Study On The Catalytic Pyrolysis Characteristics Of Ginkgo Leaf Medicine Residue And Pharmaceutical Sludge And The Drying And Blending System

During the production of traditional Chinese medicine,a large amount of traditional Chinese medicine residues and wastewater treatment sludge will be produced.In recent years,with the rapid development of Chinese Medicine Pharmaceutical Industry and the increase in environmental protection requirements,Harmless treatment or resource utilization of traditional Chinese medicine residues and pharmaceutical sludges has attracted widespread attention by people.Most of the traditional Chinese medicine residues and pharmaceutical sludges belong to general solid waste,but some are hazardous solid waste,if it is discharged without harmless treatment,it will cause great harm to the environment and human health.Pyrolysis is a reaction process of thermal decomposition of inorganic substances.The high-temperature treatment during pyrolysis can degrade the harmful substances contained in the pyrolysis object,which is an effective method for the regeneration of biomass materials.In order to study and explore the methods of harmless treatment or resource utilization of traditional Chinese medicine residue and pharmaceutical sludge,in this study,ginkgo biloba residue and pharmaceutical sludge were used as research objects.The weight loss characteristics,kinetic parameters,components of pyrolysis products,and the reaction mechanism of catalytic pyrolysis process of the raw materials under mixed pyrolysis and mixed catalytic pyrolysis were studied.This provides theoretical guidance and technical route for the pyrolysis treatment of combustible solid waste.At the same time,a comprehensive design of the pharmaceutical sludge drying and incineration process was carried out.The main research contents and results are as follows:1.The effect of the blending ratio of ginkgo biloba residue and pharmaceutical sludge on the weight loss characteristics and synergy of the mixed samples was studied by thermogravimetric analysis.Based on the pyrolysis characteristics and kinetic parameters of the obtained mixed samples,a kinetic model of the mixed pyrolysis process was established.A weightlessness prediction model was established based on particle swarm optimization algorithm and gradient boosted decision tree(PSO-GBDT).The results showed that the synergistic effect was most significant when the blending ratio of drug residue was 50wt%.The synergy in the middle temperature stage(200-500?)was obviously stronger than that in the high temperature stage.The synergy is mainly due to the release of hydroxyl groups in the raw materials and the catalysis of alkali metals and alkaline earth metals.With the increase of heating rate,the activation energy of the mixture increased from 33.94kJ/mol to 35.25kJ/mol,and the frequency factor had a compensation effect on the activation energy.In addition,the established gradient boosting decision tree model can well predict the mass loss rate of the mixture under different heating rates.The consistency between the experimental data and the predicted values confirms the accuracy of the PSO-GBDT model.2.Using thermogravimetric analysis,fixed-bed reactor and GC-MS technology to analyze the activation energy and pyrolysis product characteristics of ginkgo biloba drug residue and pharmaceutical sludge under different blending ratios,the changes of activation energy,the distribution of three-phase products,the precipitation characteristics of gas products,the components of bio-oil and the interaction mechanism were discussed.The test results showed that with the increase of the proportion of Chinese medicine residue,the activation energy of the mixture decreased first and then increases.When the blending ratio of drug residue was 50%,the activation energy was the lowest.It was proved that there was a synergistic effect among the raw materials by comparing the experimental and calculated yields of the three-phase products.The experimental yield of bio-oil was significantly lower than the calculated,while the experimental yield of gas products was higher than the calculated,indicating that a small amount of alkali metals and alkaline earth metals present in pharmaceutical sludge can affect the product distribution.In the gas product,the contents of CH₄ and H₂ decreased slightly,the content of CO₂ increased significantly,and the content of CO increased slowly.In bio-oil,the main organic compounds were phenols and olefins.Among them,the contents of nitrile,pyrazine and amine were significantly reduced,and phenolic compounds were produced by a large amount of decomposition of phenylpropane in lignin.3.Using pyrolytic carbon and sodium alginate as raw materials,a cross-linking reaction was performed through glutaraldehyde to obtain a chitosan-modified composite bioadsorbent,and an experimental study on the adsorption of tetracycline in an aqueous solution was performed.At the same time,the effects of test parameters(such as adsorption dose,contact time,initial pH of solution,and initial tetracycline concentration)on adsorption were studied,and the adsorption characteristics of the modified pyrolytic carbon were evaluated.The results showed that within the pH range(2-11)measured in the experiment,when the pH was 2,the modified pyrolytic carbon had the best adsorption capacity for tetracycline.As the acidity weakened,the adsorption capacity of the adsorbent began to decrease sharply and then reach a steady state.Under strong alkaline environment,the adsorption capacity decreases again.When the amount of modified pyrolytic carbon was 2g/L,the removal rates of tetracycline before and after modification were 36.69%and 93.79%,respectively,and the highest adsorption capacities were 85.92 and 146.06mg/g,respectively.The adsorption of tetracycline by modified pyrolytic carbon conforms to the pseudo-second-order kinetic equation and the Freundlich isotherm adsorption model,which shows that the adsorption of tetracycline on charcoal is a multi-layer adsorption on a heterogeneous surface;Throughout the entire adsorption process,although both physical and chemical adsorption are involved,chemical adsorption is the predominant one.Fourier transform infrared spectroscopy(FTIR)analysis showed that the amino group in chitosan is the functional group that plays a major role in the adsorption process.4.The catalytic pyrolysis performance of cobalt-modified USY zeolite catalyst on the mixture of ginkgo biloba residue and pharmaceutical sludge was studied.The modified catalyst was characterized by specific surface area,pore size analysis,X-ray diffraction analysis,and ammonia programmed desorption.The results showed that the modified catalyst retained the lattice diffraction peaks of the intact USY catalyst,but the specific surface area,pore volume,and average pore diameter all decreased.At the same time,the number of strongly acidic sites was significantly reduced.Among the products obtained by using the USY catalyst before and after modification,the yield of bio-oil decreased by 6.29% and 8.78%,respectively,and the yield of gaseous products increased by 9.13% and 12.28%respectively.Under the action of the catalyst,the yields of CO,CH₄,and CO₂ in the gas product increased significantly,the yields of C₂H_m increased slightly,and the yield of H₂ decreased significantly.Cobalt loading is beneficial to increase the yield of aromatic hydrocarbons in bio-oil.Except for anthracene,the production of other aromatic hydrocarbons increased,especially the production of naphthalene increased significantly.This indicates that cobalt ions can increase the formation of naphthalene and its derivatives by promoting the addition or polymerization of benzene rings.5.Research and determine the drying and incineration process of pharmaceutical sludge generated during the wastewater treatment of Shanghai Chinese Medicine Factory.According to the daily processing capacity of 20 tons,the project was designed,including the technical route,equipment design scheme,main parameters of the equipment,process flow,production technology and workshop construction drawings.And the system units in the process,such as sludge pretreatment system,drying system,waste heat utilization system,dust removal and gas removal system,etc.are explained in detail.This project can realize the reduction and harmlessness of pharmaceutical sludge.It meets the resource processing requirements within a certain range,so it is an economical and reliable processing solution.