Sasol

The previous Sasol logo

South Africa has large deposits of coal which had low commercial value due to its high fly ash content. It was thought that if this coal could be used to produce synthetic oil, petrol and diesel fuel, it would have significant benefit to South Africa. In the 1920s, South African scientists started looking at the possibility of using coal as a source of liquid fuels. This work was pioneered by P. N. Lategan, working for the Transvaal Coal Owners Association. He completed his doctoral thesis from the Imperial College of Science in London on The Low-Temperature Carbonisation of South African Coal. In 1927, a white paper from the government was issued describing various oil-from-coal processes being used overseas and their potential for South Africa. In the 1930s a young scientist named Etienne Rousseau obtained an MSc from the University of Stellenbosch. His thesis was entitled, The Sulfur Content of Coals and Oil Shales. Rousseau became Sasol's first managing director. After World War II, Angovaal bought the rights to a method of using the Fischer-Tropsch process patented by M. W. Kellogg Limited and in 1950 Sasol was formally incorporated as a state-owned company as South African Coal, Oil and Gas Corporation. Commissioning of the Sasol 1 site for the production of synfuels started in 1954. Construction of the Sasol 2 site was completed in 1980, with the Sasol 3 site coming on stream in 1982. The Zevenfontein farm house served as Sasol's first offices and is still in existence today.[10][11]

To support the required economies of scale for Coal-to-Liquids (CTL) process to be economical and competitive with crude oil, all stages of the operations, from coal mining to the Fischer-Tropsch process and product work up must be run with great efficiency. Due to the complexity of the Lurgi gasifers used the quality of the coal was paramount. The initial annual output from the Sigma underground mine in Sasolburg was 2 million tons. Annual coal production from this mine peaked in 1991 at 7.4 million tons.[10] Today the majority of the gasifers in Sasolburg have been replaced with autothermal reformers that feed natural gas piped from Mozambique. Natural gas generates approximately 40 – 60% less carbon dioxide for the same energy produced as coal and is thus significantly more environmentally friendly. Gas-to-liquids (GTL) technology converts natural gas, predominately methane to liquid fuels.[10][11] Today Sasol mines more than 40 million tons (Mt)[12] of saleable coal a year, mostly gasification feed-stock for Sasol Synfuels in Secunda. Sasol Mining also exports some 2.8 Mt of coal a year. This amounts to approximately 22% of all the coal mined in South Africa. Underground mining operations continue in the Secunda area (Bosjesspruit, Brandspruit, Middelbult, Syferfontein and Twistdraai collieries) and Sigma: Mooikraal colliery near Sasolburg. As some of these mines are nearing the end of their useful life, a R14bn mine replacement program has been undertaken. The first of the new mines is the R3.4bn Thubelisha shaft which will eventually be an operation delivering more than eight million tons per annum (mtpa) of coal over 25 years. The Impumelelo mine, which will replace the Brandspruit operation, is set for first production in 2015. It will be ramped up to produce 8.5 mtpa, and can later be upgraded to supplying some 10.5 mtpa. This coal will be used exclusively by the Sasol Synfuels plant. An underground extension of the Middelbult mine is also on the cards, with the main shaft and incline shaft being replaced by the Shondoni shaft. The first coal from the new complex is expected to be delivered in 2015.[13]

The Secunda collieries form the world's largest underground coal operations.[14]

In conjunction with the continuous improvement in the Fischer-Tropsch process and catalyst, significant developments were also made in mining technology. Coal mining at Sasol from the early days has been characterised by innovation. Sasol Mining mainly utilises the Room and pillar method of mining with a continuous miner. Sasol successfully used the longwall mining method from 1967 to 1987. Today Sasol is one of the leaders in coal mining technology and was the first to develop in-seam drilling from surface using a directional drilling methodology. This has been developed into an effective exploration tool.[15] Working with Fifth Dimension, Sasol developed a virtual reality technology to help train continuous miner operators in a 3D environment in which various scenarios can be simulated including sound, dust and other signs of movement.[16] This has recently been expanded to include shuttle car, roofbolting and load-haul dumper simulators.

The initial reactors from Kellogg and Lurgi gasifiers were tricky and expensive to operate. The original reactor design in 1955 was a circulating fluidised bed reactor (CFBR) with a capacity of about 1,500 barrels per day. Sasol improved these reactors to eventually yield about 6,500 barrels per day. The CFBR design involves moving the whole catalyst bed around the reactor which is energy intensive and not efficient as most of the catalyst is not in the reaction zone. Sasol then developed fixed fluidized bed (FFB) reactors in which the catalyst particles were held in a fixed reaction zone. This resulted in a significant increase in reactor capacities. For example, the first FFB reactors commercialised in 1990 (5 m diameter) had a capacity of about 3,000 barrels per day, while the design in 2,000 (10.7m diameter) had a capacity of 20,000 barrels per day. Further advancements in reactor engineering have resulted on the development and commercialisation of Sasol Slurry Phase Distillate (SSPD) reactors which are the corner stone of Sasol's first of a kind GTL plant in Qatar.[10][11]

The fuel price is directly linked to the oil price and is thus subject to potentially large fluctuations. With Sasol only producing fuels, this meant that its profitability was largely governed by external macroeconomic forces that it had no control over. How could Sasol be less susceptible to the oil price? The answer was right in front of them, in the treasure chest of chemicals co-produced in the Fischer-Tropsch process. Chemicals have a higher value per ton of product than fuels.

In the 1960s ammonia, styrene and butadiene became the first chemical intermediates sold by Sasol. The ammonia was then used to make fertilizers. By 1964 Sasol was a major player in the nitrogenous fertilizer market. This product range was further extended in the 1980s to include both phosphate- and potassium-based fertilizers. Today Sasol sells an extensive range of fertilizers and explosives to local and international markets and is a world leader in its low-density ammonium nitrate technology.[17]

With the extraction of chemicals from its Fischer-Tropsch product slate coupled with downstream functionalization and on purpose chemical production facilities Sasol moved from being just a South African fuels company to become an international integrated energy and chemicals company with over 200 chemical products being sold worldwide. Some of the main products produced are diesel, petrol (gasoline), naphtha, kerosene (jet fuel), liquid petroleum gas (LPG), olefins, alcohols, polymers, solvents, surfactants (detergent alcohols and oil field chemicals), co-monomers, ammonia, methanol, various phenolics, sulphur, illuminating paraffin, bitumen, acrylates and fuel oil. These products are used in the production process of numerous everyday products made worldwide and benefit the lives of millions of people around the world. They include hot-melt adhesives, car products, microchip coatings, printing ink, household and industrial paints, mobile phones, circuit boards, transport fuels, compact discs, medical lasers, sun creams, perfumes and plastic bottles.[18]

In South Africa, the chemical businesses are integrated in the Fischer-Tropsch value chain. Outside South Africa, the company operates chemical businesses based on backward integration into feedstock and/or competitive market positions for example in Europe, Asia and the U.S..[18]

Operating Business Units comprise the mining division and exploration and production of oil and gas activities, focused on feed-stock supply.[20]

Sasol Mining operates six coal mines that supply feed-stock for Secunda (Sasol Synfuels) and Sasolburg (Sasolburg Operations) complexes in South Africa. While the coal supplied to Sasol Synfuels is mainly used as gasification feed-stock, some is used to generate electricity. The coal supplied to the Sasolburg Operations is used to generate electricity and steam. Coal is also exported from the Twistdraai Export Plant to international power generation customers.

Sasol Exploration and Production International (SEPI) develops and manages the group's upstream interests in oil and gas exploration and production in Mozambique, South Africa, Canada, Gabon and Australia.[21]

These include operations in Southern Africa, North America and Eurasia.[22]

The Southern African Operations business cluster is responsible for Sasol's entire Southern Africa operations portfolio, which comprises all downstream operations and related infrastructure in the region. This combined operational portfolio has simplified and consolidated responsibilities relating to the company's operating facilities in Secunda, which are divided into a synthetic fuels and chemicals component, Sasolburg, Natref, Sasol's joint-venture inland refinery with Total SA, and Satellite Operations, a consolidation of all Sasol's operating activities outside of Secunda and Sasolburg.[23]

The International Operations business cluster is responsible for Sasol's international operations in Eurasia and North America, which include its US mega-projects in Lake Charles, Louisiana.[24]

Energy business

• Southern Africa Energy
• International Energy

The energy business manages the marketing and sales of all oil, gas and electricity products in Southern Africa, which have been consolidated under a single umbrella. In addition, this cluster oversees Sasol's international GTL (gas to liquids) ventures in Qatar, Nigeria and Uzbekistan.[25]

Chemical business

• Base Chemicals
• Performance Chemicals

The global chemicals business includes the marketing and sales of all chemical products, both in southern Africa and internationally. The chemicals business is divided into two niche groupings; Base Chemicals, where its fertilisers, polymers and solvents products lie, and performance chemicals, comprising key products which include surfactants, surfactant intermediates, fatty alcohols, linear alkyl benzene (LAB), short-chain linear alpha olefins, ethylene, petrolatum, paraffin waxes, synthetic waxes, cresylic acids, high-quality carbon solutions as well as high-purity and ultra-high-purity alumina and a speciality gases sub-division.[26]

In South Africa, the chemical businesses are integrated in the Fischer-Tropsch value chain. Outside South Africa, the chemical businesses are operated based on backward integration into feed-stock and/or competitive market positions.

Group Technology manages the research and development, technology innovation and management, engineering services and capital project management portfolios. Group Technology includes Research and Technology (R&T), Engineering and Project Services and Capital Projects.[27]

Sasol has granted final approval for a US$11 billion ethane cracker and derivatives plant near Westlake and almost the entire community of Mossville, both across the Calcasieu River from Lake Charles, Louisiana, and is the largest foreign investment in the history of the State of Louisiana. It was stated "Once commissioned, this world-scale petrochemicals complex will roughly triple the company's chemical production capacity in the United States, enabling Sasol to further strengthen its position in a growing global chemicals market. The U.S. Gulf Coast's robust infrastructure for transporting and storing abundant, low-cost ethane was a key driver in the decision to invest in America". The ethane cracker will also be supported by six chemical manufacturing plants.[28][29][30][31][32]

By January 2015 construction was in full swing. At peak the project will create 5000 construction and 1200 permanent jobs and cost $11 billion to $14 billion.[33]

ORYX GTL Plant – Qatar

The Oryx GTL plant in Qatar is a joint venture between Sasol and Qatar Petroleum, launched in 2007. The more than 32,000 barrels per day (5,100 m³/d) plant produces a combination of GTL diesel, GTL naphtha and liquid petroleum gas.[34][35]

The proposed Uzbekistan GTL project is a partnership between Sasol, Uzbekneftegaz and Petronas.[36][37][38] Sasol reconsidered its involvement in March 2016

SASOL Gas Pipeline – Temane – Mozambique

Sasol is developing a 140 MW gas-fired electricity generation plant in partnership with power utility EDM.[39] This gas project came into operation in 2004, and is a joint venture agreement between Sasol Petroleum International, Empresa Nacional de Hidrocarbonetos (ENH), and the International Finance Corporation.

The Sasol slurry phase distillate process (SPDTM) transforms natural gas into energy and chemical products, including transport fuels, base oils, waxes, paraffins and naphtha.[40] The three-stage process combines three proprietary technologies. Natural gas is combined with oxygen to form a syngas which is then subjected to a Fischer-Tropsch conversion, resulting in waxy synthetic crude. Finally, this is cracked down to produce the end product.

The strength of the process is not simply in the inherent quality of the three component technologies but more importantly how they are combined and integrated to increase efficiencies and optimise output. The liquid fuels produced through Sasol's GTL and CTL technologies are high-performance, low-emission products. The synthetic GTL-based diesel is an environmentally cleaner burning fuel as it leads to a reduction in carbon monoxide, hydrocarbon and particulate matter without compromising NOx emissions even when compared to European sulfur-free diesel.[10]

A high-temperature syngas conversion process is operated in Secunda in a series of 10 Sasol advanced Synthol (SASTM) reactors at high pressure with the aid of an iron-based Fischer-Tropsch catalyst at about 350 °C to yield primarily C₁ – C₂₀ range hydrocarbons. The process also produces water and oxygenated hydrocarbons which are then purified and marketed. The C₂ stream is split into ethylene and ethane. The ethane is further cracked to yield additional ethylene which are then converted into polyethylene for the polymer business. Propylene from Secunda and Sasolburg plants are also converted into high-value products such as polypropylene, butanol, butyl acrylate and ethyle acrylate. The acrylates are used to make superabsorbent polymers which are used in diapers. Through proprietary technology 1-hexene, 1-octene and 1-pentene are recovered from the oil stream. International customers use these as co-monomers for making speciality grade polymers. Some of the higher olefins (C₁₁ – C₁₂) are converted into detergent-range alcohols.[11]

A low-temperature syngas conversion process is operated in Sasolburg based on an iron-based catalyst in fixed-bed tubular and Sasol SPDTM processes to produce mainly linear hydrocarbon waxes and paraffins. The syngas (mixture of hydrogen and carbon monoxide) is also converted in methanol, butanol and ammonia. Ammonia is then converted into nitric acid and ammonium-based fertilizers and explosives.

In 1997 Sasol Technology Research and Development began research on the selective trimerisation of ethylene to 1-hexene. This led to the development and patenting of 6 trimerisation catalyst systems. A groundbreaking innovation was made in 2002, with the discovery of a tetramerisation catalyst that could make 1-octene in high selectivity. This was considered impossible by international experts in the field. Construction of this first-of-a-kind plant in Lake Charles, Louisiana, is under way. The ready for commissioning date is August 2013.[41]

Sasol is also involved in conventional oil refinery. Incorporated on 8 December 1967, construction started on the Natref refinery in 1968 and commissioned in Sasolburg in 1971.[42]^:166[43]^:75 It was built as a joint venture between the Industrial Development Corporation (IDC), National Iranian Oil Company and Compagnie Fransçaise de Petroles (Total) with financing by the Rembrandt Group, Volkskas and SA Mutual.[42]^:166 By 1979, prior to the Iranian Revolution, the refinery was receiving seventy percent of its oil from Iran and National Iranian Oil Company owned 17.5 percent of the facility.[44] Oil was piped 800 km from Durban via Richards Bay to the refinery.[44] The refinery is now a joint venture between Sasol Ltd and Total South Africa (Pty) Ltd. Sasol has a 63,64 percent interest in Natref and Total South Africa a 36,36 percent shareholding.[45] The refining capacity of Natref to 108,500 barrels per day. Natref is one of the only inland refineries in South Africa.[42]^:166 It was designed to get the most out of crude oil and is equipped with state-of-the-art technology. The refinery uses the bottoms upgrading refining process using medium gravity crude oil and is capable of producing 70% more white product than coastal refineries that have to rely on heavy fuel oil. Some of the products produced from the refinery are diesel, petrol, jet fuel, LPG, illuminating paraffin, bitumen and sulfur. Natref has been certified in terms of the ISO 14001 Environmental Management System.[46][47]