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Pyrolysis of Date Stones Using Natural Activated Kaolin as a Catalyst – Optimization of Variables and Identification of Bio-Oil

Ibrahim Ahmed S., Fadhil Abdelrahman B.

Journal of Ecological Engineering

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2023

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Vol. 24, nr 10

225--241

EN

This research examines the catalytic performance of the catalyst developed from natural kaolin clay as a cheap catalyst for the thermal pyrolysis of date stones (DS). Firstly, the natural kaolin clay was acid-treated, followed by thermal activation at 600 °C for 2h to obtain the activated kaolin catalyst (AKC). Several techniques, like BET surface area, pore volume distribution, XRD, FESEM, and EDX, were utilized to identify the AKC. The BET surface area of the AKC was 119.49 m2/g, while its mean pore diameter amounted to 7.13 nm, indicating its mesoporosity. The catalytic activity of the AKC was examined via the thermal pyrolysis of DS. Effect of pyrolysis temperature (400–500 °C), catalyst loading (2.5–10.0 wt.%), pyrolysis period (30–120 min), and particle size of DS (0.25, 0.297, 0.4, 0.595, and 0.841 mm) on the pyrolysis products yield was investigated. The highest yield of pyrolytic liquid was produced at 425 °C for 1h using 2.5 wt.% of the AKC and 0.40 mm participle size of the feed. At these conditions, the pyrolytic liquid yield amounted to 60.64%. The analysis of the bio-oil (BO) fraction stripped from the pyrolytic liquid was achieved by FTIR spectroscopy, 1H NMR spectroscopy, and GC-MS analysis, which indicated that the BO fraction was mainly composed of hydrocarbons and oxygenated hydrocarbons. Results from the GC-MS analysis exhibited that hydrocarbons (48.28%), oxygenates (41.42%), aromatics (10.44%), and nitrogenates (2.13%) were the main components of the BO. Alkenes and n-alkanes were the main constituents of the hydrocarbon part of the BO, while acids were the main component of oxygenates. Non-catalytic thermal cracking of DS at the optimal conditions exhibited a lower pyrolytic liquid yield than the catalytic process. Finally, the fuel properties of the BO produced via catalytic pyrolysis of DS were superior to those measured for that produced by the thermal pyrolysis process.

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Catalytic pyrolysis of metal free PCBs with ZSM-5 and Ca(OH)2

Pandere Vaibhav, Gautam Alok, Gautam Shina

Chemical and Process Engineering

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2022

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Vol. 43, nr 2

171-–182

EN

Presence of heavier molecules and toxic brominated compounds in pyrolysis products of printed circuit boards (PCB) make their use difficult. In the present work to overcome this problem PCBs were pyrolyzed in presence of catalysts such as ZSM-5 and Ca(OH)2 to study their effect on pyrolysis products. The comparison of non-catalytic pyrolysis of PCB was done with oil and gas compositions produced by both techniques. Pyrolysis experiments were done at a lab scale set-up. However, the increased concentrations of ZSM-5 were found to increase char and gases were found to be rich in CH4 and O2. The composition of oils was mainly composed of phenols, phenol derivatives and aromatic compounds, which increased with pyrolysis with ZSM-5 and Ca(OH)2. Ca(OH)2 was found effective in removing brominated compounds from oil and no halogens were observed in oil. Char produced during pyrolysis was mesoporous in nature and composed of some fractions of metals and glass fibers.

3

Catalytic pyrolysis of rice straw and product analysis

Song C., Pawłowski A., Ji J., Shan S., Cao Y.

Environment Protection Engineering

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2014

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Vol. 40, nr 1

35--43

EN

The effect of addition of NaOH on the pyrolysis of rice straw and properties of its product were investigated. The pyrolysis was examined by means of the thermogravimetric (TG) analysis, and the pyrolysis product was characterized by the elemental analysis, GC and GC-MS. The result showed that addition of NaOH can significantly change TG and DTG peak of the pyrolysis of rice straw. As a result of the catalysis, significant difference in the properties of pyrolysis products was also observed. The addition of the catalyst promoted the increase of the hydrogen content of the gaseous product (from 1.6% to 53.37%), as well as that of the H/C and O/C ratios of solid residue. GC-MS analysis indicated that the liquid product was mainly made up of ketones, phenols and furfural, and NaOH addition did not change the main constitute of the liquid product, but changed their relative content.