The last decade has seen an increased drive towards the adoption of low sulphur fuel globally – first, by the retail fuel trade, and now the mass transport and even industrial sectors of the economy. What are the reasons for the switch-over?
Sulphur is a naturally occurring chemical element – what the ancients referred to as ‘brimstone’, with its characteristic ‘rotten egg’ smell, bubbling out of the ground in its native form from hot springs or volcanoes, it was indicative of the hellish underworld of mythology or religious texts. Sulphur is actually more common in the natural world, though, as sulphate minerals (naturally occurring salts of sulphuric acid, such as gypsum which is used to make Plaster of Paris) or sulphide minerals (which make up the precious metals, like gold, silver and platinum). In minute doses, as a macronutrient, all living organisms need sulphur. In fact, it’s the third most abundant mineral in an animal’s body – a building block of amino acids, which in turn make up cells of tissues, muscle and bone.
As a fossil fuel, crude oil contains sulphur – a ‘leftover’ from that contained in the remains of dead organisms from which it’s formed, over millennia, under conditions of pressure and heat. Whilst all crude oil contains some sulphur, some crudes have less than others – heavy ‘sour’ crude has more sulphur, and light ‘sweet’ crude has less.
Although non-toxic and essential to life on earth as a macronutrient in its native form, when sulphur is transmuted to certain forms, it becomes harmful. For example, when sulphur is burned, it becomes sulphur dioxide (SO2). When a power plant, or mine or manufacturing facility, for example, burns a fuel oil with a high sulphur content, sulphur dioxide is released into the atmosphere, where it combines with water and oxygen and other materials to form sulphuric acid (SOx,), which eventually falls to earth as acid rain. Sulphur emissions have become a global environmental and human health hazard – enter low sulphur fuel. As the name suggests, these are fuels with substantially lower levels of sulphur than those which have been used by transport and industry until now.
To reduce sulphur levels in crude oil, refiners use a process called ‘hydrotreating’ to produce cleaner products. As technology improves, so too does this cleaning process and the quality of the end products – all good news for the planet.
Being at the forefront of petroleum industry technology, the retail fuel market was the first to change to low sulphur fuels which are both better for the environment and for modern vehicle engines. Reports the National Association of Automobile Manufacturers of South Africa (NAMSA), a low sulphur diesel has been available in this country since 2006. Says NAMSA, all diesel vehicles benefit from low sulphur diesel, but new vehicles are specifically designed to operate on diesel fuel with a maximum sulphur level of 50ppm (parts per million). Since 2013, ultra-low sulphur fuel has also been available to motorists in South Africa. Ultra-low sulphur fuels have a sulphur level of just 10 ppm and, in addition to making a healthy contribution to lowering SOx emissions, it’s also kinder on fuel systems, and improves a vehicle’s performance and fuel economy.
After road vehicles, it was shipping’s turn to embrace the low sulphur fuel revolution. Traditionally, ships have used heavy fuel oil (HFO) to power their low speed marine diesel engines.
To reduce SOx emissions, the European Union has adopted what’s known as the Sulphur Directive (EU 2016/802), which stipulates that ships travelling in the EU’s sulphur emission control areas only use fuel with a sulphur content of no more than 0.15%, or ‘adopt alternative solutions that produce an equal effect’, for instance installing exhaust gas scrubbers. A worldwide Sulphur Directive by the International Maritime Organisation is due to come into effect in 2020 – by this time, shipping companies must have put conversion plans in place. This means that ships operating in African waters, too, will need to use Low Sulphur Fuel Oil (LSFO) from this date.
Virtually all low and medium-speed diesel engines currently in use in industrial applications in South Africa and Africa – like those used to generate power in manufacturing facilities or at mines – are designed for HFO. But, as new gas turbines and engines – designed to use low sulphur fuels – are used in greenfield installations or to replace outdated equipment at existing plants, the demand for low sulphur fuel oil for industry is set to increase. Already, many facilities are asking for low sulphur fuel oil (LSFO).
In addition to industry standard HFO, SA Oil provides LSFO – with a sulphur level of just 1% – to mines, manufacturing facilities, and power plants across our continent, as well as to the shipping industry. From 2018, we’ll also be supplying low sulphur diesel products. Get in touch with us for more info about which fuel oil is right for your application…