Study on comminution characteristics of straw biomass

doi:10.11949/0438-1157.20241342

Abstract

Abstract:

One of the effective methods to enhance the efficiency of biomass gasification is to achieve high-efficiency and low-energy consumption in the fine powder preparation of raw biomass in a non-baked state. The comminution characteristics of five common types of straws (corn, sesame, wheat, cotton and reed) were investigated under different moisture content (0.3%—15.3%) and screen sizes (1.0, 1.5, 2.0 mm). It is found that moisture content, screen sizes and types of raw material have significant effect on specific energy consumption and particle size. With the decrease of moisture content, the specific energy consumption is reduced by 43.38%—61.64%, and can be reduced to 36.9 kW·h/t. The particle size parameter d₉₀ of the product is reduced by 3.87%—22.36%. With the same moisture content, the specific energy consumption of the 1.0 mm screen is increased by 39.04% to 169.98% compared to that of the 2.0 mm screen. Mechanical tests reveal that the reduction of moisture content decreases the shear strength of straw by 12.36%—17.13%, and increases the Young's modulus by 1.74%—9.00%. This leads to a transformation in the grinding mechanism, whereby plastic deformation is replaced by brittle fracture. On the other hand, the lignin filling the cellulose frame enhances the mechanical strength of the straw. The lignin content of cotton straw and reed are approximately twice that of the remaining three types of straw, so the specific energy consumption of cotton straw and reed comminuting is always higher than that of the other three types of straw at the same moisture content. Based on the specific energy consumption per unit mass of powder with a particle size less than 1 mm, it is found that the effective specific energy consumption E_tcan be reduced a by a range of 21.06% to 55.54% when a 2.0 mm screen is utilized in comparison to a 1.0 mm screen. A prediction model of specific energy consumption based on moisture content and particle size was established with a deviation of less than ±15%.

Key words: biomass, straw, comminution, energy consumption, moisture content, mechanical property

摘要：

生物质气流床气化工艺中，在非烘焙状态下实现原始生物质的高效、低能耗细粉制备是提高生物质气化效率的有效途径之一。研究了五种常见秸秆（玉米、芝麻、小麦、棉花和芦苇）在不同水分含量（0.3%~15.3%）和筛网尺寸（1.0、1.5和2.0 mm）下的锤磨粉碎特性。实验结果表明，水分含量、筛网尺寸和秸秆种类对秸秆粉碎的比能耗和产物粒度影响显著。随着水分含量减少，比能耗降低43.38%~61.64%，最高可以减小至36.9 kW·h/t；同时产物粒径参数d₉₀降低了3.87%~22.36%。相同水分下，1.0 mm筛网比能耗比2.0 mm筛网增加39.04%~169.98%。水分降低使得秸秆的抗剪强度减小12.36%~17.13%，杨氏模量增大1.74%~9.00%，从而导致粉碎机制由塑性变形向脆性断裂转变，是能耗降低的关键原因。另一方面，填充于纤维素构架中的木质素强化了秸秆的力学强度。棉花秸秆和芦苇的木质素含量约为其余三种秸秆的2倍，所以相同水分下棉花秸秆和芦苇粉碎的比能耗总是高于其他三种秸秆。以小于1 mm粒度的单位质量粉体比能耗为基准，发现2.0 mm筛网的有效比能耗E_t相比于1.0 mm筛网减小21.06%~55.54%。建立了基于水分含量和粒度的比能耗预测模型，误差为±15%。

关键词: 生物质, 秸秆, 粉碎, 能耗, 水分含量, 力学性能

CLC Number:

TK 6

Xincheng LU, Xiaolei GUO, Shicheng WANG, Haifeng LU, Haifeng LIU. Study on comminution characteristics of straw biomass[J]. CIESC Journal, 2025, 76(7): 3539-3551.

陆昕晟, 郭晓镭, 王世丞, 陆海峰, 刘海峰. 秸秆类生物质的粉碎特性研究[J]. 化工学报, 2025, 76(7): 3539-3551.

Figures/Tables 19

Fig.1 The coarsely milled experimental materials

Table 1 Composition of straws on a dry basis

物料	纤维素/%	半纤维素/%	木质素/%
A	50.72	25.86	11.11
B	45.62	20.88	12.75
C	40.32	33.99	11.94
D	43.45	18.77	23.07
E	50.43	21.90	22.29

Table 2 Initial moisture content of experimental materials

物料	水分含量/%
A	8.14
B	15.11
C	10.67
D	15.33
E	14.32

Fig.2 Particle size distribution of experimental materials

Table 3 Particle size parameters before comminution

物料	d₁₀/mm	d₅₀/mm	d₉₀/mm
A	3.31	6.45	12.53
B	3.61	6.97	13.85
C	4.63	8.28	14.82
D	4.80	8.75	15.39
E	4.85	8.83	15.95

Fig.3 Flow chart of the experiment

Fig.4 Hammer mill(Xulang LX-60C)

Fig.5 Example of power curve

Fig.6 Relationship between moisture content and specific energy consumption

Fig.7 Comparison of specific energy consumption of the same material under different screen sizes

Fig.8 Particle size parameters after comminution through different screen sizes

Fig.9 Shape parameters of straw particles after comminution with different screen sizes

Fig.10 Effective specific energy consumption based on target particle size

Fig.11 Packing characteristics of straw after comminution with different screen sizes

Fig.12 Mechanics parameters for straws

Fig.13 The fitting of Von Rittinger’s theoretical model

Fig.14 The relationship between characteristic parameter C and MC

Table 4 Fitting parameters and correlation coefficients

物料	a	b	适用条件	R²
A	1.74	6.03	农业秸秆 MC < 20%	0.99
B	1.31	5.38		0.97
C	1.29	7.50		0.99
D	2.45	11.48		0.99
E	2.08	16.66		0.97

Fig.15 The deviation of the fitted value from the calculated average value

References 33

[1]	Wu S L, Shen D K, Hu J, et al. Cellulose-lignin interactions during fast pyrolysis with different temperatures and mixing methods[J]. Biomass and Bioenergy, 2016, 90: 209-217.
[2]	Wu S L, Shen D K, Hu J, et al. Cellulose-hemicellulose interactions during fast pyrolysis with different temperatures and mixing methods[J]. Biomass and Bioenergy, 2016, 95: 55-63.
[3]	Pio D T, Tarelho L A C, Pinto P C R. Gasification-based biorefinery integration in the pulp and paper industry: a critical review[J]. Renewable and Sustainable Energy Reviews, 2020, 133: 110210.
[4]	Calado L C, Orzáez M J H, La Cal Herrera J, et al. Techno-economic evaluation of downdraft fixed bed gasification of almond shell and husk as a process step in energy production for decentralized solutions applied in biorefinery systems[J]. Agronomy, 2023, 13(9): 2278
[5]	Henrich E, Weirich F. Pressurized entrained flow gasifiers for biomass[J]. Environmental Engineering Science, 2004, 21(1): 53-64.
[6]	Kobayashi N, Piao G L, Kobayashi J, et al. A new pulverized biomass utilization technology[J]. Powder Technology, 2008, 180(3): 272-283.
[7]	Basu P. Biomass Gasification, Pyrolysis and Torrefaction[M]. 3rd ed. London: Academic Press, 2018: 263-329.
[8]	Luo S Y, Xiao B, Guo X J, et al. Hydrogen-rich gas from catalytic steam gasification of biomass in a fixed bed reactor: influence of particle size on gasification performance[J]. International Journal of Hydrogen Energy, 2009, 34(3): 1260-1264.
[9]	Hernández J J, Aranda-Almansa G, Bula A. Gasification of biomass wastes in an entrained flow gasifier: effect of the particle size and the residence time[J]. Fuel Processing Technology, 2010, 91(6): 681-692.
[10]	Kratky L, Jirout T. Experimental identification and modelling of specific energy requirement for knife milled beech chips in dependence on particle size characteristics and moisture[J]. Energy, 2022, 243: 122749.
[11]	Ngamnikom P, Songsermpong S. The effects of freeze, dry, and wet grinding processes on rice flour properties and their energy consumption[J]. Journal of Food Engineering, 2011, 104(4): 632-638.
[12]	Miao Z, Grift T E, Hansen A C, et al. Energy requirement for comminution of biomass in relation to particle physical properties[J]. Industrial Crops and Products, 2011, 33(2): 504-513.
[13]	Mayer-Laigle C, Rajaonarivony R K, Blanc N, et al. Comminution of dry lignocellulosic biomass(part Ⅱ): Technologies, improvement of milling performances, and security issues[J]. Bioengineering, 2018, 5(3): 50.
[14]	Eisenlauer M, Teipel U. Comminution of wood—influence of process parameters[J]. Chemical Engineering & Technology, 2020, 43(5): 838-847.
[15]	Souček J, Hanzlíková I, Hutla P. A fine desintegration of plants suitable for composite biofuels production[J]. Research in Agricultural Engineering, 2003, 49(1): 7-11.
[16]	Probst K V, Ambrose R P K, Pinto R L, et al. The effect of moisture content on the grinding performance of corn and corncobs by hammermilling[J]. Transactions of the ASABE, 2013, 56(3): 1025-1033.
[17]	Kadhim J, Aridhee A L, Abood A M, et al. Influence of screen mesh size of hammer mill at different wheat moisture[J]. Plant Archives, 2019, 19: 1138-1141.
[18]	Temmerman M, Jensen P D, Hébert J. Von Rittinger theory adapted to wood chip and pellet milling, in a laboratory scale hammermill[J]. Biomass and Bioenergy, 2013, 56: 70-81.
[19]	Mani S, Tabil L G, Sokhansanj S. Grinding performance and physical properties of selected biomass[C]//2002 ASAE Annual Meeting. Chicago, St. Joseph, 2002.
[20]	Vin-Nnajiofor M C, Li W Q, Debolt S, et al. Characterization of the composition, structure, and mechanical properties of endocarp biomass[J]. Journal of the ASABE, 2022, 65(1): 67-74.
[21]	Manouchehrinejad M, van Giesen I, Mani S. Grindability of torrefied wood chips and wood pellets[J]. Fuel Processing Technology, 2018, 182: 45-55.
[22]	Repellin V, Govin A, Rolland M, et al. Energy requirement for fine grinding of torrefied wood[J]. Biomass and Bioenergy, 2010, 34(7): 923-930.
[23]	丛宏斌, 姚宗路, 赵立欣, 等. 中国农作物秸秆资源分布及其产业体系与利用路径[J]. 农业工程学报, 2019, 35(22): 132-140.
	Cong H B, Yao Z L, Zhao L X, et al. Distribution of crop straw resources and its industrial system and utilization path in China[J]. Transactions of the Chinese Society of Agricultural Engineering, 2019, 35(22): 132-140.
[24]	刘俊杰, 严晓斌, 张美怡, 等. 中国农作物秸秆资源产量分布及利用分析[J]. 农业资源与环境学报, 2024, 41(6): 1-13.
	Liu J J, Yan X B, Zhang M Y, et al. Analysis of yield distribution and utilization of crop straw resources in China[J]. Journal of Agricultural Resources and Environment, 2024, 41(6): 1-13.
[25]	Wu S L, Shen D K, Hu J, et al. Role of β-O-4 glycosidic bond on thermal degradation of cellulose[J]. Journal of Analytical and Applied Pyrolysis, 2016, 119: 147-156.
[26]	Wu S L, Shen D K, Hu J, et al. TG-FTIR and Py-GC-MS analysis of a model compound of cellulose-glyceraldehyde[J]. Journal of Analytical and Applied Pyrolysis, 2013, 101: 79-85.
[27]	Guo Z G, Chen X L, Liu H F, et al. Theoretical and experimental investigation on angle of repose of biomass-coal blends[J]. Fuel, 2014, 116: 131-139.
[28]	Geldart D, Abdullah E C, Hassanpour A, et al. Characterization of powder flowability using measurement of angle of repose[J]. China Particuology, 2006, 4(3/4): 104-107.
[29]	裴继诚. 植物纤维化学[M]. 4版. 北京: 中国轻工业出版社, 2012: 57-159.
	Pei J C. Lignocellulosic Chemistry[M]. 4th ed. Beijing: China Light Industry Press, 2012: 57-159.
[30]	Persson S. Mechanics of Cutting Plant Material[M]. Michigan: American Society of Agricultural Engineers, 1987: 90-180.
[31]	周云龙. 植物生物学[M]. 4版. 北京: 高等教育出版社, 2011: 71-88.
	Zhou Y L. Plant Biology[M]. 4th ed. Beijing: Higher Education Press, 2011: 71-88.
[32]	Guo Q, Chen X L, Liu H F. Experimental research on shape and size distribution of biomass particle[J]. Fuel, 2012, 94: 551-555.
[33]	付敏. 木质生物质粉碎及规模化制粉机械设计及理论研究[D]. 哈尔滨: 东北林业大学, 2010.
	Fu M. Design and theoretical study of wood biomass crushing and large-scale milling machinery[D]. Harbin: Northeast Forestry University, 2010.