Coal Tar Component Cascade Separation Process Optimization

As a big country with coal resources,coal tar is one of its important by-products in the coal processing process.Its high yield,and its very complex composition,contains many compounds with high added value in its many components.Therefore,it is very important to separate and extract the components.In this paper,the middle-low temperature coal tar(M-LTCT)in northern Shaanxi is taken as the experimental research object.Firstly,the properties of coal tar in the research are analyzed and determined by using the basic properties of coking products and petroleum products,and then the coal tar is removed.Asphalt experiment,and determination of the content of phenolic compounds adsorbed on the silica gel,and finally optimized the process parameters of the coal tar component cascade separation device independently designed and built to obtain better process parameters.By using different methods to perform deasphalting experiments on coal tar,it was found that the ultrasonic-thermal extraction rate was as high as 69.2 %.The content of phenolic compounds in the hexane extract of coal tar was determined using the national standard method and the content of phenolic compounds was measured as 17 %.Through the use of constant temperature water bath shaker on the particle size of 75-80 ?m,109-120 ?m,180-250 ?m,silica gel on the adsorption of phenolic substances was measured and found that the average particle size of silica gel gradually decreased,the unit mass of silica gel adsorption Ability to gradually increase.During the investigation of the operating pressure and silica particle size,it was found that with the same particle size,both the adsorption stability time,the solvent switching time and the elution stabilization time decreased significantly with the increase of pressure.Under the same pressure,with the increase of silica gel particle size,the adsorption stability time,solvent switching time and elution stability time decreased significantly,so the particle size of silica gel increased and the operating pressure increased,By using Py-GC-MS and FTIR to analyze the residual components of the silica gel after adsorption and elution,it was found that there was no residue of phenolic compound on the eluted silica gel,but some of the remaining paraffins remained saturated Aliphatic hydrocarbons,and a small amount of alcohol compounds.Crude phenol and neutral oil obtained through the column separation of the coal tar n-hexane extract obtained by the use of PRO ? simulated distillation to obtain pure product crude phenol and neutral oil,the design parameters of each distillation column to achieve the separation requirements are as follows: Neutral oil tower theoretical plate number 6,the best feed plate for the third block;crude phenol tower theoretical plate number 7,the best feed plate number 3;in the mixed tower of the theoretical plate number For the 18,the best feeding board for the first 10.