The major challenge with using biomass as a fuel is the low bulk density, making it difficult to handle, store, transport, and use. Biomass briquetting is a densification process that increases the bulk density of biomass up to 600 Kg/m3. These briquettes are considered as a potential alternative to fossil fuel as well as firewood. 

Biomass briquettes have gained tremendous traction in India in the last decade. It is cheap and abundantly available. If you have read Steamax’s story, you would know that we were the nation’s first organized biomass briquette supplier. Our team has converted multiple industries from fossil fuel to biomass briquettes in the last 20 years. We have been supplying biomass briquettes to multiple industries all across the nation since 2010. While working in this sector, we realized that though biomass briquetting improves fuel handling and characteristics, it has several drawbacks. 

This article will share our experience with the utilization of biomass briquettes and the possible drawbacks.

Fuel Feeding Automation

The solid fuel can either be fed with automatic feeding systems or manually. The manual feeding of the fuel requires solid fuel, such as briquettes, to be fed to the furnace in a labour-intensive manner. 

Though labour is often cheap in India, the job itself is hazardous. There is a danger of serious accidents, such as back-fire, over-heating, etc. There have been numerous reported accidents over the last many years in manual briquette fired boilers. 

Additionally, manual fuel feeding also results in efficiency loss as the fire doors, through which briquette is fed to the furnace, also allow some heat to escape and excess air enters the system. This leads to a drop in the boiler’s efficiency and pollution-related issues as well. The biomass briquette fired boilers and heaters often face the challenge of black smoke coming out of chimneys because of the same reason.

The above factor necessitates the automation of fuel feeding to ensure worker’s safety and high efficiency. However, briquette feeding is difficult to automate in most cases. Owning to the large size, briquettes are usually not compatible with existing coal feeding system or screw and pneumatic feeding systems. They need to be crushed first to make it suitable for automatic feeding, which most companies, especially food processing and pharmaceuticals, don’t prefer. In most cases, automated briquette firing is not suitable with the existing system and would require replacement with new technologies, which is a capital-intensive process.

Combustion Properties

As already discussed, manual feeding of biomass leads to a drop in performance of the system and augment the pollution-related issues as well. Additionally, briquetting impacts the combustion characteristics of the biomass as well. It is a known fact that smaller particles have better combustion properties than bigger ones. The smaller particle size and lower bulk density ensures good air-fuel mixing and results in higher combustion temperature. 

Therefore, smaller-sized biomass fuel may lead to better combustion characteristics and performance of the system. Thus, fuels like pellets, loose biomass, Astillas, etc., may yield higher efficiency than biomass briquettes.

Bottom Line

Though biomass briquetting is a novel way of increasing fuel characteristics, it does have certain disadvantages. Briquettes aren’t technically suitable for automatic fuel feeding and often result in poor combustion properties than other fuels. Thus, as the world moves towards automation in every field, biomass briquettes may face the challenge to stay relevant in the changing industrial scenario. Other fuels, such as pellets, Astillas, and some loose biomass, may lead to better results. Some of these fuels are also more cost-effective than briquettes as they need minimal processing.