摘要
在偏三甲苯装置常规双塔热集成精馏工艺基础上,分析了重沸器高温凝结水通过两级闪蒸发生1.0MPa蒸汽和0.4MPa蒸汽,比直接高温凝结水外送可降低能耗2.713kg标油/t原料;以产能5×10^(4)t/a的偏三甲苯装置为例,在脱轻塔顶设置热水换热器回收塔顶低温热产生热水,可回收热量10481kW,脱轻塔顶空冷风机大部分可以停开,节约用电153.3kW·h,可节约能耗24.22kg标油/t原料,节约操作费用925万元/a,该部分投资工程费约300万,回收期短;100×10^(4)t/a PX装置吸附分离单元抽余液塔顶气富裕热量5WM,该抽余液塔顶气直接供给偏三甲苯装置重沸器作热源,可代替3.5MPa蒸汽7.614t/h,扣除产1.0MPa蒸汽的能耗差值,可以节约能耗4.321kg标油/t原料;以上措施能耗合计降低31.254kg标油/t原料。还可通过优化换热流程、热进料热出料、采用节能设备、设置在线分析仪、装置卡边操作、改用导热油作热源等措施进一步稳定装置操作及降低能耗。这些节能方法投资回收期短,经济性好,可实施性强,对同类装置的工程设计及装置节能操作具有借鉴意义。
On the basis of conventional dual tower thermal integrated distillation process for trimethylbenzene unit,it is analyzed that generating 1.0MPa steam and 0.4MPa steam by high-temperature condensate from re-boiler through two-stage flash evaporation can reduce energy consumption by 2.713kilograms of standard oil per ton of raw material compared to the direct delivery of high-temperature condensate.Taking a 50kt/a trimethylbenzene unit as an example,installing a hot water heat exchanger at the top of light component removal tower to recover the low-temperature heat at the top of the tower can recover 10481kW of heat.Most of the air cooling fans at the top of light component removal tower can be stopped,saving electricity by153.3kWh,saving energy consumption by 24.22kilograms of standard oil per ton of raw material,and saving operating cost by 9.25million yuan per year.The construction cost for this part of investment is about 3million yuan,and the payback period is short.The overhead gas from raffinate column in adsorption separation unit of the 1.0Mt/a PX unit has a surplus heat of 5WM.Directly using this overhead gas from raffinate column as the heat source for the reboiler of trimethylbenzene unit can replace 7.614t/h of 3.5MPa steam.Deducting the energy consumption difference from the generation of 1.0MPa steam,the energy consumption can be saved by4.321kilograms of standard oil per ton of raw material.The above measures reduce the energy consumption by31.254kilograms of standard oil per ton of raw material in total.Measures such as optimizing the heat ex-change process,adopting hot feed and hot discharge,using energy-saving equipment,installing online analyzers,operating the units to the nearest capacity limits and using thermal oil as the heat source can also be taken to further stabilize the unit operation and reduce the energy consumption.With short investment payback period,good economy and strong feasibility,these energy-saving methods provide reference for the engineering design and energy-saving operation of similar units.
作者
魏川林
Wei Chuanlin(Shandong Jilian Petrochemical Engineering Co.,Ltd.,Jinan Shandong 250000)
出处
《中外能源》
CAS
2024年第3期99-104,共6页
Sino-Global Energy
关键词
偏三甲苯装置
碳九芳烃
节能
优化
能耗
低温热
Trimethylbenzene unit
C9 aromatics
energy conservation
optimization
energy consumption
low temperature heat
