Modeling and prediction of desulfurization efficiency for magnesium-based seawater exhaust gas clean system

Abstract

The desulfurization efficiency is a major parameter of magnesium-based seawater exhaust gas clean system, which is one of the important means to control the sulfur dioxide emission from marine diesel engines. In this work, the RFlow, a computational fluid dynamics software, was used to analyze the flow field and sulfur dioxide absorption rate in the desulfurization tower of magnesium-based seawater exhaust gas clean system. The subdomain technology was applied for physics modeling and mesh generation of the desulfurization tower, and total number of the mesh is 2.25 million. The flow field model was set up by coupling the multi-fluid model with the dispersive k-ε turbulence model. Based on flow field model, the prediction model for desulfurization efficiency of magnesium-based seawater exhaust gas clean system was programmed in user-defined module of the RFlow software, according to the two-film theory and sulfur dioxide absorption reaction equations. The simulation results predicted a desulfurization efficiency of 97.9%, which agrees well with the practical result. In order to study the effect of gas and liquid flow rate on the desulfurization efficiency, the computational fluid dynamics prediction model was applied. And the verification tests were conducted on a container vessel. Comparing the predicted results with the experimental data, the maximum error is less than 2%. It is proved that the prediction model is reliable and useful for the magnesium-based seawater exhaust gas clean system.

Keywords

Air pollution desulfurization magnesium numerical modeling ocean vessel

Get full access to this article

View all access options for this article.

References

Endresen

Emission from International Sea Transportation and Environmental Impact. J Geophys Res 2003; 108(D17): 4560.

IMO Resolution MEPC. 176(58). Amendments to the Annex of the Protocol of 1997 to amend the International Convention for the Prevention of Pollution from Marine, 1973, as modified by the Protocol of 1978 relating thereto, 2008, http://www.imo.org/en/KnowledgeCentre/IndexofIMOResolutions/Marine-Environment-Protection-Committee-(MEPC)/Documents/MEPC.176(58).pdf

Ministry of Transport of the PRC. Implementation Plan on Domestic Emission Control Areas in Waters of the Pearl River Delta, the Yangtze River Delta and Bohai Rim (Beijing, Tianjin, Hebei) (English Version), 2015, http://zizhan.mot.gov.cn/zfxxgk/bzsdw/bhsj/201512/P020160215528398838765.pdf

Andreasen

Mayer

Use of seawater scrubbing for SO2 removal from marine engine exhaust gas. Energ Fuel 2007; 21: 3274–3279.

Anttila

Hamalainen

Tuominiemi

Method and an equipment for reducing the sulphur dioxide emissions of a marine engine. Patent 0044335A, USA, 2008.

Caiazzo

Langella

Miccio

et al . An experimental investigation on seawater SO2 scrubbing for marine application. Environ Prog Sustain 2013; 32(4): 1179–1186.

Zhu

Tang

Hao

et al . Magnesium-based seawater desulfurization system for marine flue gas. CN 2011200405654, China, 2011.

Zhu

Tang

Zhang

et al . Marine sulfur oxide emissions control research progress. J Environ Eng 2014; 8: 68–71.

Wang

Song

Yao

et al . Experimental study on removal effect of wet flue gas desulfurization system on fine particles from a coal-fired power plant. Proc Chin Soc Electr Eng 2008; 28(5): 1.

10.

Lin

Gao

Shi

et al . Numerical simulation on resistance characteristic of large scale wet flue gas desulphurization spraying scrubber. Proc Chin Soc Electr Eng 2008; 28(5): 28–33.

11.

Tang

et al . Prediction model for desulphurization efficiency of onboard magnesium-base seawater scrubber. Ocean Eng 2013; 76(2): 98–104.

12.

Caiazzo

Nardo

Giuseppe

et al . Seawater scrubbing desulfurization: a model for SO2 absorption in fall-down droplets. Environ Prog Sustain 2012; 31(2): 277–287.

13.

Cheng

et al . Experimental and the cortical studies on desulfurization efficiency of dual-alkali FGD system in a RST scrubber. Chin J Process Eng 2006; 6(5): 718–723.

14.

Zhao

Jin

Zhong

Numerical simulation of flue gas desulphurization by spray tower. Chem Eng 2007; 8: 015.

15.

Wang

Zhu

Zhang

et al . Numerical simulation research of flow field in ammonia-based wet flue gas desulfurization tower. J Energ Instit 2014; 88(3): 284–291.

16.

Wang

Zhu

et al . Simulation of the heterogeneous semi-dry flue gas desulfurization in a pilot CFB riser using the two-fluid model. Chem Eng J 2015; 264: 479–486.

17.

Zhou

Zhu

Gai

GS.

Study on a wet SOx scrubber in a marine diesel engine. Asian J Chem 2012; 24: 5739–5742.

18.

Germano

Piomelli

Moin

et al . A dynamic subgrid-scale eddy viscosity model. Phys Fluids A: Fluid 1991; 3(7):1760–1765.

19.

Marocco

Inzoli

Multiphase Euler-Lagrange CFD simulation applied to wet flue gas desulphurisation technology. Int J Multiphas Flow 2009; 35(2): 185–194.

20.

Matos

Guirardello

Mori

et al . Modeling and simulation of a pseudo-three-phase slurry bubble column reactor applied to the process of petroleum hydro desulfurization. Comput Chem Eng 2009; 33(6): 1115–1122.

21.

Unverdi

Tryggvason

Computations of multi-fluid flows. Physica D 1992; 60(1): 70–83.

22.

Bonizzi

Issa

RI.

On the simulation of three-phase slug flow in nearly horizontal pipes using the multi-fluid model. Int J Multiphas Flow 2003; 29(11): 1719–1747.

23.

Samruamphianskun

Piumsomboon

Chalermsinsuwan

Effect of ring baffle configurations in a circulating fluidized bed riser using CFD simulation and experimental design analysis. Chem Eng J 2012; 210: 237–251.

24.

Bossel

Modeling and simulation. New York: Springer-Verlag, 2013.

25.

Patankar

SV.

Numerical heat transfer and fluid flow. Washington, DC: Hemisphere Publishing, 1980, pp.125–126.

26.

Jing

et al . Modeling and application of processes of magnesia flue gas desulfurization. Tech Equip Environ Pollut Control 2005; 11: 32–38.

27.

Eden

Simulation von Rauchgassprühwäschern. PhD Thesis, Gerhard Mercator Universität, Duisburg, 1998.

28.

Guo

Pan

Zhang

et al . Dissolution rate of magnesium hydrate for wet flue gas desulfurization. Fuel 2011; 90(1): 7–10.

29.

Liu

Sun

Zhang

et al . Research on flow field design in ship exhaust gas desulfurization tower. Comput Simul 2016; 33(5): 244–248, 267 (in Chinese).

30.

Chopey

Hicks

TG.

Handbook of chemical engineering calculations. New York: McGraw-Hill, 1994.

31.

IMO MEPC. 259(68) Annex 1. 2015 Guidelines for exhaust gas cleaning systems, 2015, http://www.imo.org/en/KnowledgeCentre/IndexofIMOResolutions/Marine-Environment-Protection-Committee-(MEPC)/Documents/MEPC.259(68).pdf