The performance of a novel thermal swing sorption-enhanced reaction (TSSER) concept for simultaneous production of fuel-cell grade hydrogen and compressed carbon dioxide as a by-product from a synthesis gas feed is simulated using Na2O promoted alumina as a CO2 chemisorbent in the process. The process simultaneously carries out the water gas shift (WGS) reaction and removal of CO2 from the reaction zone by chemisorption in a single unit. Periodic regeneration of the chemisorbent is achieved by using the principles of thermal swing adsorption employing super-heated steam purge. Recently measured equilibrium and kinetic data for chemisorption and desorption of CO2 on the promoted alumina using conventional column dynamic tests as well as new experimental data demonstrating the concept of sorption-enhanced WGS reaction using the material are reviewed. The simulated performance of the TSSER process employing this material as a chemisorbent is compared with the process performance using K2CO3 promoted hydrotalcite as the chemisorbent. The promoted alumina exhibited (i) ∼15% lower H2 productivity at a slightly reduced CO to H2 conversion, and (ii) comparable compressed CO2 productivity at a higher CO2 recovery, albeit at a relatively lower product pressure. However, the steam duty for regeneration of the chemisorbent was reduced by ∼50% for the promoted alumina.
Bibliographical noteFunding Information:
The work was partly supported by the Pennsylvania Infrastructure Technology Alliance grants (PITA-442-04 and PITA-542-5), by the U.S. Department of Energy under cooperative agreement DE-P S26-04NT-42454, and by a donation from Air Products and Chemicals Inc.
- Carbon dioxide
- Fuel-cell grade hydrogen
- Promoted alumina
- Promoted hydrotalcite
- Sorption-enhanced reaction
- Thermal swing chemisorption
ASJC Scopus subject areas
- Renewable Energy, Sustainability and the Environment
- Energy Engineering and Power Technology
- Physical and Theoretical Chemistry
- Electrical and Electronic Engineering