South African energy and chemicals group Sasol today announced that it has chosen the southwestern region of the State of Louisiana as the site for a planned gas-to-liquids (GTL) facility. Sasol will embark on a feasibility study to evaluate the viability of a GTL venture in Calcasieu Parish, Louisiana, over the next 18 months. The feasibility study will consider two options: a 2 million tons per year (roughly 40,000 barrels of oil equivalent per day) facility and a 4 million tons per year (roughly 80,000 boepd) facility.
The project is slated to be the first plant in the US to produce Fischer-Tropsch GTL transportation fuels and other products from natural gas, according to Sasol. This is the second “first of a kind” announced by Sasol in the US in less than a year; in December 2010, Sasol announced the world’s first Ethylene Tetramerization Unit, also to be built in Calcasieu Parish.
Sasol has used its proprietary technology for more than 60 years to produce more than 1.6 billion barrels of liquid fuels and chemicals from coal and natural gas. GTL transportation fuel is cleaner burning than conventional diesel with a roughly comparable, and potentially lower, greenhouse gas profile, Sasol says.
A 2004 lifecycle analysis synthesis report prepared by Five Winds International for ConocoPhillips, Sasol Chevron and Shell International Gas concluded that:
Total GHG emissions of the GTL system are between 12% less and 11% more than the refinery system, based on varying assumptions and data. The majority of the scenarios suggest an at least neutral if not positive GHG performance (i.e. reduced emissions) for the GTL system. Disadvantages in the fuel production stages of the technology are offset by the fact that GTL fuels offer slight advantages in the fuel use (combustion) stage, which contribute approximately 75% or more of the total calculated GHG impact of both options.—Gas to Liquids Life Cycle Assessment Synthesis Report
|Emissions performance of GTL diesel. Source: Sasol. Click to enlarge.|
GTL fuels are virtually free of sulfur and aromatic compounds and reduce emissions of particulates, nitrogen oxides, carbon monoxide and other pollutants and will improve air quality. A 2005 PricewaterhouseCoopers study showed that GTL production offers air quality benefits compared to a conventional oil refinery due to its lower sulfur dioxide, nitrogen oxide and hydrocarbon emissions.
Sasol converts gas and coal into liquid fuels, fuel components and chemicals through proprietary Fischer-Tropsch (FT) processes. In partnership with Qatar Petroleum, it started up its first international GTL plant, Oryx GTL, in 2007. (Earlier post.) With the start-up of Oryx GTL, Sasol now operates three proprietary and distinct types of FT processes:
- Low temperature cobalt, for Oryx GTL fuels production;
- Low temperature iron, for Sasolburg wax and chemicals production; and
- High temperature iron, for Secunda fuels and chemicals production.
Sasol is also exploring GTL opportunities in Uzbekistan. Sasol continues to advance upstream oil and gas activities in Mozambique, Nigeria, Gabon, Australia, Papua New Guinea, Canada and South Africa.