Basic Information

Dr. Yanqing Niu, Professor

Department of Thermal Engineering, School of Energy and Power Engineering,  Xi’an Jiaotong University (XJTU)

Email: yqniu85@mial.xjtu.edu.cn;    Tel: 86-029-82665002

Professional Appointments

Jan, 2023 - Present         Professor in Thermal Engineering, School of Energy and Power Engineering, Xi'an Jiaotong University, China

Oct, 2015 - Dec, 2022    Associate Professor in Thermal Engineering, School of Energy and Power Engineering, Xi'an Jiaotong University, China

Dec, 2012 - Sep, 2015    Lecturer in Thermal Engineering, School of Energy and Power Engineering, Xi'an Jiaotong University, China

Professional Preparation

Sep, 2009 - Sep, 2012    Doctor of Engineering in Thermal Engineering, School of Energy and Power Engineering, Xi'an Jiaotong University, China

Sep, 2011 - Sep, 2012    Visitor in Combustion Research Facility, Sandia National Laboratories (Livermore, CA), USA

Sep, 2008 - Jul, 2009     Master-Doctor combined program graduate student, Department of Thermal Engineering, School of Energy and Power Engineering, Xi'an Jiaotong University, China

Sep, 2004 - Jul, 2008     Bachelor of Engineering in Thermal Engineering, School of Energy and Power Engineering, Xi'an Jiaotong University, China

Scientific Research

Research Interests

1) Experiment and kinetic research on char combustion and PM formation;

2) Biomass ash related problems during combustion (slagging, agglomeration, corrosion, and utilization...) with experiment and modeling;

3) Biomass pretreatment, combustion, co-combustion, gasification…;

4) Low NOx Burner and Emission Control of Combustion (NOx, SOx, and PM);

5) Resource Utilization of Fly ash.

Detailed self-introduction

I mainly focus on the studies of ash behaviors and pollutant control during the combustion of solid fuels such as coal and biomass. More detailed, it consists of the multiple slagging mechanisms during combustion of alkali-enriched fuels, ash behaviors coupled char particle combustion and the formation of multi-mode particulate matters (PM), the mechanisms and technologies of pulverized coal low-NOx combustion through self-heated. Planning to through the above-mentioned in-depth research, exploring their scientific essence, and then achieving the clean and efficient combustion of solid fuel, meanwhile, solving the thorny problems of ash slagging, PM fromation, NOx emission during combustion, etc.

Focusing on the vital ash-related issues during the combustion of alkali-enrichment fuels, I propose the concept of “triple slagging mechanisms, i.e., alkali-induced slagging, high-temperature silicates melt-induced slagging, and low-temperature silicates melt-induced slagging” by means of systematical and in-depth research (Fig.1), meanwhile, elucidates the forming mechanisms and develops the quantitative evaluation criteria and methods. All those provide theoretical guidelines for fuel selection, mix, match and slagging prediction. Attributed to above research, an invited review on ash-related issues during biomass combustion was launched on the pre-eminent journal “Progress in Energy and Combustion Science” (Invited, annual paper number:17IF 35.339cited: 600+ESI hot point paper, and ESI highly cited paper since its publication in 2016). Meanwhile, I was awarded the Most Cited Energy Article from China by Elsevier.

Fig.1 The formation and coexistence mechanism of triple slagging during biomass combustion

Aiming to the multiple ash behaviors during pulverized coal char combustion, by means of laser-optics testing, I develops the only ash inhibition char burning intrinsic kinetics model and codes (CBC, Left illustration in Fig.2) that couples of ash film, ash dilution and ash vaporization and accurately characterizes the impact of ash on overall char particle mass loss rates during combustion and gasification; The CBC kinetics model is the unique ash model that accurately characterizes the impact of ash on overall char particle mass loss rates. Recently, the model has been extended to simulate the formation of ultrafine PM during pulverized coal char combustion after coupling the mechanism of ash vaporization, homogenous nucleation, heterogeneous condensation, coagulation and coalescence, named as Char Burning and Particulate Matter Kinetics Model (CBPMK, Right illustration in Fig.2). The model of CBPMK can give high precision prediction on the dynamic behaviors of char combustion and PM formation. As a more sophisticated model, the model is the only one that has the capability of accurately characterizing the impact of ash on overall char particle mass loss rates, and thus providing more realistic and may better explain late-stage burnout data.

Fig.2 Char Burning model CBC and the framework of ultrafine PM formation model CBPMK

Focusing on the urgent requirement on the further removal on NOx and the low load stable-combustion in coal power plants and industrial boilers, I conducted detailed research on the NOx formation by a novel pulverized coal preheating-combustion coupling technology, invents the multistage air/fuel supply technology in radial and axial, self-preheating & low nitrogen combustion technology, and combustion system integration scheme of self-preheating burner and boiler furnace, meanwhile, exploits series of low-NOx swirling burners (Fig.3). The self-preheating burner improves the low NOx combustion with a value as low as 130 mg·m-3 in industrial boilers, meanwhile, it can ensure the safety operation of boiler at the load as low as 20%. So far, the burners have been applied more than 100 (covering 4.2-35 MW), and installed in 80 boilers and more than 40 users in China and Pakistan. Twelve inventive patents and nine utility model patents are authorized, and five patents are transformed by enterprise application. This study provides theoretical basis and application reference for the ultra-low NOx emission and low load flexibility modification of coal-fired boilers. The appraisal committee, organized by the Chinese Society of Power Engineering, agreed that the technology was generally at the “International advanced level”, among that the multistage air/fuel supply technology in radial and axial, pulverized coal self-preheating, and self-cleaning and slagging prevention technology of pre-combustion chamber were “International leading level”. Meanwhile, I was awarded the Science Research Famous Achievement First-Level Award in Higher Institution of Shaanxi in 2021.

Fig.3 The low-NOx self-preheating burner

Now, I has chaired two NSFC proposal, five proposals from Natural Science Basic Research Plan in Shaanxi Province and national and provincial key laboratories, one special financial grant from China Postdoctoral Science Foundation, five Fundamental Research Funds for the Central Universities, and more than ten of enterprise projects, etc. I have gained the Outstanding Young Talents in Shaanxi, the Science Research Famous Achievement First-Level Award in Higher Institution of Shaanxi, the award of most cited energy article from Elsevier (Energy connect-China), 100 Selected Chinese Postdoctoral Scholars from China Postdoctoral Science Foundation, Young Talents Support Plan from Xi'an Association for Science and Technology, Young Talent Tracking Support Plan and Outstanding Doctoral Dissertations from Xi'an Jiaotong University, and Young Scholar of Distinction Award for PhD candidate from the MOE of China, etc.

        Up to now, I has published more than 140 papers (> 110 journal articles and >30 conference paper and report), including more than 70 SCI papers (first and corresponding author: more than 50; H-index: 21). Among that, 10 papers were published in the official journal of the Combustion Institute (one in the journal of Progress in Energy and Combustion Science, 4 in Proceedings of the Combustion Institute, 6 in Combustion and Flame) and one in journal of Renewable and Sustainable Energy Reviews. The invited article published in the journal of Progress in Energy and Combustion Science has been cited more than 700 in Google, ranked as ESI hot paper (top 1‰), and awarded the Most Cited Energy Article from China (Elsevier Energy in China, total 28 papers). All the SCI papers have been cited by famous scholars including academicians, CI fellows, and editors in SCI journals for more than 2000 in Google. I have been authorized 30 inventive patents and ten utility model patents, among that six patents transformed by enterprise application. Meanwhile, I have done oral presentation more than twenty times in international conferences (such as the international symposium on combustion and ICAE) and local annual meeting of combustion. He also ever serviced as an Editor of journal of Current Chinese Science (Field: Energy) , and associate editor of the journal of IET Renew Power GenIF 3.034, and Front Energy Res (IF 3.858), an editor member of the internal journal of chemical engineering (IF2.257), guest editor of Journal of chemistry (IF 2.506)Sustainability (IF 3.889), Energies (IF 3.252), session chair in the International Conference of Power Engineering 2013 and International Conference on Applied Energy 2017, and a member of technical program committee of International Conference on Environmental Protection and Human Health 2016. He is a peer reviewer on more than thirty SCI journals such as Progress in Energy and Combustion Science, Renewable and Sustainable Energy Reviews, Proceedings of the Combustion Institute, Combustion and Flame, Combustion Science and Technology, Applied Energy, and Fuel, as well as NSF of China and Poland

Service

1) Associate Editor:  IET Renewable Power Generation (IF 3.034), 2019 – Present

   Frontiers in Energy Research (IF 3.858) , 2022 – Present

2) Academic Editor:  International Journal of Chemical Engineering (IF 2.729), 2021 – Present

3) Technical Paper and Proposal Reviewer for the following Journals and organizations:

     NSF of China, Grant proposal for the National Science Center of Poland;

    Progress in Energy and Combustion Science, Combustion and Flame, Proceedings of The Combustion Institute, Bioresource Technology, Fuel, Fuel Processing Technology, Applied Thermal Engineering, Journal of Cleaner Production, Scientific Reports, Energy & Fuels, Journal of the Energy Institute…...

Representative paper

1Niu Yanqing*, Tan Houzhang, Hui Shi’en, Ash-related issues during biomass combustion: alkali-induced slagging, silicate melt-induced slagging (ash fusion), agglomeration, corrosion, ash utilization, and related countermeasures, Progress in Energy and Combustion Science, 2016, 52: 1-61. DOI:10.1016/j.pecs.2015.09.003

2Niu Yanqing*, Lv Yuan, Lei Yu, Liu Siqi, Liang Yang, Wang Denghui, Hui Shi’en, Biomass torrefaction: properties, applications, challenges, and economy. Renewable and Sustainable Energy Reviews 2019, 115: 109395. DOI:10.1016/j.rser.2019.109395

3Liu Siqi, Niu Yanqing*, Shang Yimin, Zhu Guangqing, Hui Shi’en. A percolation model of fly ash formation during the combustion of non-uniform porous char. Combustion and Flame 2023, 251: 112720. DOI:10.1016/j.combustflame.2023.112720

4Liu Siqi, Wen Liping, Niu Yanqing*, Yan Bokang, Lei Yu, Wang Denghui, Hui Shi’en. Separate physicochemical effects of CO2 on the coal char combustion: An experimental and kinetic study. Combustion and Flame 2022, 235:111717. DOI:10.1016/j.combustflame.2021.111717

5Liu Siqi, Niu Yanqing*, Wen Liping, Kang Yaqian, Wang Yufeng, Wang Denghui, Hui Shi’en. Experimental and kinetics studies on the evolution and effects of ash film during pulverized coal char combustion, Combustion and Flame 2021, 233:111623. DOI:10.1016/j.combustflame.2021.111623  

6Niu Yanqing*, Liu Siqi, Yan Bokang, Lv Yuan, Lei Yu, Wang Denghui, Hui Shi’en. Experimental and kinetics studies on separate physicochemical effects of steam on coal char combustion, Combustion and Flame 2020, 220: 168-177. DOI:10.1016/j.combustflame.2020.06.035

7Niu Yanqing*, Liu Siqi, Shaddix Christopher R, Hui Shi’en. An intrinsic kinetics model to predict complex ash effects (ash film, dilution, and vaporization) on pulverized coal char burnout in air (O2/N2) and oxy-fuel (O2/CO2) atmospheres, Proceedings of the Combustion Institute 2019, 37(3): 2781-2790. DOI:10.1016/j.proci.2018.06.010

8Niu Yanqing, Liu Xing, Wang Shuai, Hui Shi’en*, Shaddix Christopher R *, A numerical investigation of the effect of flue gas recirculation on the evolution of ultra-fine ash particles during pulverized coal char combustion, Combustion and Flame 2017, 184, 1-10 DOI:10.1016/j.combustflame.2017.05.029

9Niu Yanqing*, Wang Shuai, Shaddix Christopher R, Hui Shi’en, Kinetic modeling of the formation and growth of inorganic nano-particles during pulverized coal char combustion in O2/N2 and O2/CO2 atmospheres, Combustion and Flame, 2016, 173: 195-207. DOI:10.1016/j.combustflame.2016.08.021

10Niu Yanqing*, Shaddix Christopher R. A Sophisticated Model to Predict Ash Inhibition during Combustion of Pulverized Char Particles, Proceedings of the Combustion Institute, 2015, 35: 561-569. DOI:10.1016/j.proci.2014.05.077

11Niu Yanqing, Zhu Yiming, Tan Houzhang*, Wang Xuebin, Hui Shi’en, Du Wenzhi. Experimental Study on The Coexistent Dual Slagging in Biomass-fired Furnaces: Alkali-induced Slagging and Silicate Melt-induced Slagging, Proceedings of the Combustion Institute 2015, 35, 2405-2413. DOI:10.1016/j.proci.2014.06.120

12Wang Xuebin, Tan Houzhang*, Niu Yanqing, Pourkashanian Mohamed, Ma Lin, Chen Erqiang, Liu Yang, Liu Zhengning, Xu Tongmo. Experimental Investigation on Biomass Co-firing in a 300 MW Pulverized Coal-fired Utility Furnace in China, Proceedings of the Combustion Institute, 2011, 33: 2725-2733. DOI:10.1016/j.proci.2010.06.055

13Niu Yanqing*, Wen Liping, Guo Xin, Hui Shi’en, Co-disposal and reutilization of municipal solid waste and its hazardous incineration fly ash. Environment International, 2022, 166107346

14Zhu Guangqing, Gong Yanhao, Niu Yanqing*, Wang Shuai, Lei Yu, Hui Shi’en, Study on NOx emissions during the coupling process of preheating-combustion of pulverized coal with multi-air staging, Journal of Cleaner Production, 2021, 292:126012. DOI:10.1016/j.jclepro.2021.126012

15Wang Denghui*, Li Hui, Yao Qi, Hui Shi’en, Niu Yanqing, Assisting effect of Al2O3 on MnOx for NO catalytic oxidation, Green Energy & Environment, 2021, 6(6): 903-909. DOI:10.1016/j.gee.2020.07.005

16Li Tian*, Niu Yanqing, Wang Liang, Shaddix Christopher, Løvås Terese, High temperature gasification of high heating-rate chars using a flat-flame reactor, Applied Energy 2018, 227, 100-107. DOI: 10.1016/j.apenergy.2017.08.075

17Niu Yanqing, Yan Bokang, Liu Siqi, Liang Yang, Dong Ning, Hui Shi’en*, Ultra-fine particulate matters (PMs) formation during air and oxy-coal combustion: Kinetics study, Applied Energy 2018, 218: 46–53. DOI:10.1016/j.apenergy.2018.02.164

18Niu Yanqing, Du Wenzhi, Tan Houzhang*, Xu Weigang, Liu Yuanyi, Xiong Yingying, Hui Shi’en. Further Study on Biomass Ash Characteristics at Elevated Ashing Temperatures: the Evolution of K, Cl, S and the Ash Fusion Characteristics, Bioresource Technology 2013, 129: 642–645 DOI:10.1016/j.biortech.2012.12.065

19Tan Houzhang*, Niu Yanqing, Wang Xuebin, Xu Tongmo, Hui Shi’en. Study of Optimal Pulverized Coal Concentration in a Four-wall Tangentially Fired Furnace, Applied Energy 2011, 88(4): 1164-1168. DOI:10.1016/j.apenergy.2010.09.026

20Niu Yanqing, Tan Houzhang*, Wang Xuebin, Liu Zhengning, LiuYang, Xu Tongmo. Study on Fusion Characteristics of Biomass Ash, Bioresource Technology 2010, 101(23): 9373–9381. DOI:10.1016/j.biortech.2010.06.144