Directional Pyrolysis Of Organic Solid Waste For In-situ Carbon Production

With the progress and development of society,the treatment of organic solid waste is facing great challenges.The pyrolysis technology can not only reduce the generation of pollutants,but also obtain high-quality additional products.The carbon obtained by thermal decomposition of organic solid waste generally has complex and rich pore structure and is often used as adsorbent and soil conditioner,which is a very useful pyrolysis product.In this paper,different kinds of organic solid waste(biomass organic solid waste and garbage organic solid waste)are selected as the research object,and the different pyrolysis characteristics and properties of pyrolytic carbon are studied,and finally the research method of producing high-quality carbon is obtained.Sawdust is a kind of material widely existing in organic solid waste at present,and it has been proved that modified pretreatment of organic solid waste can produce high quality pyrolysis products.The results showed that the yield of pyrolysis carbon of fermented sawdust decreased from 25%to 18.5%at 800℃,and the specific surface area decreased from 14.27m2/g to 10.14m2/g.However,the apparent activation energy of fermented sawdust decreased and the structure of carbon on the surface became rougher and uneven.In addition,the adsorption amount of methylene blue(MB)on the pyrolytic carbon of fermented sawdust is more than twice that of the same condition,indicating that the energy required for pyrolysis is lower and the surface structure of sawdust is changed.Meanwhile,the modified pyrolytic carbon of fermented sawdust is more suitable for adsorption of MB solution.It was found that the yield of pyrolytic carbon from fermented sawdust with MnO2 added increased from 18.5%to about 21%,indicating that MnO2 contributed to the generation of carbon,and the specific surface area of pyrolytic carbon from fermented sawdust with MnO2 added increased nearly twice,reaching 20.97m2/g.SEM shows that there are abundant pore structures on the surface of modified pyrolysis carbon like honeycomb.Finally,from the comprehensive analysis of yield and properties,the quality of pyrolytic carbon catalyzed by MnO2 and modified sawdust is relatively good.Domestic waste is another type of organic solid waste that accounts for a large proportion.Waste paper and waste cloth are selected as the research objects.The research results show that the carbon yield of paper at 800℃ reaches 31.1%,higher than that of wood chip pyrolysis carbon,while the carbon yield is only about 12%and the gas yield is about 85%at the same temperature.It shows that waste paper is more suitable for pyrolytic carbon generation raw material,cloth is more suitable for pyrolytic gas production.When the mass ratio of fermented sawdust to waste paper was 1:1,the carbon yield at 800℃ was 27.7%,which was higher than that at the pyrolysis of fermented sawdust alone and lower than that at the same temperature.The specific surface area of pyrolytic carbon obtained from fermented sawdust and waste paper at 800℃ was more than 100m2/g,and the adsorption capacity of waste paper for MB was similar to that of pyrolytic carbon obtained from fermented sawdust.From the pyrolysis results of domestic waste,it is found that the pyrolytic carbon obtained from the separate pyrolysis of waste paper is also a kind of carbon with very good quality.According to the final research results,both fermentation and MnO2 addition can modify the distribution of pyrolysis products of organic solid waste,and is conducive to the improvement of carbon quality.At the same time,the pyrolysis of waste paper is also a direction to continue to prepare high-quality carbon in the future.