Biogas Upgrading Processes Analysis using Statistical Design of Experiments

MORERO, BETZABET; CAMPANELLA , ENRIQUE A.

Puerto Iguazu

Conferencia; Properties and Phase Equilibria for Process and Product Design 2013; 2013

International Organizing Committee

Biogas is a valuable renewable fuel produced from organic waste by anaerobic digestion. Biogas main components are methane (CH4), carbon dioxide (CO2), water (H2O) and hydrogen sulfide (H2S). The presence of CO2 and H2S is a problem for biogas to be used in gas processing facilities due to process and environmental restrictions. Prior knowledge of natural gas absorber-stripper processes and its current use for CO2 capture from the flue gas facilitated using this technology in the particular case of biogas. While it is a mature technology for natural gas purification and CO2 capture, it has not been deeply studied to the particular case of biogas. The main difference is that biogas has CO2 concentrations around 40% and CO2 concentration in natural gas and in flue gas is below 15%. The objective of this work is to compare different types of solvents in biogas purification. A conventional single-loop absorber-stripper process configuration was simulated with ProMax® for three types of solvents: DGA (Diglycolamine), DEPG (Dimethyl Ethers of Polyethylene Glycol) and water. Absorption temperature, absorption pressure, CO2 concentration, solvent flow rate and vapor rate (only for DGA) were considered as varying parameters. In order to study their effects on the energy consumption, CO2 capture and CH4 recovery, a full factorial design of experiment was used. This case is that of k factors, each at only two levels. Results show a significant relationship between some parameters and the responses analyzed.