Power from the wastes
By Ana Liza Jane Banaynal
Without a doubt, Cagayan de Oro is becoming a highly urbanized city. Evidenced by the
high rising buildings, bustling cars, and swarming people, the City of Golden Friendship is
slowly losing its rural status. Although urbanization is an indicator of development, it has side effects and one of these is the rapid increase of the population, and increase in population means increase in the generation of wastes as well.
According to The City Local Environment and Natural Resources Office (CLENRO),
Cagayan de Oro City (CdOC) is now home to 602, 088 people, and each of them generating
0.54kg of waste per day. That and more wastes from business industries and other institutions are dumped in the landfill in Brgy. Zayas. Some of these waste products, specifically organic materials, are residual or cannot anymore be reused or recycled.
Years and years of wastes are dumped in the only landfill in the city, which takes decades
to decompose. Its volume grows and produces mountains of wastes that the landfill cannot
anymore hold.
The landfill is due for closure in 2015 as it will reach its maximum years of utilization by
then. Also, it is already affecting the lives of the people living nearby. The closure of the landfill can possibly sprout into the birth of an electricity generation plant, which utilizes the biogas produced by the wastes.
Electric twist
The gases produced by the wastes in the landfill, which are largely composed of Methane
(CH4), Hydrogen sulfide (H2S), and Carbon dioxide (CO2) don’t come easy as it goes through a long and complex process before it can generate electric power.
First, drilling using perforated pipes must be done. It must be placed in the lowest part of
the landfill. Such wastes will then go through anaerobic digestion. Mr. Greg Cubio of the Agricultural Engineering (AE) Department of Xavier University – Ateneo de Cagayan said, “It (anaerobic digestion) is a series of biological steps that involve microorganisms breaking down organic materials in the absence of oxygen in the wastes that found in the bottom-most part of the landfill.”
In an uncontrolled dumpsite like the one in Brgy. Zayas, landfill gases escape and mix with phosphorus, which ignite and cause fires in the area. Such fires cause greenhouse effect; the trapping of gases that increase the temperature inside the atmosphere.
Second, a series of purification will be done, which is referred to as scrubbing. It is done
to get rid of other gases that is not Methane (CH4). The concentration of Methane gas must reach 95% or it will cause engine knocking. “If it doesn’t reach that concentration level, it will lose its ability to keep the engine running,” he said.
The third step is the coupling, which is the connecting of the scrubbing engine to a generator. Shafts of the engine are “coupled” to those of the generator.
Fourth is the generation of energy. The generator produces mechanical energy. Following the production of energy is its transformation into electrical energy. This process entails the use of a transformer that converts energy into a higher voltage, which can then produce more power.
Once electric energy is transformed, it will then be dispersed to a substation. “In our case, we have a substation at Brgy. Carmen, where electricity is stored before dispersion,” Mr. Cubio said. The substation is attached to a grid, which is responsible for the distribution of electric power.technology of utilizing landfill gas has been discovered a few decades ago and has been used by several European countries to supply for their electricity needs.
In the Philippines, only few cities have adapted such technology. One example is in Payatas City, which converted its landfill into a controlled dumpsite in 2000.
Worm’s eye view
In the local context, the adaptation of this technology isn’t far off as a proposal of finding
an area for a new landfill is already underway, which draws closer the possibility of closing and converting the old landfill in Brgy. Zayas.
“The landfill has a potential to become an electricity generation plant,” Mr. Cubio said.
But it has to undergo several processes and tests and meet parameters before it can be
implemented. So far, the data are still incomplete. “Further surveying of the area has to be done to obtain the data needed,” he added.
Open possibilities
If this will be implemented, it will add to the source of electrical power. Also, it will lower the power shortage in some places in CdOC and maintain the stability of power supply.
The use of renewable gas is also beneficial to the environment. Not allowing it to escape to the atmosphere can decrease in the rate of the Ozone Layer’s depletion, which protects us
from the destructive rays of the sun.
Though the capacity of the power that can be generated by our landfill is not yet measurable, it is sure to increase renewable gas’ usefulness and save it for a better purpose.
Science has devised a way to make use or renew by-products of wastes and make it into
the most important commodity we need today – electric power. Aside from providing our need, it can help save the future of our one and only Mother Earth.
