Super Cycles: Coupling Pressure Swing Adsorption to Other Regeneration Techniques

这项由美国国家科学基金会颁发的化学和生物分离项目奖，支持普渡大学的Phillip C. Wankat教授开发一种新的气相吸附分离工艺，称为“超级循环”，该工艺将允许变压吸附（PSA）与其他再生方法相耦合。PSA是工业上常用的一种众所周知的气体分离方法，它使用低压吹扫使吸附床再生。PSA具有生产率高的优点，因此通常相对便宜。然而，由于当吸附非常强时，所需化合物的回收率（或收率）变得很低，因此PSA不能用于吸附强的化合物。热、蒸汽或高真空解吸等替代再生方法对强吸附化合物的回收率比PSA高得多，但生产率明显较低。本研究将开发一种新的方法耦合PSA与热，蒸汽或高真空解吸强吸附的化合物。新工艺保留了PSA的大部分生产率优势，同时利用热、蒸汽或高真空解吸的能力来再生吸附床。本研究的实际意义在于，对于挥发性有机化合物（VOC）的回收或中、高分子量直链烃（用于生产可生物降解洗涤剂）与支链烃的分离等强吸附化合物，PSA在商业上并不经济。由于PSA不适用于这些分离，因此使用了更昂贵的低生产率方法。超级循环的发展将大大降低分离这些化合物的资本和运营成本，这将有助于保持环境清洁，同时减少能源需求。此外，还将进一步发展一种教学方法，该方法将纳入预定的、有辅导的计算机实验室课程，让学生学习使用商业模拟器，作为讲座课程的一部分。这种教学方法已被证明可以帮助化学工程师更好地理解液体分离过程。在这项工作中，这种教学方法被推广到气体吸附分离。

CBET-0754906WankatThis NSF award by the Chemical and Biological Separations program supports work by Professor Phillip C. Wankat at Purdue University to develop a new gas phase adsorption separation process called "super cycles" that will allow coupling of Pressure Swing Adsorption (PSA) with other regeneration methods. PSA is a well-known gas separation method commonly used in industry that uses a low pressure purge to regenerate the adsorption bed. PSA has the advantage of high productivity and thus is often relatively inexpensive. However, because the recovery (or yield) of the desired compounds becomes quite low when the adsorption is very strong, PSA cannot be used for compounds that adsorb strongly. Alternate regeneration methods such as thermal, steam or high-vacuum desorption have much better recoveries of strongly adsorbed compounds than PSA, but have significantly lower productivities. This research will develop a novel method for coupling PSA with thermal, steam or high-vacuum desorption for strongly adsorbed compounds. The new process retains most of the productivity advantage of PSA while using the ability of the thermal, steam or high-vacuum desorption to regenerate the adsorption bed.The practical significance of this research is that PSA is not commercially economical for strongly adsorbed compounds such as recovery of Volatile Organic Compounds (VOC) or for the separation of medium and high molecular weight straight chain hydrocarbons (used to produce biodegradable detergents) from branched chain hydrocarbons. Since PSA is not applicable for these separations, more expensive lower productivity methods are used. Development of super cycles will significantly reduce both the capital and operating cost of separating these compounds, which will help keep the environment clean while reducing energy requirements. In addition, a teaching method that incorporates scheduled, tutored computer laboratory sessions where students learn to use a commercial simulator as part of a lecture course will be further developed. This teaching method has been shown to help chemical engineers develop a better understanding of liquid separation processes. In this work this teaching method is extended to gas adsorption separations.