Surface Effects Of Biomass Carbonization And Diatomite/montmorillonite

In recent years,as the rapid developing of global industrialization,the emission of CO₂ has increased year by year.Thus the greenhouse effect has intensified,which brings a series of negative effects to the survival and development of human.The conversion from waste biomass to biomass carbon?biochar?can reduce the emission of carbon dioxide,develop new carbon materials and alleviate the shortages of fossil energy.The raw material resources of easy prepared biochar are abundant and various in nature,and there is a lot of potential applications for biochar.In order to solve the problems of environment pollution and resource scarcity,the development and utilization of biomass carbon materials is becoming a new research hotspot of international scientists.The research of mineral substrates to provide specific structural morphology for carbon materials has attracted widespread attentions,especially for obtaining advanced carbonaceous composite materials with excellent properties.However,there are few researches on the preparation of biomass carbon and mineral composites by in-situ carbonization of mineral-associated biomass.And the research of the influence mechanism between mineral composition and biomass carbonization was less studied.Therefore,this article is focused on the symbiotic system of biomass and diatomite or montmorillonite,in-situ preparing biomass carbon mineral composites through carbon-bed pyrolysis method,investigating the effects of biomass carbonization on the microstructure and properties of diatomite or montmorillonite mineral components;exploring the influence rules of porous diatomite or lamellar montmorillonite mineral composition on biomass carbonization and structural properties of composites;researching the influence mechanism of cordierite mineral components on biochar graphitization and structural properties of graphite based nanocomposites in the system of graphite based cordierite nanocomposites;investigating the interacted mechanism of between amorphous silicon or clay minerals with biochar during the process of biomass carbonization;forming the scientific understanding of the interaction mechanism between inorganic and organic components in the carbonization process of natural mineral associated biomass.The main research findings are as follows:1.The carbonization of organic biomass components has greatly promoted the crystallization or crystal transformation process of amorphous silicon or aluminosilicate in associated mineral components,which has significant effects on the microstructure and chemical properties of diatomite or montmorillonite components.?1?In diatomite based composites,the energy effects of biomass pyrolysis carbonization significantly changes the phase transition process of siliceous components in diatomite,continues to radiate energy to the composite system,the activation of carbonization products has certain effects on the short-range ordered and long-range disordered silica tetrahedron structure and structural oxygen of opal,promoting the crystallization and crystal transformation of amorphous opal and quartz to cristobalite,the temperature of transition is reduced by 350^oC,changing the diatom shell porous morphology of diatomite,and reducing the distribution of functional groups on the surface of composite material.?2?In montmorillonite based composites,the energy effects of introduced biomass pyrolysis affects the phase transition process of aluminosilicate components in montmorillonite,the biomass attached to the surface or interlayer of montmorillonite layer structure carbonizes and breaks the chemical bonds,the carbonization products prepared by polymerization has activated the layer or surface of aluminoxy octahedron and silicone tetrahedron in montmorillonite,promotes the crystalline structure decomposition of montmorillonite components,the temperature of decomposition is reduced by 300^oC,changing the layered structure morphology of montmorillonite minerals at low temperature,reducing the distribution of functional groups on the surface of composite material,significantly increasing the particle size of composite.2.The surface effects of inorganic amorphous silicon or aluminosilicate in characteristic mineral components has obviously altered the carbonization of associated organic biomass and as-prepared biochar composite materials,which has enhanced the pore structure and adsorption properties of composite materials.?1?In biochar based diatomite composite materials,the carbonization of introduced cellulosic biomass and primary biomass produces large amounts of biochar particles on the surface or in pores of the diatom porous structure,forming the morphology of diatom shell mesoporous structure,the diatomite components has affected the carbonization process of biomass and ordered structure of amorphous carbon,increasing the distribution of functional groups and mesoporous pore channels,enhancing the adsorption property of methylene blue onto composite?153.2 mg/g?,the adsorption of methylene blue onto composite possesses the chemical adsorption and heterogeneous surface multilayer physical adsorption nature.?2?In biochar based montmorillonite composite materials,pyrolysis of carboxymethyl cellulose produces much particles of biochar on the layer surface or in the structural layers of montmorillonite,forming a lamellar coated granular characteristic structure,the prepared biomass carbon enters the interlayer or attaches to the surface of the montmorillonite,increasing the silicon containing functional groups on the surface of composite and the structure defects of prepared biomass carbon,increasing the distribution of mesoporous pore channels,enhancing the adsorption property of methylene blue onto composite?93.5 mg/g?,the adsorption of methylene blue onto composite possesses the intraparticle diffusion adsorption and heterogeneous surface multilayer physical adsorption character.3.The high temperature carbonized crystalline phase of montmorillonite mineral is cordierite,the microsize cordierite component has prominent influences on the graphitization of associated biochar and structural properties of the as-prepared graphite nanocomposite materials,which has greatly enhanced the surface adsorption properties of organic pollutants onto composite materials.The high temperature carbonization product forms the porous layered feature structure and reduces the ordered graphitization degree of carbonization products,increasing the distribution of mesoporous pore channels in the region of 2-5 nm,significantly enhancing the adsorption property of methylene blue onto composite?988.928 mg/g?,the adsorption of methylene blue onto composite fits the mechanism of single layer adsorption and pseudo-first-order kinetic adsorption characters.