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

Recent advances in siloxanes removal from biogas and their efficiency: a short review

Camila M. A. C. Alves, Flávia O. M. S. Abreu, Rinaldo S. Araújo, and Mona Lisa M. Oliveira

Programa de Pós-Graduação em Ciências Naturais, Universidade Estadual do Ceará (UECE), Fortaleza, Brazil

E-mail: camila.alves@aluno.uece.br

Received: 20 March 2022  Accepted: 22 August 2022

Abstract:

Siloxanes are semi-volatile silicon compounds with properties that make them possible to use in industrial products of daily use. Due to this, the siloxanes contained in shampoos and conditioners, for example, are transported through the sewage and tailings for wastewater, soils, and landfills. Consequently, the biogas from sources contaminated will have a high concentration of siloxanes. In the process of combustion of gas containing these compounds, other compounds are formed as SiO and SiO₂, and when they are in the condensed form inside the chambers, they have properties similar to those of ordinary glass. This process may cause incrustations in the engine components and the other system units, increasing the wear of the parts and the stops for maintenance, decreasing the thermal and electrical conductivity of the biogas. Searching methods for removing siloxanes from biogas in the literature, several methods were proposed, such as adsorption, absorption, gas cooling, biological removal, membranes, and others. Thus, this work aims to present the primary methods for removing several siloxane compounds from biogas from landfills and sewage and compare the removal efficiency. In general, activated carbon is the most consolidated in the literature and can vary from 13.3 to 100% in the removal efficiency of several siloxane compounds, depending on the removal process. However, industries have observed some limitations in the real process use of this material for siloxane removal into biogas.

Keywords: Siloxanes; Removal; Biogas; Review

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-022-02460-1

Chemical Papers 77 (1) 1–9 (2023)