Process And Equipment Optimization Of Low-temperature Coal Tar Hydrogenation To Light Oil

China's coal resources are abundant,but oil and natural gas are lacking.With the rapid development of the economy,the demand for energy is also increasing.It is of great significance to vigorously develop"coal to oil"to find new oil substitute energy.With the improvement of coking technology level,a large amount of coal tar is produced as a by-product.Hydrogenation of coal tar to produce a better light fuel oil can not only reduce the import of petroleum,but also improve the economic utilization value of coal tar to reduce the pollution of the tar burning to the air.In this paper,several representative coal tar hydrogenation technologies are reviewed firstly,and the characteristics of each process are summarized and their advantages and disadvantages are analyzed and summarized.Secondly,the simulation calculation of the fixed bed hydrogenation equipment is carried out in order to obtain the axial variation law of the temperature between the catalyst beds.At the same time,the calculation of the cold hydrogen amount is carried out,and the comparison with the actual value shows that there is a waste of resources in the amount of cold hydrogen.Finally,the analysis is carried out in conjunction with the problems occurring in the industrial production process and the corresponding corrective measures.The main results of the article are as follows:?1?For the comparative analysis of the technology used by coal tar deep processing enterprises,the advantages and disadvantages of different technologies are summarized.According to the actual production,the effects of temperature,pressure,hydrogen oil volume ratio and space velocity on the hydrogenation process are discussed.Among them,high temperature and high pressure help to increase the sulfur-nitrogen removal rate,the hydrogen-carbon ratio of the product increases,and the color of the oil appears obvious.Improvement,will also significantly inhibit the rate of coke reaction,so that the operating cycle of the device is extended;the hydrogen-oil ratio increases the catalyst surface area carbon rate;the space velocity determines the reactor volume,the residence time of the reactants in the catalyst bed and the catalyst The amount,and in general,the hydrogenation depth of the oil at a low space velocity is high.?2?The industrial fixed bed was simulated and the kinetic model of hydrodesulfurization and hydrodenitrogenation reaction was combined with the thermal effect of the reaction to obtain the temperature rise of the seven-stage catalyst bed.The temperature change showed a step rise.It can be seen from the change of the slope that the reaction rate is gradually reduced,and the error is found to be about 2?by comparison with the actual bed inlet and outlet temperature.In the calculation of cold hydrogen content,the cold hydrogen addition amount of the model is 57220.8 Nm³/h,which is lower than the total cold hydrogen content of the existing production process of 7.5×10⁴ Nm³/h.?3?Analysis of the problems occurring in the current production process,high pressure heat exchanger leakage mainly due to the reaction of hetero-atoms such as organic sulfur and nitrogen in the raw materials with chloride ions to form corrosive NH₄Cl and NH₄HS.In addition,the technology of hydrogenation low-gas separation to hydrogen recovery technology can increase the output of refined oil.The technical reform of stripping steam in the hydrogenation fractionation system not only improves energy efficiency,but also reduces environmental pollution.Hydrogenated condensate increases plate heat exchangers to reduce energy waste.