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Fuel wood

Fuel. Wood, paper, coal, and gas are just a few of tlie products commonly tliought of as fuels. However, from a chemical standpoint, tlie conunon fuel elements are carbon (C) and hydrogen (H). Carbon is found in coal, coke, lignite, and peat. Otlier carbon fuels include fat, petroleum, and natural gas. Hydrogen is conunonly found in conjunction witli tliese carbon compounds. [Pg.204]

England suffers from timber and fuel wood scarcity. [Pg.1238]

What is the source of the vast amount of energy consumed by our mechanized society The largest of all of our energy sources is the sun, and energy from the sun is stored in our fuels (wood, coal, petroleum) as a result of the photosynthesis process. [Pg.430]

The burning of slash following deforestation, whether intentional or unintentional, results in far greater direct and indirect losses of nutrients than deforestation alone. This is particularly true in many tropical forests where only a small fraction (if any) of the aboveground biomass is removed prior to burning. Carbon losses from slash fires in the tropical dry forest were 4-5 fold greater than C losses from wood export (Table IV) (55). Slash fires in tropical dry forests resulted in N losses of 428-500 kg ha whereas fuel wood export of the relatively N-poor coarse woody debris amounted to approximately 41 kg N ha" Losses of P increase with increasing fire severity. P losses of 10-77 kg ha" as a result of severe fires is not uncommon (Table TV) (53, 58, 60). [Pg.439]

Table IV. Biomass and nutrient losses associated with wood harvest (fuel wood or timber export) and fire in selected forest ecosystems. Table IV. Biomass and nutrient losses associated with wood harvest (fuel wood or timber export) and fire in selected forest ecosystems.
If we look at the past 2000 years history of fuels, usage has consistently moved in the direction of a cleaner fuel wood —> coal —> petroleum —> propane —> methane as shown on the next page. [Pg.621]

Growing of different types of tree species (fruit, timber and fuel wood, medicinal, and aesthetic species) over time has been changing gradually. The fruit trees dominated much more over timber trees a few decades ago but the gap between them has diminished over time remarkably. A recent study conducted across the country showed that about 50 years ago, proportions of fruit and timber trees were 86% and 7%, respectively, which are now closer to 60% and 34%, respectively (Basak 2002). [Pg.447]

Global production of roundwood was 3335 million in 1999 (3352 million m in 2000), about 50 % of which was as fuel wood, of which 90 % was consumed in developing countries. Industrial roundwood production (1550 million m in 1999) was dominated by developed countries (79 % of total annual production). This trend will change, in particular with the emergence of China as a major economic force. [Pg.8]

The firing of fuel wood has been identified as one of the main causes of pollutant emissions from small-scale (<100 kW) combustion of wood fuels. The emissions are a result of insufficient combustion efficiency. This thesis presents a new measurement method to analyse the thermochemical conversion of biofuels in general, as well as to explain the main reason of the inefficient combustion of fuel wood in particular. [Pg.3]

The objectives of this project are consistent with the objectives (1) and (4) above. The general objective of this project has been to verify a new measurement method to analyse the thermochemical conversion of biofuels in the context of PBC, which is based on the three-step model mentioned above. The sought quantities of the method are the mass flow and stoichiometry of conversion gas, as well as air factors of conversion and combustion system. One of the specific aims of this project is to find a physical explanation why it is more difficult to obtain acceptable emissions from combustion of fuel wood than from for example wood pellets for the same conditions in a given PBC system. This project includes the following stages ... [Pg.14]

An experimental series showing the differences between fuel wood, wood pellets, and wood chips with respect to conversion behaviour as function of volume flux of primary air. [Pg.14]

The method was tested with two wood fuels, namely wood pellets and fuel wood. The mass flow of conversion gas was measured at three levels of standard volume flows of primary air (50,100, and 150 m n/h). Double tests were carried out at each volume flow of air. The mass-balance result is presented in Table 1 and Table 2 above. [Pg.34]

Three standard wood fuels have been studied (a) wood chips, (b) wood pellets, and (c) fuel wood. Figure 17 displays the three types of wood fuels. The fuel wood is from softwood, namely pine and spruce. Table 3 shows the wood fuel data. The moisture, ash and elementary analysis is carried out by an accredited laboratory in Sweden according to Swedish test standards (SS). [Pg.35]

Method Wood pellets Wood chips Fuel wood... [Pg.36]

Figure 18 displays mass flux curves plotted against time. This particular selection of curves shows the difference in conversion gas rates with respect to wood fuel. Wood chips are significantly easier to convert than 6 mm wood pellets, which in turn have higher mass flux of conversion gas than fuel wood for a given volume flux of primary air through the conversion system. [Pg.36]

Figure 19 shows the stoichiometric coefficient y versus time. The y-coefficient is the molar ratio between the amount of hydrogen in the conversion gas and the amount of carbon in the conversion gas. In this particular selection of y-graphs the dynamic ranges for the different wood fuels during a batch are fuel wood 3 0, wood pellets 2.6 0, and wood chips 2.4 0. These dynamic ranges are quite representative of the whole range of volume fluxes tested. [Pg.37]

The air factor curves of the conversion system look very much like the inverted mass flux curves, see Figure 21. As a matter of fact, they are negatively coupled, that is, if one goes up the other one goes down. This particular selection of graphs is representative for the whole test. Consequently, the air factors for the wood chips and the wood pellets were close to or below one, whereas the fuel wood in most of the cases were above one during the whole batch run. [Pg.38]

It can also be stated from Figure 22 that the wood chips have the highest range of conversion gas rates (50-90 g/m, s), whereas the fuel wood has the significantly lowest range of mass flux of conversion gas (12-31 g/m, s). [Pg.39]

As been demonstrated by the graphs above, the fuel wood is significantly more difficult to thermochemically convert than wood pellets and wood chips, at a given volume flux of primary air and for the conversion concept studied. The relatively low conversion gas rates should be one of the most crucial factors in the explanation of... [Pg.39]


See other pages where Fuel wood is mentioned: [Pg.1072]    [Pg.1072]    [Pg.5]    [Pg.39]    [Pg.16]    [Pg.188]    [Pg.347]    [Pg.433]    [Pg.438]    [Pg.439]    [Pg.448]    [Pg.187]    [Pg.76]    [Pg.9]    [Pg.33]    [Pg.446]    [Pg.447]    [Pg.449]    [Pg.452]    [Pg.452]    [Pg.454]    [Pg.35]    [Pg.47]    [Pg.805]    [Pg.3]    [Pg.10]    [Pg.11]    [Pg.40]   
See also in sourсe #XX -- [ Pg.114 ]




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