Prepare Furfural And Soil Conditioner From Bagasse By Means Of Microwave Pyrolysis

Wood cellulose as the main ingredient in agricultural and forestry biomass is the most abundant renewable resource in the land, it is not only the treasure of valuable natural polymer materials, but also the reserves of rich chemical energy and relatively complete plant nutrients. However, it is dangerous if we blindly use the biomass and do not consider the role of the biomass in the ecosystem cycle. Only the rational development and making full use of the biomass can we achieve and ensure the sustainable development goal. In this study, microwave pyrolysis of bagasse under different conditions was studied. Attempts were made to increase the yield of furfural in the liquid product and at the same time to recycle the solid char product as soil amendments. After a reasonable improvement of biochar, it could be used to prevent soil nutrient loss and destruction of soil organic matter balance caused by over-exploitation of biomass.The renewable lignocellulosic bagasse was used as the raw materials in this study, and microwave assisted pyrolysis processing technology was used to pyrolysis the bagasse. After comparing various methods, the UV-visible spectrophotometry was selected to determine the furfural content in the bio-oil. The influence of microwave power, reaction time and catalyst amount, etc. on the furfural yield in the bio-oil were systematic evaluated. When the red clay of the addition of bagasse dry weight between 0-200%, the red clay of the addition level of 100% dry weight of bagasse, the bagasse pyrolysis of furfural yield was 4% of dry weight, among the same groups it was significantly greater than other treatments.Based on the initial single factor experiments and then the complete response surface statistical analysis, the best process parameters obtained were:microwave power 900w, reaction time 33.7min,14.7% of the amount of phosphoric acid, and the red clay amount of 103.1%.The solid products from the microwave assisted pyrolysis were collected, and analyzed with the infrared spectrum and scanning electron microscopy. The infrared spectra showed the P-O-C stretching vibration of aliphatic. The esterification occurred between hydroxyl groups of wood cellulose and phosphate. The organophosphate in bagasse coke makes it possible to have the potential of being a slow release fertilizer. The infrared spectra of bagasse coke with the added red clay appeared to have an intensive absorbance of Si-C, indicating the formation of a stable organic-inorganic complex in mixture. The scanning electron microscopy also showed the mixture were porous, and there existed a new layer which is different either from the clay or the sugar cane coke between the coke and clay, indicating the existence of organic-inorganic complex in new clay and coke mixture.After neutralized with hydrated lime, the acidic bagasse coke become the soil conditioner which rich in organic and inorganic plant nutrients. A series of physical and chemical properties of the soil with the application of the red soil conditioner were measured in this study, including soil organic matter content, total nitrogen, rapidly available phosphorus, available potassium, cation exchange capacity, water content and pH. The results showed that using 100% red clay as the catalyst had the best effects on the adsorption of the decomposed organic matter during pryolysis. Red clay and bagasse mixture increased soil organic matter content, total nitrogen, rapidly available phosphorus, available potassium, cation exchange capacity and moisture content, improving the pH of soil. The physical and chemical properties of soil of the best cabbage potting were the control groups'4.5 times,1.5 times,26.5 times,9.8 times,1.2 times,11.2 times,1.3 times respectively.The practical effect of the soil amendments were tested using soybean, cabbage, pea and radish pot experiment in this study. The results showed that: (1)Red clay as a catalyst added to the bagasse pyrolysis can benefits the formation and accumulation of organic matter in the pyrolysis residues under high temperature condition. And 100% addition level gave the best results. (2)The soil amendments have significant improved effects:after the cabbage plants grown in soil for the second planting of peas showed significant differences, the plant height, fresh weight, dry weight, root wet weight, root dry weight of the best group were the control groups'1.4 times, 2.2 times,2.5 times,1.1 times,2.0 times respectively. (3)Soybean planting percentage, plant height, dry weight of aerial part, dry weight underground part, root nodule number, pod number per plant were increased by 33.3%,24.3%,115%,60%, 326% and 267% respectively in the soybean pot culture test. Drought survival rate of Chinese cabbage seedlings, plant height, fresh weight and dry weight of aerial part, the fresh weight of underground part were increased by 2.3 times,0.36 times and 12.3 times,6.8 times and 5.5 times.Combining the preparation of furfural and preparation of organic and inorganic biological soil amendments, is a useful attempt by both efficient use of biomass and conservation of soil fertility, it provides a new way for sustainable development of biomass refining.