Study On The Catalytic Hydrochlorination Process For The Resource Recycling Of Chlorinated Organic Solid Waste

Chlorinated organic solid waste is one of the key issues in environmental pollution control.Since the chlorine atom is a strong electron-withdrawing group,the chlorinecontaining compound has a high electronegativity,is difficult to be degraded,and is highly toxic.It can accumulate in the nature for a long time,and is extremely harmful to the environment and human health.Catalytic hydrogenation dechlorination has the advantages of easy operation,high efficiency,green environmental protection,etc.It meets the requirements of environmental protection and the concept of sustainable development,and has become an important means of resource utilization of chlorinecontaining solid waste.This thesis starts from the three directions of non-selective dechlorination,selective dechlorination and dechlorination coupling,and is devoted to the research of catalytic hydrodechlorination process for the utilization of organic solid waste containing chlorine.The details are as follows:On the basis of an overview of some common chlorine-containing compounds in industry,introduce the treatment methods of chlorine-containing compound solid waste,and discuss the advantages of using catalytic hydrodechlorination and dechlorination coupling to treat chlorine-containing solid waste On the basis of the key factors of hydrogen treatment of solid waste containing chlorine,the basis for selecting the topic and the main research content are further proposed.Using Pd/C as a catalyst,three studies were conducted from three perspectives:benzene-based chlorine-containing organic solid waste non-selective dechlorination,polychlorinated organic solid waste selective dechlorination,and pyridine-based chlorine-containing organic solid waste non-selective dechlorination A variety of different systems of chlorine-containing solid waste(2,3,5-trichloro-p-xylylene ether,1,2,3-trichlorobenzene,2-chloropyridine)catalytic hydrodechlorination resource utilization technology,and system The effects of parameters such as solvents and alkali additives on the catalytic conversion rate and selectivity were investigated.Among them,the total selectivity of 2,3,5-trichloro-p-xylylene diether to obtain p-xylylene ether and 2-chloro-p-xylylene ether is>99%;with DMSO as the solvent,1,2,3 The selectivity of trichlorobenzene hydrodechlorination to prepare dichlorobenzene can reach 95%;in 2-chloropyridine catalytic hydrodechlorination,the use of potassium carbonate as an alkali auxiliary agent can ensure that the heterocycle is not excessively hydrogenated and converted Both the rate and selectivity reached 99%.The direct catalytic hydrodechlorination technology system was extended to the system of dechlorination coupling preparation of high value-added chemicals.The industrial route to obtain biphenyl-derived compounds by dechlorinating and coupling industrial solid wastes containing aromatic compounds with Pd/C as catalysts was studied.Among them,using methanol as a hydrogen donor,with the aid of a phase transfer catalyst,the efficient hydrodechlorination coupling of chlorobenzene to biphenyl is realized;4-chlorophthalic anhydride can also perform well under the catalytic hydrogenation conditions of Pd/C,3,3’,4,4’-biphenyltetracarboxylic dianhydride was prepared by dechlorination coupling.On the basis of summarizing the research results of the thesis,some prospects for the utilization of catalytic hydrodechlorination of solid waste containing chlorine are prospected.