Synthesis Of High-efficiency Coal-water Slurry Dispersant Using Industrial Solid Waste Of Dye Intermediates And Performance Evaluation Study

Gasification is the leading technology of modern coal chemical industry,and coal water slurry gasification is widely used in modern coal chemical industry.Increasing the concentration of gasification coal water slurry can improve the gasification efficiency of coal water slurry,increase the production of syngas,reduce the consumption,and bring obvious economic benefits to enterprises.High efficiency naphthalene dispersant is the key to the preparation of high concentration coal water slurry.However,due to the high price of industrial naphthalene,the production cost of coal chemical enterprises is increased.Therefore,it is urgent for coal chemical enterprises to develop high efficiency and low cost coal water slurry dispersant.In Ordos and Wuhai areas of Inner Mongolia,a production and supply system has been formed to produce dye intermediate 2-naphthol and its downstream derivatives using industrial naphthalene as raw materials.In the production process,a large number of solid wastes containing inorganic salts and naphthalene organic compounds are generated,which are rich in sulfonic acid group,phenolic hydroxyl group and other hydrophilic groups.These groups are the required structure of naphthalene series dispersants,so it is of practical significance to study the production of high efficiency naphthalene series coal water slurry dispersants from these solid wastes containing naphthalene series homologous materials.According to the composition of solid waste,this paper selected naphthalene,2-naphthol,J-acid and Tobias acid as model compounds,respectively using 4 model compounds as raw materials to explore the process route and reaction parameters of the synthesis of coal water slurry dispersant,which can be used to guide the experiment of synthesizing coal water slurry dispersant with actual solid waste as raw materials.The reaction parameters were optimized by orthogonal test and single factor experiment,and 5 dispersants were prepared,including β-Naphthalene Sulfonate(NSF),2-naphthol(NF),J-acid(JS),naphthalene and Tobias acid chemical combination(NTSS)and solid waste(GF).The results of pulping evaluation show that the five kinds of dispersing agents have good dispersibility.Compared with the commercially available β-Naphthalene Sulfonate(NNO)dispersant,the amount of dispersant added by GF dispersant can be reduced by about 1‰,and the constant viscosity concentration can be increased by about 1.5 percentage points,and the stability is better.The regulation mechanism of dispersing agent on slurry performance was studied by FT-IR,GPC,XPS and UV-Vis instruments.Dispersant under the condition of 6‰addition: The adsorption capacity of GF and NNO dispersants on the surface of HT coal is 1.44 mg /g and 1.11 mg /g,and the adsorption thickness is 1.33 nm and 0.73 nm,respectively.The Zeta potential on the surface of HT coal particles modified by the two dispersants is-29.94 m V and-23.93 m V,respectively.The O/C values are0.2779 and 0.2899,respectively.The adsorption capacity of GF and NNO dispersants on the surface of the HN coal is 1.32 mg /g and 1.10 mg/g,and the adsorption thickness is 1.25 nm and 0.56 nm,respectively.The Zeta potential and O/C values of modified HN coal particles are-31.46 m V,-25.35 m V and 0.2478 and 0.2480,respectively.The characterization data show that the dispersant is adsorbed on the surface of pulverized coal in the form of a single molecular layer,and the stronger the modification effect of the dispersant on the surface of pulverized coal,the more obvious the viscosity reduction effect on the coal water slurry.The characterization results can better explain the slurry formation performance of the dispersant.Based on the results of laboratory basic research,a set of pilot equipment(50 Kg/day)for continuous production of high efficiency coal water slurry dispersant was established from the perspective of industrial production,and industrial naphthalene was used to achieve continuous production of the device.The results showed that the level of the reaction process of NSF dispersant synthesized by the continuous pilot production was basically the same as that of the laboratory basic research,about 98%.By comparing the slurry performance,the slurry viscosity of the NSF dispersant produced in the pilot test at the same concentration is 879 m Pa·s,which is little different from that of the NSF dispersant produced in the laboratory at 943 m Pa·s,and the fluidity level is the same.