Source: https://transportgeography.org/contents/chapter4/transportation-and-energy/energy-sources-evolution/
Two centuries later, the difference is we burn biomass in industrial furnaces or boilers instead of in open air. Like your body needs good food to keep you healthy, these biomass boilers need high-quality biomass briquettes to function efficiently.
Biomass is organic materials from plants and animals. Mostly agricultural waste, organic industrial waste and waste from farms and forestry. When this biomass is mechanically compressed under high pressure and temperature, it’s called biomass briquettes.
Naturally, biomass is made of different materials having different characteristics. It is heterogeneous, has different densities, water content, shapes and sizes. The non-uniformity makes it hard to store, transport and use. This results in increased overall costs. And damages the biomass furnace or boiler it is used in.
To overcome these problems, biomass is densified or mechanically compressed into biomass briquettes. They combust well, are efficient and keep the furnaces and boilers in good shape.
Plain densification of biomass into briquettes is not good enough. Its quality depends on various factors. Here are some of the most important ones:
The moisture content of biomass briquettes largely depends on the moisture content of the initial raw biomass. The briquettes crack easily if the moisture content is higher than 15%. If the moisture content is too low, the briquettes become fragile and turn into a powder called fines.
The optimum moisture content for high-quality biomass briquettes is ~8%. They produce high-density briquettes that burn longer and generate more heat for you.
When biomass briquettes are burned in furnaces or boilers, some amount of ash is produced. The left-over ash may block air holes. This lowers the oxygen supply in the combustion chamber. That’s why it’s important to choose biomass briquettes that have the least amount of ash.
Generally, grasses and field crops have higher ash content than wood. This is because they consume more nutrients during growth. When you’re choosing biomass briquettes, remember that the lower the ash content, the higher it’s quality.