Design and Analysis of Packed Bed Activated Carbon Reactor for the Enrichment of Biogas

Abstract

Abstract- Biogas produced by anaerobic digestion of organic matters has reasonable potential to replace natural gas need of the world energy consumption. According to the UK National Non-Food Crops Centre (NNFCC), the anaerobic digestion (AD) industry experienced rapid growth in recent years. Thus, there is an increasing demand for the enriched biogas, to be used as vehicle fuel or injected to the natural gas grid. Since a typical biogas contains 50-65% methane, 30- 45% carbon dioxide, 1000 - 10,000 ppm hydrogen sulphide, the removal of carbon di-oxide and hydrogen sulphide is required for upgrading the biogas. A number of methods exist for enriching biogas including water scrubbing system, membrane separation, chemical absorption, cryogenic separation and physical adsorption. Among these methods, adsorption by activated carbons (AC) is considered as an efficient and economical approach. The uniqueness of the activated carbon as adsorbents is due to their high surface area, developed pore volume and surface properties. Accordingly, this research has been focused on adsorption of activated carbon. An activated carbon packed-bed reactor designed and commissioned at laboratory scale. Biogas mixture passed through the packed bed reactor and benchmarked against the Standard Industrial Activated Carbon (SIAC). Break through curves were used to assess the adsorption capacities. It is envisioned that this method can transform the enrichment of bio-gas for power generation systems. The results obtained from the current research could be utilized as a guide for the further design and operation of the industrial system.