Since COP21 was held in 2015, climate change, mainly associated with greenhouse gas emissions, has become a global issue. Coal is an abundant and cheap fuel, but it is one of the main sources of CO₂ emission. However, the use of low-rank coal (LRC) with high moisture content is on the rise, mainly due to the increased demand for electricity in many developing countries. The increased use of LRC with high moisture content emits much more greenhouse gases than expected. Therefore, efficient LRC drying technologies are in demand in order to improve the efficiency of coal-fired power plants and thus to reduce greenhouse gas emissions. Another practical option is to substitute a part of coal with biomass, which is CO₂ neutral. A great deal of effort is ongoing to increase the mixing ratio of biomass in coal-biomass co-firing and co-gasification. This stimulates the utilization of waste materials such as agricultural byproducts, forest residues, and MSW (municipal solid waste). In order to utilize these non-conventional biomass fuels, heat treatment (e.g., torrefaction) to increase the uniformity and calorific value of fuel is typically required. In addition, bio-char that can be produced via torrefaction, pyrolysis, and gasification is excellent for reducing greenhouse gas emissions. This Special Issue covers a variety of areas for the efficient use of coal and biomass as below, but not limited to these: Low-rank coal drying; Biomass pyrolysis; Tar reforming; Biomass torrefaction; Coal-biomass co-firing; Coal-biomass co-gasification; Waste to energy; Coal-biomass briquette; Bio-char; Value-added materials extracted from coal.
Keywords: low-rank coal drying; biomass torrefaction; black pellet; coal-biomass co-firing; co-gasification; bio-char; biomass pyrolysis; waste to energy.