Sasol Willing to Consider Using ‘Green Hydrogen’ to Produce Lower-Carbon Fuels
by Terence Craemer (Craemer Media’s Engineering News) South African energy and chemicals group Sasol, which is under increasing pressure to lower its carbon dioxide (CO2) emissions, has indicated a willingness to participate in demonstration projects aimed at deploying its Fischer-Tropsch assets in combination with ‘green hydrogen’, produced from renewable energy and water using electrolysis.
Sasol’s current hydrogen-production methodology involves the use of coal and water in a process that is highly carbon-intensive. This coal-based hydrogen is, in turn, used in Fischer-Tropsch reactors to produce a suite of products, including diesel and kerosene, or jet fuel.
The carbon-intensity of Sasol’s process arises largely as a consequence of coal having an inherently low hydrogen composition, which means that a high volume of coal is needed to produce only small amounts of hydrogen. As a consequence, Sasol’s coal-to-liquids facility in Secunda, in Mpumalanga, is widely considered to be the world’s largest single-point CO2 emitter globally, with yearly emissions of 56-million tons.
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The injection of green hydrogen into Sasol’s process would eliminate upstream emissions, which are materially larger than the emissions generated when the jet fuel is burnt in flying.
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Green jet fuel is a “huge export opportunity for South Africa” as a result of the country’s intrinsic resource advantage – which means its renewable energy will be cheaper than in most other countries – and its vast experience in the production of synthetic fuels. South Africa produces about eight-billion litres a year of synthetic fuels.
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Upscaling the opportunity to meet 20% of global aviation fuel demand, would require 250 GW of electrolyser capacity, supported by a renewables fleet of 600 GW. At such a scale, supplying South Africa’s domestic electricity demand would be a by-product of the renewables fleet, whose bulk energy would supply South Africa’s green jet-fuel production across a Fischer-Tropsch fleet ten times that of Secunda. READ MORE