Biomass briquettes
Biomass briquettes are a biofuel substitute to coal and charcoal. They are used to fire industrial boilers that produce electricity from steam. The most common use of the briquettes are in boilers when combined with coal in cofiring. This reduces carbon dioxide emissions by partially replacing coal used in power plants with materials that are already contained in the carbon cycle. Manufacturers mainly use three different types of ways to create the briquettes, each depending on the way the biomass is dried out. Although biomass briquettes are usually manufactured, biomass has been used throughout history all over the world from simply starting campfires to the mass generation of electricity.
Composition and Production
Biomass briquettes are made of green waste and are commonly used for electricity generation, for heat and as cooking fuel. These compressed compounds contain various sorts of organic materials, including rice husk, bagasse, ground nut shells, municipal solid waste, agricultural waste, or anything that contains a high nitrogen content. The actual composition of the briquettes varies by area due to the availability of raw materials. The raw materials are gathered and compressed into pellets in order to burn longer and make transportation of the goods easier [1]. These briquettes are very different from charcoal because they do not have large concentrations of carbonaceous substances and added materials. Compared to fossil fuels, the briquettes produce low greenhouse gas emissions because the material used is already a part of the carbon cycle.[2]
One of the most common variables of the biomass briquette production process is the way the biomass is dried out. Manufacturers can use torrefaction, carbonization, or varying degrees of pyrolysis.[3]
Compaction is another factor which has a profound effect on production. Some materials burn more efficiently if compacted at low pressures, such as corn stover grind. Other materials such as wheat and barley-straw require high amounts of pressure to produce heat.[4] There are also different press technologies that can be used. A piston press is used to create solid briquettes for a wide array of purposes. Screw extrusion is used to compact biomass into loose, homogeneous briquettes that are substituted for coal in cofiring. This technology crates a doughnut-like briquette. The hole in the center of the briquette allows for a larger surface area, creating a higher combustion rate.[5]
History
People have been using biomass briquettes in Nepal since before recorded history. The first commercial production plant was created in 1982 and produced almost 900 metric tons of biomass and more factories were created that were more efficient in 1984. They used a combination of rice husks and molasses. The King Mahendra Trust for Nature Conservation (KMTNC) along with the Institute for Himalayan Conservation (IHC) created a mixture of coal and biomass in 2000 using a unique rolling machine.[6]
In 1945, Japan started developing technology to harness the energy from sawdust briquettes, called Ogalite. This was done independent of the Nepal research. Japan increased production fourfold by developing screw press and piston press technology.[7]
Cofiring
Cofiring relates to the combustion of two different types of materials. The process is used to decrease CO2 emissions, but not halt them. The combination of materials usually contains a high carbon emitting substance such as coal and a lesser CO2 emitting material such as biomass. Even though CO2 will still be emitted through the combustion of biomass, the carbon sequestered is nearly negligible because the material gathered for the composition of the briquettes are still contained in the carbon cycle. Boilers in power plants are traditionally heated by the combustion of coal, but if cofiring were to be implemented, then the CO2 emissions would decrease while still maintaining the heat inputted to the boiler. Implementing cofiring would require few modifications to the current characteristics to power plants, as only the fuel for the boiler would be altered. Also, as cheap as coal is, a moderate investment would be required for implementing biomass briquettes into the combustion process. This is the most cost-efficient means of biomass, thus making co-firing a near-term solution for the greenhouse gas emission problem.[8]
Compared to Coal
The use of biomass briquettes has been steadily increasing as industries realize the benefits of containing pollution with favorable economics. Briquettes provide higher calorific value per dollar than coal used for firing industrial boilers. Along with higher calorific value, biomass briquettes on average saved 30-40% of boiler fuel cost. [9] However, in the long run, briquettes can only limit the use of coal to a small extent, but it is increasingly being pursued by industries and factories all over the world. Both raw materials can be produced or mined domestically in the United States, creating a fuel source that is free from foreign dependence and less polluting than raw fossil fuel incineration. [10]
Environmentally, the use of biomass briquettes produces much fewer greenhouse gases, specifically, 13.8% to 41.7% CO2 and NOX. There was also a reduction from 11.1% to 38.5% in SO2 emissions when compared three different types of coal. Biomass briquettes are also fairly resistant to water degradation, an improvement over the difficulties encountered with wet coal. However, the briquettes are best used as a supplement to coal to create a high energy fuel that emits fewer pollutants in a cofiring scenario.[11]
Usage In Undeveloped World
The Legacy Foundation has developed a set of techniques to produce biomass briquettes through artisanal production in rural villages that can be used for heating and cooking. These techniques were recently pioneered by Virunga National Park in eastern Democratic Republic of Congo, following the massive destruction of the Mountain Gorilla habitat for charcoal.[12]
Pangani, Africa, is an area covered in coconut groves. After harvesting the meat of the coconut, the indigenous people would litter the ground with the husks, believing them to be useless. The husks later became a profit center after it was discovered that coconut husks are well suited to be the main ingredient in bio briquettes. This alternative fuel mixture burns incredibly efficiently and leaves little residue, making it a good source for cooking in the undeveloped country.[13]
Usage in Developing World
Two major components of the developing world are China and India. The economies are rapidly increasing due to cheap ways of harnessing electricity and emitting large amounts of carbon dioxide. The Kyoto Protocol attempted to regulate the emissions of the three different worlds, but there were disagreements as to which country should be penalized for emissions based on its previous and future emissions. The United States has been the largest emitter but China has recently become the largest per capita. The United States had emitted a rigorous amount of carbon dioxide during its development and the developing nations argue that they should not be forced to meet the requirements. At the lower end, the undeveloped nations believe that they have little responsibility for what has been done to the carbon dioxide levels.
The use of biomass briquettes is strongly encouraged by issuing Carbon Credits. One Carbon Credit is equal to one free ton of carbon dioxide to be emitted into the atmosphere. India has started to replace charcoal with biomass briquettes in regards to boiler fuel, especially in the southern parts of the country because the biomass briquettes can be created domestically, depending on the availability of land. Therefore, constantly rising fuel prices will be less influential in an economy if sources of fuel can be easily produced domestically.[14]
Usage in Developed World
Coal is the largest carbon dioxide emitter per unit area when it comes to electricity generation. It is also the most common ingredient in charcoal. There has been a recent push to replace the burning of fossil fuels with biomass. The replacement of this nonrenewable resource with biological waste would lower the carbon footprint of grill owners and lower the overall pollution of the world.[15]
Citizens are starting to manufacture briquettes at home. The first machines would create briquettes for homeowners out of compressed sawdust, however, current machines allow for briquette production out of any sort of dried biomass.[16] Home production
The United States Department of Energy has financed several projects to test the viability of biomass briquettes on a national scale. The scope of the projects is to increase the efficiency of gasifiers as well as produce plans for production facilities.[17]
Reference List
- ^ "Feed Biomass." Biomass.net. Web. 30 Nov. 2010.
- ^ "Biomass Briquettes for Green Electricity Production." Bionomicfuel.com. 4 May 2009. Web. 30 Nov. 2010.
- ^ Chohfi, Cortez, Luengo, Rocha, and Juan Miguel. “Technology to Produce High Energy Biomass Briquettes.” Techtp.com. Web. 30 Nov. 2010.
- ^ Mani, Sokhansanj, and L.G. Tabil. “Evaluation of compaction equations applied to four biomass species.” University of Saskatchewan College of Engineering. Web. 30 Nov. 2010.
- ^ "Biomass Briquetting: Technology and Practices - Introduction." Centre for Ecological Sciences INDIAN INSTITUTE OF SCIENCE BANGALORE. Web. 04 Dec. 2010.
- ^ Ramesh Man Singh. “History of Bio-Briquetting .” brgcnn.net. 2008. Web. 30 November 2010.
- ^ "Biomass Briquetting: Technology and Practices - Introduction." Centre for Ecological Sciences INDIAN INSTITUTE OF SCIENCE BANGALORE. Web. 04 Dec. 2010.
- ^ PRABIR, B. and BUTLER, J. and LEON, M., "Biomass co-firing options on the emission reduction and electricity generation costs in coal-fired power plants", Renewable Energy, 36 (2011), 282-288. doi:10.1016/j.renene.2010.06.039
- ^ "Biomass Briquette." Www.gcmachines.com. Web. 30 Nov. 2010.
- ^ Yugo Isobe, Kimiko Yamada, Qingyue Wang, Kazuhiko Sakamoto, Iwao Uchiyama, Tsuguo Mizoguchi and Yanrong Zhou. “Measurement of Indoor Sulfur Dioxide Emission from Coal–Biomass Briquettes.” springerlink.com. Web. 30 November 2010.
- ^ Montross, Neathery, O'Daniel, Patil, Sowder and Darrell Taulbee. (2010). "Combustion of Briquettes and Fuels Pellets Prepared from Blends of Biomass and Fine Coal". International Coal Preparation 2010 Conference Proceeding (161-170). Google Books. Web. 29 November 2010
- ^ "How Biomass Briquettes Could Save the Endangered Mountain Gorilla" GreenUpgrader. 5 Mar. 2010. Web. 04 Dec. 2010.
- ^ "Bio-briquettes." Africanrootsfoundation.org. Web. 30 Nov. 2010.
- ^ "Biomass Briquette." Www.gcmachines.com. Web. 30 Nov. 2010.
- ^ “Biomass Briquettes.” Biomass.com. Web. 30 November 2010.
- ^ "AGICO - Biomass Briquette Machine." AGICO Biomass Briquette Machine. Web. 30 Nov. 2010.
- ^ "DOE Selects Projects to Advance Technologies for the Co-Production of Power and Hydrogen, Fuels or Chemicals from Coal-Biomass Feedstocks." United States Department of Energy. 18 Aug. 2010. Web. 04 Dec. 2010.
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