Amine based amino acid salts were investigated in this study by using a bubbling CO2 absorption and regeneration reactor to assess their CO2 absorption performance from the simulated biogas and regeneration characteristics. In addition, monoethanolamine (MEA) and piperazine (PZ) were also experimented to compare with these amine based amino acid salts. In the experiments, the typical biogas consisting of 40% CO2 and 60% CH4 was used under the ambient circumstance, while 35°C and 75°C were adopted to act as the absorption and regeneration temperatures of solvents, respectively. And pure CH4 was also used to act as the sweeping gas during CO2 regeneration stage. The results showed that when the equilibrium CO2 absorption and regeneration statuses were reached, the net CO2 cyclic capacities of all the four MEA-based amino acid salts were higher than MEA, and MEA-based L-ornithinate (MEAORN) with 30% weight fraction owned the highest value (about 0.733 mol/mol), which was approximate 82.43% higher than PZ with 15% weight fraction gaining the second higher CO2 cyclic capacity. Furthermore, CO2 removal costs from biogas of different absorbents were assessed and compared when considering the regeneration energy consumption and investment of absorber and desorber. Results showed that no matter the scale of CO2 absorption plant was taken into application, the CO2 removal costs of MEAORN and PZ might be less than MEA. And MEAGLY might have the potential to act as the most promising alternative to replace MEA in the large-scale biogas upgrading plants.
|Number of pages||7|
|Journal||Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery|
|Publication status||Published - 2014|
- amino acid
- biogas purification
- chemical absorption process