Preparation of mw-assisted n-modified palm shell activated carbon for h2s removal from simulated pome biogas

Loading...
Thumbnail Image
Date
2016-01-01
Authors
Norhusna Mohamad Nor
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
The presence of H2S in biogas could disturb the conversion of methane (CH4) to renewable energy due to its corrosive effect to equipment and its toxicity to human health. The main objective of this study is to develop a nitrogen-modified palm shell activated carbon (N-PSAC) via microwave (MW) heating method for H2S removal from simulated POME biogas. A preliminary study on choosing preferable method of producing high performance of sorbent was done and MW heating method was selected compared to conventional heating method. The preparation of a high quality of N-PSAC sorbent was done under MW heating variables; 900 °C of MW heating temperature, 400 ml/min of N2 flow rate, 10 minute of MW heating time and 3 g of sample amount. MW heating method provides better incorporation of nitrogen functional groups in the N-PSAC carbon’s matrix and well-developed surface and porous structures are believed to be predominant factors that contribute in high H2S sorption capacity. The details characterizations of the N-PSAC sorbent before and after H2S sorption concluded that both physical and chemical sorptions were taken place during the sorption process. A complete breakthrough analysis of various operating conditions namely relative humidity, operating temperature, amount of sorbent, biogas feed flow rate and H2S feed concentration were influencing the sorption capacity of H2S onto N-PSAC sorbent. It can be concluded that the existing settings in Felda Besout palm oil mill (i.e. 35 °C, 45% RH and 3000 ppm H2S) are favorable for H2S sorption by using the N-PSAC sorbent without altering the operating parameters. The MW dry-regeneration method is proven to regenerate H2S saturated N-PSAC sorbent up to 100% regeneration efficiency and was tested for 20 regeneration cycles. The predictions of H2S sorption equilibrium showed that Freundlich isotherm model fitted well with the experimental data. The thermodynamic properties evaluates the H2S sorption using N-PSAC sorbent as an exothermic process with spontaneous and randomly distributed. The activation energy and frequency factor for H2S sorption were found to be 15.60 kJ/mole and 3.90 x 102 cm3/g.min, respectively. The deactivation kinetic model was found to give a very good agreement with the experimental data of H2S sorption.
Description
Keywords
Citation