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An Introduction to Biorefinery

Image by EMSL via Flickr A biorefinery is a facility that integrates biomass conversion processes and equipment to produce fuels, power, and value-added chemicals from biomass. The biorefinery concept is analogous to today’s petroleum refinery, which produces multiple fuels and products from petroleum.By producing several products, a biorefinery takes advantage of the various components in biomass and their intermediates, therefore maximizing the value derived from the biomass feedstock. A biorefinery could, for example, produce one or several low-volume, but high-value, chemical products and a low-value, but high-volume liquid transportation fuel such as biodiesel or bioethanol. At the same time, it can generate electricity and process heat, through CHP technology, for its own use and perhaps enough for sale of electricity to the local utility. The high value products increase profitability, the high-volume fuel helps meet energy needs, and the power production h...

Biomass Combined Heat and Power Generation

Image via Wikipedia Biomass conversion technologies transform a variety of wastes into heat, electricity and biofuels by employing a host of strategies. Conversion routes are generally thermochemical or biochemical, but may also include chemical and physical. Physical methods are frequently employed for size reduction of biomass wastes but may also be used to aggregate and densify small particles into pellets or briquettes. A wide range of conversion technologies are under continuous development to produce biomass energy carriers for both small and large scale energy applications. Combustion is the most widely used technology that releases heat and can also generate power by using boilers and steam turbines. The simplest way is to burn the biomass in a furnace, exploiting the heat generated to produce steam in a boiler, which is then used to drive a steam turbine. At the smaller scale, biomass pellet and briquette combustion systems mainly used for domestic and industrial hea...

Biomass Energy in Southeast Asia

The rapid economic growth and industrialization in Southeast Asia is characterized by a significant gap between energy supply and demand. The energy demand in the region is expected to grow rapidly in the coming years which will have a profound impact on the global energy market. In addition, the region has many locations with high population density, which makes public health vulnerable to the pollution caused by fossil fuels. Another important rationale for transition from fossil-fuel-based energy systems to renewable ones arises out of observed and projected impacts of climate change. Due to the rising share of greenhouse gas emissions from Asia, it is imperative on all Asian countries to promote sustainable energy to significantly reduce GHGs emissions and foster sustainable energy trends. Rising proportion of greenhouse gas emissions is causing large-scale ecological degradation, particularly in coastal and forest ecosystems, which may further deteriorate environmental sustainabi...

Utilization of Biogas and Digestate

An anaerobic digestion plant produces two outputs, biogas and digestate; both can be further processed or utilized to produce secondary outputs. Biogas can be used for producing electricity and heat, as a natural gas substitute and also a transportation fuel. A combined heat and power plant system (CHP) not only generates power but also produces heat for in-house requirements to maintain desired temperature level in the digester during cold season. CHP systems cover a range of technologies but indicative energy outputs per m3 of biogas are approximately 1.7 kWh electricity and 2.5kWh heat. The combined production of electricity and heat is highly desirable because it displaces non-renewable energy demand elsewhere and therefore reduces the amount of carbon dioxide released into the atmosphere. In Sweden, compressed biogas is used as a transportation fuel for cars and buses. Biogas can also be upgraded and used in gas supply networks. The use of biogas in solid oxide fuel cells is bei...

Woody Biomass Conversion Technologies

There are many ways to generate electricity from biomass using thermo-chemical pathway. These include directly-fired or conventional steam approach, co-firing, pyrolysis and gasification. 1. Direct Fired or Conventional Steam Boiler Most of the woody biomass-to-energy plants use direct-fired system or conventional steam boiler, whereby biomass feedstock is directly burned to produce steam leading to generation of electricity. In a direct-fired system, biomass is fed from the bottom of the boiler and air is supplied at the base. Hot combustion gases are passed through a heat exchanger in which water is boiled to create steam. Biomass is dried, sized into smaller pieces and then pelletized or briquetted before firing. Pelletization is a process of reducing the bulk volume of biomass feedstock by mechanical means to improve handling and combustion characteristics of biomass. Wood pellets are normally produced from dry industrial wood waste, as e.g. shavings, sawdust and sander dust. Pelle...

A Glance at Biomass Energy

The electricity generation capacity of renewable resources reached an estimated 240 gigawatts worldwide in 2007. Renewable resources represent 5 percent of global power capacity and 3.4 percent of global power generation. Renewable energy supplies 18 percent of the final energy consumption worldwide, counting traditional biomass, large hydropower, and "new" renewables (small hydro, modern biomass, wind, solar, geothermal, and biofuels). Traditional biomass, primarily for cooking and heating, represents about 13 percent and is growing slowly or even declining in some regions as biomass is used more efficiently or replaced by more modern energy forms. Large hydropower represents 3 percent and is growing modestly, primarily in developing countries. New renewables represent 2.4 percent and are growing very rapidly in developed countries and in some developing countries. Clearly, each of these three forms of renewable energy is unique in its characteristics and trends. Biomas...