温度和CO<sub>2</sub>对热解成型生物质炭孔隙结构和表面分形维数的影响

doi:10.11896/j.issn.1005-023X.2018.17.005

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Abstract By applying different pyrolysis temperature and CO₂ concentration conditions and using a fixed tube furnace, the present work prepared a series samples of biochar briquettes, whose pore structures and surface fractal dimensions were analyzed by SEM and nitrogen isothermal adsorption, and calculated using FHH method. The relationship between char samples’ pore structure and surface fractal dimension was investigated, as well as the effects of temperature and CO₂ concentration on them. The results showed that surface fractal dimension could well characterize pore structural complexity and surface irregularity, as it coincides with content fraction of micropore area and volume, rather than with BET surface area, total pore volume and average pore size. Both BET surface area and surface fractal dimension of biochar briquette reach peak value at 600 ℃ pyrolysis temperature under pure nitrogen. Under the mixed atmosphere of CO₂ and N₂, the increment of CO₂ concentration will lead to gradual increase of BET surface area, but a biphasic (decrease → increase) change in surface fractal dimension with an inflection point of 10% CO₂ concentration.

Key words： pyrolysis temperature CO₂ concentration biochar briquette FHH method pore structure surface fractal dimension

Published: 19 September 2018

CLC number:

TQ016

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	Articles by authors
	LIU Zewei
	YAN Sijia
	XIA Zihao
	TIAN Lin
	LIU Yukang
	WANG Jingcheng
	HU Jianhang

Cite this article:

LIU Zewei,YAN Sijia,XIA Zihao, et al. Effects of Temperature and CO₂ on Pore Structure and Surface Fractal Dimension of Pyrolytic Carbonized Biochar Briquettes[J]. Materials Reports, 2018, 32(17): 2925-2931.

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http://www.mater-rep.com/EN/10.11896/j.issn.1005-023X.2018.17.005 OR http://www.mater-rep.com/EN/Y2018/V32/I17/2925

1 He S S, Li W, Wang L Z, et al. Combustion characteristics and working condition optimization for wood and herb biomass[J]. Materials Review B: Research Papers,2017,31(3):50(in Chinese).
何姗姗,李薇,王灵志,等.木质与草本生物质燃烧特性及工况优化研究[J].材料导报:研究篇,2017,31(3):50.
2 Heidenreich S, Foscolo P U. New concepts in biomass gasification[J].Progress in Energy & Combustion Science,2015,46:72.
3 Cheah S, Jablonski W S, Olstad J L, et al. Effects of thermal pretreatment and catalyst on biomass gasification efficiency and syngas composition[J].Green Chemistry,2016,18(23):6291.
4 Xie M, Lv D, Shi X, et al. Sorption of monoaromatic compounds to heated and unheated coals, humic acid, and biochar: Implication for using combustion method to quantify sorption contribution of carbonaceous geosorbents in soil[J].Applied Geochemistry,2013,35(4):289.
5 Tan X, Liu Y, Zeng G, et al. Application of biochar for the removal of pollutants from aqueous solutions[J].Chemosphere,2015,125:70.
6 Wang S, Gao B, Zimmerman A R, et al. Removal of arsenic by magnetic biochar prepared from pinewood and natural hematite[J].Bioresource Technology,2015,175:391.
7 Chen Y, Yang H, Wang X, et al. Biomass-based pyrolytic polyge-neration system on cotton stalk pyrolysis: Influence of temperature[J].Bioresource Technology,2012,107:411.
8 Obi O F. Evaluation of the physical properties of composite briquette of sawdust and palm kernel shell[J].Biomass Conversion & Biorefi-nery,2015,5(3):271.
9 Liu Z, Zhang F, Liu H, et al. Pyrolysis/gasification of pine sawdust biomass briquettes under carbon dioxide atmosphere: Study on carbon dioxide reduction (utilization) and biochar briquettes physicochemical properties[J].Bioresource Technology,2018,249:983.
10 Wang Q, Han K, Gao J, et al. Investigation of maize straw char briquette ash fusion characteristics and the influence of phosphorus additives[J].Energy & Fuels,2017,31(3):2822.
11 Wang Q, Han K, Gao J, et al. The pyrolysis of biomass briquettes: Effect of pyrolysis temperature and phosphorus additives on the quality and combustion of bio-char briquettes[J].Fuel,2017,199:488.
12 Tumuluru J S, Hess J R, Boardman R D, et al. Formulation, pretreatment, and densification options to improve biomass specifications for co-firing high percentages with coal[J].Industrial Biotechnology,2012,8(3):113.
13 Lee H M, Kim H G, An K H, et al. The effect of CO₂ activation on the electrochemical performance of coke-based activated carbons for supercapacitors[J].Journal of Nanoscience & Nanotechnology,2015,15(11):8797.
14 Wang J, Xiong Z, Kuzyakov Y. Biochar stability in soil: Meta-analysis of decomposition and priming effects[J].Global Change Biology Bioenergy,2016,8(3):512.
15 Deng L, Lu B, Li J, et al. Effect of pore structure and oxygen-containing groups on adsorption of dibenzothiophene over activated carbon[J].Fuel,2017,200:54.
16 Liu L. Effect of pore structure and surface chemical properties on adsorption properties of activated carbons[J].Chinese Journal of Environmental Engineering,2012,6(4):1299.
17 Khanmohammadi Z, Afyuni M, Mosaddeghi M R. Effect of pyrolysis temperature on chemical and physical properties of sewage sludge biochar[J].Waste Management & Research,2015,33(3):275.
18 Chen D, Chen X, Sun J, et al. Pyrolysis polygeneration of pine nut shell: Quality of pyrolysis products and study on the preparation of activated carbon from biochar[J].Bioresource Technology,2016,216:629.
19 Usman A R A, Abduljabbar A, Vithanage M, et al. Biochar production from date palm waste: Charring temperature induced changes in composition and surface chemistry[J].Journal of Analytical & Applied Pyrolysis,2015,115:392.
20 Mandelbrot B B. Stochastic models for the Earth’s relief, the shape and the fractal dimension of the coastlines, and the number-area rule for islands[J].Proceedings of the National Academy of Sciences of the United States of America,1975,72(10):3825.
21 Kaizhi L I, Yang H, Chen Y, et al. Investigation of the forming property and fractal dimension of cotton char pore structure during biomass pyrolysis[J].Proceedings of the CSEE,2012,32:115.
22 He Wei, Liu Yuting, He Rong, et al. Combustion rate for char with fractal pore characteristics[J].Combustion Science & Technology,2013,185(11):1624.
23 Fu P, Hu S, Xiang J, et al. Study on the gas evolution and char structural change during pyrolysis of cotton stalk[J].Journal of Analytical & Applied Pyrolysis,2012,97(9):130.
24 Fu P, Hu S, Xiang J, et al. Evaluation of the porous structure deve-lopment of chars from pyrolysis of rice straw: Effects of pyrolysis temperature and heating rate[J].Journal of Analytical & Applied Pyrolysis,2012,98(98):177.
25 Guizani C, Sanz F J E, Salvador S. Effects of CO₂ on biomass fast pyrolysis: Reaction rate, gas yields and char reactive properties[J].Fuel,2014,116:310.
26 Kwon E E, Jeon Y J, Yi H. New candidate for biofuel feedstock beyond terrestrial biomass for thermo-chemical process (pyrolysis/ga-sification) enhanced by carbon dioxide (CO₂)[J].Bioresource Technology,2012,123(1):673.
27 Borrego A G, Garavaglia L, Kalkreuth W D. Characteristics of high heating rate biomass chars prepared under N₂ and CO₂ atmospheres[J].International Journal of Coal Geology,2009,77(s3-4):409.
28 Fu P, Yi W, Li Z, et al. Evolution of char structural features during fast pyrolysis of corn straw with solid heat carriers in a novel V-shaped down tube reactor[J].Energy Conversion & Management,2017,149:570.
29 Huo W, Zhou Z, Wang F, et al. Experimental study of pore diffusion effect on char gasification with CO₂ and steam[J].Fuel,2014,131(3):59.