|
||||||||||||||||||||||||||||
|
||||||||||||||||||||||||||||
|
We are looking for importers and end buyers of wood pellets produced from Southern Yellow Pine the following specification: White pellet, less than 1% bark content. Moisture content of 7 - 10% Ash content of approximately 0.5% Energy content of 17.2 GJ/mt (4.8mwh/t) Cylindrical shape. Dimensions: Diameter: 8mm Length: Max. 32mm No chemicals added. Packing - in bulk Quantity- 20000 mt every 45 days. The Pellets are a modern form of densified biomass offering interesting opportunities for development of Renewable Energy in Europe. The market exists for domestic pellet heating but also boilers at commercial and industrial levels and finally for large scale plants, using pellets for electricity and/or heat production. The actual European technology is leading this sector. This solid fuel is actually mainly produced by wood residues but should also be produced by mixed biomass residues through a quite simple process of milling, drying and compacting. The main advantage of compactation is the high density of the product in comparison with the other unprocessed biomass and therefore containing a high energy content. It also enables the production of a standardised fuel and reduction in the cost of handling, storage and transport. The cheap process technologies already exist and are highly competitive in comparison with the fossil fuels. Actually, around 1,4 tons oil equivalent per dwelling is used in Europe for households (EEA, 2008). The development of pellets seems very important in order to improve the energy security and emission saving in Europe. The primary target group is professionals on all levels such as producers and distributors of pellets, plant manufactures, energy consultants’ etc. Moreover the handbook gives the consumers an easy to use guide to the pellet market. All together this will increase the transparency of the pellet market and create increase the competition on quality, plants and services for the benefits of producers and consumers on all levels. The quality of fuel pellets may vary considerably. Factors that have an influence on pellet quality include the raw material, durability and water content. The quality of the wood pellets can be difficult to assess and therefore the consumer should make sure that the manufacturer delivers a product that meets a series of minimum standards. This chapter describes: * Different types of fuel pellets * The influence of the wood pellet quality on distribution, handling, combustion, environment and economy * Demands on the quality of wood pellets * Tools for the consumer to evaluate the quality of wood pellets * Future developments in standardisation and certification The dimensions of fuel pellets vary between 3 and 25 mm in diameter depending on the die block that is used in production. The length generally varies between 5 and 40 mm. If the product exceeds 25 mm in diameter it is called a briquette. Heating with wood pellets is normally quite simple and the need for inspection and care of the burner and boiler is often limited. However, combustion problems can arise e.g. if the amount of ash increases causing the system to slag and the efficiency to decrease. These problems are often caused by wood pellets of low quality or by the wrong choice of plant or system settings. If the pellets are dark it can be because they contain a dark type of wood or bark, but it may also be caused by blackened wood, caused by an intense drying of a wet/humid raw material. A number of European Pellet Standards are in existence. A pan European standard CEN/TC 335 for biomass is also being developed and will replace the voluntary UK standard for premium pellets as developed by British Biogen before it merged with the Renewable Energy Assocation. At present in the European categorisation for premium pellets are: * Size between 4 & 20mm * Ash content either <1% (Low), <3% (Standard) or <6% (High) to be clearly labelled * Moisture content below 10% Calorific value > 4.7kWh/kg * Bulk density > 600kg/m Sulphur content < 300ppm, Chlorine <800ppm * Only additives lignin and trace amounts of vegetable oil as a die lubricant An important factor for the quality of the fuel pellets is the content of dust in the product. Dust can arise during the production of the pellets, handling at the plant and during transportation. Dust that arises during production is normally removed by the manufacturer, but other sources of dust can cause problems. The dust hinders the pellets from moving, which can lead to bridge formation over the screw conveyor in the pellet silo. Dust and pellets are easily separated during handling and storage. This gives a heterogeneous material which causes an uneven fuel supply. Normally, the smaller the plant the more sensitive it is to pellet dust. The durability of fuel pellets is of high importance to the consumer. Wood pellets with a low durability are particularly sensitive to mechanical stress during transportation and when handled by the consumer, which results in the formation of dust. The durability is amongst other things determined by the content of lignin and water and how hard the pellets were pressed. As moisture content has a great influence on durability pellets must be stored in a dry place. The content of water in the pellets is often between 5-10 % of total weight. The water content of wood pellets is significant to the heating value, which in wood pellets often lies between 4.7 and 5.0 MWh/tonne wood pellets. The large variation in water content which occurs in wood chips, does not occur in wood pellets. This is because it is not possible to pelletise material with a water content above 15 %. Furthermore, the pellets will swell and fall apart if they are exposed to humidity after pressing. Origin: Russia, Ukraine, Belarus, U.S.A., Canada, Brasil, China Раздел: Главная / English / Import from Russia / Wood pellets |
|
|
|||||||||||||||||||||||||
| Russian exporters and Russian importers. IGOR V. ALEKSEEV s.p. | ||||||||||||||||||||||||||||
2010-07-26