Mathias Leimbrink

Conceptual Design of Post-Combustion CO2 Capture Processes - Packed Columns and Membrane Technologies

Abstract CO 2 removal from flue gas emitted by coal fired power plants is an important objective for process sustainability. However, solvent regeneration in state-of-the-art absorption processes results in power plant efficiency losses of 7 to 15 % (Neveux et al., 2013). Process intensification, combining different and innovative technologies for gas separation, can result in highly efficient processes capable of reducing the energy penalty caused by CO 2 capture. Current approaches for conceptual process design (CPD) however rarely consider emerging technologies like membrane contactors or hybrid process configurations. We present a multi-stage approach to overcome this drawback, which bases on process decomposition in different levels, combined with an efficient screening of promising materials and process design variants by means of shortcut methods. The approach follows the idea of an iterative refinement, in which the modeling accuracy increases while the number of process variants decreases.

CHAPTER 10:Enzymatic Reactive Absorption and Distillation

In this work, innovative concepts for reactive separation processes, such as reactive absorption and distillation, that make use of bio-based catalysts, in specific enzymes, are discussed. Enzymatic Reactive Absorption (ERA) and Distillation (ERD) offer potential for energy and investment savings or improved selectivity by exploiting enzyme merits like high enantioselectivity and high reaction rates at milder reaction conditions than chemical catalysts. Potential process equipment, application strategies to supply enzyme for ERA and ERD processes as well as suitable modeling and design approaches are presented. Despite the huge potential, addressing these issues is crucial in order to promote ERA and ERD as vital technologies for process intensification in bio-based industries. The application of the enzyme carbonic anhydrase in an ERA column with common MDEA-based solvent can drastically improve the absorption of CO2 by more than 9-fold. Furthermore, the production of butyl butyrate and enantiomerically pure (R)-1-phenylethyl acetate or (S)-2-pentanol were successfully demonstrated in an ERD column. These processes provided high conversion rates of the substrates and purities of the product stream at milder process conditions compared to conventional processes.