Category Archives: Cellulosic Energy Cropping Systems

Co-Fired Combustion

Co-flred combustion involves using biomass to supplement the primary feed, typically coal or natural gas. Two methods of co-firing biomass exist. The first method, direct co­firing, involves biomass being co-fed directly into the boilers with the coal or natural gas. Direct co-fire technology allows up to 20% of the feed to be supplied by biomass without significant changes to the […]

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Energy Density

Energy density, often termed “heating value”, refers to the amount of energy released per unit fuel combusted, usually measured in terms of energy content per unit mass for solids (e. g. MJ/kg) and per unit volume for liquids (e. g. MJ/l). Energy density can be expressed in two forms, higher heating value (HHV) or lower heating value (LHV). HHV represents […]

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Biocatalysis

Alternatively, the transformation of organic compounds into all kind of industrial products can also be performed by biocatalysis. Biocatalysis can be defined as the use of biolo­gical systems (including whole cells or isolated components thereof, natural and modi­fied enzymes and catalytic antibodies) to perform chemical transformations on organic compounds [31-33]. Millions of years of evolution have created thousands of microorgan­isms […]

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Repowering

Repowering is the option of replacing existing equipment with new technology. The United States has roughly 1400 operating coal-fired generating units producing almost 2 billion MWh of electricity per year [1]. By 2015, more than 90% of those units will be over 30 years old. Furthermore, in addition to producing almost 50% of the United States’ electric power, these older […]

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Catalysis

The transformation of organic compounds into all kind of industrial products can also be done using chemical catalysts. Chemical catalysis uses an added — but not consumed — sub­stance to augment a chemical reaction. Catalytic conversion will be a primary tool for indus­try to produce valuable fuels, chemicals, and materials from biomass platform chemicals.

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Direct Hydrothermal Liquefaction

Direct hydrothermal liquefaction involves converting high-moisture biomass to an oily liquid. Depending on the biomass used, the resulting bio-oil can have a heating value com­parable to bunker crude oil (30-40 MJ/kg). The resulting oil can be burned in boilers or upgraded and refined into higher value fuel or chemical compounds. Direct hydrothermal liquefaction works by contacting biomass with water at […]

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Ash Content

Conversion of biomass feedstock, either thermochemically or biochemically, results in a solid residue. In themochemical processing via combustion in air, the residue consists solely of ash. For biochemical processing, it contains both ash and other unconverted material, especially lignin. The bioprocess residue can be further processed thermochemically to yield ash as the final solid residue. The ash content negatively affects […]

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Thermochemical Conversion Route

Alternatively, biomass can be converted into fuels and chemicals indirectly (by gasification to syngas followed by catalytic conversion to liquid fuels or basic chemicals) or directly to a liquid product by thermochemical means such as pyrolysis or liquefaction. Thermochemical conversion processes use heat and pressure to convert biomass into liquid, bio-oil or gaseous intermediates. These intermediates, such as syngas and […]

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