Direct combustion

Direct Combustion. Direct combustion of oil shale has been used to produce heat for power generation at specific sites and is being carried out in Estonia and Israel. 

Shale ok production in the former Soviet Union is also declining. The orky significant shale ok operations are in Estonia. Most of the rich (208 L/1 (50 gal/short ton)) Estonian ok shale is combusted directly as fuel. 

Dubau L. 2002. Electrocatalyseurs platine-mthenium nanodisperses pour une pile a combustion directe de methanol. PhD Thesis, University of Poitiers, Prance. 

The dry combustion-direct injection technique provides many advantages over other methods, such as quick response and complete oxidation for determining the carbon content of water. Its primary shortcoming is the need for rapid discrete sample injection into a high-temperature combustion tube. When an aqueous sample is injected into the furnace, it is instantaneously vapourised at 900 °C and a 5000-fold volume increase can be expected. Such a sudden change in volume causes so-called system blank and limits the maximum volume of injectable water sample, which in turn limits the sensitivity [106,107]. 

A dry combustion-direct injection apparatus was applied to water samples by Van Hall et al. [51 ]. The carbon dioxide was measured with a non-dispersive infrared gas analyser. Later developments included a total carbon analyser [97], a diffusion unit for the elimination of carbonates [98], and finally a dual tube which measured total carbon by combustion through one pathway and carbonate carbon through another. Total organic carbon was then calculated as the difference between the two measurements [99]. 

Sharp [48] has described a dry combustion-direct injection system built for oceanographic analyses. This unit used 100 xl samples, injected into a 900 °C oven in an atmosphere of oxygen. The output from a non-dispersive infrared carbon dioxide analyser was linearised and integrated. 

Thermophotovoltaic systems convert the radiant energy produced by fuel combustion directly into electricity. Snch systems can potentially attain high overall conversion efficiencies. Because they may use renewable as well as fossil fnels, they permit a smooth pathway for an environmentally benign method of electrical energy generation (Catalano, 1996). 

An understanding of the environmental fate of these elements is necessary in the total assessment of associated health risks. Mercury is known to cycle between the geosphere and biosphere (35). Once in the hydrosphere, it can be converted by sediment flora into highly toxic methylmercury whereupon it is incorporated into aquatic life and ultimately accumulates in human food chains (31). Limited bacterial conversion of inorganic to organic mercury has been shown to occur in soil humus (36) and in animal tissue as well (37). There is no evidence that alkylated mercury is generated from coal combustion directly if it did it would probably be dissociated to the elemental form (14). 

Epoxybutane and tetrahydrofuran both have the molecular formula C4HgO—that is, they are constitutional isomers—and so it is appropriate to compare their heats of combustion directly. Angle strain from the three-membered ring of 1,2-epoxybutane causes it to have more internal energy than tetrahydrofuran, and its combustion is more exothermic. 

The total carbon contents of a variety of fines, breccias and crystalline rocks have been measured by a number of investigators S4 63) Samples were either combusted directly in an oxygen atmosphere to CO2 or first heated in vacuo and the gases released converted to C02. Fig. 2 summarises the data obtained by Moore et al.7 S4-56) for Apollo 11 to Apollo 15 samples and the following general conclusions may be drawn64-1 ... 

Co-combustion Direct Coal mixed with biomass... 

UNA is investigating the installation of pyrolysis units from Pyrovac, with a total capacity of 120 kton/a at the Hemweg power plant. With this so-called Pyrocycling process the main objectives are to produce char and oil, which can be co-combusted directly with the pulverised coal or, if desired, be stored and co-combusted later at Hemweg or at another power plant. 

The results are usually outlined in the diagrams as NO, emissions of the combustion reactor related to 6 % O2 in the flue gas over the fuel mass flow rate of the pyrolysis process. The higher the fuel mass flow rate of the pyrolysis process the more pyrolysis gas and thus rebum fuel is injected into the combustion. Directly related to the flow rate of the pyrolysis gas into the combustion is the air ratio in the reduction zone of the combustion reactor. The outline of the NO, emissions over the air ratio describes the rebum efficiency of the injected gas, whereas the outline over the fuel mass flow rate gives information on the biomass ratio on the overall process. 

The projected Fiscal Year 1980 Biomass Energy Systems Program budget for thermochemical conversion activities (direct combustion, direct liquefaction, gasification and indirect liquefaction) is approximately 17 million. 

The standard state of each element is defined as the most stable form at 1 atm and the temperature specified (most frequently enthalpies of formation are measured and quoted at 298 K), The direct reaction cannot conveniently be carried out, but it is relatively easy to measure the enthalpy of combustion of methane in an apparatus called a flame calorimeter. As AH = q)p (Section 2.7), when methane is burnt with oxygen the heat produced gives the enthalpy of combustion directly,... 

Approximately 6% of the battery weight is carbon. This will either be combusted directly adding to the available energy, or dissolve in the steel bath where it will be oxidised by injected oxygen prior to tap. In both cases, it is a useful addition to, or replacement for, charge carbon that is typically added at the rate of 0.5 to 2% of the scrap weight. 

Bio-briquette combustion decreases the generation of dust and soot to one-fifth to one-tenth that of direct coal combustion. Direct coal combustion increases the generation of dust and soot because the volatile matter released at low temperatures (200°C-400°C [390°F-750°F]) does not completely combust To the contrary, bio-briquettes simultaneously combust the low ignition point biomass, which permeates the coal particles, assuring the combustion of volatile matter at low combustion tanperatures. As a result, the amount of generated dust and soot is significantly reduced. 

Direct Firing. The firing of pottery or vitreous enamelware in a fuel-fired kiln or furnace without protection of the ware from the products of combustion. Directional Solidification. This is a technique for preparing lamellar or fibrous composites of ceramics and/or metals by growth from a molten eutectic... 

The changes that may affect the value of stored coal are loss in heating value, reduction of coking power, reduction of average particle size (weathering or slacking), and, most important, losses from self-ignition or spontaneous combustion. Direct loss of stored coal by wind or water erosion is possible and may become a serious nuisance. 

METHOD 80 - DETERMINATION OF SULPHUR IN POLYMERS. OXYGEN FLASK COMBUSTION - DIRECT TITRATION PROCEDURE. 

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