| In recent years, the biomass as a kind of renewable energy are paid great attention by people. It can be used as a supplementary of primary energy. Biomass pyrolysis technology is one of the most important direction of biomass utilization at home and abroad. Biomass pyrolysis gas has been applied in rural areas such as gas supply, centralized heating and power generation. But the raw material problem is the key problem how to use biomass efficiently. Mushroom bran is waste of mushroom cultivation and it has characteristics such as origin concentration, particle size uniform,low moisture content and easy to industrialization. The efficient utilization of mushroom bran, which can reduce the cost of mushroom cultivation, increase the overall economic benefit of planting mushrooms. It can also will exert positive effects on rural ecological environment improvement, etc.The paper mainly studies the key technical problem in the process of mushroom bran pyrolysis. Research work mainly includes the elemental analysis, industrial analysis, calorific value and the alkali metal ion content of mushroom bran and sawdust. The change rule of pyrolysis temperature in the middle of pyrolysis furnace when mushroom bran and sawdust pyrolysis. What effects the pyrolysis terminal temperature make on pyrolysis product yield distribution, pyrolysis gas composition and gas nature of mushroom bran and sawdust. Pyrolysis gas composition of different warming stages in the pyrolysis process. Pyrolysis regularity of mushroom bran and sawdust has been compared. Detemining pyrolysis gas composition and pyrolysis char adsorption parameters, then the pore structure of pyrolysis radius were observed by electron microscopy.The following conclusions are concluded through experiments. In the process of mushroom cultivation, the cellulose, hemicellulose and lignin of mushroom bran made by sawdust under the action of enzyme is degraded to varying degrees, the lignin which pyrolysis difficultly has the biggest amount of degradation. The mushroom bran best pyrolysis temperature is 700 ?. However, in order to get higher gas production rate, the temperature can be raised to 900 ?.At this time, the pyrolysis gas production rate is 56%, the tar production rate reduced to 17%, the carbon yield of28%.When the pyrolysis temperature above 700 ?, the hydrogen and carbon monoxide content increase rapidly and methane decrease. Pyrolysis gas calorific value remains the same and low calorific value is 11 MJ/m3.At 300? to 350? in the process of pyrolysis, there was a exothermic reaction area, at this time the reactions violently. In order to get high quality gas, tar and char, studying the pyrolysisconditions respectively are necessary. The content of cellulose, hemicellulose, and lignin in the biomass and structure density at different levels lead to different heat transfer rate have effect on the pyrolysis. Inherent metal ions in the biomass have impact, too. Studies have shown that the influence of the former than the latter.Mushroom bran calorific value is about two-thirds of wood. The content of fixed carbon and moisture is basic equal. In mushroom bran, volatile content is decreased and ash content is increased. The content of K ion in mushroom bran is only 1/17 of sawdust; Na ion is 1/2;Ca ion is 1/6.7;Mg ion is 1/17 and Fe ion content is basic equal.Mushroom bran pyrolysis gas production rate and carbon yield were greater than sawdust, and oil production rate is less than sawdust.To sum up, the mushroom bran is available biomass resources with high quality.The paper work is just the preliminary exploration in the utilization of mushroom bran pyrolysis and it will provide theoretical basis and technical support for the subsequent application. |
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