Study On Nitrogen-resistant Combustion-supporting Catalyst From Fly Ash

At present, countries all over the world involving China have stored more heavy oil and low-grade oil than before. The situation has not been significantly improved recently unless these resources can be used effectively, As projects of coal-to-oil and coke making launched, inferior oil with high nitrogen material from coal liquefaction ,coking gas oil ,other low-quality residue oil and or so was produced greatly .The inferior oil is difficult to complete combustion, and will produce smoke （soot and tar） causing environmental pollution. At the same time this process will decreased the heat efficiency of transfer burner, so that heavy equipment can not work properly because of corrosion. For this type of organic fuel,the general agent or promote burning, poisoning and loss of activity of the catalyst is easy to lose promoting burning performance.The anti-nitrogen flame retardants can promote an increase in the extent of such high nitrogen fuels, and combustion heat value of combustion efficiency and reduce soot emissions.In this paper, power plant emissions of solid waste - fly ash as raw material, the use of alkali-soluble extract of the Si element, and as anti-N anti-N-type matrix developed to promote burning agent.Firstly, chemical and phase analysis of fly ash, based on their chemical composition and phase characteristics, was made. The process of amorphous silicon extraction using NaOH solution under the conditions of low temperature avoids roasting process,and overcomes the low hydrogenalkali fusion of sodium oxide relatively large liquid to solid, while water consumption and SiO₂ dissolution rate is not high. Sodium hydroxide solution as the solvent, low atmospheric pressure response, was examined under a fixed ratio of ash alkali leaching temperature, alkali concentration, mixing time on the amorphous silica dissolution effect.Using orthogonal test method to determine the optimum conditions of extraction of amorphous SiO₂: NaOH concentration 8mol / L, alkaline ash mass ratio of 2:1, the reaction temperature is 95℃, reaction time was 6h.Then CO₂ gas precipitation method with the catalytic activity of SiO₂ is adopted . The temperature of carbon-carbon sub-divided silicon concentration on the substrate surface area, pore structure were discussed emphasisly. Experiments show that the activity of SiO₂ prepared surface area up to 730㎡/g.Better conditions for the silicon concentration of carbon is 45g / L, temperature 30℃, the CO2 gas was injected under the conditions of access activity of SiO₂ prepared surface area, wide pore size distribution and uniform and stable, with well-developed pore structure, experimental results show tahat this structure can increase the activity of SiO₂ catalytic properties, can be used in heterogeneous catalysis.The above ultra-stable Y zeolite matrix and the proportion of beating can be mixed （ie matrix + sieve）to combustion improver with alkali nitrogen .The results showed that the anti-N matrix and ultra-stable Y zeolite with rare earth metals cerium modified direct impregnation method （matrix + zeolite + active elements）, more pronounced catalytic effect to promote combustion, can reduce the coal liquefaction residue ignited and improve its combustion efficiency.When the content of 5% of its coal ,liquefaction residue burning is 8.4% decline and the combustion efficiency is 20.27%.