions for minimizing environmental impact.

Main Methods:

• Direct measurement of CO and CO2 concentrations in emissions from filter cake combustion at temperatures ranging from 500 to 1000°C.
• Experimental testing of filter cake-based CWSP combustion in operational boilers.
• Comparative analysis of emissions from CWS and CWSP versus conventional solid fuels.

Main Results:

• CO and CO2 concentrations remained relatively constant at high temperatures (>900°C).
• Lowering combustion temperatures to 750-850°C sustainably reduced CO and CO2 emissions by 1.2-1.7 times.
• CWS and CWSP combustion significantly reduced NOx and SOx emissions compared to coal powder, with CO and CO2 levels comparable.

Conclusions:

• Low-temperature combustion (750-850°C) is feasible and environmentally beneficial for coal processing wastes.
• Optimizing combustion temperature is crucial for reducing CO and CO2 emissions in CWS and CWSP technologies.
• Sustainable and environmentally friendly utilization of coal processing wastes in CWS and CWSP requires low-temperature combustion strategies.