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Our SO2 compliance journey

Our SO2 compliance journey

Since 2015, we have implemented several projects at our operations in Secunda, Sasolburg and Natref to reduce our emissions in accordance with committed air quality improvement roadmaps to meet the minimum emission standards (MES) as prescribed in the National Environmental Management: Air Quality Act, 39 of 2004 (“NEM:AQA”). We have spent more than R7 billion over the last 5 years on emission reduction projects and as such have already achieved MES compliance for 98% of our emission sources as these operations. The only remaining challenge relates to achieving the concentration-based limit for sulphur dioxide (SO2) emissions from the boilers at the SO’s steam plants. The journey to identify a suitable solution for SO2 and ultimately develop the GHG and air quality reduction roadmap, has been detailed below. 

Technologies investigated for identifying a suitable solution

In March 2020 the revised SO2 concentration limit of 1000 mg/Nm3 was promulgated. This allowed Sasol to assess coal beneficiation as a potential compliance option.

Coal beneficiation description

However, given the material environmental impact of coal beneficiation, its inconsistency with the principles of NEMA and with Sasol’s broader sustainability objectives, recognising Sasol’s decarbonisation strategy and associated transition to lower carbon feedstocks, it was recognised that the adoption of coal beneficiation as a compliance solution does not support these principles and objectives and would not be aligned with Sasol’s holistic approach to environmental sustainability. Accordingly, Sasol cannot adopt coal beneficiation as a compliance solution for SO2 emissions from the boilers at the steam plants. Sasol does however have a solution to enable Secunda Operations to effectively reduce its SO2 footprint from the boilers at its steam plant to optimally improve ambient air quality. This is through the implementation of an integrated air quality and GHG reduction roadmap which includes an integrated design to enable the achievement of multiple environmental improvements, and with SO2 reduction as a key focus.  

Integrated air quality and GHG reduction roadmap

The integrated roadmap involves the turning down of boilers, not only to reduce SO2 emissions (with benefits anticipated to be realised from 2025 onwards), but to also have a favorable impact on the reduction of GHGs (towards meeting our committed reduction targets and net zero ambition) and other pollutants (PMs and NOx) emitted from the boilers. The implementation of the integrated roadmap will see the overall mass of SO2 (and other pollutants) emitted, per day and per final product, reduced. In this manner, Sasol (through our Secunda Operations) envisage to achieve a 30% total load reduction in SO2 emissions by 2030 - significantly more than what would otherwise be achieved under the applicable concentration limit equivalent load in the MES. To further understand what a load reduction means in comparison to a concentration reduction refer to the video below.

 

To achieve the reduction objectives, the SO2 emissions from the boilers at the Secunda Operations’ steam plants must be regulated on an alternative emission load. Clause 12A of the MES permits an existing plant, such as the steam plants at the Secunda Operations, to apply to the NAQO to be regulated on an alternative emission load in certain instances, including the steam plants’ current circumstances.

The NAQO previously granted the Secunda Operations a postponement of compliance with the new plant standard for SO2 until 31 March 2025. Therefore, the application for an alternative emission load for SO2 emissions from the boilers at the steam plants is to govern such emissions from 01 April 2025 onwards only.

Two alternative load limits have been requested in the application. Firstly, an interim limit where the first phase implementation of the integrated roadmap will involve the turn down of one boiler which will already yield a 4% SO2 reduction by April 2025. This interim limit is further needed during the implementation and commissioning period of the various components of the integrated roadmap with beneficial operation anticipated by 31 March 2030. Secondly, a final limit from 1 April 2030 onwards, where the full implementation of the integrated roadmap would have been completed and beneficial operation will continue.

To enable full implementation, multiple projects are required, including construction of a plant to manage the fine coal (the feedstock for the steam plant which is a by-product from the mining of coarse coal for our process), and the construction of the renewable energy plants, from which Sasol is procuring and energy efficiency projects, which will progressively take place between 2025 and 2030.

Technical journey to SO2 compliance

Sasol approaches environmental compliance and sustainability with the overarching guiding principle of ensuring holistic environmental solutions (not reducing one pollutant while negatively affecting other environmental media). Therefore, all studies undergo a rigorous investigation process to identify if they are technically and practically feasible as well as identifying any adverse environmental consequences.

To reduce SO2 emissions from our pulverized coal fired boilers to achieve compliance with the MES, Sasol dedicated a significant number of human and monetary resources over the last 17 years on measures to execute technical studies towards finding a solution. To date, Sasol has invested R246 million (2023 present value) on these measures which have required almost 200 resources ranging from scientists, chemists, multi discipline engineers to project managers, engineering managers and cost controllers.

The numerous technical studies since at least 2006, included abatement technology investigations and included consultations and appointments of numerous global and local experts.