| As an important fine chemical product in the rubber industry,rubber additives are used in various stages of rubber processing through chemical methods to save energy and save time.With the increasing demand for rubber in China and even the world,the rubber additives industry has experienced unprecedented rapid development At the same time,environmental governance has encountered various tests.Toxic rubber raw materials,organic solvents,intermediates,rubber additives and outdated production processes directly lead to the generation of toxic gases and excessive discharge of sewage,which not only brings serious pollution to the environment,but even threatens human life health.The above problems are the main factors that restrict the development of rubber additives and intermediates in China.Nowadays,the core competitiveness of the rubber additives industry is mainly reflected in the greening of raw materials,the simplification of the synthesis process and the cleanliness of the production process,as well as the research and development of special functional rubber additives.However,the research and development of high-efficiency and environmentally friendly rubber additives,the development and industrialization of rubber additive engineering technology,and the research and development of rubber additive cleaning technology still have common problems in the field,especially the industry's "bottleneck" problem,This seriously restricts the development of the field of rubber additives.This article focuses on the production process technology of 2,2'-dibenzoylaminodiphenyl disulfide,a rubber peptizer,and focuses on solving the key issues related to green chemicals in the entire production process of "raw materials——synthetic processes——products" technical challenge.On this basis,we use Aspen Plus chemical process simulation software to design,analyze and optimize the production process of 2,2'-dibenzoylaminodiphenyl disulfide to obtain the logistics parameters,equipment parameters and Optimal production plan including "three wastes" emissions.The main content and main conclusions of this paper include the following aspects:1.Aiming at the "three high" problems existing in the synthesis of o-nitrochlorobenzene,2,2'-dibenzoylaminodiphenyl disulfide,a rubber auxiliary and plasticizer,we have high costs,high energy consumption and high emissions.We Using C7H5NS,NaOH,H2SO4 and H2O2 as the source of synthetic raw materials,the three-step synthesis in the original synthesis process is reduced to two-step synthesis,which can not only effectively improve the synthesis yield,reduce the synthesis steps,but also effectively solve the catalyst difficulty Recycling problems,avoid the use of volatile organic solvents,so as to achieve a green synthesis process.2.The Aspen Plus software was used to establish the benzothiazole process model,and the operating parameters of the laboratory and small test were used as the initial simulation values to simulate the production process of 2,2'-dibenzoylaminodiphenyl disulfide,using control With the variable method,the sensitivity analysis and optimization analysis of the feed flow and the target product mass flow at each stage were carried out.The simulation results show that different logistics have different effects on the target product mass flow at each stage,that is,the mass flow of C7H5NS,H2O2 and C7H5ClO directly participating in the reaction process,as the reactant feed increases,the product mass flow is basically linear Increase and gradually stabilize at the maximum value;for the materials that NaOH,H2SO4 and Na2CO3 indirectly participate in the reaction,the principle of action is to indirectly affect the mass flow of the target product by adjusting the pH value in the reactor and the amount of by-products produced,and as the feed increases,the target product the mass flow rate eventually approaches a certain value.Therefore,we can obtain the optimal mass flow of the feed logistics,which is basically consistent with the actual industrial production.3.Based on the analysis of the above feed logistics,we have conducted sensitivity analysis and optimization of the temperature of each reactor,the mass flow of the main product and the composition of the logistics.The results show that when the temperature of the oxidation reactor is low,the flow rate and flow composition of the main products fluctuate greatly,and the temperature should be controlled below 400C.As the temperature of the reaction kettle rises,the flow rate and stream composition of the main products tend to stabilize and reach the maximum value.However,if the temperature of the acylation kettle is too high,the flow rate of the main product will show a downward trend.The temperature of ring-opening reaction and acylation reaction is controlled within the range of 110-120?,which can maximize the reaction yield.The above results indicate that changing the temperature of the reaction kettle can help to reasonably regulate the mass flow and logistics composition of the main products,and the simulation results are basically consistent with the actual industrial production.4.Based on the developed green synthesis process and the best process parameters obtained by simulation,industrial scale production of 2,2'-dibenzoylaminodiphenyl disulfide of 10,000 tons was carried out.Compared with the original o-nitrochlorobenzene synthesis method,this method has the following advantages:The yield of 2,2'-dibenzoylaminodiphenyl disulfide increased from around 72%to over 90%;It avoids the use of neurotoxic o-nitrochlorobenzene in the original synthesis method and the metal catalyst Raney nickel,which is difficult to recover with the existing environmental protection technology,and overcomes the environmental protection problem of volatile amine tail gas easily generated in the original synthesis method;The drying process is eliminated and the use of organic solvent ethanol is avoided,which has obvious green characteristics. |
PDF Full Text Request