Application of biomass boiler and wood pellet fuel

Due to the growing concerns over environmental protection and the need to address the energy crisis, many countries have implemented policies aimed at reducing emissions and promoting the use of renewable energy sources. As a result, there has been a significant shift towards replacing or upgrading coal-fired boilers with biomass boilers.

Traditional coal-fired boilers are known for emitting significant amounts of black smoke and sulfur gases, often without the presence of desulfurization equipment. These emissions can cause pollution in the surrounding areas. To address this issue, many coal-fired boiler owners opt for using biomass fuel as a replacement for coal, as transitioning to gas or electricity would require substantial effort and expenses. However, since most coal-fired boilers are not suitable for burning biomass fuel, specialized biomass fuel burning devices have been developed. These devices are designed specifically to accommodate the characteristics of biomass fuel and minimize pollutant emissions.

Different types of biomass pellet boiler

Biomass boilers utilize biomass energy, such as biomass pellets, as fuel. They can be classified into different types based on the energy medium they utilize, including biomass steam boilers, biomass hot water boilers, biomass hot blast stoves, and biomass thermal oil furnaces.

In terms of purpose, biomass boilers can be further classified into biomass thermal boilers and biomass electric power boilers. Both types generate power through the combustion of biomass fuels. Biomass thermal boilers utilize the thermal energy produced, while biomass electric power boilers convert the thermal energy into electric power. Among these, biomass thermal boilers are currently the most popular type, as their technology is well-established and widely used.

According to the scale, biomass thermal boiler can be classified into 2 types.

Small biomass boiler

Biomass boilers can utilize solid or gasified biomass fuels and generate heat in the form of hot water. Small biomass boilers are known for their compact size, simple structure, and relatively low cost. However, they have lower energy conversion efficiency and provide a limited energy supply. Typically, small biomass boilers are used for home heating in rural areas and for hot water supply purposes.

Large-scale biomass boiler

These types of biomass boilers use solid biomass fuel and are designed to provide hot water or steam. They are characterized by mature technology, high energy supply, and low energy loss. However, it’s worth noting that some biomass boilers may experience fuel clogging due to incomplete combustion, and the supporting facilities may not be fully optimized or complete.

Two common biomass fuels

Biomass molding fuel can generally be categorized into two types: biomass briquettes and wood pellet fuel. Biomass briquettes are typically more than 15cm in length with a diameter of 30-40mm. They are produced using a biomass briquette press. On the other hand, wood pellets have a diameter of 6-8mm and are made using a wood pellet mill. Wood pellet fuel has gained popularity over biomass briquettes due to its higher density, wider application, and convenience of use. Wood pellets burn more efficiently than biomass briquettes.

Biomass pellet fuel typically contains around 70% fiber content. It has significantly lower sulfur content compared to coal. The high density of biomass pellets makes them easy to store and transport. They can be used in various types of equipment. Biomass pellets burn more efficiently, producing less smoke and ash compared to coal. They also have a combustion speed that is 11% higher than coal.

Advantages of wood pellet fuel over coal

• Biomass fuels have low carbon content (maximum 50%) compared to coal, resulting in a lower heat value.
• Biomass fuels have high hydrogen content, making them easier to burn. The carbon and hydrogen combine into low molecular hydrocarbons, releasing volatiles at high temperatures.
• Biomass fuels have high oxygen content, leading to a lower heat value.
• Biomass fuel has a lower density than coal, making it easier to burn completely. The residual carbon content is lower than coal ash.
• Biomass fuels have low sulfur content (<0.12%), eliminating the need for a desulfurizer device.
• Biomass fuel is carbon-neutral, resulting in zero carbon emissions.
• The use of biomass fuel allows for the recycling of waste materials and reduces environmental damage. The residual ash after burning can be used to produce fertilizer.
• Biomass fuel can be co-fired with coal, improving combustion efficiency.