Low calorific value

A low calorific value gas, which includes nitrogen from air, could be produced for boiler or turbine use in electric power production, or an intermediate calorific value gas containing no nitrogen for an industrial fuel gas, or synthesis gas for chemical and methane production could be provided. This approach which has been studied in Russia, Europe, Japan, and the United States, is stiU noncommercial in part because it is not economically competitive. 

Clinker treatments are additives designed to reduce the amount of clinkering formations that takes place in boilers fired by bark, bagasse, and similar low-calorific-value fuels. These fuels can give rise to considerable amounts of noncombustible deposits that must be continuously or regularly removed from the furnace area. Clinker treatments are formulated for use with various types of furnace, including slant, pin hole, and chain grate furnaces. 

The use of air alone leads to a relatively low calorific value product gas, of the order of 4-6 MJ/mi (LHV basis), which is not attractive for H2 production in view of the large bulk of N2 to be separated from it compared to a preseparation from the air. Only the application of hydrogen in ammonia production would need N2 as cofeedstock. Therefore, in this context only steam- or oxygen-blown gasification concepts are dealt with. The raw product gas can, thus, be produced by an oxygen-blown or indirectly heated steam-blown processes. 

Low-antimony lead alloys, 14 770 Low-birefringence polycarbonates, 19 822 Low-blush copolymers, 26 538 Low boiling node, in separating nonideal liquid mixtures, 22 303 Low-calorie beer, 3 577 Low calorie sweeteners, 12 38 Low calorific value (LCV) gas, 26 575—576... 

The kerogen content of different oil shales, i.e., the average yield of oil of an oil shale can vary greatly. Most oil shales have oil yields between 50 and 150 1 oil/t oil shale, rich shales may even yield more than 200 1/t. A particular characteristic of oil shale is its high areal density, which can exceed 1 million b/acre at its thickest (Bunger et al., 2004). Oil shale can also be used directly as fuel for electricity generation, as, for instance, in Estonia. However, oil shale is characterised by a low calorific value between 7.5 and 9 MJ/kg (based on LHV), which is about one fifth of the energy content of crude oil (Porath, 1999). 

Advantages of MtrTN are low volatility, low calorific value (which means less erosion of gun barrels) and a good degree of flashlessness. The Italian Navy was greatly impressed by the considerably reduced. flash in Metriolo propellenti ... 

He introduced before WWII the low calorific value propellants (such as G" Pulver) by substituting DEGDN TEGDN for NG. He also introduced NGu (Nitroguanidine) as a cooling agent and this propint became known as Gudolpulver... 

The temperature of the propellent gases depends on the heat of explosion and on the gas composition. The greater the heat of explosion, and hence the temperature of gases, the more readily the secondary flame arises. Powders of a low calorific value may therefore give, no secondary flame if the temperature of the gas mixture is lower than the temperature of ignition. 

The proven reserves of the Georgian sub-bituminous coal approximately amount to 354-404 Mt, and the lignite reserves are 71-76 Mt. Owing to its high ash content - up to 35-40 % - and its volatile content the Georgian coal is hampered with a relatively low calorific value (11.3-18.0 MJ/kg) (see Figure 7 [30]). 

Jerusalem artichoke tubers contain little or no starch, virtually no fat, and have a relatively low calorific value. Of the small amount of fat present, trace amounts of monounsaturated and polyunsaturated fatty acids have been reported, but no saturated fatty acids (Whitney and Rolfes, 1999). The polyunsaturated fatty acids linoleic (18 2 cis, cis n-6) and a-linoleic acid (18 3 n-3) have been recorded as present at 24 mg and 36 mg-100 g 1 of raw tuber, respectively (Fineli, 2004). The tubers are a good source of dietary fiber, because of the presence of inulin. 

The cyclone combustion chamber. Here the air is injected tangentially into a usually cylindrical chamber and exhausts through a centrally located exit hole at one end. The cyclone combustors are usually used to bum eflBciently diflBcult-buming materials such as high-ash-content and brown coals, anthracite, high-sulFur-content oils, damp vegetable refuse, poor-quahty-low-calorific-value fuels, etc. 

Possum, M., Beyer, R.V., (1998) Co-Combustion of natural gas and low calorific value gas from biomass. SINTEF Energy Research, Report prepared for lEA Biomass Gasification Activity, Trondheim. 

Of course, also other aspects of pressurised fluidised bed gasification were studied, like tar composition in the generated low calorific value (LCV) gas and carbon conversion. The ignition of the LCV gas during pressurised combustion of the LCV gas was also of interest. Besides the fuel, the main process parameters were the applied air stoichiometry and operating pressure. 

The DWSA installation can be divided into two main parts. The first part consists of an air preheater, fluidised bed reactor, solid fuel dosing vessel with on-line mass determination system and a hot gas cleaning section, containing a cyclone and a ceramic candle filter (Schumacher type). In the fluidised bed reactor the solid fuel is gasified with air to produce a low calorific value (LCV) gas that is cleaned of fly ash and unreacted solid carbonaceous material. Air and also additional nitrogen can be preheated and is introduced into the reactor by four nozzles just above the distributor plate. The reactor is electrically heated in order to maintain a constant temperature over bed as well as freeboard section. The solid fuel is fed into the bed section in the bottom part Just above the distributor by a screw feeder from beside. The hot gas cleaning section ensures a good gas-solid separation efficiency, with filter temperatures of about 500 C. 

Hoppesteyn P.D.J, (1999) Application of Low Calorific Value Gaseous Fuels in Gas Turbine Combustors. DPhil thesis, Technical University Delft. 

The gas generated is burned in the combustion chambers and expands through the gas turbine, generating 4.2 MW of electricity. The gas turbine is a single-shaft industrial gas turbine. The fuel supply system, fiiel injectors and the combustors have been redesigned to suit the low calorific value gas (5 MJ/nm ). 

Andrics J. Hoppestcyn P. D. J. (1997) Pressurized combustion of biomass-derived low calorific value, fuel gas. In Biomass, Gasification and Pyrolysis, (Ed. by M. Kaltschmitt A. V. Bridgwater), pp. 1282-291. 

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