Calorific value experiment

If the same quantities of fuel and air were supplied to a calorific value experiment at Tq (Fig. 1.7) then the steady-flow energy equation for that process would yield... 

In an experiment to determine the calorific value of the fuel at temperature 1, . and for the same fuel flow the steady flow energy equation would yield... 

The USDOE experience has proven that there are three types of syngas, each with different calorific values. These are summarized in Table 6.1. 

Effective Calculated Calorific Values of Propellants. If it is assumed that for a certain muzzle velocity and a given projectile, the product of the charge weight and calorific value of a propint is constant, then by knowing the calorific value and wt of one propint, it is possible to calculate the calorific value of a second proplnr of a similar nature (if its chge wt had been previously deed experi men tally). For example, if for one propint the values were 820kcalAg and wt 4.3kg and for a 2nd propint Xkcal and 6.2kg, respectively, then... 

Being one of the leaders in this technique since 1974, Gaz de France has experimented gas mixing operations in 7 UGS facilities and has a wide experience in inert injection and more generally in mixing gases [7] [8], These operations take place under very different practical conditions and each of them was designed so that the withdrawn gas can be sent out without any specific operating constraints (calorific value) over several decades. 

Based on the preliminary experiments, the gasifier produces about 12 NmVh of product gas. This gas has a calorific value of approx. 5 MJ/Nm and contains approx. 20 %vol. CO and 20 %vol. H2. 

The gas flow increases after about IhSO, which corresponds to a temperature of about 320 °C, until 3hl0 (equivalent to a temperature of 480 C for the final pyrolysis ten erature of 550 °C and 750 "C), So, we ve a remarkable gas production during lh20. It is difficult to determine the best gas flow more experiments could be carried out for a finer analyse. We could also analyse the calorific value of these gas during the experiments (we have done it in order to not interfere with the pyrolysis process and in the general results). 

Results of the char analyses are given in Table II. They are only presented for two specific experiments since the characteristics did not vary considerably with reactor temperature or residence times. The calorific value of the straw char was higher than that of the stover char by about 20%. The calorific value of the straw char on a unit weight basis was about 1.6 times greater than the straw feed and the calorific value of the stover char was about 1.4 times greater than the stover feed. Further characterization of the char will be carried out in Phase II. Of particular interest are the burning characteristics, hygroscopicity, ash and acid insoluble ash content and measured calorific value. 

Energy in the char and gas averaged 77% of the gross calorific value of the feedstock. In these experiments, energy to pyrolyse the feedstock was supplied by propane. About 100 MJ were required to heat the kiln to 870 K. Another 121 MJ/h were required to maintain this temperature and 189 MJ/h were required to maintain a temperature of 1170 K. About 90% of this heat was lost in the exhaust and in an actual system most could be recovered for process heating. Calculations were made to predict thermal efficiencies of a self-sustaining system where a portion of the product is recycled and combusted to provide process heat thermal efficiencies of about 65% were predicted. 

It is interesting to compare these experiments with previous experiments on peat pyrolysis using the same unit. Ground sod peat with a degree of decomposition of 27% (Baturin formula - Baturin, 1975 H4 on the Von Post scale) was air dried to 12% moisture content and fed in at rates up to 18 kg/h (Campion, 1978). Yields and calorific values at reaction temperatures of 1120 K are compared with stover and straw pyrolysis at 1170 K in Table III. 

Five year old Ontario hybrid poplar was used during the experiments. It had a calorific value of 4700 cal/g and was hammermilled to a size range of 600 to 800 microns. The wood was then oven dried prior to gasification. 

In the early experiments that were made with water-gas mixtures in attempts to synthesize valuable organic liquids, methane apparently was the only product obtained until the effect of pressure was understood, after which the progress toward methanol synthesis was rapid. Aside from the work that had to do quite largely with the production of methane for the enrichment of water-gas or other low calorific value gaseous mixtures in countries without cheap oil, considerable attention has been paid to a study of the effects of various catalysts on the synthesis from the viewpoint of perfecting the methanol and higher alcohol syntheses. Processes have, at the same time, been proposed for the synthesis of liquid fuels from water-gas mixtures in an attempt to produce motor fuels from cheap coal. 

Experimental results on only the yield of methane in tests in the continuous flow unit are shown in Figure 12, a plot of the methane yield, expressed as percent of the calorific value of the coal converted into methane, vs. the precent of B.t.u. in coal converted to gas. The methane concentrations obtained in the flow unit are, as stated above, lower than those in the autoclave tests consequently, the points for the continuous flow experiments also lie below the autoclave correlation curve at all... 

Gas densitometers can measure, continuonsly and indirectly, the calorific value of natural gas, can accnrately control the calorific value of send-out town gas and can accurately monitor process gas. Comparison with conventional combustion-type calorimeters, based on actual experience at the works, reveals the tendencies shown in Table 5. 

The sample flow which is split off from the main stream is burned in the second component of the energy flowmeter. This second component is called a Flow-Titrator . The Flow-Titrator performs two functions. It controls the sample stream flow to maintain zero differential pressure at the flow separator. It also mixes the sample flow with a stoichiometric quantity of air and bnms the mixture. The Flow-Titrator design is patterned after the Therm-Titrator, which is a commercial instmment mannfactured by Precision Measurement Incorporated for measuring the calorific value of natural gas. It has been established in previous experiments that the ratio of the main flow to the sample flow is always the same and is independent of the flow magnitude or the gas composition. Thus the air flow in the Flow-Titrator is in direct proportion to the energy flow in the main hne. 

Since the lead smelter owned by OAO Kazzinc has ten years of experience in smelting lead-zinc sulphide concentrates by the Kivcet technology, a method of comparing physical and chemical properties of the bulk concentrate to the characteristics of typical lead-zinc raw materials has been developed. This method was used to decide on the feed composition and process operating conditions. Two major features of the bulk concentrate that affect the results of the smelting in the Kivcet unit were examined the calorific value and the desulphurization rate. 

Experiments on the Comparative Effect of dijferent Combustibles. Lavoisier examined the calorific values of coal, coke, charcoal, and wood by comparing the weights and prices of each required to evaporate 2800 lb. of water. 

The experiments were conducted in the flowthrough and circulation modes. In flowthrough mode, the optimal residence time of the gas—air mixture in the reaction zone was 0.14—0.16 s. The maximum yield of formaldehyde, achieved at a content of nitrogen oxides of 0.14—0.16%, was 2.4—2.8% with respect to methane, which corresponds to a formaldehyde content in the gas mixture of 0.80—0.93 vol %. The supplied air oxygen was oxidized only partially, its content in the collected gas was 11.5—12.5%. The discharge gas also contained 30—31% unreacted methane, 56—57% nitrogen, 1.0—1.5% carbon oxides, 1% water vapoiu, 0.1% nitrogen oxides, and trace amounts of formaldehyde. Its calorific value was 2800-3000 kcal/m. ... 

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