Definition (extracted from ^1):
Solid fuel refers to various forms of solid material that can be burnt to release energy, providing heat and light through the process of combustion. Solid fuels can be contrasted with liquid fuels and gaseous fuels. Common examples of solid fuels include wood, charcoal, peat, coal, hexamine fuel tablets, wood pellets, corn, wheat, rye, and other grains, but we consider only coal and pellets.
Solid fuels, compared to liquid fuels or gaseous fuels, are often cheaper, easier to extract, more stable to transport and in many places are more readily available. Coal, in particular, is utilized in the generation of 38.1% of the world’s electricity because it is less expensive than its liquid and gas counterparts. However, solid fuels are also heavier to transport, require more destructive methods to extract/burn and often have higher carbon, nitrate and sulphate emissions. With the exception of sustainable wood/biomass solid fuel is normally considered non-renewable as it requires thousands of years to form.
Solid fuels are composed of organic materials and can contribute to poor air quality. The burning of solid fuels releases more organic aerosol than liquefied petroleum gas and releases many volatile organic compounds, which can contribute to poor air quality through the formation of secondary pollutants such as tropospheric ozone and secondary organic aerosol. The emissions from solid fuels are likely drivers of poor air quality in regions where solid fuels are a dominant fuel source, with volatile organic compound emissions from solid fuels significantly more reactive with the hydroxyl radical compared to those from liquefied petroleum gas.
Significant datas for liquid fuel [^2]:
- Molecular Weight : 170.0 g/mol
- Density: 1300 kg/m^3
- CO2 after use : 2.42 kgCO2/kg
- N2O after use : 0.0014 kt/PJ ^4
- Calorific value : 4.86 kWh/kg^3
We consider several methods for production:
- Coal extraction
- Pelletizing
The solid fuel section deals with the coal extraction part, for the burning part (to produce electricity), it is processed in the "electricity" section.
^1: Solid Fuel Wikipedia page, https://en.wikipedia.org/wiki/Solid_fuel [^2]: Engineering Toolbox, https://www.engineeringtoolbox.com ^3: Lee, J.S., 2015. Calorific value of wood pellets (Doctoral dissertation, University of British Columbia). ^4: Winiwarter, W., 2005. The GAINS model for greenhouse gases-version 1.0: nitrous oxide (N2O).https://previous.iiasa.ac.at/web/home/research/researchPrograms/air/IR55-GAINS-N2O.pdf