What is Co-firing?Co-firing usually refers to several fuels burn together to provide heat or power in a power plant. Mostly the co-firing is biomass and fossil fuels, such as coal and natural gas in a power plant. As wood pellets is popular biomass fuel, so more and more power plant start to co-firing combusting type.

Co-fired Power Stations Application
Coal-fired power stations that provide both power and heat to district heating networks (such as in Northern Europe) or even industrial facilities may significantly increase the efficiency and the economics of biomass co-firing. Appropriate policies are needed to seek an efficient use of the avail able biomass resource by encouraging the use of co-firing in connection with CHP wherever suitable. Policies should also take into account the co-benefits from the use of agricultural residues or demolition waste, which would otherwise constitute a disposal challenge.

typical power stations boiler system

Why Choose Wood Pellets in Co-firing Plant with Coal
• Lowest cost renewable power
• Relatively easy to implement
–Covered storage
–Separate feed system
–Separate milling
–No change to remaining process

In most cases, biomass co-firing in coal power plants takes place by mixing biomass with coal before the burners, but biomass can also be gasified and burned in separate burners, after which the gaseous fuel or steam is mixed with the boiler streams of the coal-fired power plant. The advantage of biomass co-firing is that it reduces greenhouse gas emissions from coal-fired power and enables power generation from biomass with the high efficiency achieved in modern, large-size coal-fired power plants, which is much higher than the efficiency of dedicated, 100% biomass power plants. The total energy efficiency can be increased even further if biomass co-firing takes place in combined heat and power (CHP) plants. The other advantage of biomass co-firing is that the incremental investment for burning biomass in coal-fired plant is significantly lower than the cost of dedicated biomass power.

wood pellets

biomass power station

Biomass Co-firing Patterns
Local availability of large quantities of cheap biomass makes biomass co-firing more economically attractive. If local sources are not sufficient, high energy-density, pre-treated biomass (e.g. wood pellets) can be used. In these cases, long-distance transportation and logistics (e.g. an inland harbour) play an important role on the economic viability. In developing countries, the use of waste streams from agriculture and forestry may also create additional value and job opportunities, and contribute to the rural development.

Rational Utilization Of Biomass Products in Co-firing Plants
However, to exploit the co-firing potential with no environmental impact urgent measures and technology preparation are needed in emerging economies such as India and China, where coal-fired power capacity is rapidly growing and large sources of biomass are available. The indicators developed by international organizations to measure the sustainability of bio-energy (including protection of soil and water resources, bio-diversity, land allocation and tenure, and food prices) need to be integrated into the policy measures.