Energy and chemicals group Sasol has moved to formally appeal a decision of the National Air Quality Officer (NAQO) to decline its application to have its Secunda boilers regulated using a load-based emission limit for sulphur dioxide (SO₂) rather than the prevailing concentration-based emissions limit used for setting Minimum Emission Standards (MES).

The plants are currently operating on the basis of a ten-year postponement, until March  31, 2025, from meeting new plant standards for SO₂ emissions, which was granted on February 23, 2015.

The appeal has been lodged with Forestry, Fisheries and the Environment Minister Barbara Creecy following NAQO’s rejection in early July of Sasol’s “alternative” approach, which the JSE-listed company claims to have made in line with Clause 12A of the MES.

The application was rejected on several grounds, including the fact that the Secunda Operations are located within the Highveld Priority Area, wherein the national ambient air quality standards for SO₂ and particulate matter (PM) emissions are frequently exceeded.

Through the appeal process, Sasol states that the Minister is empowered to consider its 12A application afresh.

In practical terms, the company is requesting that it be allowed to reduce its SO₂ emissions by reducing the total number of boilers in use at Secunda and thus the load, rather than by reducing the concentration of SO₂ produced by each  boiler.

The group argues in its appeal that this approach will result in an improvement of ambient air quality within the local airshed over-and-above MES compliance, while ensuring that its operations continue.

The Secunda complex is located in the Mpumalanga province where the majority of Eskom’s coal-fired power stations are also located, which has resulted in the air in the area being highly polluted.

Sasol also claims that its proposed ‘integrated emission reduction solution’ will achieve double the reductions on SO₂ emissions than would be the case under the concentration-based limit, while also reducing PM and nitrogen oxides, or NOx, emissions.

The plant’s greenhouse-gas emissions, Sasol adds, would also be reduced by 30% by 2030, as the proposal involves “turning down” the steam boilers used to produce coal-based electricity and replacing it with renewable electricity or displacing it through energy efficiency.

Sasol notes that it has procured more than half its 1 200-MW renewable-energy target and that the first renewable electricity is expected to become available in 2025.

The remaining operating boilers will continue to produce the steam required for the production of synthetic fuels and chemicals.

The solution is contingent, however, on the SO₂ emissions from the boilers at the steam plants of its Secunda Operations being regulated using a load-based emission limit instead of the concentration limit currently being prescribed in the MES from April 1, 2025 onwards.

In a statement confirming the appeal, Sasol sought to illustrate the difference between the two approaches to limiting SO₂ by using the analogy of sugar and caffeine consumption in cups of coffee, whereby the number of cups represented the boilers, the sugar represented SO₂ and caffeine represented PM and NOx.

Under the load-based approach the total number of cups of coffee consumed is reduced, lowering both the sugar (SO₂) and the caffeine (PM and NOx) intake, whereas under the concentration-based approach only the number of spoons of sugar is reduced and the caffeine intake remains unchanged.

Sasol argues that its proposal does not seek an exemption from regulation, with Sasol energy operations and technology VP Simon Baloyi stating that it is taking full responsibility for reducing its environmental footprint.

“However, this requires time, effort and capital,” he adds.