Effect of ash chemical components on biomass gasification properties

doi:10.11949/0438-1157.20230009

Abstract

Abstract:

Gasification is one of the effective ways to realize the efficient and clean utilization of biomass resources. The chemical composition of ash is the main factor affecting the gasification of biomass. The influence of different inorganic components on the gasification characteristics of biomass is not yet perfect. In this paper, the raw corn stalk sample was first pre-treated by acid washing to remove the original ash compositions. Then the chemical modulus of different inorganic components was severally loaded on the de-ashing feedstock. After that, the role of ash chemical composition was systematically investigated by a rapid fixed-bed gasification reactor. The addition of inorganic fluxes could enhance the real time yield of hydrogen and restrain the release of methane. The alkaline additives (Ca, Fe, Mg, K, Na) tend to increase H₂ and CO₂ yields, which have a significant effect on the improvement of the syngas quality (H₂/CO), especially Fe based additives can improve H₂/CO from 0.75 to 1.54. The addition of acidic additives (Si, Al, P) contributes to CO generation and reduces the cold gas efficiency (CGE). In addition, P, Na and K were prone to escape from the solid phase to the gas phase as the volatile fraction, and Si would totally stay in the solid slag. Furthermore, it can be obtained that P is one of the main factors causing ash sintering and melting problems except for Na and K. All the obtained data was meaningful to provide a modifying reference for alleviating ash-related problems, modifying flux addition principle and the efficient utilization of biomass wastes during gasification process.

Key words: biomass, fixed-bed, syngas, ash chemical compositions, slag sintering, gasification efficiency, online test

摘要：

气化利用是实现生物质资源高效清洁利用的有效方式之一，灰化学组成是影响生物质气化的主要因素，不同无机组分对生物质气化特性的影响规律尚不完善。通过酸洗脱灰耦合灰化学模化物负载的方式，对灰化学成分的作用进行了系统的研究。结果表明，P是除Na、K之外，造成气化灰渣烧结熔融的主要因素之一；不同助剂的加入均可抑制CH₄析出，酸性助剂(Si、Al、P)的添加有助于CO的生成，降低体系的冷煤气效率(CGE)和合成气品质(H₂/CO)；碱性助剂(Ca、Fe、Mg、K、Na)趋向于提高H₂和CO₂产率，对体系H₂/CO改善作用显著，Fe基助剂可使其由0.75提升至1.54。

关键词: 生物质, 固定床, 合成气, 灰化学组成, 残渣烧结, 气化效率, 在线检测

CLC Number:

TK 6

Zefeng GE, Yuqing WU, Mingxun ZENG, Zhenting ZHA, Yuna MA, Zenghui HOU, Huiyan ZHANG. Effect of ash chemical components on biomass gasification properties[J]. CIESC Journal, 2023, 74(5): 2136-2146.

葛泽峰, 吴雨青, 曾名迅, 查振婷, 马宇娜, 侯增辉, 张会岩. 灰化学成分对生物质气化特性的影响规律[J]. 化工学报, 2023, 74(5): 2136-2146.

Figures/Tables 11

Table 1 Proximate and ultimate analyses of cornstalk

项目	工业分析/%(mass, ad)				元素分析/%(mass, ad)
项目	水分	灰分	挥发分	固定碳^①	C	H	O^②	N	S
原料	6.62±0.48	7.56±0.61	68.60±2.93	17.22±0.82	38.64±0.53	6.86±0.36	38.93±1.23	1.20±0.16	0.19±0.03
脱灰物料	4.00±0.32	0.08±0.01	81.90±1.25	14.02±0.36	44.50±0.72	7.65±0.22	42.43±1.41	1.13±0.08	0.13±0.02

Table 2 Ash chemical composition of cornstalk

组分	质量分数/%
SiO₂	45.18
Al₂O₃	1.16
CaO	6.32
Fe₂O₃	1.05
MgO	3.16
K₂O	33.86
Na₂O	0.45
P₂O₅	8.82

Fig.1 The scheme of fixed-bed gasification reactor coupled with syngas on-line detection system

Fig.2 The releasing rate of syngas under gasification condition

Fig.3 The real-time ration variation of syngas with different flux addition

Fig.4 The variation and quantitative analysis of syngas yield and effect of auxiliaries

Fig.5 The analysis on gasification efficiency of biomass with different additives

Table 3 The content of different kinds of elements in the gas-solid phase

元素	k_x-_total/(mg/kg)	k_x-_solid/(mg/kg)	k_x-_gaseous/(mg/kg)
Si	32607.65	31738.20	869.45
Al	36955.35	27600.45	9354.90
P	30540.65	6592.48	23948.17
Fe	49378.13	39471.68	9906.45
Ca	50109.82	32843.24	17266.58
Mg	41564.25	27842.16	13722.09
Na	49862.88	19469.72	30393.16
K	56875.47	10909.70	45965.77

Fig.6 The distribution of different elements in the gaseous and solid phases

Fig.7 The sintering melting behavior of gasification residue under different additives

Fig.8 The catalysis and migration analysis of inorganic ash elements during gasification process

References 36

1	许光文, 姜新东, 谢英鹏, 等. "双碳"目标两步走战略与年亿吨规模减碳途径分析[J]. 中国发展, 2022, 22(2): 3-11.
	Xu G W, Jiang X D, Xie Y P, et al. Two-step strategy to achieve "double carbon" and method analysis of annual carbon reduction of 100 million tons[J]. China Development, 2022, 22(2): 3-11.
2	张会岩, 杨海平, 陆强, 等. 生物质定向热解制取高品质液体燃料、化学品和碳材料研究进展[J]. 工程热物理学报, 2021, 42(12): 3031-3044.
	Zhang H Y, Yang H P, Lu Q, et al. Progress of directional pyrolysis of biomass to produce high-quality liquid fuels, chemicals and carbon materials[J]. Journal of Engineering Thermophysics, 2021, 42(12): 3031-3044.
3	戴晓虎, 陈淑娴, 蔡辰, 等. 秸秆主流能源化技术研究与经济性分析[J]. 环境工程, 2021, 39(1): 1-17.
	Dai X H, Chen S X, Cai C, et al. Research and economic analysis of mainstream energy technologies for straw[J]. Environmental Engineering, 2021, 39(1): 1-17.
4	Anniwaer A, Chaihad N, Zhang M J, et al. Hydrogen-rich gas production from steam co-gasification of banana peel with agricultural residues and woody biomass[J]. Waste Management, 2021, 125: 204-214.
5	AlNouss A, McKay G, Al-Ansari T. Enhancing waste to hydrogen production through biomass feedstock blending: a techno-economic-environmental evaluation[J]. Applied Energy, 2020, 266: 114885.
6	Zhang X Y, Zhu S J, Song W J, et al. Experimental study on conversion characteristics of anthracite and bituminous coal during preheating-gasification[J]. Fuel, 2022, 324: 124712.
7	Chen Q, Wei B, Chen J Q, et al. In-situ study of fractal properties of coal char particles during catalytic gasification [J]. Journal of Fuel Chemistry and Technology, 2022, 50(5): 523-529.
8	张波, 张力, 杨仲卿, 等. NiO/CaO添加剂下生物质水蒸气气化特性[J]. 工程热物理学报, 2016, 37(9): 1961-1967.
	Zhang B, Zhang L, Yang Z Q, et al. Influence of NiO/CaO additive on biomass steam gasification[J]. Journal of Engineering Thermophysics, 2016, 37(9): 1961-1967.
9	Czerski G, Śpiewak K, Grzywacz P, et al. Assessment of the catalytic effect of various biomass ashes on CO₂ gasification of tire char[J]. Journal of the Energy Institute, 2021, 99: 170-177.
10	Li F H, Yu B, Li J G, et al. Exploration of potassium migration behavior in straw ashes under reducing atmosphere and its modification by additives[J]. Renewable Energy, 2020, 145: 2286-2295.
11	Yan L B, Cao Y, Li X Z, et al. Characterization of a dual fluidized bed gasifier with blended biomass/coal as feedstock [J]. Bioresource Technology, 2018, 254: 97-106.
12	Zhang Z, Liu J, Shen F H, et al. Temporal release behavior of potassium during pyrolysis and gasification of sawdust particles[J]. Renewable Energy, 2020, 156: 98-106.
13	Sadhwani N, Adhikari S, Eden M R, et al. Southern pines char gasification with CO₂—kinetics and effect of alkali and alkaline earth metals[J]. Fuel Processing Technology, 2016, 150: 64-70.
14	Ge Z F, Cao X, Zha Z T, et al. The mineral transformation and molten behaviors of biomass waste ashes in gasification-melting process[J]. Fuel Processing Technology, 2022, 226: 107095.
15	Lu H, Bai J, Vassilev S V, et al. The crystallization behavior of anorthite in coal ash slag under gasification condition[J]. Chemical Engineering Journal, 2022, 445: 136683.
16	Vargas S, Frandsen F J, Dam-Johansen K. Rheological properties of high-temperature melts of coal ashes and other silicates[J]. Progress in Energy and Combustion Science, 2001, 27(3): 237-429.
17	Wang W, Lemaire R, Bensakhria A, et al. Review on the catalytic effects of alkali and alkaline earth metals (AAEMs) including sodium, potassium, calcium and magnesium on the pyrolysis of lignocellulosic biomass and on the co-pyrolysis of coal with biomass[J]. Journal of Analytical and Applied Pyrolysis, 2022, 163: 105479.
18	刘成昌, 赵林, 孙峰, 等. 灰化方法对高碱燃料成灰特性影响的实验研究[J]. 工程热物理学报, 2022, 43(5): 1416-1421.
	Liu C C, Zhao L, Sun F, et al. Experimental study on the effects of ashing method on the ash characteristics of high-alkali fuel[J]. Journal of Engineering Thermophysics, 2022, 43(5): 1416-1421.
19	Liu Y J, Yan T G, An Y, et al. Influence of water leaching on alkali-induced slagging properties of biomass straw[J]. Journal of Fuel Chemistry and Technology, 2021, 49(12): 1839-1849.
20	Zhao H L, Bai Z Q, Guo Z X, et al. In situ study of the decomposition of pyrite in coal during hydropyrolysis[J]. Journal of Analytical and Applied Pyrolysis, 2021, 154: 105024.
21	Ge Z F, Cao X, Zha Z T, et al. The influence of a two-step leaching pretreatment on the steam gasification properties of cornstalk waste[J]. Bioresource Technology, 2022, 358: 127403.
22	Chen X D, Kong L X, Bai J, et al. The key for sodium-rich coal utilization in entrained flow gasifier: the role of sodium on slag viscosity-temperature behavior at high temperatures[J]. Applied Energy, 2017, 206: 1241-1249.
23	Zeng M X, Ge Z F, Ma Y N, et al. On-line analysis of the correlation between gasification characteristics and microstructure of woody biowaste after hydrothermal carbonization[J]. Bioresource Technology, 2021, 342: 126009.
24	Singh D, Yadav S. Steam gasification with torrefaction as pretreatment to enhance syngas production from mixed food waste[J]. Journal of Environmental Chemical Engineering, 2021, 9(1): 104722.
25	Reinmöller M, Kong L X, Laabs M, et al. Methods for the determination of composition, mineral phases, and process-relevant behavior of ashes and its modeling: a case study for an alkali-rich ash[J]. Journal of the Energy Institute, 2022, 100: 137-147.
26	Zha Z T, Wang K, Ge Z F, et al. Morphological and heat transfer characteristics of biomass briquette during steam gasification process[J]. Bioresource Technology, 2022, 356: 127334.
27	Siddiqui H, Thengane S K, Sharma S, et al. Revamping downdraft gasifier to minimize clinker formation for high-ash garden waste as feedstock[J]. Bioresource Technology, 2018, 266: 220-231.
28	Zhang J L, Zhang R, Bi J C. Effect of catalyst on coal char structure and its role in catalytic coal gasification[J]. Catalysis Communications, 2016, 79: 1-5.
29	He Q, Yu J Q, Song X D, et al. Utilization of biomass ash for upgrading petroleum coke gasification: effect of soluble and insoluble components[J]. Energy, 2020, 192: 116642.
30	Huang Y Q, Yin X L, Wu C Z, et al. Effects of metal catalysts on CO₂ gasification reactivity of biomass char[J]. Biotechnology Advances, 2009, 27(5): 568-572.
31	Cao J, Xiao G, Xu X, et al. Study on carbonization of lignin by TG-FTIR and high-temperature carbonization reactor[J]. Fuel Processing Technology, 2013, 106: 41-47.
32	郭学文, 张海霞, 朱治平. 准东高钠煤流化床气化特性及钠的迁移规律研究[J]. 工程热物理学报, 2017, 38(2): 440-446.
	Guo X W, Zhang H X, Zhu Z P. Fluidized bed gasification performance and sodium transformation of Zhundong high sodium coal[J]. Journal of Engineering Thermophysics, 2017, 38(2): 440-446.
33	Yang J, Ma L P, Liu H P, et al. Chemical behavior of fluorine and phosphorus in chemical looping gasification using phosphogypsum as an oxygen carrier[J]. Chemosphere, 2020, 248: 125979.
34	Dahou T L, Defoort F, Jeguirim M, et al. Towards understanding the role of K during biomass steam gasification[J]. Fuel, 2020, 282: 118806.
35	Mei Y G, Wang Z Q, Zhang H, et al. In-situ study of effect of migrating alkali metals on gasification reactivity of coal char[J]. Journal of Fuel Chemistry and Technology, 2021, 49(6): 735-741.
36	Ge Z F, Kong L X, Bai J, et al. Crystallization kinetics and T_CV prediction of coal ash slag under slag tapping conditions in an entrained flow gasifier[J]. Fuel, 2020, 272: 117723.

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