Catalytic co-pyrolysis of sugarcane bagasse and waste plastics using zeolite and hydroxyapatite based catalyst for high quality pyrolysis oil in a fixed-bed reactor / Hamizura Hassan
Kesusutan sumber asli, permintaan petroleum yang besar dan kebimbangan alam sekitar telah mencetus motivasi kajian pada bahan api boleh diperbaharui dari biomas. Kajian ini bertujuan menyelidik co-pirolisis dan co-pirolisis bermangkin ke atas hampas tebu (SCB) dan polietilena berkepadatan tinggi (HDPE) atau polietilena teraftalat (PET) di dalam reaktor lapisan tetap pemanasan perlahan menggunakan pemangkin zeolit (FAU-EAFS) dan hidroksiapatit-zeolit (HAP-ZE) yang disediakan dari arka elektrik sanga relau. Dalam proses co-pirolisis, kesan suhu tindak balas (400-700 ℃) dan nisbah biomas kepada plastik (100:0-0:100) ke atas hasil keluaran, komposisi kimia dan juga kesan bersinergi telah dikaji. 63.69 wt% hasil cecair optimum dicapai pada 600 °C dan nisbah SCB kepada HDPE 60:40 di dalam co-pirolisis SCB dan HDPE manakala 60.94 wt% hasil cecair dicapai pada 600 °C dan nisbah SCB kepada PET 40:60. Dalam bahagian co-pirolisis bermangkin, kesan suhu tindak balas (400-700 ℃), nisbah pemangkin kepada bahan mentah (1:10-1:2) dan nisbah plastik kepada biomas (0:100-100:0) ke atas hasil keluaran dan komposisi kimia telah dikaji. 68.56 wt% and 71.01 wt% maksimum minyak-pirolisis diperolehi dalam co-pirolisis bermangkin SCB dan HDPE menggunakan pemangkin FAU-EAFS dan HAP-ZE. Co-pirolisis bermangkin SCB dan PET menggunakan pemangkin FAU-EAFS dan HAP-ZE, menghasilkan 42.95 wt% and 45.64 wt%, maksimum minyak-pirolisis. Co-pirolisis bermangkin SCB dan HDPE menggalakkan pengeluaran hidrokarbon dan alkohol manakala co-pirolisis bermangkin SCB dan PET meningkatkan pengeluaran aromatik dan asid. Berbanding HAP-ZE, FAU-EAFS menunjukkan prestasi yang lebih baik dalam pengeluaran hidrokarbon dan aromatik semasa co-pirolisis bermangkin SCB dan HDPE atau PET kerana keasidan yang kuat dan saiz liang yang lebih besar yang meningkatkan tindak balas peretakan dan penyahoksigen dan kecekapan resapan wap pirolisis ke dalam liang pemangkin. Kelakuan pirolisis haba, co-pirolisis dan co-pirolisis bermangkin bagi SCB dan HDPE telah ditentukan menggunakan analisis termogravimetri manakala parameter kinetik telah dikira menggunakan kaedah Coats-Redfern. Di kawasan kedua di mana uraian selulosa dan hemiselulosa menjadi dominan, kolerasi paling sesuai untuk HDPE diperihalkan oleh mekanisme tindak balas kimia tertib pertama, manakala sampel tindak balas lain dikawal oleh model resapan. Manakala, di kawasan ketiga di mana tindak balas di antara SCB dan HDPE berlaku, kesemua sampel tindak balas mengikut mekanisme tindak balas tertib. Penambahan pemangkin FAU-EAFS dan HAP-ZE menghasilkan tenaga pengaktifan yang lebih rendah di kawasan kedua di dalam co-pirolisis bermangkin SCB dan HDPE.
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Depletion of natural resources, massive demand for petroleum, and environmental concern have motivated studies on renewable fuel from biomass conversion. This study aims to investigate the co-pyrolysis and catalytic co-pyrolysis of sugarcane bagasse (SCB) with high-density polyethylene (HDPE) or polyethylene terephthalate (PET) in a slow-heating fixed-bed reactor over faujasite type zeolite (FAU-EAFS) and hydroxyapatite-zeolite (HAP-ZE) catalysts prepared from electric arc furnace slag. In co-pyrolysis process, the effects of reaction temperature (400-700 ℃) and biomass-to-plastic ratio (100:0-0:100) on the products yields, chemical compositions as well as synergistic effect were investigated. The optimum liquid yield of 63.69 wt% was achieved at 600 °C and 60:40 SCB: HDPE ratio in co-pyrolysis of SCB and HDPE while 60.94 wt% of liquid yield was achieved at 600 °C and 40:60 SCB: PET ratio in co-pyrolysis of SCB and PET. In catalytic co-pyrolysis section, the effects of reaction temperature (400-700 ℃), catalyst-to-feedstock ratio (1:10-1:2) and biomass-to-plastic ratio (100:0-0:100) on the product yields and chemical compositions were investigated. The maximum pyrolysis oil yield of 68.56 wt% and 71.01 wt% were obtained under catalytic co-pyrolysis of SCB and HDPE over FAU-EAFS and HAP-ZE, respectively. The catalytic co-pyrolysis of SCB and PET over FAU-EAFS and HAP-ZE, produced maximum pyrolysis oil yield of 42.95 wt% and 45.64 wt%, respectively. The catalytic co-pyrolysis of SCB and HDPE promoted the production of hydrocarbon and alcohol while the catalytic co-pyrolysis of SCB and PET enhanced the aromatic and acid production. Compared to HAP-ZE, the FAU-EAFS showed better performance in the production of hydrocarbon and aromatic during catalytic co-pyrolysis of SCB with HDPE or PET, due to its strong acidity and larger pore size which enhanced cracking and deoxygenation reactions and diffusion efficiency of pyrolysis vapors into the catalyst pore. Thermal pyrolysis, co-pyrolysis and catalytic co-pyrolysis behaviour of SCB and HDPE were determined using thermogravimetric analysis while the kinetic parameters were calculated via Coats-Redfern method. In the second region, where the decomposition of cellulose and hemicellulose are dominant, the best correlation for HDPE can be described by first order chemical reaction mechanism, whereas the other reaction samples are controlled by diffusion model. Meanwhile, in the third region, where the interaction between SCB and HDPE took place, all of the reactions samples followed the order of reaction mechanisms. An addition of FAU-EAFS and HAP-ZE catalysts resulted in lower activation energy in the second region during co-pyrolysis of SCB and HDPE.
Catalytic co-pyrolysis of sugarcane bagasse and waste plastics using zeolite and hydroxyapatite based catalyst for high quality pyrolysis oil in a fixed-bed reactor / Hamizura Hassan
Catalytic co-pyrolysis of sugarcane bagasse and waste plastics using zeolite and hydroxyapatite based catalyst for high quality pyrolysis oil in a fixed-bed reactor_Hamizura Hassan_K4_2019_MYMY