节能技术在新建芳烃联合装置中的应用

新建芳烃联合装置中节能技术被广泛应用:热联合技术将高温塔的塔顶和塔底物料作为低温塔的再沸热源,实现热源的联合应用,充分确保了低温热的二次利用,并且节约燃料和占地面积;传热效率更高、结构更紧凑的纯逆流板式换热器,换热效果突出,加热炉负荷显著降低;旨在预热空气、提高加热炉燃烧效率的烟气余热回收系统的应用,保证了每台加热炉热效率在90%以上,其板式空气预热器具有阻力小、不易积灰、结构紧凑、使用寿命长的优点;选用乙苯脱烷基型催化剂,乙苯单程转化率高(在70%以上),装置内部二甲苯循环量减少,从而降低了二甲苯分馏、吸附分离和异构化单元的规模,相应装置投资及能耗也得到一定程度的降低,其能耗比乙苯异构型催化剂的平均能耗降低5%左右;高效机泵、变频风机、高性能塔盘和精细控制系统的广泛应用,也是该装置的主要节能手段。

The Application of Energy-saving Technology in New Integrated Aromatics Plants

Energy-saving technology has been tion technology uses the materials at the top for the low temperature tower, achieving an in widely used in new integrated aromatics and bottom of the high temperature tower tegrated plants ： Heat integraas the heat source application of heat sources,ensuring a secondary utilization of low temperature heat,saving fuel and reducing physical footprint of plants.Fully reverse flow plate heat exchangers,which have higher heat transfer efficiency and more compact structures,have excellent heat exchange effect and the load on heating furnaces is considerably lower.The application of a flue gas residual heat recovery system,designed to pre-heat air and increase the combustion efficiency of heating furnaces ,ensures that the heat efficiency of each heating furnace exceeds 90% .The plate-type air preheater used in such system is characterized by small resistance,low soot deposition,compact structure and long service life.If an ethyl benzene de-alkylation catalyst is used,the ethyl benzene conversion per pass will be high （over 70%） and the circulation volume of xylene inside the plant will drop ,leading to declines in the scales of the xylene fractionation,adsorption stripping and isomerization units.As a result,investments and energy consumption of the relevant plants will also drop.Compared with an ethyl benzene isomerization catalyst, the energy consumption of an ethyl benzene de-alkylation catalyst is about 5% lower on average.The wide applica- tion of high-efficiency pumps,fans with variable control systems are other major energy-saving frequency control,high-performance column trays and fine approaches used in integrated aromatics plants.