GE, Sasol Develop Water Technology that Provides Biogas

Sasol and General Electric’s GE Power & Water have developed technology that will clean wastewater while also providing biogas as a by-product for power generation.

This water treatment technology, known as Anaerobic Membrane Bioreactor Technology (AnMBR), will be further developed at a new demonstration plant at Sasol’s R&D campus at its Sasol One Site in Sasolburg, South Africa, the companies say.

The partnership leverages GE’s ecomagination-qualified ZeeWeed 500 membrane and decades of membrane bioreactor experience and Sasol’s expertise in biological treatment of Fischer-Tropsch (FT) derived effluents.

The companies expect the technology will be commercially ready early in 2015. Sasol will have exclusive rights to apply this technology to FT-based plants while GE will have the right to market the technology for other industrial uses.

AnMBR involves anaerobic microorganisms that are able to live in environments devoid of oxygen, such as sediment layers on floors of lakes, dams and the ocean. These organisms are almost ubiquitous, found in the human digestive system, under the earth surface, deserts and mountain peaks, to name a few.

Sasol currently uses aerobic microbes to treat gas-to-liquids (GTL) and coal-to-liquids (CTL) effluents in ORYX GTL, Qatar and Synfuels, Secunda facilities.

One of the by-products from the FT process is an effluent stream rich in organic acids and alcohols. Traditional (aerobic) treatment technologies treat this effluent by converting the organics to carbon dioxide.

The benefit of the AnMBR is that the microorganisms convert these organics into a methane rich bio-gas that can then be used as feedstock to generate power, Sasol says. This then results in an overall efficiency improvement in the GTL process. By converting the effluents to a valuable product (power), the GTL value proposition increases, the company says.

Another benefit of the AnMBR is that it produces almost 80 percent less waste biosolids than the previous generation process, Sasol says.

Sasol pioneered the treatment of effluents from the GTL process in Ras Laffan, Qatar, where effluents are treated and recycled for use as irrigation water in the city of Ras Laffan. The company’s second generation offering, which is currently being designed for the US GTL facility, is the aerobic Membrane Bioreactor (MBR).

A growing number of investors are focusing on industrial wastewater treatment, according to a New York Times Dealbook piece published in late October.