不同炭化时间对五节芒生物炭理化特征和微观结构表征的影响

任丽花; 叶菁; 杨冬雪; 翁伯琦; 王义祥

doi:10.19303/j.issn.1008-0384.2020.05.013

不同炭化时间对五节芒生物炭理化特征和微观结构表征的影响

doi: 10.19303/j.issn.1008-0384.2020.05.013

1.
福建省农业科学院农业质量标准与检测技术研究所，福建　福州　350003
2.
福建省农业科学院农业生态研究所/福建省红壤山地农业生态过程重点实验室，福建　福州　350013
3.
福建省环境监测中心站，福建　福州　350003

基金项目: 国家重点研发计划项目（2016YFD0501404-3）；福建省财政专项——福建省农业科学院科技创新团队建设项目（STIT2017-3-9）；福建省红壤山地农业生态过程重点实验室开放课题（Aephrs-201803）

详细信息

作者简介:
任丽花（1977−），女，博士，助理研究员，研究方向：细胞生物学、环境生态（E-mail：1272547936 @qq.com）

通讯作者:
王义祥（1978−），男，博士，研究员，研究方向：农业环境与生态修复（E-mail：sd_wolong@163.com）

中图分类号: X 705
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出版历程
- 收稿日期: 2020-01-03
- 修回日期: 2020-04-20
- 刊出日期: 2020-05-01

Effects of Hydrothermal Carbonization Time on Chemistry and Microstructure of Biochar Made from Miscanthus floridulus

1.
Institute of Agricultural Quality Standards and Testing Technology Research, Fujian Academy of Agricultural Sciences, Fuzhou, Fujian　350003, China
2.
Agriculture Ecology Institute, Fujian Academy of Agricultural Sciences/Fujian Key Laboratory of Agricultural Ecological Process of Red Soil Mountain, Fuzhou, Fujian　350013, China
3.
Fujian Provincial Environmental Monitoring Center, Fuzhou, Fujian　350003, China

摘要

摘要: 目的研究不同炭化时间对五节芒生物炭制备过程中理化特征及其微观结构表征的影响，探求其作为生物质能源的潜在应用价值。方法以五节芒为原材料，利用高温高压反应釜，在200℃下，水热炭化停留0、1.5、3.0、6.0、9.0 h制备生物炭，研究不同炭化时间对五节芒水热炭的有机碳、总氮、总磷、C/N、灰分、pH值、产率、元素损失率等的影响，并利用扫描电镜对其微观结构表征进行研究。结果在本试验条件下，五节芒生物炭有机碳含量为39.90%～54.82%，C/N为57.90～81.22，生物炭产率为57.3%～67.1%。五节芒生物炭中有机碳含量、总氮含量、C/N、碳损失率、磷损失率及灰分损失率随炭化时间的延长而增加，总磷含量、灰分含量、pH值及炭产率随炭化时间的延长而降低，氮损失率则在炭化达6 h时明显高于其他处理，9 h明显低于其他处理。扫描电镜观察结果显示五节芒生物炭富含淀粉颗粒，随炭化时间的延长，表面炭化现象比较明显，基本组织表面因增厚堆叠而开始变得杂乱，维管束大部分遭到破坏，薄壁细胞堵塞，薄壁细胞的边缘变厚但轮廓开始变得清晰，生物炭表面淀粉颗粒发生糊化，之后观察到了更多的形状不规则球体或椭球体的微球聚集融合，五节芒生物炭表面出现大量的微球结构。结论水热炭化改变了五节芒生物炭的理化特性和微观结构，且随炭化时间延长生物炭产率和pH值降低，碳、磷元素损失率增加；本试验条件下炭化3 h以上可显著改善生物炭的理化特性。
- 五节芒 /
- 水热炭化 /
- 反应时间 /
- 生物炭
Abstract: Objective The heating time in a hydrothermal carbonization process used to convert Miscanthus floridulus into biochar was varied to examine the chemical and microstructural differences in the resulting material for potential applications. Method An experiment applying 200℃ hydrothermal carbonization on the perennial grass in a pressurized reaction cauldron for 0, 1.5, 3.0, 6.0, and 9.0 h was conducted. Properties including organic carbon, total nitrogen, total phosphorus, C/N ratio, ash, pH, yield, and loss of elements of the biochar were determined, and microstructure observed under a scanning electron microscope (SEM). Results After the carbonization, the biochar had an organic carbon content ranging from 39.90% to 54.82%, a C/N ratio from 57.90 to 81.22, and a yield from 57.3% to 67.1%. The longer the treatment time, the higher the organic carbon, total nitrogen, C/N ratio, carbon loss, phosphorus loss and ash loss were in the biochar. The total phosphorus, total ash, pH and yield decreased as well. The rate of nitrogen loss peaked after 6 h of carbonization but was significantly lower at 9 h compared with other treatment time. Under SEM, the biochar appeared with numerous starch particles. Prolonged carbonization significantly charred the surface with disorganized, thickened, and stacked tissues. Most of the vascular bundles was damaged, the thin-walled cells blocked, and the edges thickened with clear outlines. The starch granules began to slacken followed by the appearance of many irregular-shaped or ellipsoidal microspheres that coalesced and fused together. Conclusion The hydrothermal carbonization converted M. floridulus into biochar with changed chemistry and microstructure. Prolonged heating decreased the yield, pH, carbon, and phosphorus in the material. A carbonization time longer than 3 h could already significantly alter the properties of the biochar as observed under the experimental conditions.
- Miscanthus floridulus /
- hydrothermal carbonization /
- duration /
- biochar

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图 1 炭化时间对五节芒生物炭微观结构的影响

注: a、b、c为炭化0 h的表面结构, d、e、f为炭化1.5 h的表面结构, g、h、i为炭化3 h的表面结构, j、k、l为炭化6 h的表面结构, m、n、o为炭化9 h的表面结构

Figure 1. Effects of carbonization time on microstructure of M. floridulus biochar

Note: a, b, and c are surface structures of biochar treated by 0 h carbonization; d, e, and f, those under 1.5 h treatment; g, h, and i, those under 3 h treatment; j, k, and l, those under 6 h treatment; and, m, n, and o, those under 9 h treatment.

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表 1 不同水热炭化反应时间制备的五节芒生物炭理化指标

Table 1. Effect of varied carbonization time on physiochemical properties of M. floridulus biochar

炭化时间 Carbonization duration	0 h	1.5 h	3 h	6 h	9 h
有机碳 Organic carbon/%	39.90±1.64 c	48.11±0.87 b	50.21±0.97 b	53.90±0.42 a	54.82±0.57 a
总氮 Total nitrogen/%	0.69±0.02 b	0.68±0.03 b	0.73±0.02 b	0.67±0.04 b	0.91±0.04 a
总磷 Total phosphorus/%	0.11±0.01 a	0.10±0.00 ab	0.09±0.00 b	0.08±0.01 b	0.08±0.00 b
C/N	57.90±0.21 d	70.21±0.95 b	68.80±0.50 b	80.22±0.85 a	60.41±1.05 c
灰分 Ash/%	2.46±0.03 a	1.98±0.06 b	1.47±0.03 c	1.36±0.05 c	1.46±0.03 c
pH值 pH value	5.62±0.05 a	4.80±0.06 b	4.30±0.09 c	4.29±0.03 c	4.29±0.03 c
注：同行数字后不同小写字母表示不同处理之间差异显著（P＜0.05）。表2 同。 Note: Different lowercase letters after the same line of numbers indicate significant differences between different processing（P＜0.05）.The same as Table 2.

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表 2 不同水热炭化时间下五节芒生物炭的产率和养分损失率

Table 2. Yield and nutrient loss of biochar under various carbonization treatment time

炭化时间 Carbonization duration	1.5 h	3 h	6 h	9 h
产率 Carbon yield/%	67.1±0.61 a	64.1±0.40 b	58.4±0.50 c	57.3±0.62 c
碳损失率 Carbon loss rate/%	19.1±0.32 b	19.3±0.21 b	21.1±0.36 a	21.2±0.35 a
氮损失率 Nitrogen loss rate/%	33.4±0.42 b	32.1±0.35 c	43.1±0.40 a	24.6±0.38 d
磷损失率 Phosphorus loss rate/%	42.0±0.32 c	47.5±0.31 b	57.5±0.50 a	58.3±0.45 a
灰分损失率 Ash loss rate/%	46.0±0.25 d	61.7±0.42 c	67.7±0.42 a	66.0±0.42 b

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参考文献(45)

[1]	TITIRICI M M, ANTONIETTI M. Chemistry and materials options of sustainable carbon materials made by hydrothermal carbonization [J]. Chemical Society Reviews, 2010, 39(1): 103−116. doi: 10.1039/B819318P
[2]	王艳秋. 生物质碳及水热炭化技术介绍 [J]. 江西化工, 2018(1):154−155. doi: 10.3969/j.issn.1008-3103.2018.01.052 WANG Y Q. Introduction of Biomass carbon and hydrothermal carbonization technology [J]. Jiangxi Chemical Industry, 2018(1): 154−155.(in Chinese) doi: 10.3969/j.issn.1008-3103.2018.01.052
[3]	陈温福, 张伟明, 孟军, 等. 生物炭应用技术研究 [J]. 中国工程科学, 2011, 13(2):83−89. doi: 10.3969/j.issn.1009-1742.2011.02.015 CHEN W F, ZHANG W M, MENG J, et al. Researches on biochar application technology [J]. Engineering Sciences, 2011, 13(2): 83−89.(in Chinese) doi: 10.3969/j.issn.1009-1742.2011.02.015
[4]	CALUCCI L, RASSE D P, FORTE C. Solid-state nuclear magnetic resonance characterization of chars obtained from hydrothermal carbonization of corncob and Miscanthus [J]. Energy & Fuels, 2013, 27(1): 303−309.
[5]	TITIRICI M M, THOMAS A, ANTONIETTI M. Back in the black: hydrothermal carbonization of plant material as an efficient chemical process to treat the CO₂ problem? [J]. New Journal of Chemistry, 2007, 31(6): 787. doi: 10.1039/b616045j
[6]	吴倩芳, 张付申. 水热炭化废弃生物质的研究进展 [J]. 环境污染与防治, 2012, 34(7):70−75. doi: 10.3969/j.issn.1001-3865.2012.07.015 WU Q F, ZHANG F S. Progress on hydrothermal carbonization of waste biomass [J]. Environmental Pollution & Control, 2012, 34(7): 70−75.(in Chinese) doi: 10.3969/j.issn.1001-3865.2012.07.015
[7]	MACÍAS F, CAMPS ARBESTAIN M. Soil carbon sequestration in a changing global environment [J]. Mitigation and Adaptation Strategies for Global Change, 2010, 15(6): 511−529. doi: 10.1007/s11027-010-9231-4
[8]	FUNKE A, ZIEGLER F. Hydrothermal carbonization of biomass: a summary and discussion of chemical mechanisms for process engineering [J]. Biofuels, Bioproducts and Biorefining, 2010, 4(2): 160−177. doi: 10.1002/bbb.198
[9]	张进红, 林启美, 赵小蓉, 等. 水热炭化温度和时间对鸡粪生物质炭性质的影响 [J]. 农业工程学报, 2015, 31(24):239−244. doi: 10.11975/j.issn.1002-6819.2015.24.036 ZHANG J H, LIN Q M, ZHAO X R, et al. Effect of hydrothermal carbonization temperature and time on characteristics of bio-chars from chicken manure [J]. Transactions of the CSAE, 2015, 31(24): 239−244.(in Chinese) doi: 10.11975/j.issn.1002-6819.2015.24.036
[10]	张进红, 林启美, 赵小蓉, 等. 不同炭化温度和时间下牛粪生物炭理化特性分析与评价 [J]. 农业机械学报, 2018, 49(11):298−305. doi: 10.6041/j.issn.1000-1298.2018.11.035 ZHANG J H, LIN Q M, ZHAO X R, et al. Physico-chemical characteristics and evaluation of cow manure hydrochar at different carbonization temperatures and durations [J]. Transactions of the Chinese Society for Agricultural Machinery, 2018, 49(11): 298−305.(in Chinese) doi: 10.6041/j.issn.1000-1298.2018.11.035
[11]	张曾, 单胜道, 吴胜春, 等. 炭化条件对猪粪水热炭主要营养成分的影响 [J]. 浙江农林大学学报, 2018, 35(3):398−404. doi: 10.11833/j.issn.2095-0756.2018.03.002 ZHANG Z, SHAN S D, WU S C, et al. Carbonization with main nutrients in pig manure hydrochar [J]. Journal of Zhejiang A & F University, 2018, 35(3): 398−404.(in Chinese) doi: 10.11833/j.issn.2095-0756.2018.03.002
[12]	李飞跃, 吴旋, 李俊锁, 等. 温度对畜禽粪便水热炭产率及特性的影响 [J]. 环境工程学报, 2019, 13(9):2270−2277. doi: 10.12030/j.cjee.201812168 LI F Y, WU X, LI J S, et al. Effects of temperature on hydrothermal carbonization yield and characteristics of livestock manure [J]. Chinese Journal of Environmental Engineering, 2019, 13(9): 2270−2277.(in Chinese) doi: 10.12030/j.cjee.201812168
[13]	赵丹, 张琳, 郭亮, 等. 水热碳化与干法碳化对剩余污泥的处理比较 [J]. 环境科学与技术, 2015, 38(10):78−83. ZHAO D, ZHANG L, GUO L, et al. Comparison of hydrothermal carbonization and dry pyrolysis for domestic wastewater sludge treatment [J]. Environmental Science & Technology, 2015, 38(10): 78−83.(in Chinese)
[14]	PARSHETTI G K, LIU Z G, JAIN A, et al. Hydrothermal carbonization of sewage sludge for energy production with coal [J]. Fuel, 2013, 111: 201−210. doi: 10.1016/j.fuel.2013.04.052
[15]	向天勇, 钱广, 朱杰, 等. 稻秸水热炭化的多轮沉积反应 [J]. 浙江农业学报, 2018, 30(1):137−143. doi: 10.3969/j.issn.1004-1524.2018.01.18 XIANG T Y, QIAN G, ZHU J, et al. Multiple deposition reaction of rice straw by hydrothermal carbonization [J]. Acta Agriculturae Zhejiangensis, 2018, 30(1): 137−143.(in Chinese) doi: 10.3969/j.issn.1004-1524.2018.01.18
[16]	邢献军, 范方宇, 施苏薇, 等. 锯末水热生物炭特征研究 [J]. 太阳能学报, 2018, 39(2):299−306. XING X J, FAN F Y, SHI S W, et al. Feature research of hydrothermal biochar from sawdust [J]. Acta Energiae Solaris Sinica, 2018, 39(2): 299−306.(in Chinese)
[17]	宫磊, 贾通通, 王在钊, 等. 瓜子皮、茶叶、树叶和核桃壳的水热炭化产物及机理 [J]. 青岛科技大学学报(自然科学版), 2018, 39(1):22−28. GONG L, JIA T T, WANG Z Z, et al. Biomass product after hydrothermal carbonization and its mechanism of melon skin, tea, leaves and walnut shells [J]. Journal of Qingdao University of Science and Technology(Natural Science Edition), 2018, 39(1): 22−28.(in Chinese)
[18]	吴倩芳, 吴建芝, 张付申. 水热炭化餐厨垃圾制备纳米铁/炭复合材料 [J]. 环境工程学报, 2013, 7(2):695−700. WU Q F, WU J Z, ZHANG F S. Fe/C nano-materials development from kitchen garbage under hydrothermal condition [J]. Chinese Journal of Environmental Engineering, 2013, 7(2): 695−700.(in Chinese)
[19]	韦思业. 不同生物质原料和制备温度对生物炭物理化学特征的影响[D]. 北京: 中国科学院大学, 2017. WEI S Y. Influence of biomass feedstocks and pyrolysis temperatures on physical and chemical properties of biochar[D]. Beijing: University of Chinese Academy of Sciences, 2017.(in Chinese)
[20]	向天勇, 朱杰, 钱广, 等. 预增压对稻秸水热炭化的影响 [J]. 安徽农业科学, 2017, 45(29):50−55. doi: 10.3969/j.issn.0517-6611.2017.29.017 XIANG T Y, ZHU J, QIAN G, et al. Effect of pre-pressurization on hydrothermal carbonization of rice straw [J]. Journal of Anhui Agricultural Sciences, 2017, 45(29): 50−55.(in Chinese) doi: 10.3969/j.issn.0517-6611.2017.29.017
[21]	董向元, 郭淑青, 吴婷婷, 等. 液固比对生物质水热炭化产物结构演变的影响 [J]. 太阳能学报, 2017, 38(7):2005−2011. DONG X Y, GUO S Q, WU T T, et al. Influence of liquid to biomass ratio on structural evolution of products derived from biomass hydrothermal carbonization [J]. Acta Energiae Solaris Sinica, 2017, 38(7): 2005−2011.(in Chinese)
[22]	张传涛, 邢宝林, 黄光许, 等. 水热炭化-KOH活化制备核桃壳活性炭电极材料的研究 [J]. 材料导报, 2018, 32(7):1088−1093. doi: 10.11896/j.issn.1005-023X.2018.07.007 ZHANG C T, XING B L, HUANG G X, et al. Preparation of walnut shell activated carbons via combination of hydrothermal carbonization and KOH activation [J]. Materials Review, 2018, 32(7): 1088−1093.(in Chinese) doi: 10.11896/j.issn.1005-023X.2018.07.007
[23]	查湘义. 生物质水热炭化技术的现状及进展 [J]. 北京农业, 2013(30):248. doi: 10.3969/j.issn.1000-6966.2013.30.205 ZHA X Y. Current situation and progress of hydrothermal carbonization technology of biomass [J]. Beijing Agriculture, 2013(30): 248.(in Chinese) doi: 10.3969/j.issn.1000-6966.2013.30.205
[24]	陈慧娟, 宁祖林, 张卓文. 五节芒生物学特性及能量生产动态变化[J]. 草业学报, 2012, 21（6）: 252－257. CHEN H J, NING Z L, ZHANG Z W. Studies on the biological characteristics and dynamics of energy production of Miscanthus floridulus[J]. Acta Prataculturae Sinica, 2012, 21（6）: 252－257.（in Chinese）
[25]	易自力. 芒属能源植物资源的开发与利用 [J]. 湖南农业大学学报(自然科学版), 2012, 38(5):455−463. YI Z L. Exploitation and utilization of Miscanthus as energy plant [J]. Journal of Hunan Agricultural University(Natural Sciences Edition), 2012, 38(5): 455−463.(in Chinese)
[26]	萧运峰, 高洁, 王锐. 五节芒的生产性状及饲用价值的研究 [J]. 四川草原, 1997(1):20−24. XIAO Y F, GAO J, WANG R. Research on the production traits and feeding value of Miscanthus [J]. Journal of Sichuan Grassland, 1997(1): 20−24.(in Chinese)
[27]	解新明, 周峰, 赵燕慧, 等. 多年生能源禾草的产能和生态效益 [J]. 生态学报, 2008, 28(5):2329−2342. doi: 10.3321/j.issn:1000-0933.2008.05.050 XIE X M, ZHOU F, ZHAO Y H, et al. A summary of ecological and energy-producing effects of perennial energy grasses [J]. Acta Ecologica Sinica, 2008, 28(5): 2329−2342.(in Chinese) doi: 10.3321/j.issn:1000-0933.2008.05.050
[28]	宁祖林, 陈慧娟, 王珠娜, 等. 几种高大禾草热值和灰分动态变化研究 [J]. 草业学报, 2010, 19(2):241−247. doi: 10.11686/cyxb20100234 NING Z L, CHEN H J, WANG Z N, et al. A study on the dynamic change of gross caloric value and ash content of the several tall grasses [J]. Acta Prataculturae Sinica, 2010, 19(2): 241−247.(in Chinese) doi: 10.11686/cyxb20100234
[29]	罗煜, 赵立欣, 孟海波, 等. 不同温度下热裂解芒草生物质炭的理化特征分析 [J]. 农业工程学报, 2013, 29(13):208−217. doi: 10.3969/j.issn.1002-6819.2013.13.027 LUO Y, ZHAO L X, MENG H B, et al. Physio-chemical characterization of biochars pyrolyzed from Miscanthus under two different temperatures [J]. Transaction of the CSAE, 2013, 29(13): 208−217.(in Chinese) doi: 10.3969/j.issn.1002-6819.2013.13.027
[30]	于延冲, 易自力, 周功克. 能源植物芒草研究进展与综合利用现状 [J]. 生命科学, 2014, 26(5):474−480. YU Y C, YI Z L, ZHOU G K. Research progress and comprehensive utilization of Miscanthus [J]. Chinese Bulletin of Life Sciences, 2014, 26(5): 474−480.(in Chinese)
[31]	孙峰, 王栋, 袁建, 等. 芒草的研究进展以及研究价值 [J]. 河南农业, 2017(11):48−49. SUN F, WANG D, YUAN J, et al. Research progress and value of Miscanthus [J]. Agriculture of Henan, 2017(11): 48−49.(in Chinese)
[32]	SMITH A M, ROSS A B. The influence of residence time during hydrothermal carbonization of Miscanthus on bio-coal combustion chemistry [J]. Energies, 2019, 12(3): 523. doi: 10.3390/en12030523
[33]	鲍士旦. 土壤农化分析[M]. 北京: 中国农业出版社, 1999.
[34]	GASKIN J W, STEINER C, HARRIS K, et al. Effect of low-temperature pyrolysis conditions on biochar for agricultural use [J]. Transactions of the ASABE, 2008, 51(6): 2061−2069. doi: 10.13031/2013.25409
[35]	吴艳姣, 李伟, 吴琼, 等. 水热炭的制备、性质及应用[J]. 化学进展, 2016, 28(1): 121－130. WU Y J, LI W, WU Q, et al. Preparation, properties and applications of hydrochar[J]. Progress in Chemistry, 2016, 28(1): 121－130.（in Chinese）
[36]	WIEDNER K, NAISSE C, RUMPEL C, et al. Chemical modification of biomass residues during hydrothermal carbonization-What makes the difference, temperature or feedstock? [J]. Organic Geochemistry, 2013, 54(1): 91−100.
[37]	吴志丹, 尤志明, 江福英, 等. 不同温度和时间炭化茶树枝生物炭理化特征分析 [J]. 生态与农村环境学报, 2015, 31(4):583−588. doi: 10.11934/j.issn.1673-4831.2015.04.022 WU Z D, YOU Z M, JIANG F Y, et al. Physico-chemical properties of tea-twig-derived biochars different in temperature and duration of pyrolysis [J]. Journal of Ecology and Rural Environment, 2015, 31(4): 583−588.(in Chinese) doi: 10.11934/j.issn.1673-4831.2015.04.022
[38]	张千丰, 孟军, 刘居东, 等. 热解温度和时间对三种作物残体生物炭pH值及碳氮含量的影响 [J]. 生态学杂志, 2013, 32(9):2347−2353. ZHANG Q F, MENG J, LIU J D, et al. Effects of pyrolysis temperature and duration time on pH, carbon and nitrogen contents of biochars produced from three crop residues [J]. Chinese Journal of Ecology, 2013, 32(9): 2347−2353.(in Chinese)
[39]	LEHMANN J. Bio-energy in the black [J]. Frontiers in Ecology and the Environment, 2007, 5(7): 381−387. doi: 10.1890/1540-9295(2007)5[381:BITB]2.0.CO;2
[40]	CHEN W F, MENG J, HAN X R, et al. Past, present, and future of biochar [J]. Biochar, 2019, 1(1): 75−87. doi: 10.1007/s42773-019-00008-3
[41]	ZHANG L, LIU S S, WANG B B, et al. Effect of residence time on HTC [J]. Bioresources, 2015, 10(3): 3979−3986.
[42]	HE B J, ZHANG Y, YIN Y, et al. Preliminary characterization of raw oil products from the thermochemical conversion of swine manure [J]. Transactions of the ASAE, 2001, 44(6): 1865−1871. doi: 10.13031/2013.7025
[43]	ROMÁN S, NABAIS J M V, LAGINHAS C, et al. Hydrothermal carbonization as an effective way of densifying the energy content of biomass [J]. Fuel Processing Technology, 2012, 103: 78−83. doi: 10.1016/j.fuproc.2011.11.009
[44]	XIAO L P, SHI Z J, XU F, et al. Hydrothermal carbonization of lignocellulosic biomass [J]. Bioresource Technology, 2012, 118: 619−623. doi: 10.1016/j.biortech.2012.05.060
[45]	赵志瑞, 赵秀梅, 颜嘉晨, 等. 不同水热炭化条件处理青霉素菌渣制备生物炭 [J]. 环境工程学报, 2019, 13(3):732−739. doi: 10.12030/j.cjee.201808108 ZHAO Z R, ZHAO X M, YAN J C, et al. Biochar preparation from penicillin residues treatment under different hydrothermal carbonization conditions [J]. Chinese Journal of Environmental Engineering, 2019, 13(3): 732−739.(in Chinese) doi: 10.12030/j.cjee.201808108