Briquetting

Briquetting is the process of compressing a loose material into a compact solid form called a briquette. It is used for a wide range of materials, including agricultural residues, wood waste, coal fines, charcoal dust, and metal fines. Briquetting aims to improve handling, storage, and energy content.

The typical briquetting workflow involves preparing the feedstock by drying and size reduction, followed by compacting through a press. Depending on the material and binder, briquettes can be produced without added binders or with binders such as starch, molasses, clay, or lignosulfonates.

There are several briquetting technologies. Mechanical briquetting uses piston or screw presses to apply high pressure and produce briquettes, while hydraulic briquetters use pressurized fluid resistance. Some processes rely on natural binders, such as lignin in wood, to bind the particles when heated.

Common applications include fuel for heating and cooking, electricity generation in small-scale plants, and waste management where fines are converted into value-added fuel. Briquettes tend to have higher energy density, lower moisture, and reduced dust compared with loose materials.

Material considerations include moisture content, ash content, and calorific value. Biomass briquettes may require drying to a moisture content of around 8–12% for optimal quality. Coal and charcoal briquettes may require binding and stabilization to control durability and ash.

Limitations include equipment costs, energy requirements for drying and compression, and the need for quality control to ensure uniform density and durability. Despite these, briquetting offers waste valorization, improved handling, and potential emissions reductions in suitable applications.