Pellet fuel (or pellets ) is a biofuel made from compressed or biomass organic matter. Pellets can be made from one of the five general categories of biomass: industrial waste and by-products, food scraps, agricultural residues, energy crops, and virgin timber. Wood pellets are the most common types of fuel pellets and are generally made from compacted sawdust and related industrial waste from wood milling, wood products and furniture manufacture, and construction. Other industrial waste sources include empty bunches, palm shells, coconut shells, and tree tops and twigs removed during logging operations. The so-called "black pellets" are made of biomass, refined to resemble hard coal and developed for use in existing coal-fired power plants. Pellets are categorized based on their calorific value, moisture content and ash, and their dimensions. They can be used as fuel for power generation, commercial or residential heating, and cooking. The pellets are very dense and can be produced with low moisture content (below 10%) allowing them to be burned with very high combustion efficiency.
Furthermore, regular geometry and its small size allow automatic feeding with very fine calibration. They can be fed to the burner via auger feeding or by pneumatic conveying. Its high density also allows for compact storage and long distance transport. They can be easily blown from a tanker to a storage bunker or a silo at the customer's premises.
Various pellet stoves, central heating furnaces, and other heating appliances have been developed and marketed since the mid-1980s. In 1997, a fully automated wood pellet boiler with the same level of comfort as an oil and gas boiler available in Austria. With the spike in fossil fuel prices since 2005, demand for pellet heating has increased in Europe and North America, and considerable industry has emerged. According to the International Energy Agency Task 40, wood pellet production has more than doubled between 2006 and 2010 to more than 14 million tonnes. In the 2012 report, the Biomass Energy Resources Center said that it expects the production of wood pellets in North America to double again in the next five years.
Video Pellet fuel
Produksi
Pellets are produced by compressing wood materials that have already passed through the hammer mill to provide a mass like a uniform dough. This mass is fed to the press, where it is squeezed through a hole that has the required size (usually 6 mm in diameter, sometimes 8 mm or more). High press pressure causes the temperature of the wood to greatly increase, and lignin polymorizes slightly, forming a natural "glue" that holds the pellets together when it cools.
Pellets can be made from grass and other non-woody biomass forms that do not contain lignin: distillers dried grains (brewing byproducts) can be added to provide the required durability. A 2005 news story from Cornell University News shows that grass pellet production is more advanced in Europe than North America. This shows the benefits of grass as a feedstock including short growth times (70 days), and ease of cultivation and processing. The story quotes Jerry Cherney, a professor of agriculture at the school, who states that grass produces 96% of the heat of wood and that "any grass mixture can be used, cut in mid to late summer, left in the fields to clean it, mineral, then baled and pellet.Reating straw is not required for pelleting, making processing costs less than with wood pelleting. "In 2012, the Nova Scotia Department of Agriculture announced as a convertible demonstration project from an oil-fired boiler to a grass pellet at a research facility.
Rice husk pellet pellet is made by tampering the rice husk obtained as a by-product of rice growing from the fields. It also has similar characteristics to wood pellets and is more environmentally friendly, since its raw material is a waste product. The energy content is about 4-4.2 kcal/kg and the water content is usually less than 10%. The size of pellets is generally maintained around 6mm in diameter and 25mm in length in the form of a cylinder; although larger cylindrical or briquette forms are not uncommon. This is much cheaper than similar energy pellets and can be compacted/manufactured from the skin on the farm itself, using inexpensive machines. They are generally more environmentally friendly compared to wood-pellets. In regions of the world where wheat is the dominant food crop, wheat bran can also be compacted to produce energy-pellets, with characteristics similar to rice-husk pellets.
The report by CORRIM (Consortium On Research on Renewable Industrial Materials) for the Lifecycle Inventory of Pellet Manufacturing and Wood Utilization estimates the energy required to dry, petroleze and transport less than 11% pellets of pellet energy content if using industrial waste is dry. If pellets are made directly from forest materials, it takes up to 18% of energy to dry wood and an additional 8% for transportation and manufacturing energy. The environmental impact analysis of wood pellets exported by the Department of Chemical and Mineral Engineering, University of Bologna, Italy and the Center for Clean Energy Research, at the University of British Columbia, published in 2009, concluded that the energy consumed to send Canadian wood pellets from Vancouver to Stockholm 15,500 km through the Panama Canal), about 14% of the total energy content of wood pellets.
Standard pellet
Pellet according to the norms commonly used in Europe (DIN 51731 or ÃÆ' - Norm M-7135) has less than 10% moisture content, which is uniform in density (higher than 1 ton per cubic meter, thus sinking in water) bulk density of about 0.6-0.7 tons per cubic meter), has good structural strength, and low dust and ash content. Because wood fibers are broken down by hammer factories, there is almost no difference in finished pellets between different wood types. Pellets can be made from almost any type of wood, provided that the pellets are equipped with good instrumentation, the differences in feed ingredients can be compensated in the press regulations. In Europe, the main production areas are located in southern Scandinavia, Finland, Central Europe, Austria, and countries Baltic.
Pellets according to European standard norms containing recycled wood or external contaminants are considered Class B Pellets. Recycled materials such as particle board, processed or painted wood, melamine-coated resin panels and the like are not particularly suitable for use in pellets, as they can produce harmful emissions and uncontrolled variations in pellet burning characteristics.
Standards used in the United States are different, developed by the Pellet Fuels Institute and, as in Europe, are not mandatory. However, many manufacturers comply, because the assurance of US-manufactured or imported combustion gear may not include damage due to non-compliant pellets. Prices for US pellets jumped during 2007-2008 fossil fuel price inflation, but then fell sharply and were generally lower on a per-BTU basis than most fossil fuels, excluding coal.
Regulatory bodies in Europe and North America are in the process of tightening emission standards for all forms of wood heat, including wood pellets and pellet stoves. These standards will become mandatory, with independent certified testing to ensure compliance. In the United States, new regulations beginning in 2009 have completed the EPA review review process, with new rules issued for comment on June 24, 2014. The American Lumber Standard Committee will become an independent certification body for new pellet standards.
Maps Pellet fuel
Dangers
Wood pellets, especially freshly made ones, are chemically active and can deplete the atmosphere of oxygen needed to sustain life. Wood pellets can also emit large amounts of toxic carbon monoxide. Fatal accidents occur in private storage rooms and on ships. When handled, wood pellets emit fine dust that can cause a serious dust explosion.
Operation pellet stove
There are three types of common heating pellets, free standing pellet stoves, pellet stove inserts and boiler pellets.
pellet stove "looks like a traditional wood stove but operates more like a modern furnace. [Fuel, wood or other biomass pellets, stored in a storage place called a hopper.) Hopper can be found on top of the tool, side or long distance.] A mechanical auger [automatically feeds] pellets into a burning pot, where they are burned at very high temperatures so they do not create clogged creosote and very little ash or emissions.. "Heat-exchange tubes ": Send the heated air into the room..." Convection Fan ": Circulate the air through the heat exchange pipes and enter the room... The biggest difference between the pellet stove and... woodstove, is that, inside, the stove pellets are high-tech devices with circuit boards, thermostats, and fans - all working together to [regulate temperature and] heat up your space efficiently. "
A pellet stove insert is a stove inserted into an existing stone fireplace or a prefabricated wood fireplace. See Install the fireplace
Pellet Boiler is a standalone central heating and hot water system designed to replace traditional fossil fuel systems in residential, commercial and institutional applications. Automatic or automatic pellet boilers include silos for bulk pellet storage, fuel delivery systems that drive fuel from silo to hopper, logic controllers to set the temperature in multiple heating zones and automatic ash eraser system for long automatic operation long.
The basket pellet allows one to heat their home using pellets in the stove or existing fireplace.
output and energy efficiency
The energy content of wood pellets is about 4.7 - 5.2 MWh/ton (~ 7450 BTU/lb).
High efficiency pellet stoves and wood boilers have been developed in recent years, usually offering a burning efficiency of over 85%. The latest generation of wood pellet boilers can work in condensation mode and therefore achieve a 12% higher efficiency rating. Wood pellet boilers have limited control over the rate and presence of combustion compared to liquid or gas-fired systems; However, for this reason they are more suitable for hydronic heating systems due to the greater ability of hydronic systems to store heat. Pellet burners that can be fitted to boilers using oil are also available.
Air pollution emissions
Emissions such as NO x , SO x and volatile organic compounds from pellet burning equipment are generally very low compared to other forms of heating combustion. A known problem is the emission of fine particles into the air, especially in urban areas that have high concentrations of pellet heating systems or coal or oil heating systems at close range. The PM Emission <2.5 sub/p> of this older pellet and boiler stove can be a problem at close range, especially compared to natural gas (or renewable biogas), although in large installations of electrostatic precipitators, cyclonic separators, or baghouse particle filters can control particulates when properly maintained and operated.
Global warming
There is uncertainty at what level makes heat or electricity by burning wood pellets contributing to global climate change, as well as how the impact on climate is compared to the impact of using competing heat sources. Factors in uncertainty include timber sources, carbon dioxide emissions from production and transportation as well as from final burning, and what time scale is appropriate to consider.
A report by the Manomet Center for Conservation Sciences, "Biomass Sustainability and Carbon Policy Studies" issued in June 2010 for the Massachusetts Department of Energy Resources, concluded that biomass combustion such as wood pellets or wood chips releases large quantities of CO2 into the air. , creating "carbon debt" that is not retired for 20-25 years and thereafter net benefits. In June 2011 the department was preparing to file its final regulations, expecting to significantly tighten controls on the use of biomass for energy, including wood pellets. Biomass energy advocates have debated the conclusions of the Manomet report, and scientists have shown negligence in the report, suggesting that climate impacts are worse than those reported.
Up to ca. 2008 is generally assumed, even in scientific papers, that biomass energy (including from wood pellets) is carbon neutral, mainly because vegetation regrowth is believed to reclaim and store carbon emitted into the air. Then, scientific papers studying biomass climatic implications are beginning to emerge that deny the simple assumption of carbon neutrality. According to the Biomass Energy Resources Center, the assumption of carbon neutrality "has turned into recognition that the implications of carbon biomass depend on how fuel is harvested, what forest types, what types of forest management are applied, and how biomass is used over time and across the landscape. "
In 2011, twelve leading environmental US organizations adopted policies that set a high bar for government biomass energy incentives, including wood pellets. It states that, "[b] iomass sources and eligible facilities for incentives (governments) should result in lower GHG, cumulative and net GHG life emissions and ocean acidification, within 20 years and also in the long run, rather than energy sources which they replace or compete with. "
Sustainability
The wood products industry is worried that if large-scale timber energy use is institutionalized, the supply of raw materials for construction and manufacturing will be significantly constrained.
Cost
Due to the rapid increase in popularity since 2005, the availability and cost of pellets may be a problem. This is an important consideration when purchasing a pellet stove, stove, pellet basket or other device known in the industry as Bradley Burners. However, the production of pellets is currently increasing and there are plans to bring some new online pellets factory in the US in 2008-2009.
The cost of pellets can be affected by the building cycle leading to fluctuations in the supply of sawdust and offcuts.
Per Office of Energy and Planning New Hampshire released on the updated Fuel Price on October 5, 2015, the cost of Fuel Oil # 2 shipped can be compared to the cost of Bulk Wood Fuel Pellets using their BTU equivalents: 1 tonne of pellets = 118, 97 gallons of Crude Oil # 2. It assumes that a ton of pellets produces 16.5 million BTU and one gallon of # 2 Oil Fuel produces 138,690 BTU. So, if Crude Oil # 2 shipped cost $ 1.90/Gal, the breakeven price for pellets is $ 238.00/Ton shipped.
Usage by region
Europe
Use across Europe varies due to government regulations. In the Netherlands, Belgium, and the UK, pellets are used primarily in large-scale power plants. The UK's largest power plant, the Drax power plant, converts some of its units into pellet pellets starting in 2012; in 2015 Drax has made Britain the largest recipient of wood pellet exports from the US. In Denmark and Sweden, pellets are used in large-scale power plants, medium-sized district heating systems, and small-scale residential heat. In Germany, Austria, Italy, and France, pellets are used primarily for small-scale residential and industrial heat.
The UK has initiated a grant scheme called Renewable Heat Incentives (RHI) that allows the installation of non-domestic and domestic wood pellet boilers to receive payments over a period of between 7-20 years. This is the first such scheme in the world and aims to increase the amount of renewable energy generated in the UK, in line with EU commitments. Scotland and Northern Ireland have separate but similar schemes. Beginning in spring 2015, biomass owners - both domestic and commercial - must purchase fuel from BSL (List of Biomass Suppliers) approved suppliers to receive RHI payments.
Pellets are widely used in Sweden, the main pellet producer in Europe, primarily as an alternative to central heating being fired with oil. In Austria, the leading market for central heating furnace pellets (relative to the population), estimated / 3 of all new domestic heating furnaces is pellet pellets. In Italy, a large market for automated pellet stoves has been developed. The main use of Italian for pellets is the small-scale residential and industrial boilers for heating.
In 2014 in Germany, the overall consumption of wood pellets per year consists of 2.2 million tons. These pellets are consumed mainly by the small-scale residential heating sector. Co-firing plants that use the pellet sector for energy production are not widespread in the country. The largest number of certified wood pellets with DINplus and these are the best quality pellets. As a rule, lower quality pellets are exported.
New Zealand
Total sales of wood pellets in New Zealand was 3-5,000 tons in 2003. The recent development of new wood pellet mills has provided a large increase in production capacity.
United States
Some companies import European-made boilers. In 2009, about 800,000 Americans used wood pellets for heat. It is estimated that 2.3 million tons of wood pellets will be used for heat in the US by 2013. Exports of US wood pellets to Europe grew from 1.24 million tons in 2006 to 7 million tons in 2012, but forests grew even higher.
Other uses
Horse bedding
When a small amount of water is added to the wood pellets, they expand and return to sawdust. This makes them suitable for use as a horse bed. The ease of storage and transport is an added benefit of traditional bedding. However, some wood species, including walnuts, can be toxic to horses and should not be used for bedding.
In Thailand, rice pellets are produced for animal beds. They have a high absorption rate that makes them ideal for that purpose.
Absorbent
Wood pellets are also used to absorb contaminated water when drilling oil or gas wells.
Cooking
Pellet wood grills have gained popularity as a versatile way of grilling, burning, and smoking. The size of the pellets makes it useful to create a wood-fired grill that still controls its temperature appropriately.
See also
- Solid fuel
- Heat that can be updated
- Pellet mill
- Pellet stove
- Woodchips
- Firelog
- Biochar
References
External links
- The European Biomass Association
- Institute of Pellet Fuels
- Biomass Energy
Source of the article : Wikipedia
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