Beijing University of Chemical Technology, School of Life Science and Technology, Beijing, China.
Beijing University of Chemical Technology, School of Life Science and Technology, Beijing, China; Beijing University of Chemical Technology, Beijing Advanced Innovation Centre for Smart Matter Science and Engineering, Beijing, China.
J Environ Manage. 2018 Jul 1;217:196-206. doi: 10.1016/j.jenvman.2018.03.061. Epub 2018 Apr 5.
The extraction of vegetable oils is an energy-intensive process. It has moreover a significant environmental impact through hexane emissions and through the production of organic-loaded wastewater. A rice bran oil process was selected as the basis, since full data were available. By using Aspen Plus v8.2 simulation, with additional scripts, several improvements were examined, such as using heat exchanger networks, integrating a Vapor Recompression Heat Pump after the evaporation and stripping, and examining a nitrogen stripping of hexane in the rice bran meal desolventizing unit followed by a gas membrane to recover hexane. Energy savings by the different individual and combined improvements are calculated, and result in a 94.2% gain in steam consumption and a 73.8% overall energy saving. The power consumption of the membrane unit reduces the overall energy savings by about 5%. Hexane separation and enrichment by gas membranes facilitates its condensation and re-use, while achieving a reduction of hexane emissions by over 50%. Through the considerable reduction of required steam flow rates, 61% of waste water is eliminated, mostly as organic-loaded steam condensate. Through overall energy savings, 52% of related CO emissions are eliminated.
植物油提取是一个能源密集型过程。通过正己烷的排放和有机废水的产生，它对环境有重大影响。选择米糠油工艺作为基础，因为有完整的数据。通过使用 Aspen Plus v8.2 模拟，并使用附加脚本，研究了几种改进方法，例如使用换热器网络、在蒸发和汽提后集成蒸汽再压缩热泵，以及在米糠脱溶单元中对正己烷进行氮气汽提，然后使用气体膜回收正己烷。计算了不同单独和组合改进措施的节能效果，结果表明蒸汽消耗减少了 94.2%，总能耗节约了 73.8%。膜组件的电力消耗使总节能减少了约 5%。气体膜对正己烷的分离和浓缩有助于其冷凝和再利用，同时减少了 50%以上的正己烷排放。通过大幅减少所需蒸汽流量，消除了 61%的废水，主要是有机负荷蒸汽冷凝物。通过总能耗节约，消除了 52%相关的 CO 排放。
