关键词: 芳烃联合装置, 低温热利用, 流程优化, 节能减排, 热阱, 能耗, CO₂排放量, 对二甲苯

Abstract:

The utilization of low temperature heat and process optimization for aromatics complex were introduced. The tower top low temperature heat of the raffinate tower and the extraction tower was used to produce hot water, a small amount of the hot water was used to heat demineralized water from FCC unit, and most of the hot water was used to produce 0.35 MPa steam to solvent regeneration unit by the second type of heat pump technology. A small amount of the toluene tower top gas phase heat source was used to replace 3.50 MPa reboiled steam of the isomerization stripper, while the rest was used to produce 0.62 MPa low low pressure steam together with the low temperature heat of the heavy aromatics tower top. Most of the low low pressure steam was pressurized and used as the reboiled heat source for the aromatics extraction unit. The comprehensive utilization of low temperature heat between the aromatics complex and the external units was realized, and the heat exchange process of heavy aromatics tower and isomerization stripper bottom was optimized. After the implementation of the project, every year the aromatics complex saved 102.7 kt of standard coal, CO₂ emissions reduced by 256.1 kt, and energy consumption of p-xylene reduced by 3.22 GJ/t.

Key words: aromatics complex, low temperature heat utilization, process optimization, energy saving and emission reduction, heat sink, energy consumption, CO₂ emissions, PX