Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
8077330 | Energy | 2014 | 11 Pages |
Abstract
In this paper, the optimization of xylene fractionation and disproportionation units in a para-xylene plant is performed through a new method for systematic design based on GCC (grand composite curve) and CGCC (column grand composite curve). The distillation columns are retrofitted by CGCC firstly. Heat Integration between the columns and the background xylene separation process are then explored by GCC. We found that potential retrofits for columns suggested by CGCC provide better possibilities for further Heat Integration. The effectiveness of the retrofits is finally evaluated by means of thermodynamics and economic analysis. The results show that energy consumption of the retrofitted fractionating columns decreases by 7.13Â MW. With the improved thermodynamic efficiencies, all columns operate with less energy requirements. Coupled with Heat Integration, the energy input of the para-xylene plant is reduced by 30.90Â MW, and the energy outputs are increased by 17Â MW and 58Â MW for generation of the 3.5Â MPa and 2.5Â MPa steams. The energy requirement after the Heat Integration is reduced by 12% compared to the original unit. The retrofits required a fixed capital cost of 6268.91Â ÃÂ 103Â $ and saved about 24790.74Â ÃÂ 103Â $/year worth of steam. The payback time is approximately 0.26 year for the retrofits.
Related Topics
Physical Sciences and Engineering
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Energy (General)
Authors
Ting Chen, Bingjian Zhang, Qinglin Chen,