煤浆法烟气脱硫中草酸和紫外线强化煤砷浸出过程

doi:10.11949/0438-1157.20230513

摘要/Abstract

摘要：

以N₂、O₂、SO₂三种气体模拟烟气，在1 L的光反应器中，研究了主要因素对煤砷浸出、As(Ⅲ) 氧化以及SO₂脱除的影响规律，分析了过程机理，确定了浸出过程速率控制步骤。结果表明，紫外线照射和草酸均能有效提高砷浸出率，180 min时，在遮光和pH为2.5的条件下，加入1.0 mmol/L草酸能使砷浸出率提高32.9%，在紫外线照射下，可使砷浸出率再提高21.3%，且浸出液中的As(Ⅲ) 占总砷之比小于13%，还能提高SO₂脱除率。低pH有利于煤中砷的浸出，但对SO₂的脱除不利。煤砷浸出率和SO₂脱除率均随温度的提高而显著增大。动力学分析计算得出煤砷浸出过程的表观活化能为4.9 kJ/mol，说明砷浸出过程受已反应固体层内的扩散过程控制。自由基猝灭实验表明，硫酸根自由基和羟基自由基是紫外线照射下草酸强化煤砷浸出体系中的主要自由基。ATR-FTIR与XPS表征结果进一步证实了浸出液的测定结果。

关键词: 紫外线, 草酸, 砷, 自由基, 二氧化硫, 动力学模型, 氧化

Abstract:

Currently, coal is still the main energy source in our country. During coal combustion, arsenic will be discharged into the atmosphere with flue gas. Arsenic is highly toxic and harmful to the environment and human health. Therefore, it is of great practical significance to study the arsenic removal technology from coal. Using N₂, O₂ and SO₂ to simulate flue gas, the effects of main factors on arsenic leaching from coal, As(Ⅲ) oxidation and SO₂ removal were studied in a 1 L photoreactor. The process mechanism was analyzed, and the rate control step of the leaching process was determined. The results showed that both ultraviolet(UV) irradiation and oxalic acid could effectively increase the extraction ratio of arsenic. At 180 min, under pH 2.5 and dark conditions, adding 1.0 mmol/L oxalic acid could increase the arsenic extraction ratio by 32.9%. Under UV irradiation, the arsenic extraction ratio could be further increased by 21.3%, and the ratio of As(Ⅲ) in the leaching solution to the total arsenic was less than 13%, and the SO₂ removal efficiency could also be improved. Low pH was beneficial for arsenic leaching from coal, but unfavorable for SO₂ removal. Both arsenic extraction ratio and SO₂ removal efficiency increased significantly with the increase of temperature. The apparent activation energy for process of arsenic leaching from coal was calculated to be 4.9 kJ/mol, indicating that the arsenic leaching process was controlled by the diffusion process in the reacted solid layer. The free radical quenching experiments showed that sulfate radical and hydroxyl radical were the main free radicals in the oxalic acid-enhanced coal arsenic leaching system under UV irradiation. ATR-FTIR and XPS characterization results further confirmed the measured results of the leaching solution.

Key words: ultraviolet light, oxalic acid, arsenic, free radicals, sulfur dioxide, kinetic model, oxidation

中图分类号:

X 592

李锦潼, 邱顺, 孙文寿. 煤浆法烟气脱硫中草酸和紫外线强化煤砷浸出过程[J]. 化工学报, 2023, 74(8): 3522-3532.

Jintong LI, Shun QIU, Wenshou SUN. Oxalic acid and UV enhanced arsenic leaching from coal in flue gas desulfurization by coal slurry[J]. CIESC Journal, 2023, 74(8): 3522-3532.

图/表 13

图1 实验流程图1—气体钢瓶;2—开关阀;3—减压阀;4—稳压阀;5—转子流量计;6—气体混合瓶;7—皂膜流量计;8—斜管压差计;9—搅拌桨;10—紫外灯;11—温度计;12—反应器;13—加热套;14—冷却器;15—电子皂膜流量计;16—尾气吸收装置

Fig.1 Schematic diagram of the experimental apparatus1—gas cylinder; 2—switch valve; 3—pressure reducing valve; 4—pressure maintaining valve; 5—rotor flow meter; 6—gas mixing bottle; 7—soap film flow meter; 8—inclined tube manometer; 9—agitator; 10—ultraviolet lamp; 11—thermometer; 12—reactor; 13—heating jacket; 14—water cooler; 15—electronic soap film flowmeter; 16—absorption vessel

图2 紫外线照射和草酸浓度对煤中铁浸出率的影响(a)和对砷浸出率的影响(b) (pH=2.5,50℃)

Fig.2 Effect of UV irradiation and oxalic acid concentration on extraction ratio of iron (a) and on extraction ratio of arsenic from coal (b)

图3 紫外线照射及草酸浓度对As(Ⅲ)/As(total)的影响(a)和对烟气脱硫率的影响(b) (pH=2.5，50℃)

Fig.3 Effects of UV irradiation and oxalic acid concentration on As(Ⅲ)/As(total) ratio (a) and on flue gas desulfurization efficiency (b)

图4 pH对煤中铁浸出率的影响(a)和对砷浸出率的影响(b) (UV,1.0 mmol/L草酸,50℃)

Fig.4 Effect of pH on extraction ratio of iron (a) and on extraction ratio of arsenic from coal (b)

图5 pH对烟气脱硫率的影响(UV,1.0 mmol/L草酸,50℃)

Fig.5 Effects of pH on flue gas desulfurization efficiency

图6 温度对煤中铁浸出率的影响(a)和对砷浸出率的影响(b) (UV,1.0 mmol/L草酸,pH=2.5)

Fig.6 Effect of temperature on extraction ratio of iron (a) and on extraction ratio of arsenic from coal (b)

图7 紫外线照射下1.0 mmol/L草酸强化过程中1-(1-F2)1/3随时间t的变化(a)和1-3(1-F2)2/3+2(1-F2)随时间t的变化(b)

Fig.7 Variation of 1-(1-F2)1/3 with time (a) and variation of 1-3(1-F2)2/3+2(1-F2)with time (b) during 1.0 mmol/L oxalic acid enhanced process under UV irradiation

图8 砷浸出过程的lnk-1/T关系

Fig.8 Plots of lnkversus 1/T for arsenic leaching process

图9 温度对烟气脱硫率的影响（UV，1.0 mmol/L草酸，pH=2.5）

Fig.9 Effect of temperature on flue gas desulfurization efficiency

图10 自由基猝灭剂对As(Ⅲ)/As(total)的影响（UV，1.0 mmol/L草酸，50℃，pH=2.5）

Fig.10 Effect of radical quenchers on As(Ⅲ)/As(total) ratio

图11 浸出后煤样和原煤样的ATR-FTIR光谱

Fig.11 ATR-FTIR spectra of coal residue and raw coal

图12 原煤样与浸出后煤样的XPS谱图

Fig.12 As 3d5/2, S 2p3/2 and Fe 2p3/2 XPS spectra of raw coal and coal residue

表1 原煤样与浸出后煤样的XPS谱图参数

Table 1 XPS parameters of raw coal and coal residue

煤样	组分	结合能/ eV	半峰宽/ eV	积分面积	面积占比/%
原煤样	黄铁矿铁	707.96	2.00	1016.03	34.16
	Fe²⁺	710.70	2.00	1269.06	42.66
	Fe³⁺	712.78	2.00	689.56	23.18
浸出后煤样	黄铁矿铁	707.01	2.00	219.83	20.70
	Fe²⁺	710.82	2.00	446.60	42.06
	Fe³⁺	713.07	2.00	395.30	37.24
原煤样	As(Ⅲ)	44.04	1.00	87.44	70.94
原煤样	As(Ⅴ)	45.63	1.00	35.82	29.06
浸出后煤样	As(Ⅲ)	44.21	1.00	17.57	26.37
浸出后煤样	As(Ⅴ)	45.72	1.00	49.07	73.63
原煤样	黄铁矿硫	162.97	1.70	309.19	30.59
	有机硫	165.79	1.70	149.74	14.82
	硫酸盐硫	168.29	1.70	551.68	54.59
浸出后煤样	黄铁矿硫	162.22	1.70	57.85	7.89
	有机硫	164.80	1.70	62.66	8.54
	硫酸盐硫	168.73	1.70	612.92	83.57

参考文献 45

1	Wang C B, Liu H M, Zhang Y, et al. Review of arsenic behavior during coal combustion: volatilization, transformation, emission and removal technologies[J]. Progress in Energy and Combustion Science, 2018, 68: 1-28.
2	Liu H M, Wang C B, Sun X, et al. Volatilization of arsenic in coal during isothermal oxy-fuel combustion[J]. Energy & Fuels, 2016, 30(4): 3479-3487.
3	López-Antón M A, Díaz-Somoano M, Fierro J L G, et al. Retention of arsenic and selenium compounds present in coal combustion and gasification flue gases using activated carbons[J]. Fuel Processing Technology, 2007, 88(8): 799-805.
4	Zhang Y, Wang C B, Li W H, et al. Removal of gas-phase As₂O₃ by metal oxide adsorbents: effects of experimental conditions and evaluation of adsorption mechanism[J]. Energy & Fuels, 2015, 29(10): 6578-6585.
5	Kang Y, Liu G J, Chou C L, et al. Arsenic in Chinese coals: distribution, modes of occurrence, and environmental effects[J]. Science of the Total Environment, 2011, 412/413: 1-13.
6	Sundaram H P, Cho E H, Miller A. SO₂ removal by leaching coal pyrite[J]. Energy & Fuels, 2001, 15(2): 470-476.
7	Black A, Craw D. Arsenic, copper and zinc occurrence at the Wangaloa coal mine, southeast Otago, New Zealand[J]. International Journal of Coal Geology, 2001, 45(2/3): 181-193.
8	Sun W S, Liu J C, Wang L C, et al. Aluminum-enhanced coal pyrite leaching during SO₂ removal with coal slurry[J]. Water, Air, & Soil Pollution, 2016, 227(7): 221.
9	Moses C O, Kirk Nordstrom D, Herman J S, et al. Aqueous pyrite oxidation by dissolved oxygen and by ferric iron[J]. Geochimica et Cosmochimica Acta, 1987, 51(6): 1561-1571.
10	鲁真真, 孙文寿, 郭远峰, 等. 氧气摩尔分数和紫外光照射对烟气浸出煤中砷的影响[J]. 高校化学工程学报, 2019, 33(4): 989-997.
	Lu Z Z, Sun W S, Guo Y F, et al. Effects of O₂ mole fraction and ultraviolet irradiation on arsenic leaching from coal with flue gas[J]. Journal of Chemical Engineering of Chinese Universities, 2019, 33(4): 989-997.
11	Wang W, Qu Y P, Yang B, et al. Lactate oxidation in pyrite suspension: a Fenton-like process in situ generating H₂O₂ [J]. Chemosphere, 2012, 86(4): 376-382.
12	Schoonen M A A, Harrington A D, Laffers R, et al. Role of hydrogen peroxide and hydroxyl radical in pyrite oxidation by molecular oxygen[J]. Geochimica et Cosmochimica Acta, 2010, 74(17): 4971-4987.
13	Santana-Casiano J M, González-Dávila M, Millero F J. The role of Fe(Ⅱ) species on the oxidation of Fe(Ⅱ) in natural waters in the presence of O₂ and H₂O₂ [J]. Marine Chemistry, 2006, 99(1/2/3/4): 70-82.
14	Cohn C A, Mueller S, Wimmer E, et al. Pyrite-induced hydroxyl radical formation and its effect on nucleic acids[J]. Geochemical Transactions, 2006, 7: 3.
15	Rimstidt J D, Vaughan D J. Pyrite oxidation: a state-of-the-art assessment of the reaction mechanism[J]. Geochimica et Cosmochimica Acta, 2003, 67(5): 873-880.
16	Zhang Y, Zhou J T, Li C Y, et al. Reaction kinetics and mechanism of iron(Ⅱ)-induced catalytic oxidation of sulfur(Ⅳ) during wet desulfurization[J]. Industrial & Engineering Chemistry Research, 2012, 51(3): 1158-1165.
17	Emett M T, Khoe G H. Photochemical oxidation of arsenic by oxygen and iron in acidic solutions[J]. Water Research, 2001, 35(3): 649-656.
18	Zhou L, Zheng W, Ji Y F, et al. Ferrous-activated persulfate oxidation of arsenic(Ⅲ) and diuron in aquatic system[J]. Journal of Hazardous Materials, 2013, 263: 422-430.
19	Ren H T, Ji Z Y, Wu S H, et al. Photoreductive dissolution of schwertmannite induced by oxalate and the mobilization of adsorbed As(V)[J]. Chemosphere, 2018, 208: 294-302.
20	Sundman A, Karlsson T, Sjöberg S, et al. Complexation and precipitation reactions in the ternary As(V)-Fe(Ⅲ)-OM (organic matter) system[J]. Geochimica et Cosmochimica Acta, 2014, 145: 297-314.
21	Mangiante D M, Schaller R D, Zarzycki P, et al. Mechanism of ferric oxalate photolysis[J]. ACS Earth and Space Chemistry, 2017, 1(5): 270-276.
22	Xu T Y, Zhu R L, Shang H, et al. Photochemical behavior of ferrihydrite-oxalate system: interfacial reaction mechanism and charge transfer process[J]. Water Research, 2019, 159: 10-19.
23	Sun J, Bostick B C, Mailloux B J, et al. Effect of oxalic acid treatment on sediment arsenic concentrations and lability under reducing conditions[J]. Journal of Hazardous Materials, 2016, 311: 125-133.
24	王明仕, 杨娜娜, 钦凡, 等. 贵州省某村煤中砷含量及赋存状态[J]. 煤炭转化, 2010, 33(4): 1-4.
	Wang M S, Yang N N, Qin F, et al. Content and occurrence of arsenic in coal of a village in Guizhou Province[J]. Coal Conversion, 2010, 33(4): 1-4.
25	刘恩栋, 杨宁光. 一种新的方便的测定天然水中三价砷的方法[J]. 交通环保, 1998(6): 21-22.
	Liu E D, Yang N G. A new and convenient method for the determination of trivalent arsenic in natural water[J]. Environmental Protection in Transportation, 1998(6): 21-22.
26	Nogueira A A, Souza B M, Dezotti M W C, et al. Ferrioxalate complexes as strategy to drive a photo-FENTON reaction at mild pH conditions: a case study on levofloxacin oxidation[J]. Journal of Photochemistry and Photobiology A: Chemistry, 2017, 345: 109-123.
27	Dong H Y, Wei G F, Yin D Q, et al. Mechanistic insight into the generation of reactive oxygen species in sulfite activation with Fe(Ⅲ) for contaminants degradation[J]. Journal of Hazardous Materials, 2020, 384: 121497.
28	Romero A, Santos A, Vicente F, et al. Diuron abatement using activated persulphate: effect of pH, Fe(Ⅱ) and oxidant dosage[J]. Chemical Engineering Journal, 2010, 162(1): 257-265.
29	韩东晖, 李瑛, 李开明, 等. UV强化草酸络合Fe³⁺活化过硫酸盐氧化降解苯胺[J]. 环境科学, 2018, 39(9): 4257-4264.
	Han D H, Li Y, Li K M, et al. Enhanced degradation of aniline by PS oxidation in the presence of UV and ferric oxalate[J]. Environmental Science, 2018, 39(9): 4257-4264.
30	Hislop K A, Bolton J R. The photochemical generation of hydroxyl radicals in the UV-vis/ferrioxalate/H₂O₂ system[J]. Environmental Science & Technology, 1999, 33(18): 3119-3126.
31	梁柱, 罗平, 殷井云, 等. UV-vis/H₂O₂/草酸铁络合物法调理对污泥脱水性能的影响[J]. 绿色科技, 2017(6): 1-4.
	Liang Z, Luo P, Yin J Y, et al. Effect of UV-vis/H₂O₂/ferrioxalate complex method on the dewatering performance of sludge[J]. Journal of Green Science and Technology, 2017(6): 1-4.
32	Neppolian B, Celik E, Choi H. Photochemical oxidation of a r s e n i c ( Ⅲ ) to arsenic(V) using peroxydisulfate ions as an oxidizing agent[J]. Environmental Science & Technology, 2008, 42(16): 6179-6184.
33	廖斌,衷水平.砷钙渣稳定化技术研究[J]. 矿产保护与利用, 2013(3): 51-54.
	Liao B, Zhong S P. Research on calcium arsenate residue stabilization technology[J]. Conservation and Utilization of Mineral Resources, 2013(3): 51-54.
34	Kuo D T F, Kirk D W, Jia C Q. The chemistry of aqueous S(Ⅳ)-Fe-O₂ system: state of the art[J]. Journal of Sulfur Chemistry, 2006, 27(5): 461-530.
35	易平贵, 俞庆森, 宗汉兴. 黄铁矿化学脱硫的热力学分析[J]. 煤炭转化, 1999, 22(1): 47-52.
	Yi P G, Yu Q S, Zong H X. Thermodynamic analysis for chemical desulfurization of pyrite in coal[J]. Coal Conversion, 1999, 22(1): 47-52.
36	Daggupati V N, Naterer G F, Gabriel K S. Diffusion of gaseous products through a particle surface layer in a fluidized bed reactor[J]. International Journal of Heat and Mass Transfer, 2010, 53(11/12): 2449-2458.
37	Wang H H, Li G Q, Zhao D, et al. Dephosphorization of high phosphorus oolitic hematite by acid leaching and the leaching kinetics[J]. Hydrometallurgy, 2017, 171: 61-68.
38	Ashraf M, Zafar Z I, Ansari T M. Selective leaching kinetics and upgrading of low-grade calcareous phosphate rock in succinic acid[J]. Hydrometallurgy, 2005, 80(4): 286-292.
39	Mendive C B, Bredow T, Blesa M A, et al. ATR-FTIR measurements and quantum chemical calculations concerning the adsorption and photoreaction of oxalic acid on TiO₂ [J]. Physical Chemistry Chemical Physics, 2006, 8(27): 3232-3247.
40	Kim E J, Batchelor B. Macroscopic and X-ray photoelectron spectroscopic investigation of interactions of arsenic with synthesized pyrite[J]. Environmental Science & Technology, 2009, 43(8): 2899-2904.
41	Zhang X S, Song X D, Wang J F, et al. CO₂ gasification of Yangchangwan coal catalyzed by iron-based waste catalyst from indirect coal-liquefaction plant[J]. Fuel, 2021, 285: 119228.
42	Yamashita T, Hayes P. Analysis of XPS spectra of Fe²⁺ and Fe³⁺ ions in oxide materials[J]. Applied Surface Science, 2008, 254(8): 2441-2449.
43	Wang X Q, Wang B, Chen Y F, et al. Fe₂P nanoparticles embedded on Ni₂P nanosheets as highly efficient and stable bifunctional electrocatalysts for water splitting[J]. Journal of Materials Science & Technology, 2022, 105: 266-273.
44	Zoroufchi Benis K, Soltan J, McPhedran K N. Electrochemically modified adsorbents for treatment of aqueous arsenic: pore diffusion in modified biomass vs. biochar[J]. Chemical Engineering Journal, 2021, 423: 130061.
45	Zhang B, Yan G H, Zhao Y M, et al. Coal pyrite microwave magnetic strengthening and electromagnetic response in magnetic separation desulfurization process[J]. International Journal of Mineral Processing, 2017, 168: 136-142.

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