Cleaning the mess with Green Energy

Wasantha Ramanayake

Raising its ugly head, garbage is once again agonizing Colombo shifting from Mount Lavinia recently, that had troubled Colombo earlier. Municipal Solid Waste (MSW) or simply garbage is not properly disposed of, but lays open, scattered everywhere spreading disease and devouring rate payers’ money.

With the ever increasing volume corresponding to the increase in population and the decrease in the availability of lands for dumping, it is a frequent public nuisance and bothers the city dwellers of disease. In a nutshell, it is all about mosquitoes, flies, rodents, stink, noxious seepage etc.

Increasing dumping sites a hazard

And Dengue is a nightmare which has claimed 156 deaths during the past six months, according to media reports, with more than 10,000 cases. In its aftermath recently President Mahinda Rajapaksa took a decision to take all the garbage filing sites under the government control. Could not the latest developments in the science and technology take the bull by the horns?

Such a development in technology is Plasma Gasification which would virtually vaporize any waste except for metals, glass and concrete etc., into inflammable gases that could in turn burn to produce electricity, so the advocates say.

The main advantage of the technology as pointed out by them is that 99.9% of the waste fed into the reactor would be converted into the energy or other salable products.

Plasma reactor would be an environment friendly garbage disposer that produces bonus electricity, a green energy, without any harmful emissions. It is said to be a better and effective solution over and above the other MSW disposal methods such as land filing and incineration both are proved to be hazardous. The land filing has never been a success story here.

Dumping and Land filing; Karadiyana

So called sanitary MSW disposal site at Karadiyana managed by a private company, according to the Environmental Foundation Limited (EFL) has been a health hazard that compelled the residents along with the EFL went to Kesbewa Magistrate court against the unhealthy and mismanaged garbage disposal site.

They complained to the court about the pollution and unhygienic conditions such as pollution of the groundwaterand/or aquifers by leakage and residual soil contamination during landfill usage, as well as after landfill closure.

One of the petitioners, Mahesh told that the dumping site affects the residents of five villages including Werahera, Tenth Mile Post, Bokundara and Kardiyana. The villages are located in a low lying area. Mahesh says that the site had blocked water stream from Maharagama at Bokundara. “Just an hour’s rain is enough to flood Bokundra village and a section of the Colombo – Horana main road,” he said.

“The stink is unbearable. The swarms of flies would not allow us to leave our food uncovered. It is a menace, ” says Mahesh who live close to the site. Mahesh pointed out that the dumping site is located closer to the Attidiya Birds sanctuary and the Bolgoda Lake both are of the two environmentally important and significant.

Bloemendhal

“The water in the Bolgoda Lake has been blackened, so is the water in the wells. There is no more fish in the lake.” Mahesh said that the dumping site is just ten meters away from the Bolgoda Lake. Mahesh says that swarms of mosquitoes that bred in the foul environ would bring disease previously unknown. It was just two years before dengue took its toll on a child there. “Not only dengue there can be any disease,” he was angry. Karadiyana site just as the Bloemendhal site best illustrates how hazardous a dumping site along with associated nuisance problems (e.g., dust, odour,vermin, or noise pollution) could be.

Hundreds of tons of the daily garbage output of the city dwellers had created a virtual hillock in the Bloemendhal road already raising health concerns from its seeping noxious emissions. Long suffering residents near Bloemendhal reacting similarly objected to the dumping at the Bloemendhal site. The Colombo Municipality had to turn to an alternative site close to Kotikawatte where the residents too were up in arms over the unhealthy dumping of garbage. These facts compel and point to look for advanced and innovative solutions.

Also Methane generated by decaying waste is a greenhouse gas more potent than carbon dioxide responsible for the global warming and climate change. Disease vectors such as rats and flies, particularly from improperly operated landfills, are common in such sites. In contrast, it is reported that in recent years, some countries, such as Germany, Austria, Belgium, and Switzerland, have banned the disposal of untreated waste in landfills. In these countries, only the ashes from incineration or the stabilized output of processed waste from mechanical biological treatment plants may be deposited.

Incarceration vs. Plasma Gasification

As an alternative, garbage is burnt in incinerators in many countries in Europe, Japan, and Canada. But the main argument opposed to the incineration is that the combustion of carbon based materials is incomplete, would leave ash, tar and char that would contain toxic materials such as heavy metals that would require safe disposing.

 Whereas plasma gasification would not release toxic heavy metals into the environment; instead they would be locked inside vitrified glasses. Further they argue that inorganic materials such as metal glass, soil, concrete, silica would not be affected by burning unlike in the plasma gasification. The advocates further point out that incineration would leave dioxins and furans and nitrogen oxides which are toxic and could be cancerous.

Dr. Mahesh Jayaweera attached to the Ministry of Environment said that the technology is in its infancy; however, said that its impact on environment is minimal provided that the air cleaners are in place to trap harmful emissions.

The technology is a controlled partial oxidation that was different from the combustion in the incinerators. “The advantage is that it is renewable, and garbage is available in abundance,” he pointed out.

He said that the temperature inside the reactor is so high, “Even a car would be vaporized in seconds,” he said.

The temperature inside the reactor should be around 5000 °C; “which is very high.” So could be the initial capital, could be even higher than the capital investment for a coal power plant of similar capacity.

Thus, the only limiting factor is the relatively higher capital cost in the area of $50 -75 million just for 10MW power plant which would be roughly five times the cost of the construction of the coal fired power plant. “With the improvements in the technology the cost would come down,” he said.

Dr. Jayaweera pointed out that the waste fed into the Plasma Reactor leaves only vitrified glass which is inert or recyclable metal. Vitrified glass could be used in the construction industry and the emission called “Syn” gas, a mixture of carbon monoxide and hydrogen could be used to produce electricity. “I have seen even ornamental articles carved out of the vitrified glass,” he added.

Dr. Jayaweera said that the USA, Malaysia and Canada are leading the technology. Commenting on the impact on the environment, he noted that Plasma Gasification would not emit toxic substance in to the environment, provided that the toxic gas captures are in place.

The advocates of the technology claimed that the heat recovered from the process could be used for several applications including the operation of the cold storage facilities for food and would also be eligible to apply for the carbon credit under the Clean Development Mechanism under the Kyoto Protocol.

Dr. Ms. Ajantha Perera of Environment Ministry emphasized that MSW should be sorted out and organic matter should be used to manufacture compost as it would help to develop the agricultural sector. She said that the masses would be encouraged to participate in the process rather than individuals benefiting. “Government should formulate common policy that would blend both agriculture and waste disposal,” she emphasized.

Lost Hope

It was interesting to note that the Ceylon Electricity Board (CEB) had issued a Letter of Intent(LoI)on August 15, 2007, to Colombo Renewable Energy Private Ltd. to purchase power produced by a Plasma Gasification Plant which the company with proposed to be set up in Muthurajawela. A joint venture with a Malaysian company, Plasma Renewable Energy Company, claimed to permanently solve the city’s garbage menace while supplying much needed electricity.

According to the then media reports Company’s Managing Director D. Lakshman Perera had claimed that initially 100 tons of compost residues from MSW would be fed to the Plasma reactor under the first phase which could be increased up to 1000 tons with the completion of project. However, the project is yet to see the light of the day.

When inquired, Power and Energy Ministry Secretary M.M.C. Ferdinando said that number of companies had dropped the projects after obtaining the LOI. The Colombo Renewable Energy Company Ltd. could not be traced to make any inquiry. Meanwhile, an official of the Sustainable Energy Authority said that a proposal had been made to set up a 10 MW power plant that uses the technology to produce power out of MSW. “But the proposal is yet to be evaluated,” he said.

After all the growing concern of the garbage issue should be exploited to explore novel technologies such as plasma gasification for MSW management. There is definitely a dearth of discussion among experts which would render the people groping in the dark. It is also high time that authorities took care of garbage as “an asset” not definitely as “a liability” in the greater interest of the people.