Sasol Wax operates a catalyst preparation plant as well as the three slurry bed FT reactors in which syngas from the ATRs is processed to produce wax hydrocarbons. These hydrocarbons are further processed into a range of liquid final products, which are blended, solidified and packed. The downstream paraffin plant uses feed from the wax plants to make a range of paraffin products.

Both crude and high purity methanol are also produced at the wax plant. The crude methanol is further distilled into high purity methanol at the Solvents plant.

Sasol Solvents supplies alcohols, ketones, esters, acrylic acid esters, ethyl acetate, ethers and mining chemicals to customers worldwide. Production of solvents at Sasolburg draws on a number of input sources.

• Heavy alcohol final products (pentylol and hexylol), are produced via distillation from raw product that is transferred from Secunda.
• Further raw materials for Solvents blending are transferred via road tanker from Secunda, Sasolburg, and outside suppliers to the Solvents Blending plant. These materials are mixed to formulations according to customer specifications.
• The Solvents Mining Chemicals plant also receives raw product from Secunda, Sasolburg, and outside suppliers, where it is stored on site, blended to customer specifications and supplied in drums or via road tankers

Sasol Polymers supplies ethylene, propylene, polyethylene, polypropylene, polyvinyl chloride, chlor-alkali chemicals and mining reagents to domestic and international customers, from both the Sasolburg and Secunda facilities.

A mixture of ethane and ethylene is piped to Sasolburg from Secunda where it enters the Ethylene Purification Unit (EPU) which separates the ethylene and ethane by distillation. Further ethylene is also produced in Sasolburg. Ethylene is used in the polyethylene and polyvinylchloride manufacturing plants or sold directly to customers.

Ethane from the EPU is then routed to the Cracking Unit where it is cracked to ethylene. Once cracked, the ethylene/ethane gas mixture goes through a quenching, scrubbing and drying phase where after the gas is selectively hydrogenated to convert acetylene to ethylene. Thereafter the product is purified to remove light and heavy components, as well as unreacted ethane.

Propane and ethane are also sent from Natref to the Ethylene Purification Unit and Cracking Units to produce ethylene.

The Midlands Site in Sasolburg also includes chlorine, hydrochloric acid, sodium hydroxide and calcium chloride production. Vinyl Chloride Monomer (VCM) is produced and then further processed at the polyvinyl chloride (PVC) plant ¹.

¹ Sasol, 2022. “Air Quality Management”.

Ammonia is also produced at the Sasolburg Infrachem facility using the Haber-Bosch process. In this process, nitrogen produced in the Air Separation Units and hydrogen contained in the FT off gases are reacted directly to produce ammonia. Excess CO2 from FT is removed from the ammonia feed gas in the Benfield unit prior to ammonia production. This CO2 stream is partially worked up to high grade CO2 for the food industry, although further CO2 is released into the atmosphere when the Benfield solution is regenerated, representing a significant source of GHG emissions.

Ammonia is sold as a final product, as well as used downstream in Sasolburg’s nitric acid plant where it is reacted with oxygen. NO is selectively converted to NO2. NO2 is fed to a series of absorber columns to produce nitric acid HNO3. Ammonium nitrate is also produced and sold as a solid product. Sasol’s Nitro division produces and markets industrial explosives, mining explosive accessories and fertiliser products and related services, mainly for the Southern African mining and agriculture markets.

Sasol Olefins & Surfactants produces alcohols, surfactants and related products, high purity alumina and related speciality products¹. The phenolics value chain includes a range of phenolic products including phenol, cresols, and xylenols manufactured from tar acid supplied from Secunda. Solid waste from the process is incinerated while effluent is first cleaned to recover phenolics before the water is treated at Sasol Bio-works.

The Merisol Plant located within the Sasolburg site is a global player in the manufacturing of speciality chemical products, derived from phenolic feedstocks, such as phenol, o/m/pcresols, xylenols and C3-C4 alkyl phenols. Since the Gasification Plant was decommissioned with the conversion of Sasol I to natural gas feed stock, the Merisol Plant has been receiving partially processed gas water from Secunda via rail. This gas water is treated in several processes to remove various valuable chemicals (tar acids) in various plants (i.e. TNPE, OCN, and ATAR). During these processes and chemical work-up, phenol rich effluent, referred as to as the C-stream, is normally pre-treated to remove suspended solids and oils before recovery of phenolics via solvent extraction.

The Cyanide plant located at the Midlands Site manufactures liquid sodium cyanide (NaCN), for sale to the South African gold mining industry. Acrylic Acid and Acrylate (AAA) and Butanol are also produced on the Midland site.

Ammonia is sold as a final product, as well as used downstream in Sasolburg’s nitric acid plant where it is reacted with oxygen. NO is selectively converted to NO2. NO2 is fed to a series of absorber columns to produce nitric acid HNO3. Ammonium nitrate is also produced and sold as a solid product. Sasol’s Nitro division produces and markets industrial explosives, mining explosive accessories and fertiliser products and related services, mainly for the Southern African mining and agriculture markets.

¹ Products are used in detergents, cleaning, personal care items, oilfield and enhanced oil recovery, paint and coatings, lubricants, bio ceramics, synthetic sapphires, catalysts, high-performance abrasives and many other industrial intermediates