Aug 31, 2012
Biogas-from-sludge solution could yield power savings for water plantsBack
Africa|Cleaning|Engines|Gas|Generators|Projects|Waste|Water|WEC Projects|Africa|South Africa|By-product|Chemical Compounds|Cleaning|Electricity|Electricity Grid|Energy|Energy-generation Potential|Fuel Gas Engine Generators|Possible Electricity Saving|Product|Jason Gifford|Power|Waste|Water|Wastewater Treatment
© Reuse this
Jason Gifford, spokesperson for the Energy Division of WEC Projects, a firm which is implementing South Africa’s first biogas-to-power plant at a municipal wastewater treatment works, explains that biogas produced during the sewage treatment process has the potential to reduce the plant’s dependence on the national electricity grid.
“Biogas can be used to fuel gas engine generators at treatment works and provide a percentage of the electricity these plants use for operation,” he explains.
Considering that there are around 50 major municipalities in South Africa with a wastewater treatment plant large enough to operate an effective biogas plant, 30 MW is a conserva- tive estimate of the possible electricity saving.
Treatment plants traditionally use a natural process, known as anaerobic digestion, which involves the decomposition of organic matter in the absence of oxygen, to convert a large proportion of the solid sewage sludge, produced in the mainstream treatment processes, into biogas.
Following anaerobic digestion, the biogas produced is termed raw fuel, as it contains water, hydrogen sulphide as well as a variety of volatile organic and chemical compounds that can damage the moving parts in engines.
“For biogas to be an effective fuel, it therefore needs to be conditioned and have these contami- nants removed to ensure long-term sustainability of the plant engine and a lower overall running cost,” says Gifford.
A biogas-to-power plant may provide wastewater treatment works with an on-site energy source that could enable it to offset a portion of its running costs.
Critically, Gifford emphasises that, as the mandate of municipal water works is not to generate electricity, but to clean wastewater, it is important to outsource the running of biogas- to-power plants to specialised contractors.
“In certain international cases, the function of biogas-to-energy operations at water works has exceeded the initial mandate of cleaning effluent and has become the primary focus of the entire plant, resulting in a deterioration of the quality of the treated effluent,” he notes.
Gifford adds that the true financial benefit of municipal biogas plants is evident when savings are not lost to other divisions within the municipality, but reinvested into the effluent treatment works for maintenance and upgrade.
In addition, he says, the cost of a fully commissioned biogas-to-power operation, including full automation and remote monitoring, can be recouped after four to seven years, making it a financially viable long-term energy option.
Edited by: Martin Zhuwakinyu© Reuse this Comment Guidelines (150 word limit)
Other Oil and Gas News
Updated 2 hours 20 minutes ago Despite various challenges related to the extraction of shale oil and gas, as countries grow accustomed to the idea, the use of shale as a form of energy will be more widely pursued, international oil and gas market analyst Michael Lynch said on Tuesday. Speaking at...
Updated 4 hours ago South Africa is becoming more and more dependent on imported petrol and diesel, MPs heard on Tuesday. "Increasingly, we are relying a lot on imports of finished products... these figures have been climbing in recent years," energy department deputy director general...
Updated 2 hours 33 minutes ago Despite various challenges related to the extraction of shale oil and gas, as countries grow accustomed to the idea, the use of shale as a form of energy will be more widely pursued, international oil and gas market analyst Michael Lynch said on Tuesday. Speaking at...
Updated 2 hours 36 minutes ago A consortium led by two Kenyan firms won a government tender to build a 1 000-MW, coal-fired power plant, company officials said on Tuesday, part of moves to satisfy rising demand for energy in East Africa's biggest economy. Kenya suffers from regular blackouts due...
Updated 2 hours 42 minutes ago The announcement of the successful bidder for the construction of Durban’s long-awaited passenger cruise terminal was imminent, Transnet National Ports Authority (TNPA) CEO Tau Morwe told delegates at the African Ports Evolution Conference in Durban on Tuesday. ...
Recent Research Reports
Road and Rail 2014: A review of South Africa's road and rail infrastructure (PDF report)
Creamer Media’s Road and Rail 2014 report examines South Africa’s road and rail transport system, with particular focus on the size and state of the country’s road and rail network, the funding and maintenance of these respective networks, and the push to move...
Real Economy Year Book 2014 (PDF Report)
This edition drills down into the performance and outlook for a variety of sectors, including automotive, construction, electricity, transport, steel, water, coal, gold, iron-ore and platinum.
Real Economy Insight: Automotive 2014 (PDF Report)
This four-page brief covers key developments in the automotive industry over the past 12 months, including an overview of South Africa’s automotive market, trade figures, production and the policies influencing the sector.
Real Economy Insight: Construction 2014 (PDF Report)
This five-page brief covers key developments in the construction industry over the past 12 months. It provides an overview of the sector and includes details of employment in the sector, infrastructure and municipal spending, as well as insight into companies’...
Real Economy Insight: Electricity 2014 (PDF Report)
This five-page brief covers key developments in the electricity industry over the past 12 months, including details of State-owned power utility Eskom’s generation activities, funding and tariffs, independent power producers and prospects for the sector.
Real Economy Insight: Road and Rail 2014 (PDF Report)
This six-page brief covers key developments in the road and rail industries over the past 12 months, including details of South Africa’s road and rail network and prospects for both sectors.
This Week's Magazine
South African State-owned defence industrial group Denel has announced its fourth consecutive year of profits. The group's results for the financial year 2013/2014 were recently announced at its head office in Centurion, south of Pretoria. Revenues grew by 17%, net...
There is little opportunity for JSE-listed infrastructure company Group Five to grow shareholder value in the domestic market, says CEO Mike Upton. He says value can still be found in the private sector, in the renewable and industrial power sector, as well as in...
The National Association of Automobile Manufacturers of South Africa (Naamsa) has announced the event dates of the 2015 Johannesburg International Motor Show (JIMS). The event will take place from October 14 to October 25, 2015, at the Johannesburg Expo Centre, Nasrec.
UK engineering support services provider Babcock is set to deliver the largest order of global truck manufacturer DAF’s truck tractors in Southern Africa to bulk carrier road-based logistics company Ngululu Bulk Carriers (NBC), with 133 trucks to be delivered in...
Digital radio communications in the African local government space can open up the world, but have many challenges to overcome, notes integration and migration of legacy radio communications infrastructure with digital mobile radio company Emcom Wireless head of...