Search

Your search keyword '"Cheng, Zhanjun"' showing total 560 results
Start Over Author "Cheng, Zhanjun"
560 results on '"Cheng, Zhanjun"'

167. The effect of CaO on coal gasification reaction with high-temperature copper slag as catalyst.

Author

Yang, Hanqi, Dong, Xinjiang, Zuo, Zongliang, Luo, Siyi, Cheng, Zhanjun, and Wang, Junzhi

Subjects
COAL gasification, COPPER catalysts, COPPER slag, CATALYST supports, SLAG, COPPER surfaces, CHEMICAL kinetics, SYNTHESIS gas
Abstract

In order to improve the calorific value and reducibility of the syngas produced by traditional coal gasification technology, and to solve the problem of high cost of heat source in coal gasification, this paper proposes to use high-temperature copper slag as the heat carriers and catalyst for coal gasification, and CaO as the CO2 adsorbent during the coal gasification reaction. In this way, the proportion of H2 in the syngas gas can be increased, and the coal gasification reaction can be improved. In the experiment, the samples with different ratios were fully mixed, and then thermogravimetric experiment and gasification experiment were carried out. Through research, the following rules were found. The use of high-temperature copper slag as the heat source and catalyst in coal gasification can lead to a 20% increase in the final weight loss rate. Additionally, when CaO is used as the CO2 adsorbent during the coal gasification reaction, a noticeable secondary weight loss occurs at around 600°C and can reach a maximum speed of 0.19%/min. The use of the C/S/CaO = 1/1/2 ratio can result in a maximum weight loss rate of 23%. Meanwhile, the C/S/CaO = 1/2/1 group has been shown to achieve a maximum weight loss speed of 0.5%/min, and the C/S/CaO = 1/1/1 group exhibits a maximum secondary weight loss speed of 0.32%/min. The samples after gasification experiment were analyzed by SEM, CaO produced clustered iron-based and porous structure on the surface of copper slag in gasification reaction. Based on the Coats-Redfern method, kinetics of gasification reaction is obtained, and the optimum fitting function is C2, mechanism functions didn't change with the variation of C/S/CaO. The research results suggest that CaO and copper slag can both enhance the coal gasification reaction. In addition, CaO is proven to be a more affordable and accessible CO2 adsorbent compared to other alternatives. [ABSTRACT FROM AUTHOR]

Published
2023
Full Text
View/download PDF

181. Experimental and kinetic modeling studies of low- to moderate-temperature oxidation of 2-furfuryl alcohol in a jet-stirred reactor.

Author

Wang, Jinglan, Gao, Xuezhi, Ding, Weimeng, Luan, Pengpeng, Li, Wang, Lv, Tenglong, Cheng, Zhanjun, Wei, Lixia, Yang, Jiuzhong, Zhao, Long, Yan, Beibei, and Chen, Guanyi

Abstract

2-Furfuryl alcohol, a promising platform chemical, and alternative fuels or additives, is produced from the hydrogenation of furfural. However, the low- to moderate-temperature oxidation study of 2-furfuryl alcohol is scarce up to now. The present study first performed the oxidation experiments in a jet-stirred reactor at the equivalence ratios of 0.5, 1.0, and 2.0. The oxidation species were identified and measured by the synchrotron vacuum ultraviolet photoionization mass spectrometry. No negative-temperature-coefficient behavior was observed. A detailed kinetic model was developed to better understand the consumption of 2-furfuryl alcohol and the formation of oxidation products. The present model can well reproduce the experimental results. Based on the rate of production analysis, H-abstraction reactions on hydroxymethyl group forming hydroxyl(2-furyl)methyl radical are the dominant pathways. Besides, the formation and consumption of main products, such as furfural, furan, acrolein, acetaldehyde, etc., are also discussed. Fuel radicals control the formation of furfural. Furan has multiple formation sources, such as the H-addition reactions on 2-furfuryl alcohol, furfural, and 2-hydroxyfuran. Acrolein is produced by the H-addition reaction on 2-hydroxyfuran and OH-addition reactions on furan. Also, the present work compares and discusses peak concentration for major oxidation products of 2-furfuryl alcohol and 2-methyl furan under the same simulated condition. 2-Furfuryl alcohol oxidation produces a higher concentration of furfural, furan, and acrolein than that of 2-methyl furan. OH on hydroxymethyl group promotes the H-abstraction reactions on the side chain and inhibits the OH-addition reaction on the furan ring. [ABSTRACT FROM AUTHOR]

Published
2023
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results