Sorption-enhanced processes

A sorption-enhanced process being developed by Air Products and Chemicals promises to reduce manufacturing costs by another 25-30 percent by removing C02 during the reaction. 

This chapter is organised as follows firstly, enhanced processes concepts are presented (Section 6.2), then the sorbent properties and performances (Section 6.3), thirdly enhanced reactor configurations (Section 6.4) are discussed and finally, examples of performances and economic benefits of sorption-enhanced processes for CO2 capture are shown (Section 6.5). 

The Ohio State University proposed a method to combine coal gasification with a carbonation/calcination reaction (CCR) process to produce hydrogen [27]. CCR is also a sorption-enhanced process. In contrast to the ZECA process, the CCR method uses CaO to promote WGS reaction as follows ... 

In the sorption-enhanced reforming (SER) process, one of the gaseous reaction products (C02) of the catalytic reforming reaction is separated from the reaction zone by sorption. As a result, the equilibrium of the reaction is shifted toward products according to the Le Chatelier s principle. Balasubramanian et al. [18] studied the SMR reaction in the presence of CaO as a C02 acceptor. Thus, in addition to reactions 2.4 and 2.6, the reaction of C02 with the C02 acceptor (CaO) takes place in the reaction zone ... 

Hufton, J. et al., Sorption enhanced reaction process for the production of hydrogen, Proc. U.S. DOE Hydrogen Prog. Rev., Herndon, VA, 179,1997. 

Hufton, J.R., S. Mayorga, and S. Sircar, Sorption-enhanced reaction process for hydrogen production, AIChE., 45(2), 248-255, 1999. 

Waldron, W.E., J.R. Hufton, and S. Sircar, Production of hydrogen by cyclic sorption enhanced reaction process, AIChE., 47(6), 1477-1479, 2001. 

Ding and Alpay also studied sorption-enhanced reforming with K-HTC as sorbent [28], using a commercial Ni-based catalyst. They found that the SER process benefits from higher pressures and that lower steam to methane ratios can be used than in ordinary reforming. Reijers et al. [25] have shown that K-HTC is an effective sorbent between 400 and 500 °C, with an C02 uptake of approx. 0.2 mmol g 1. This capacity is low compared with calcium oxides and lithium zirconates. Above 500 °C, the C02 sorption capacity of K-HTC decreases rapidly to zero [36]. 

Sorption-Enhanced Reaction Process for Production of Hydrogen Air Products... 

In this section the methods developed in the previous section will be applied to analyze the dynamic behavior of integrated reaction separation processes. Emphasis is placed on reactive distillation and reactive chromatography. Finally, possible applications to other integrated reaction separation processes including membrane reactors and sorption-enhanced reaction processes will be briefly discussed. More details about reactive distillation processes were provided in Ref. [39]. For chromatographic reactors the reader should refer to Chapter 6 of this book, for sorption-enhanced reaction processes to Chapter 7, and for membrane reactors to Chapter 12. 

The theory presented above also applies to other integrated reaction separation processes which fall into the class of systems illustrated in Fig. 5.1. Typical examples are sorption-enhanced gas phase reactions (as described in Chapter 7) or membrane reactors (as described in Chapter 12). 

As in reactive distillation and reactive chromatography, many sorption-enhanced reaction processes are controlled by phase equilibrium in addition to reaction equilibrium. The situation is different for membrane reactors, where phase equilibrium between the phases adjacent to the membrane is often trivial and the process is... 

S. G. Mayorga, J. R. Hufton, S. Sircar, et ah, Sorption enhanced reaction process for production of hydrogen -Phase 1, final report, U.S. dept, of energy DE-FC36-95G010059, 1997. 

SER [Sorption Enhanced Reaction] A modification of the steam reforming process for making hydrogen, in which a selective adsorbent removes the carbon dioxide, thereby reducing the temperature required from 800 to 1000°C to 500 to 800°C Developed by Air Products and Chemicals Ltd. in 1998. 

Xiu, G.H., Li, P., and Rodrigues, A.E. Subsection-controlling strategy for improving sorption-enhanced reaction process. Chemical Engineering Research Design, 2004, 82 (2), 192. 

Sorption-Enhanced Reaction Process (SERP) for H2 Production... 

Carvill, B.T., Hufton, J.R., Anand, M., and Sircar, S. Sorption enhanced reaction process. AIChE Journal, 1996, 42, 2765. 

SERP. See adsorption, pressure swing SE-SMR. See sorption-enhanced steam methane reforming process Shanxi New Style Fuel and Stove Company, 520... 

Natural substances, especially natural organic matter, have important effects on halocarbon photoreactions in the environment. These effects include the initiation of indirect photoreductions of dissolved or sorbed halocarbons via the intermediacy of solvated electrons or excited states. Evidence is presented here that sorption enhances the quantum efficiencies of these indirect photoreactions, although more studies are required to better define these processes. 

Pressure swing reactors (PSR) or sorption enhanced reaction process (SERP)... 

Simulation of a Sorption Enhanced Steam reforming Process... 

Jprgensen [71] simulated a sorption enhanced steam reforming process em-plo3dng an extended PGT model derived by Lindborg [91] and Lindborg et al [92]. The reactor configuration used operating the novel chemical process is defined in table 10.6. 

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