Abstract

STRICKROTH, A.; SCHUMACHER, M.; HASSE, G.W.  and  KGOMO, I.. Next-generation, affordable SO₂ abatement for coal-fired power generation - A comparison of limestone-based wet flue gas desulphurization and Sulfacid® technologies for Medupi power station. J. S. Afr. Inst. Min. Metall. [online]. 2020, vol.120, n.10, pp.581-589. ISSN 2411-9717.  http://dx.doi.org/10.17159/2411-9717/1252/2020.

Coal is used to generate more than three-quarters of South Africa's electricity, while numerous coal-fired boilers are employed for steam generation in industrial processes. However, coal-fired power generation is responsible for the release of the largest quantities of SO₂ emissions to the atmosphere and leads to detrimental health and welfare effects in communities in the proximity of coal-fired plants. The classical industrial SO₂ abatement solution for the coal-fired power generation industry is wet flue gas desulphurization, which uses a limestone adsorbent and produces a gypsum by-product (WFGD L/G). In South Africa, due to the poor quality of the limestone the gypsum product is unsaleable and is co-disposed with coal ash. In comparison, the Sulfacid® process technology converts SO₂ contained in industrial flue gas into saleable sulphuric acid using a catalytic process requiring only water and air. This process does not require limestone. The scale of the latest commercial applications of the Sulfacid^® SO₂ abatement technology in the chemical, fertilizer, and copper mining industries demonstrates the potential and readiness of this technology to be employed in the coal-fired electricity and steam production sectors. This paper provides a first-order direct comparison between the techno-economic aspects of the WFGD (L/G) and Sulfacid® technologies using the requirements specified for the 6 x 800 MWe Eskom coal-fired Medupi power station. The results indicate that affordable flue gas desulphurization technology exists that could be adopted by the South African industry to reduce SO₂ emissions to legislative limits and beyond.

Keywords : SO₂ abatement; coal-fired power; and heat generation; sulphuric acid; wet fluidized gas desulphurization; Sulfacid^®; waste-to-chemicals.

        · text in English     · English ( pdf )