In its World Energy Outlook 2011 Executive Summary, the International Energy Agency projected that supplies of biofuels for energy would triple by 2035, reaching an equivalent of 4 million barrels of oil per day, fueled by subsidies of up to $1.4 trillion.
As the world explores every possibility for answering ever-increasing demands for energy, there’s a growing trend in the U.S. power industry toward converting traditional coal plants to biomass plants, or to plants that can handle a combination of biofuels and solid fuels. Every conversion, large or small, affects the entire power-generation chain, from fuel feed to air flow to ash handling.
While conversions can pay big dividends in the long view, both financially and environmentally, the process is costly, and there are many potential pitfalls waiting to trip up firms that have little or no experience in the unique technologies of biomass firing. Systems designed for co-firing biomass and solid fuels present special problems in engineering feed systems that keep a steady and consistent flow to the boiler, maintain power output, and meet emissions standards.
Direct co-firing often involves the use of biomass in pellet form, to match coal’s burn specs, and it takes well-grounded experience to design an efficient system that can handle factors such as premixing the biomass and fossil fuel.
Indirect co-firing conversions are more involved and require a greater investment, with separate systems for coal and biomass, but can give greater results over the long term with the best of both worlds.
Biofuels for indirect co-firing can consist of a variety of forms, from sawdust and chips to bark, putting demands on a feed system that simply aren’t present with coal. A fuel-feed system for biomass also should be custom planned for the size and needs of the facility, utilizing components such as underpile drag chain reclaimers, screw reclaimers, or radial stacker reclaimers, according to the fuel demands and available budgets for adaptation—including necessary redundancy or back-up for fail-safe operation.
Whether for direct or indirect co-firing, fuel feeds and boilers alike must be optimized to take the higher volume associated with biomass, as well as erosion and corrosion not common with coal, caused by foreign particles and impurities such as dirt and sand.
Given the scope and necessary capital investment for any biomass conversion, there is one quality that should be sought, above all others, in choosing a company to carry out the project: experience. Process Barron has over 20 years of experience in the field of biomass fuel systems, and can handle every stage of biomass adaptation, from design and engineering to installation, maintenance and repair. Visit our Biomass Solutions page on the web at http://processbarron.com/biomass.