SCI和EI收录∣中国化工学会会刊

Chinese Journal of Chemical Engineering ›› 2020, Vol. 28 ›› Issue (4): 1023-1028.DOI: 10.1016/j.cjche.2020.02.007

• Fluid Dynamics and Transport Phenomena • Previous Articles     Next Articles

Predictive models for characterizing the atomization process in pyrolysis of methyl ricinoleate

Xiaoning Mao, Qinglong Xie, Ying Duan, Shangzhi Yu, Xiaojiang Liang, Zhenyu Wu, Meizhen Lu, Yong Nie   

  1. Biodiesel Laboratory of China Petroleum and Chemical Industry Federation, Zhejiang Provincial Key Laboratory of Biofuel, and College of Chemical Engineering, Zhejiang University of Technology, Hangzhou 310014, China
  • Received:2019-07-30 Revised:2019-12-01 Online:2020-07-27 Published:2020-04-28
  • Contact: Yong Nie
  • Supported by:
    We are grateful to the National Natural Science Foundation of China (grant number 21776261), the Zhejiang Province Public Welfare Technology Application Research Project (grant number 2017C31016) and the China Postdoctoral Science Foundation (grant number 2017M612029).

Predictive models for characterizing the atomization process in pyrolysis of methyl ricinoleate

Xiaoning Mao, Qinglong Xie, Ying Duan, Shangzhi Yu, Xiaojiang Liang, Zhenyu Wu, Meizhen Lu, Yong Nie   

  1. Biodiesel Laboratory of China Petroleum and Chemical Industry Federation, Zhejiang Provincial Key Laboratory of Biofuel, and College of Chemical Engineering, Zhejiang University of Technology, Hangzhou 310014, China
  • 通讯作者: Yong Nie
  • 基金资助:
    We are grateful to the National Natural Science Foundation of China (grant number 21776261), the Zhejiang Province Public Welfare Technology Application Research Project (grant number 2017C31016) and the China Postdoctoral Science Foundation (grant number 2017M612029).

Abstract: Pyrolysis of methyl ricinoleate (MR) can produce undecylenic acid methyl ester and heptanal which are important chemicals. Atomization feeding favors the heat exchange in the pyrolysis process and hence increases the product yield. Herein, predictive models to characterize the atomization process were developed. The effect of spray distance on Sauter mean diameter (SMD) of atomized MR droplets was examined, with the optimal spray distance to be 40-50 mm. Temperature mainly affected the physical properties of feedstock, with smaller droplet size obtained at increasing temperature. In addition, pressure had significant influence on SMD and higher pressure resulted in smaller atomized droplets. Then, a model for SMD prediction, combining temperature, pressure, spray distance, and structural parameters of nozzle, was developed through dimensionless analysis. The results showed that SMD was a power function of Reynolds number (Re), Ohnesorge number (Oh), and the ratio of spray distance to diameter of swirl chamber in the nozzle (H/dsc), with the exponents of -1.6618, -1.3205 and 0.1038, respectively. The experimental measured SMD was in good agreement with the calculated values, with the error within ±15%. Moreover, the droplet size distribution was studied by establishing the relationship between the standard deviation of droplet size and SMD. This study could provide reference to the regulation and optimization of the atomization process in MR pyrolysis.

Key words: Atomization, Methyl ricinoleate pyrolysis, Predictive model, Sauter mean diameter (SMD), Spray distance

摘要: Pyrolysis of methyl ricinoleate (MR) can produce undecylenic acid methyl ester and heptanal which are important chemicals. Atomization feeding favors the heat exchange in the pyrolysis process and hence increases the product yield. Herein, predictive models to characterize the atomization process were developed. The effect of spray distance on Sauter mean diameter (SMD) of atomized MR droplets was examined, with the optimal spray distance to be 40-50 mm. Temperature mainly affected the physical properties of feedstock, with smaller droplet size obtained at increasing temperature. In addition, pressure had significant influence on SMD and higher pressure resulted in smaller atomized droplets. Then, a model for SMD prediction, combining temperature, pressure, spray distance, and structural parameters of nozzle, was developed through dimensionless analysis. The results showed that SMD was a power function of Reynolds number (Re), Ohnesorge number (Oh), and the ratio of spray distance to diameter of swirl chamber in the nozzle (H/dsc), with the exponents of -1.6618, -1.3205 and 0.1038, respectively. The experimental measured SMD was in good agreement with the calculated values, with the error within ±15%. Moreover, the droplet size distribution was studied by establishing the relationship between the standard deviation of droplet size and SMD. This study could provide reference to the regulation and optimization of the atomization process in MR pyrolysis.

关键词: Atomization, Methyl ricinoleate pyrolysis, Predictive model, Sauter mean diameter (SMD), Spray distance