镇海炼化80×10~4t/a汽柴油加氢装置能耗现状与对策

镇海炼化Ⅱ套加氢装置,系处理30×104t/a焦化汽油与50×104t/a直馏煤油的混合装置,加工能力达80×104t/a。近期,装置反应炉消耗燃料上升,催化剂活性下降,换热器换热效果变差,电耗增加,装置综合能耗已接近13kg标油/t。分析显示,装置综合能耗构成中,燃料气占50%,蒸汽占19%,电耗占23%。通过实施更换反应器上部催化剂,稳定催化剂活性,适当提高加工量以降低单耗,对换热器进行抽芯清洗堵漏,改变加氢反应的混氢点,停用反应加热炉,加强管理和优化操作等节能措施,装置能耗由2008年1~5月份的月均12.88kg标油/t,下降到9.434kg标油/t。但长远来看,装置仍存在能源的不合理利用因素,主要表现为:由于实际工况与设计有很大偏离,反应器后的换热器E201、E202/ABC换热面积不能满足换热要求,反应器出口温度升高,尚有部分热能浪费;汽提塔进料换热器E204/ABCD总换热面积为840m2,但在当前工况下,冷、热料温度均在165℃上下,二者温差很小,换热效果不理想。

Analysis of Energy Consumption of 80x104t/a Gasoline/Diesel Hydrogenation Unit in Zhenhai Refining and Chemical Co.

Sinopec Zhenhai Refining and Chemical Company＇s second hydrogenation unit is a hybrid unit processing coker gasoline （30×10 4t/a） and virgin kerosene （50×10 4t/a）.In recent months,the fuel consumption by the reaction furnace of the unit has risen ,the activity of catalyst has dropped, the heat exchange effect of the heat exchanger has deteriorated and the unit＇s power consumption has gone up.The overall energy consumption of the unit approached 13kg of oil equivalent per ton of feedstock.Analysis showed that of the total energy consumption by the unit,50% was fuel gas, 19% was steam and 23% was electric power.The company took a series of measures to raise the energy efficiency of the unit,including renewing the catalysts at the top of the reactor, stabilizing the activity of catalysts, duly raising processing volumes to reduce unit consumption,cleaning the core of the heat exchanger and stopping leakage,changing the hydrogen-mixing in hydrogenation,stopping the use of the reaction heating furnace,strengthening management and optimizing operations.As a result,the unit＇s energy consumption dropped to 9.434kg of oil equivalent per ton of feedstock from the monthly average of 12.88kg of oil equivalent per ton of feedstock during January to May 2008.In the long run,there is still room for raising the energy efficiency of the unit.As the actual working conditions deviate greatly from the designed working conditions ,the heat exchange areas of the heat exchangers E201 and E202/ABC behind the reactor fall short of the areas required for heat exchange.As the temperature at the outlet of the reactor rises,some heat is wasted.The total heat exchange area of the feedstock heat exchanger E204/ABCD for the stripping tower is 840m2;however,at the current working conditions,the temperatures of cold and hot feedstock are both at about 165℃ and there is a very small difference between their temperatures ,resulting in a non-ideal effect of heat exchange.