Preparation Of Mw-Assisted N-Modified Palm Shell Activated Carbon For H2s Removal From Simulated Pome Biogas

Nor, Norhusna Mohamad (2016) Preparation Of Mw-Assisted N-Modified Palm Shell Activated Carbon For H2s Removal From Simulated Pome Biogas. PhD thesis, Universiti Sains Malaysia.

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Abstract

Kehadiran H2S di dalam biogas boleh menganggu proses pertukaran gas metana (CH4) kepada tenaga yang boleh diperbaharui disebabkan oleh kesan pengaratan kepada peralatan dan kesan keracunan kepada kesihatan manusia. Objektif utama kajian ini adalah untuk mengubahsuai sejenis karbon teraktif tempurung kelapa sawit melalui pengubahsuaian nitrogen (N-KTTKS) dan kaedah pemanasan ketuhar gelombang mikro (GM) untuk menyingkirkan H2S daripada POME biogas yang disimulasi. Satu kajian awal mengenai pemilihan kaedah yang terbaik untuk menghasilkan bahan penyerap yang lebih berkualiti telah dilakukan dan kaedah pemanasan GM telah dipilih berbanding dengan kaedah pemanasan secara konvensional. Bahan penyerap N-KTTKS yang berkualiti tinggi telah dihasilkan melalui pemanasan GM dan kondisi pembolehubah GM yang digunakan adalah; 900 °C suhu pemanasan GM, 400 ml/min kadar aliran N2, 10 minit masa pemanasan GM, dan 3 g jumlah sampel. Kaedah pemanasan GM mnghasilkan penyatuan kumpulan berfungsi nitrogen di dalam matriks karbon N-KTTKS dengan lebih baik dan membangunkan struktur permukaan dan poros karbon, seterusnya dipercayai menjadi faktor utama yang menyumbang kepada kapasiti penyerapan H2S yang tinggi. Dengan menggunakan bahan penyerap N-KTTKS bagi sebelum dan selepas penyerapan H2S, hasil butiran pencirian menyimpulkan bahawa kedua-dua penyerapan fizikal dan kimia telah berlaku semasa proses penyerapan H2S. Satu analisis penembusan yang lengkap untuk pelbagai keadaan operasi iaitu kelembapan, suhu operasi, jumlah bahan penyerap, kadar aliran biogas dan kepekatan suapan H2S telah mempengaruhi kapasiti penyerapan H2S ke atas bahan penyerap N-KTTKS. Dapat disimpulkan bahawa tetapan sedia ada (iaitu 35 °C, 45% RH dan 3000 H2S ppm) di kilang minyak sawit Felda Besout adalah sesuai untuk penyerapan H2S dengan menggunakan bahan penyerap N-KTTKS tanpa mengubah parameter operasi. Penjanaan semula secara kering melalui kaedah GM terbukti dapat menjana semula bahan penyerap N-KTTKS tepu H2S sehingga lebih daripada 100% keberkesanan penjanaan semula dan telah diuji untuk 20 kitaran penjanaan semula. Ramalan keseimbangan penyerapan H2S menunjukkan bahawa model isoterma Freundlich sesuai dengan data eksperimen.Sifat-sifat termodinamik menilai penyerapan H2S menggunakan bahan penyerap N-KTTKS sebagai proses eksotermik dengan spontan dan secara rawak. Tenaga pengaktifan dan faktor frekuensi bagi penyerapan H2S adalah 15.60 kJ/mol dan 3.90 x 102 sm3/g.min, setiap satu. Model kinetik pendeaktifan didapati menepati data eksperimen penyerapan H2S. ________________________________________________________________________________________________________________________ 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.

Item Type:	Thesis (PhD)
Additional Information:	Full text is available at http://irplus.eng.usm.my:8080/ir_plus/institutionalPublicationPublicView.action?institutionalItemId=3128
Subjects:	T Technology T Technology > TP Chemical Technology > TP1-1185 Chemical technology
Divisions:	Kampus Kejuruteraan (Engineering Campus) > Pusat Pengajian Kejuruteraan Kimia (School of Chemical Engineering) > Thesis
Depositing User:	Mr Mohd Jasnizam Mohd Salleh
Date Deposited:	03 Sep 2018 08:02
Last Modified:	03 Sep 2018 08:02
URI:	http://eprints.usm.my/id/eprint/41654

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