Review of black liquor supercritical water gasification for hydrogen production with high value-added chemicals recovery

doi:10.11949/0438-1157.20220555

Abstract

Abstract:

Harmless and resourceful utilization of black liquor plays an important role in reducing environmental pollution and alleviating energy shortages. Supercritical water gasification technology is a new and efficient technology for the harmless resource utilization of organic wastewater. It has unique advantages in the harmless and resourceful treatment of papermaking black liquor by utilizing the special properties of water in the supercritical state. The progress of hydrogen production and high value-added chemicals recovery by supercritical water gasification of black liquor in recent years is reviewed. The hydrogen production mechanism is presented and the effects of temperature, pressure, concentration, residence time, and catalyst on hydrogen production by black liquor supercritical water gasification are systematically summarized. The reaction, the separation and recovery mechanism of high economic value salts of black liquor in supercritical water and the development status of supercritical water gasification reaction units for black liquor are introduced. Finally, the prospect of supercritical water gasification of black liquor for hydrogen production and resourceful, harmless treatment to recover useful components is presented.

Key words: black liquor, supercritical water, gasification, hydrogen production, salt recovery, reactor

摘要：

造纸黑液的无害化资源化利用对造纸工业减少环境污染、缓解能源短缺具有重要意义。超临界水气化技术是一种新型且高效的有机废水无害化资源化利用技术，利用水在超临界状态下的特殊性质使其在无害化资源化处理造纸黑液时具有独特的优势。回顾了近年来造纸黑液超临界水气化制氢与高附加值化学品回收的进展，介绍了制氢反应机理，系统总结了温度、压力、浓度、停留时间和催化剂等因素对黑液超临界水气化制氢的影响，介绍了造纸黑液里各类有用无机盐在超临界水条件下的反应、分离回收及造纸黑液超临界水气化反应装置的发展现状。针对现存问题对造纸黑液超临界水气化制氢和资源化无害化处理回收有用成分进行了展望。

关键词: 造纸黑液, 超临界水, 气化, 制氢, 盐回收, 反应器

CLC Number:

X 799.3

Xingang QI, Libo LU, Yunan CHEN, Zhiwei GE, Liejin GUO. Review of black liquor supercritical water gasification for hydrogen production with high value-added chemicals recovery[J]. CIESC Journal, 2022, 73(8): 3338-3354.

戚新刚, 路利波, 陈渝楠, 葛志伟, 郭烈锦. 造纸黑液超临界水气化制氢与高附加值化学品回收研究进展[J]. 化工学报, 2022, 73(8): 3338-3354.

Figures/Tables 22

Fig.1 Comparison of reaction potential energy and reaction process between supercritical water gasification and conventional pyrolysis gasification[31]

Table 1 Mechanism of alkali-catalyzed water gas conversion reaction［50］

方案1	方案2	方案3
$C O 3 2 -$ +H₂O 2OH^-+CO₂	2CO+2OH^- 2HCOO^-	$C O 3 2 -$ +H₂O $H C O 3 -$ + OH^-
2CO +2OH^-2HCOO^-	2HCOO^- HCOH + $C O 3 2 -$	OH^-+CO HCOO^-
2HCOO^-+2H₂O2HCOOH + 2OH^-	2H₂O+ $C O 3 2 -$ 2OH^-+H₂CO₃	HCOO^-+H₂O $H C O 3 -$ + H₂
2HCOOH 2CO₂+ 2H₂	H₂CO₃ H₂O + CO₂	2 $H C O 3 -$ H₂O + $C O 3 2 -$ + CO₂
2OH^- + CO₂ $C O 3 2 -$ + H₂O	HCOH H₂+ CO	H₂O+COHCOOHH₂+ CO

Table 1 Mechanism of alkali-catalyzed water gas conversion reaction［50］

方案1	方案2	方案3
$C O 3 2 -$ +H₂O 2OH^-+CO₂	2CO+2OH^- 2HCOO^-	$C O 3 2 -$ +H₂O $H C O 3 -$ + OH^-
2CO +2OH^-2HCOO^-	2HCOO^- HCOH + $C O 3 2 -$	OH^-+CO HCOO^-
2HCOO^-+2H₂O2HCOOH + 2OH^-	2H₂O+ $C O 3 2 -$ 2OH^-+H₂CO₃	HCOO^-+H₂O $H C O 3 -$ + H₂
2HCOOH 2CO₂+ 2H₂	H₂CO₃ H₂O + CO₂	2 $H C O 3 -$ H₂O + $C O 3 2 -$ + CO₂
2OH^- + CO₂ $C O 3 2 -$ + H₂O	HCOH H₂+ CO	H₂O+COHCOOHH₂+ CO

Fig.2 Comparison of fitted rate constants in the Arrhenius equation for water-gas conversion reactions under alkali-catalyzed and non-catalyzed conditions[50]

Fig.3 Supercritical water gasification of dilute black liquor in different continuous reactors(a) 23 MPa, 600—700℃, 0.81%(mass)[61]; (b) 25 MPa, 400—600℃, 2.5%(mass) [38]

Fig.4 Color of dilute black liquor after supercritical water gasification reaction [38](25 MPa, 400—600℃, 2.5%(mass))

Fig.5 Supercritical water gasification in an intermittent batch reactor at different temperatures[62](25 MPa, 600—750℃, 9.5%(mass))

Fig.6 Carbon gasification efficiency in the quartz tube reactor at different temperature and pressure conditions [60](22—40 MPa, 375—650℃, 2.5%(mass))

Fig.7 Hydrogen yield (a) and COD removal ratio (b) for a continuous reactor with different feed concentrations [61]

Fig.8 Gas composition and carbon gasification efficiency at different concentration conditions in the intermittent reactor[62](23—26 MPa, 750℃, 2.5%—9.5%(mass))

Fig.9 Gas fraction and carbon gasification efficiency for different residence times[62](23—26 MPa, 700℃, 9.5%(mass))

Fig.10 Gas fraction (a) and COD removal ratio (b) for different residence time in the continuous reactor [38]

Fig.11 Effect of different metal oxides on the carbon gasification efficiency of black liquor supercritical water gasification[39]

Fig.12 Effect of different metal oxides on the hydrogen yield of black liquor supercritical water gasification [39] (600℃, 12.6%(mass), 24—26 MPa)

Fig.13 Sulfate reduction reaction scheme and energy barrier under gas phase conditions[76]

Fig.14 Sulfate reduction reaction scheme and energy barrier under supercritical water conditions[76]

Fig.15 Phase diagram of two types of brine systems: (a) Type 1 brine system; (b) Type 2 brine system [80]

Fig.16 Schematic diagram of supercritical water inorganic salt separator[83-85]

Fig.17 Variation pattern of inorganic salt recovery with K/(K+Na)[86]

Fig.18 Schematic diagram of the intermittent reactor[14,40] system at the State Key Laboratory of Multiphase Flow in Power Engineering, Xi'an Jiaotong University1—Ar gas bottle; 2—pressure sensor; 3—temperature sensor; 4—data acquisition station; 5—wet gas flow meter; 6—intermittent kettle; 7—electric furnace

Fig.19 Schematic diagram of the experimental setup for continuous tubular flow supercritical water gasification to hydrogen[38]

Fig.20 Schematic diagram of continuous fluidized supercritical water gasification reactor for hydrogen

Table 2 Comparison of black liquor supercritical water gasification reactors

原料	国家	型式	操作参数	处理量	气化效果	盐回收
硫酸盐法黑液^[60]	泰国	间歇反应器（石英毛细管，内径 1 mm；外径 2 mm，长度15 cm）	650℃，40 MPa，无催化剂	—	碳气化率84.1%	否
硫酸盐法黑液^[70]	法国	间歇反应器(体积为5 ml)	450℃，40 MPa，催化剂：CeO₂	—	碳气化率30%	否
硫酸盐法黑液^[39]	中国	间歇反应器(体积为12 ml)	600℃，23 MPa，催化剂：Co₂O₃等	—	碳气化率80.11%，H₂产量 21.67mol/kg	否
烧碱法黑液^[62]	中国	间歇反应器(体积为10 ml)	700℃，23 MPa	—	碳气化率98.17%，H₂产量 62.38 mol/kg	否
硫酸盐法黑液^[88]	俄罗斯	连续管流式反应器(不锈钢AISI 321H，内径10 mm，长度 127 mm)	750℃，30 MPa	0.01 g/min	碳气化率91%	否
硫酸盐法黑液^[41,69]	芬兰	连续管流式反应器(Inconel 625或不锈钢316，内径1.1 cm，长度50.8 cm)	700℃，30 MPa	0.63 g/min	碳气化率75%，H₂产量7.87 mol/kg	否
硫酸盐法黑液^[61]	西班牙	连续管流式反应器 (Inconel 625,内径13 mm, 长度0.373 m)	700℃，23 MPa，催化剂：NaOH	5 g/min	碳气化率52.7%，H₂产量38.68 mol/kg	否
硫酸盐法黑液^[68]	中国	连续管流式反应器	500℃，24 MPa，催化剂：Ni/ZrO₂	—	碳气化率74.87%	否
烧碱法黑液^[38]	中国	连续管流式反应器(Hastelloy C-276, 内径 10.85 mm，长度1.24 m)	600℃，23 MPa	5 kg/h	碳气化率67.89%，H₂产量11.26 mol/kg	否
硫酸盐法黑液	中国	流态化反应器	640℃，23 MPa	30 g/min	碳气化率98.41%，H₂产量32.84 mol/kg	是

References 88

1	Bajpai P. Biermann's Handbook of Pulp and Paper: Volume 1: Raw Material and Pulp Making [M]. Amsterdam: Elsevier, 2018.
2	陈俊峰, 李光荣. 碱法制浆造纸黑液的资源化利用[J]. 广东化工, 2018, 45(3): 94-95.
	Chen J F, Li G R. Resource utilization of alkaline pulping black liquor[J]. Guangdong Chemical Industry, 2018, 45(3): 94-95.
3	Darmawan A, Ajiwibowo M W, Yoshikawa K, et al. Energy-efficient recovery of black liquor through gasification and syngas chemical looping[J]. Applied Energy, 2018, 219: 290-298.
4	Darmawan A, Hardi F, Yoshikawa K, et al. Enhanced process integration of black liquor evaporation, gasification, and combined cycle[J]. Applied Energy, 2017, 204: 1035-1042.
5	付丹. 造纸黑液处理技术研究进展[J]. 辽宁化工, 2015, 44(4): 385-386, 391.
	Fu D. Research progress in the treatment technology of papermaking black liquor[J]. Liaoning Chemical Industry, 2015, 44(4): 385-386, 391.
6	Dong X Y, Guo S Q, Li S, et al. Physicochemical characteristics and combustion reactivity of reed stalk hydrochar obtained under dilute black liquor condition[J]. Biomass Conversion and Biorefinery, 2022. DOI:10.1007/s13399-022-02394-4 .
7	唐华, 王大伟, 栾小娟. 制浆黑液燃烧特性实验研究进展[J]. 中国造纸, 2020, 39(9): 68-73.
	Tang H, Wang D W, Luan X J. Experimental research progress of combustion characteristics of pulping black liquor[J]. China Pulp & Paper, 2020, 39(9): 68-73.
8	靳福明. 碱回收炉烟气排放及控制措施可行性技术分析[J]. 中国造纸, 2018, 37(3): 64-71.
	Jin F M. Technical analysis on emission control method of recovery boiler[J]. China Pulp & Paper, 2018, 37(3): 64-71.
9	Haddad M, Labrecque R, Bazinet L, et al. Effect of process variables on the performance of electrochemical acidification of Kraft black liquor by electrodialysis with bipolar membrane[J]. Chemical Engineering Journal, 2016, 304: 977-985.
10	Haddad M, Mikhaylin S, Bazinet L, et al. Electrochemical acidification of Kraft black liquor by electrodialysis with bipolar membrane: ion exchange membrane fouling identification and mechanisms[J]. Journal of Colloid and Interface Science, 2017, 488: 39-47.
11	Haddad M, Labrecque R, Bazinet L, et al. Effect of process variables on the performance of electrochemical acidification of Kraft black liquor by electrodialysis with bipolar membrane[J]. Chemical Engineering Journal, 2016, 304: 977-985.
12	Ma M S, Dai L, Si C L, et al. A facile preparation of super long-term stable lignin nanoparticles from black liquor[J]. ChemSusChem, 2019, 12(24): 5216.
13	谭惠珊. 碱法制浆黑液中木质素的提取与纯化[D]. 天津: 天津科技大学, 2017.
	Tan H S. The extraction and purification of lignin from alkaline pulping black liquor[D]. Tianjin: Tianjin University of Science & Technology, 2017.
14	Chen Y N, He Y Y, Jin H, et al. Resource utilization of landfill leachate gasification in supercritical water[J]. Chemical Engineering Journal, 2020, 386: 124017.
15	Domínguez-Robles J, Palenzuela M D V, Sánchez R, et al. Coagulation–flocculation as an alternative way to reduce the toxicity of the black liquor from the paper industry: thermal valorization of the solid biomass recovered[J]. Waste and Biomass Valorization, 2020, 11(9): 4731-4742.
16	An X J, Zhong B, Chen G T, et al. Evaluation of bioremediation and detoxification potentiality for papermaking black liquor by a new isolated thermophilic and alkali-tolerant Serratia sp. AXJ-M[J]. Journal of Hazardous Materials, 2021, 406: 124285.
17	Narra M, Rudakiya D M, Macwan K, et al. Black liquor: a potential moistening agent for production of cost-effective hydrolytic enzymes by a newly isolated cellulo-xylano fungal strain Aspergillus tubingensis and its role in higher saccharification efficiency[J]. Bioresource Technology, 2020, 306: 123149.
18	Durai-Swamy K, Mansour M N, Warren D W. Pulsed combustion process for black liquor gasification[R]. Oak Ridge: Office of Scientific and Technical Information (OSTI), 1991.
19	Andersson J, Furusjö E, Wetterlund E, et al. Co-gasification of black liquor and pyrolysis oil: evaluation of blend ratios and methanol production capacities[J]. Energy Conversion and Management, 2016, 110: 240-248.
20	Naqvi M, Yan J, Dahlquist E. Black liquor gasification integrated in pulp and paper mills: a critical review[J]. Bioresource Technology, 2010, 101(21): 8001-8015.
21	Nohlgren I. Non-conventional causticization technology: a review[J]. Nordic Pulp & Paper Research Journal, 2004, 19(4): 470-480.
22	Zetterholm J, Pettersson K, Leduc S, et al. Resource efficiency or economy of scale: biorefinery supply chain configurations for co-gasification of black liquor and pyrolysis liquids[J]. Applied Energy, 2018, 230: 912-924.
23	Marklund M, Tegman R, Gebart R. CFD modelling of black liquor gasification: identification of important model parameters[J]. Fuel, 2007, 86(12/13): 1918-1926.
24	Maxim F, Contescu C, Boillat P, et al. Visualization of supercritical water pseudo-boiling at Widom line crossover[J]. Nature Communications, 2019, 10: 4114.
25	Ai L Q, Zhou Y S, Chen M. A reactive force field molecular dynamics simulation of the dynamic properties of hydrogen bonding in supercritical water[J]. Journal of Molecular Liquids, 2019, 276: 83-92.
26	Andreani C, Romanelli G, Parmentier A, et al. Hydrogen dynamics in supercritical water probed by neutron scattering and computer simulations[J]. The Journal of Physical Chemistry Letters, 2020, 11(21): 9461-9467.
27	Savage P E. Organic chemical reactions in supercritical water[J]. Chemical Reviews, 1999, 99(2): 603-622.
28	Hou R, Quan Y H, Pan D. Dielectric constant of supercritical water in a large pressure-temperature range[J]. The Journal of Chemical Physics, 2020, 153(10): 101103.
29	Ren C, Ge Z W, Ou G B, et al. Supercritical water partial oxidation mechanism of ethanol[J]. International Journal of Hydrogen Energy, 2021, 46(44): 22777-22788.
30	Chen Y N, Yi L, Yin J R, et al. Sewage sludge gasification in supercritical water with fluidized bed reactor: reaction and product characteristics[J]. Energy, 2022, 239: 122115.
31	Jin H, Wu Y, Guo L J, et al. Molecular dynamic investigation on hydrogen production by polycyclic aromatic hydrocarbon gasification in supercritical water[J]. International Journal of Hydrogen Energy, 2016, 41(6): 3837-3843.
32	Chen Y N, Yi L, Wei W W, et al. Hydrogen production by sewage sludge gasification in supercritical water with high heating rate batch reactor[J]. Energy, 2022, 238: 121740.
33	Ge Z W, Guo L J, Jin H. Catalytic supercritical water gasification mechanism of coal[J]. International Journal of Hydrogen Energy, 2020, 45(16): 9504-9511.
34	Ge Z W, Guo S H, Ren C, et al. Non-catalytic supercritical water partial oxidation mechanism of coal[J]. International Journal of Hydrogen Energy, 2020, 45(41): 21178-21185.
35	Guo S H, Meng F R, Peng P, et al. Thermodynamic analysis of the superiority of the direct mass transfer design in the supercritical water gasification system[J]. Energy, 2022, 244: 122722.
36	Ren C, Guo S H, Wang Y, et al. Thermodynamic analysis and optimization of auto-thermal supercritical water gasification polygeneration system of pig manure[J]. Chemical Engineering Journal, 2022, 427: 131938.
37	Barros T V, Carregosa J D C, Wisniewski Jr A, et al. Assessment of black liquor hydrothermal treatment under sub- and supercritical conditions: products distribution and economic perspectives[J]. Chemosphere, 2022, 286: 131774.
38	Cao C Q, Guo L J, Chen Y N, et al. Hydrogen production from supercritical water gasification of alkaline wheat straw pulping black liquor in continuous flow system[J]. International Journal of Hydrogen Energy, 2011, 36(21): 13528-13535.
39	Cao C Q, Xie Y P, Mao L H, et al. Hydrogen production from supercritical water gasification of soda black liquor with various metal oxides[J]. Renewable Energy, 2020, 157: 24-32.
40	Cao C Q, Zhang Y, Li L H, et al. Supercritical water gasification of black liquor with wheat straw as the supplementary energy resource[J]. International Journal of Hydrogen Energy, 2019, 44(30): 15737-15745.
41	de Blasio C, de Gisi S, Molino A, et al. Concerning operational aspects in supercritical water gasification of kraft black liquor[J]. Renewable Energy, 2019, 130: 891-901.
42	Özdenkçi K, Prestipino M, Björklund-Sänkiaho M, et al. Alternative energy valorization routes of black liquor by stepwise supercritical water gasification: effect of process parameters on hydrogen yield and energy efficiency[J]. Renewable and Sustainable Energy Reviews, 2020, 134: 110146.
43	Akiya N, Savage P E. Roles of water for chemical reactions in high-temperature water[J]. ChemInform, 2002, 33(43): 293.
44	Kruse A, Dahmen N. Water — a magic solvent for biomass conversion[J]. The Journal of Supercritical Fluids, 2015, 96: 36-45.
45	Güvenatam B, Heeres E H J, Pidko E A, et al. Lewis-acid catalyzed depolymerization of protobind lignin in supercritical water and ethanol[J]. Catalysis Today, 2016, 259: 460-466.
46	Kruse A, Bernolle P, Dahmen N, et al. Hydrothermal gasification of biomass: consecutive reactions to long-living intermediates[J]. Energy Environ. Sci., 2010, 3(1): 136-143.
47	Brock E E, Savage P E. Detailed chemical kinetics model for supercritical water oxidation of C₁ compounds and H₂ [J]. AIChE Journal, 1995, 41(8): 1874-1888.
48	Park K C, Tomiyasu H. Gasification reaction of organic compounds catalyzed by RuO₂ in supercritical water[J]. Chemical Communications, 2003(6): 694-695.
49	Watanabe M, Hirakoso H, Sawamoto S, et al. Polyethylene conversion in supercritical water[J]. The Journal of Supercritical Fluids, 1998, 13(1/2/3): 247-252.
50	Wang R Y, Guo L J, Jin H, et al. DFT study of the enhancement on hydrogen production by alkaline catalyzed water gas shift reaction in supercritical water[J]. International Journal of Hydrogen Energy, 2018, 43(30): 13879-13886.
51	Ding Z Y, Frisch M A, Li L X, et al. Catalytic oxidation in supercritical water[J]. Industrial & Engineering Chemistry Research, 1996, 35(10): 3257-3279.
52	Akiya N, Savage P E. Kinetics and mechanism of cyclohexanol dehydration in high-temperature water[J]. Industrial & Engineering Chemistry Research, 2001, 40(8): 1822-1831.
53	Wang B S, Hou H, Gu Y S. Water-catalyzed mechanism for the pyrolysis of formic acid[J]. Chemical Physics, 1999, 243(1/2): 27-34.
54	Akiya N, Savage P E. Role of water in formic acid decomposition[J]. AIChE Journal, 1998, 44(2): 405-415.
55	Elliott D C. Catalytic hydrothermal gasification of biomass[J]. Biofuels, Bioproducts and Biorefining, 2008, 2(3): 254-265.
56	Elliott D C, Sealock L J. Aqueous catalyst systems for the water-gas shift reaction(1): Comparative catalyst studies[J]. Industrial & Engineering Chemistry Product Research and Development, 1983, 22(3): 426-431.
57	Sınağ A, Kruse A, Schwarzkopf V. Key compounds of the hydropyrolysis of glucose in supercritical water in the presence of K₂CO₃ [J]. Industrial & Engineering Chemistry Research, 2003, 42(15): 3516-3521.
58	Kruse A, Gawlik A. Biomass conversion in water at 330—410 ℃ and 30—50 MPa. Identification of key compounds for indicating different chemical reaction pathways[J]. Industrial & Engineering Chemistry Research, 2003, 42(2): 267-279.
59	Kang S M, Li X L, Fan J, et al. Hydrothermal conversion of lignin: a review[J]. Renewable and Sustainable Energy Reviews, 2013, 27: 546-558.
60	Sricharoenchaikul V. Assessment of black liquor gasification in supercritical water[J]. Bioresource Technology, 2009, 100(2): 638-643.
61	Casademont P, Sánchez-Oneto J, Scandelai A P J, et al. Hydrogen production by supercritical water gasification of black liquor: use of high temperatures and short residence times in a continuous reactor[J]. The Journal of Supercritical Fluids, 2020, 159: 104772.
62	Cao C Q, Xu L C, He Y Y, et al. High-efficiency gasification of wheat straw black liquor in supercritical water at high temperatures for hydrogen production[J]. Energy & Fuels, 2017, 31(4): 3970-3978.
63	Bühler W, Dinjus E, Ederer H J, et al. Ionic reactions and pyrolysis of glycerol as competing reaction pathways in near- and supercritical water[J]. The Journal of Supercritical Fluids, 2002, 22(1): 37-53.
64	Ibrahim A B A, Akilli H. Supercritical water gasification of wastewater sludge for hydrogen production[J]. International Journal of Hydrogen Energy, 2019, 44(21): 10328-10349.
65	He C, Wang K, Giannis A, et al. Products evolution during hydrothermal conversion of dewatered sewage sludge in sub- and near-critical water: effects of reaction conditions and calcium oxide additive[J]. International Journal of Hydrogen Energy, 2015, 40(17): 5776-5787.
66	Zhang L H, Xu C B, Champagne P. Energy recovery from secondary pulp/paper-mill sludge and sewage sludge with supercritical water treatment[J]. Bioresource Technology, 2010, 101(8): 2713-2721.
67	Yan Z Y, Tan X Y. Hydrogen generation from oily wastewater via supercritical water gasification (SCWG)[J]. Journal of Industrial and Engineering Chemistry, 2015, 23: 44-49.
68	晏波, 吴君章, 何凤媚, 等. Ni/ZrO₂催化超临界水气化造纸黑液产氢资源化研究[C]//第八届全国氢能学术会议. 2007.
	Yan B, Wu J Z, He F M, et al.Study on the hydrogen production from pulp and paper millwastewater by supercritical water gasification (SCWG) in a continuous flow reactor with Ni/ZrO₂ catalyst[C]// Proceedings of the 8th National Conference on Hydrogen Energy. 2007.
69	de Blasio C, Lucca G, Özdenkci K, et al. A study on supercritical water gasification of black liquor conducted in stainless steel and nickel-chromium-molybdenum reactors[J]. Journal of Chemical Technology & Biotechnology, 2016, 91(10): 2664-2678.
70	Boucard H, Watanabe M, Takami S, et al. Beneficial use of CeO₂ nanocatalyst for black liquor conversion under sub and supercritical conditions[J]. The Journal of Supercritical Fluids, 2015, 105: 66-76.
71	Pokhrel D, Viraraghavan T. Treatment of pulp and paper mill wastewater—a review[J]. Science of the Total Environment, 2004, 333(1/2/3): 37-58.
72	Saari J, Sermyagina E, Kaikko J, et al. Evaluation of the energy efficiency improvement potential through back-end heat recovery in the kraft recovery boiler[J]. Energies, 2021, 14(6): 1550.
73	Lin J H, Liao Q X, Hu Y P, et al. Effects of process parameters on sulfur migration and H₂S generation during supercritical water gasification of sludge[J]. Journal of Hazardous Materials, 2021, 403: 123678.
74	Liu S K, Li L H, Guo L J, et al. Sulfur transformation characteristics and mechanisms during hydrogen production by coal gasification in supercritical water[J]. Energy & Fuels, 2017, 31(11): 12046-12053.
75	Ding K L, Li S Y, Yue C T, et al. Simulation experiments on the reaction system of CH₄-MgSO₄-H₂O[J]. Chinese Science Bulletin, 2008, 53(7): 1071-1078.
76	Wang R Y, Lu L B, Chen J, et al. Combining experiment and density functional theory to study the mechanism of thermochemical sulfate reduction by hydrogen in supercritical water[J]. Journal of Molecular Liquids, 2021, 330: 115654.
77	Yue C T, Li S Y, Ding K L, et al. Thermodynamics and kinetics of reactions between C₁—C₃ hydrocarbons and calcium sulfate in deep carbonate reservoirs[J]. Geochemical Journal, 2006, 40(1): 87-94.
78	Duverger-Nédellec E, Voisin T, Erriguible A, et al. Unveiling the complexity of salt(s) in water under transcritical conditions[J]. The Journal of Supercritical Fluids, 2020, 165: 104977.
79	Valyashko V M. Phase equilibria in water-salt systems: some problems of solubility at elevated temperature and pressure[J]. High Temperature High Pressure Electrochemistry in Aqueous Solutions, 1976, 4: 153-157.
80	王润宇. 碱及无机硫在超临界水气化过程中反应机理的研究 [D]. 西安; 西安交通大学, 2021.
	Wang R Y. Study on the reaction mechanism of alkali and inorganic sulfur in supercritical water gasification process [D]. Xi'an: Xi'an Jiaotong University, 2021.
81	Marshall W L. Water and its solutions at high temperatures and pressures[J]. Chemistry, 1975, 48: 6-12.
82	Schubert M, Aubert J, Müller J B, et al. Continuous salt precipitation and separation from supercritical water(Part 3): Interesting effects in processing type 2 salt mixtures[J]. The Journal of Supercritical Fluids, 2012, 61: 44-54.
83	Schubert M, Regler J W, Vogel F. Continuous salt precipitation and separation from supercritical water(Part 1): Type 1 salts[J]. The Journal of Supercritical Fluids, 2010, 52(1): 99-112.
84	Schubert M, Regler J W, Vogel F. Continuous salt precipitation and separation from supercritical water(Part 2): Type 2 salts and mixtures of two salts[J]. The Journal of Supercritical Fluids, 2010, 52(1): 113-124.
85	Schubert M, Müller J B, Vogel F. Continuous hydrothermal of glycerol and its degradation products on the continuous salt separation and the enhancing effect of K₃PO₄ on the glycerol degradation[J]. The Journal of Supercritical Fluids, 2014, 95: 364-372.
86	Wang R Y, Deplazes R, Vogel F, et al. Continuous extraction of black liquor salts under hydrothermal conditions[J]. Industrial & Engineering Chemistry Research, 2021, 60(10): 4072-4085.
87	Azadi P, Farnood R. Review of heterogeneous catalysts for sub- and supercritical water gasification of biomass and wastes[J]. International Journal of Hydrogen Energy, 2011, 36(16): 9529-9541.
88	Fedyaeva O N, Vostrikov A A, Shishkin A V, et al. Conjugated processes of black liquor mineral and organic components conversion in supercritical water[J]. The Journal of Supercritical Fluids, 2019, 143: 191-197.

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