Matters ‘COPE’ overlooked

Browsing the internet, before commenting on Dr. Janaka Ratnasiri’s above captioned article, to update myself on what the future holds on coal power generation, as a preamble or a prelude, I came across the following:

“While the amount of electricity generation from coal has declined in recent years, in part due to the rising accessibility of renewable sources of energy, the coal power industry has continued to build new coal-fired generation plants at a rapid pace. The global installed coal power generation capacity is projected to be on the rise over the next decades and predicted to reach a capacity of over 2.2 terawatts in 2050. As of 2019, China had the highest installed capacity from its Coal Power Plants amounting to about 1,005 gigawatts in total. The United States comes distant second with over 246 gigawatts of coal power plant capacity, followed by India at about 229 gigawatts.”

At the same time, there is encouraging news that China has carried out extensive research in converting coal to ‘Clean Coal’, to facilitate the use of coal in an environmentally satisfactory and economically viable way, with clean coal technologies. China has made remarkable progress in this and Clean Coal technologies have now entered into commercialization in stages.

It should also be admitted that 100 percent reliance cannot be kept in renewable sources, specially the major components being Solar and Wind due to vagaries of climate. Developed countries such as Germany have standby Coal plants to meet any short-fall in energy.

Coming to Dr. Janaka Ratnasiri’s reference to Fly Ash, Fishing and diseases, it is considered appropriate to quote what the internationally famed consultants on Coal Power Plants – Ramboll of Denmark, appointed on Norochcholai Coal Plant-had said in their report, for the information of those who have had no access to this document.

Impact from Fly Ash

To the extent at all possible will be recycled and reused in, for example the cement production and brick production just as fly ash under the right conditions can be reused in road construction or similar. However, the bottom ash and possibly part of the fly ash from the electrostatic precipitators as well can be reused. Therefore, an ash disposal site will be constructed inside the coal power plant. The design includes a low permeability bottom liner sloped towards sump pits. The leachate is collected in a sedimentation pond. The clarified water can be used for dust control. The design of the fly ash deposit lives up to modern recommendations for design of similar waste deposits. The consultant is, therefore, convinced that these measures will provide the necessary prevention of the ground water resource.

The environmental viability of ash recycling in the construction industry is given by the prevailing practice in numerous countries of the world, where ash from coal-fired coal plants is recycled in the industry. Trace elements are not considered an issue that valuable fly ash shall not be used for such applications. In these countries, very often demand for such fly ash exceeds the supply. The small amounts of [ignition oil] contaminated ash will not be recycled, but dumped into the ash landfill. It would be unwise not to recycle a maximum of non-contaminated and reusable fly ash.

Sulphur Emission and Particulate Emission

Based on combustion calculations for the selected boiler design and a range of possible coal types, the limiting coal type with respect to sulphur content has been selected. This will have a maximum sulphur content of 0.65 % and a sulphur/HHV ratio of less than 0.11% per kcal/kg. When coal of this type or with less sulphur is burned, the smoke emission from the stack should be according to the national standards, and no flue gas desulphurisation plant [FGD] is required.

As regards NO2 the plant design ensures emission below the required levels and the dispersion simulations show low concentrations of 15 to 30% of the maximum levels for all operational scenarios.

As for Particulate Emission the report says, “The concentration levels in the air at the areas surrounding the plant have been obtained through atmospheric dispersion simulation. The outcome was that the resulting concentrations will be only a small fraction [3-4%] of the allowable maximum. As such, the smoke emitted will be almost without dust, which is often seen from a modern power plant, where the smoke escapes from the stack with a little content of water vapour. The vapour spreads in the air within a short distance from the stack, and hereafter the emission is completely invisible’

Impact on Fishing

The cooling water system will be dosed with hydrochlorite [to a final concentration of 3-4 ppm] for 20 to 30 minutes every six hours. The dosing is required to avoid microbial growth within the cooling system. The hypochlorite treated water is diluted at the same rate as the heat. This means that the dilution will be about five times within the near vicinity of the outlet [Equal to temperature decreasing from 7 o to 1.5 o C]. It is also demonstrated that significant dilution will occur further down-stream of the plant. Any chloro-amines formed by the action of hypochlorite and ammonia, will similarly be diluted to an immeasurable concentration. It is concluded in the EIA that the small area affected by the discharged cooling water will have no adverse effect on the coastal fish population and the coastal fishing economy.

Diseases

In the preparation of this report on Norochcholai Coal-fired Plant, the Consultants have met the people of the area and to a question posed, the consultants had replied ‘The planned coal fired power plant will meet the ambient air quality standards which were set so as not to harm people, animals and environment. Consequently, there will be no fear of tuberculosis, cancer or any other disease induced by the coal fired power plant’.

In conclusion it should be said that the efficient working of the Coal Plant is left in the hands of the operators to adhere meticulously, to the recommendations made by the consultants, else sporadic outbursts may crop up from the inhabitants of the area, mostly comprising of fishermen, and those small scale farmers.

G. A. D. SIRIMAL

Boralesgamuwa