Skol Brewery Ltd Rwanda uses energy produced from wastewater to heat boilers

Posted By GWE / March 9, 2018 / Related technologies: ANUBIX™ – B,

The Skol Brewery has partnered with the GWE to turn wastewater organic pollutants into biogas to power its boiler equipment.

Rwanda has a strong need for sustainable technologies, with the World Health Organization’s African Regional Office identifying, that Rwanda undoubtedly faces significant environmental challenges, and needs to invest significantly in adapting to current climate challenges as well as in adaptation to future climate change1. Water shortages are also a significant problem in Rwanda, with water needs in Kigali city being only met at 50% or less especially in a dry season in a city with urbanization growth rate of more than 9% annually2.

Skol Brewery Rwanda’s new installation, incorporating some of the world’s most efficient and proven GWE waste-to-energy technologies, aligns Skol Brewery with top international environmental wastewater standards and demonstrates the company is taking important action to ensure the sustainability of its operations, says Jean Pierre Ombregt, GWE CEO.

ANUBIX™ – B reactor at Skol Brewery, Rwanda

Wastewater treatment with continuous biogas generation

The new process at the Kigali plant involves GWE’s ANUBIX™ – B system globally distributed anaerobic wastewater treatment technology proven in hundreds of industrial wastewater treatment plants, including dozens of breweries. Skol Kigali’s new continuous system – which replaces an old sequential batch reactor – highly efficiently removes organic waste material from production wastewater, converting more than 90 percent of the wastewater’s Chemical Oxygen Demand (COD).

The new wastewater treatment plant is a reliable method of turning organic waste into usable biogas. This organic material is transformed into biogas (mainly methane) to replace the need for an equivalent amount of fossil fuel to power the plant boilers equipment, while the treated wastewater effluent leaving the plant delivers high environmental benefits through achieving discharge limits of 250mg/L COD.

The new process – now successfully in its first full year of operation – begins with pre-treatment, followed by a modern treatment line utilizing mentioned before, ANUBIX™-B system at the heart of the process. Sludge management costs are reduced thanks to dewatering unit which is used to process any excess sludge. Because it is a continuous system, green energy can be generated consistently. This baseload green energy capacity represents a further significant advance on the plant’s previous Sequence Batch Reactor system. With the GWE process removing more than 92% of COD load and radically improving the effluent water quality, meaning that Skol Brewery has a minimal impact on local water systems.

“Using this sort of technology to not only treat wastewater and turn it into green energy but also to power existing boilers or otherwise utilize the additional biogas is becoming increasingly common as forward-thinking companies strive to meet sustainability initiatives and minimize their negative impacts on the environment. Larger anaerobic treatment installations can even generate additional profit in perpetuity because excess biogas or energy can be sold back to the grid,” Jean Pierre Ombregt, GWE CEO.

Developing countries like Rwanda are highly aware of the need for sustainability and are increasingly implementing technologies to safeguard the environment and precious natural resources like water. While there is still a long way to go – and this applies to everyone, globally – early adopters of environmentally harmonious technologies like Skol Brewery will pave the way for further advances in energy-efficiency that will benefit communities and the country as a whole.


  1. World Health Organisation – African Office. MDG Goal 7: Ensure environmental sustainability – Other MDGs
  2. Felix Rubogora (2017) Persistent Water Shortage in Kigali City: Who are the Most Affected?. Arts Social Sci J 8: 261. doi: 10.4172/2151-6200.1000261