New SRC system produces cooking gas from waste water
THE Scientific Research Council (SRC) has launched a new energy project where cooking gas is produced from waste water.
The council, which has offered to pass on the technology to companies and householders who are interested in producing their own electricity and gas from waste water, has been using the new technology to operate the cooker at its food- processing facility.
The system, known as the “Up-Flow Anaerobic Sludge Blanket (UASB) reactor”, produces biogas from any waste water, whether it is domestic, agro-processing or industrial.
Energy Minister Phillip Paulwell, who yesterday officially launched the project, said that with the escalating oil prices, it was imperative to seek the most cost-effective methods of generating alternative sources of energy.
“We are experiencing another energy crisis and we are seeing the development of this technology which will enable us to save on our energy cost,” he said.
The minister said that millions of litres of untreated waste water is discharged into harbours and nearby rivers daily, and urged the private sector, hospitals, schools, householders and farmers to buy into the concept of waste water to produce energy.
Paulwell said he would be meeting shortly with the National Housing Trust and the National Housing Development Corporation to convince them of the need to utilise this system.
“We will convince them as government to lead the way so that in future schemes we can use this technology to deal with waste,” the minister said.
Julia Brown, manager for the Process Development Division of the SRC, told the Observer that the whole idea was to have the bacteria added to the waste water from the food processing division, under anaerobic or airless conditions.
The 220 gallons of waste water produced daily by the facility does not contain its natural bacteria as in the case of domestic fuel, and as such it is added.
For this system, she said, there are several bio-digesters so the sludge (solid emitted from the waste water) is removed and used to inoculate the UASB. The waste water is then fed unto the sludge into the bottom of the reactor. As the bacteria thrives, it will break down organic or pollutants in the waste water over an eight-hour period.
In the breakdown process, Brown said, it produces biogas as well as clean water which is 80 per cent treated. This water is used for irrigation.
Brown said that when fed to the system the 220 gallons of water can produce three to five cubit metres of biogas per day. “This might sound small but it can do quite a bit. It can run cookers, it can even run small diesel engines,” she said.
The gas produced by the SRC is now used to supply the cookers in the experimental kitchen at the food-processing facility.
Brown explained that the amount of gas the system produces is enough to cook a family of five three meals per day which requires about a cubit metre of gas.
“As long as you produce the system and feed the system, you will produce gas,” she said.
She said the SRC has since enhanced the system by installing a holder which stores the gas so none is lost.
The SRC has also implemented a similar system at another small food processing facility, which Brown said, provides 80 per cent of the gas they need.
She said there was a similar system to be commissioned in August to provide all the electrical needs for another factory.
The amount of gas produced, she said, would be dependent on the type of waste being used.
Brown told the Observer that the SRC would assist with the initial set-up and maintenance of the system for clients. “For all projects we do the entire package where we go in set up and commission a finished product,” she said.
What makes this technology so attractive, Brown said, was its simplicity. “It is a natural process, does not utilise any additional input and it is pretty much like leaving your waste in a container to degrade for a couple of days.”
In the meantime, Brown said the bio-digester septic tank, used for single households and housing development, was a prototype of the anaerobic system. This, she said, was being introduced in Kingston and St Andrew for the treatment of domestic sewage.
The SRC, she said, also has a bio-digester to deal with animal waste as well as food cuttings.
“We have several new single households which have bio-digester septic tanks in place as an alternative to soak-away pits as they are not environmentally sound,” she said.
For a single household, it could cost about $300,000 to install a system. However she said there are options you can utilise to cut cost.
For households that would want to run electricity, Brown said, they would have to produce more waste. “So the best way to go when the quantities are not high is to go for cooking,” she said.
Brown said most of the developments in Kingston and St Andrew were using bio-digester septic tanks.
She said the project has generated interest throughout the region.