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.

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.

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.

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