ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Design simulations for a biogas purification process using aqueous amine solutions

Richard A. Gawel

Department of Solid State Chemistry, Faculty of Materials Science and Ceramics, AGH University of Science and Technology, Aleja Mickiewicza 30, 30-059 Krakow, Poland

E-mail: ragaw@agh.edu.pl

Abstract: Using the simulation program CHEMCAD, performance characteristics, design optimization, and costs of an absorption/stripping system used to purify 100 kg h⁻¹ of biogas in a biogas power plant were investigated. Potential absorbents used in the chemical absorption process were the following aqueous solutions: pure diglycolamine, diglycolamine/piperazine, and diglycolamine/methyldiethanolamine/piperazine. Mixtures for agricultural biogas purification to below 1 vol. % of CO₂ and 4 × 10⁻⁴ mass % of H₂S were determined via a simulation in the above mentioned program. The chosen mixtures were then entered into an absorption/desorption system and simulations for each unit were provided by CHEMCAD. From the simulation results, the design parameters were calculated and entered into each unit’s “cost estimation” section in the aforementioned program to estimate the purchase costs of the apparatuses. Taking into account the installation, maintenance, as well as other additional costs, the actual machine purchase costs were multiplied by the Lang factor. Costs of additional streams were also calculated by multiplying the ten-year utility losses by their respective cost factors. From these calculations, the absorbent mixture, allowing biogas production at the lowest estimated costs for ten years, was found.

Keywords: amine sweetening – biogas purification – chemical absorption – cost comparison

Full paper is available at www.springerlink.com.

DOI: 10.2478/s11696-012-0211-x

Chemical Papers 66 (11) 1010–1018 (2012)