Optimization of wet flue gas desulfurization system using recycled waste oyster shell as high-grade limestone substitutes

Jonghun Lim, Hyungtae Cho, Junghwan Kim

Research output: Contribution to journalArticlepeer-review


Wet flue gas desulfurization, which is performed in many thermal power plants, has a high desulfurization efficiency and produces desulfurized gypsum as a by-product. Currently, high-grade limestone with a CaCO3 content of 94 wt% or more is used to produce desulfurized gypsum with a purity of 93 wt% or more. However, high-grade limestone resources are depleting, so new substitutes to this are required. The objective of this work is to optimize the wet flue gas desulfurization system using recycled waste oyster shells as high-grade limestone substitutes. The process model was developed for predicting the optimal blending ratio of waste oyster shells to limestone with constraints of desulfurization efficiency and purity of desulfurized gypsum. A mathematical model was addressed for optimized process costs, which was a nonlinear programming problem that minimizes the total annualized cost (TAC) by considering the total product cost (TPC) and equivalent annual cost; these vary according to the blending ratio. The optimal blending ratio of waste oyster shells is 16.160 wt% or 599.536 kg/h, TPC and TAC are reduced by $ 840,721 and $ 760,543, respectively. The waste oyster shell can be utilized 4,901 t/y, which is about 20.66 wt% of the total landfilled waste oyster shell. The results of this study suggest waste oyster shells, which pose landfill and odor problems, can be used as excellent substitutes for high-grade limestone for high economic and environmental benefits.

Original languageEnglish
Article number128492
JournalJournal of Cleaner Production
Publication statusPublished - 2021 Oct 10

Bibliographical note

Funding Information:
This work was supported by the Korean Institute of Industrial Technology within the framework of the following projects: “ Development of Global Optimization System for Energy Process [grant number EM-21-0022 , IR-21-0029 , IZ-21-0052 ]”, “ Development of complex parameter smart analysis modules for color customering [grant number EH-21-0008 ]” and “ Development of AI Platform Technology for Smart Chemical Process [grant number kitech JH-21-0005 ]”.

Publisher Copyright:
© 2021 The Authors

All Science Journal Classification (ASJC) codes

  • Renewable Energy, Sustainability and the Environment
  • Environmental Science(all)
  • Strategy and Management
  • Industrial and Manufacturing Engineering


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