Clean Coal Tech - No Logic!

TNB and SESB are trying to convince Sabahans to accept coal-fired power plant in the East Coast, not just any part of the East Coast but a location with infrastructure in place, meaning nearest to the electricity grid, fresh water supply, road, and sea front where they can land their coal and use the sea water for cooling purpose and waste disposal. That was why they chose Silam and now Sandakan.

They claimed they have several coal power plants operating in Peninsular Malaysia without environmental problems and using Clean Coal Technology (CCT). They quoted Manjung in Perak, Tanjung Bin in Johore and Sejingkat in Sarawak.

In the case of Manjung, Tanjung Bin and Sejingkat, they are all built at isolated locations faraway from human settlement and activities. Moreover in these areas there is not ecosystem to protect unlike Silam and Sandakan.

The environment in all these places is different from Sabah, they all are facing an open sea, which can carry their waste discharged out to the ocean, unlike Silam and Sandakan which are essentially a bay, full of coral and marine life.

TNB and SESB in their proposal claimed they are using clean coal and clean coal technology.

“Clean coal” is an attempt by the coal industry to try and make itself relevant in the age of renewable energy.

What is (so-called) “clean coal”?

Coal is a highly polluting energy source. It emits much more carbon per unit of energy than oil, and natural gas. CO₂ represents the major portion of greenhouse gases. It is, therefore, one of the leading contributors to climate change. From mine to sky, from extraction to combustion, coal pollutes every step of the way. The huge environmental and social costs associated with coal usage make it an expensive option for developing countries. From acid drainage from coal mines, polluting rivers and streams, to the release of mercury and other toxins when it is burned, as well as climate-destroying gases and fine particulates that wreak havoc on human health, COAL is unquestionably, a DIRTY BUSINESS.

It is a major contributor to climate change – the biggest environmental threat we face. It is the most carbon-intensive fossil fuel, emitting 29% more than oil, 80% more carbon dioxide (the main driver of climate change) per unit of energy than gas.

Mercury is a particular problem. According to the United Nations Environment Program (UNEP), mercury and its compounds are highly toxic and pose a ‘global environmental threat to humans and wildlife.’ Coal-fired power and heat production are the largest single source of atmospheric mercury emissions. At present there are no commercially available technologies to prevent mercury emissions from coal-fired power plants.

“Clean coal” technology (CCT) refers to technologies intended to reduce pollution. But no coal-fired power plants are truly ‘clean’.

Giving the meaning of "Clean Coal" Technologies

• Coal is a vital fuel in most parts of the world.
• Burning coal without adding to global carbon dioxide levels is a major technological challenge which is being addressed.
• The most promising "clean coal" technology involves using the coal to make hydrogen from water, then burying the resultant carbon dioxide by-product and burning the hydrogen.
• The greatest challenge is bringing the cost of this down sufficiently for "clean coal" to compete with nuclear power on the basis of near-zero emissions for base-load power.

Burning coal produces about 9 billion tonnes of carbon dioxide each year which is released to the atmosphere, about 70% of this being from power generation. Other estimates put carbon dioxide emissions from power generation at one third of the world total of over 25 billion tonnes of CO₂ emissions.

New "clean coal" technologies are addressing this problem so that the world's enormous resources of coal can be utilised for future generations without contributing to global warming. Much of the challenge is in commercializing the technology so that coal use remains economically competitive despite the cost of achieving "zero emissions".

Managing wastes from coal

Burning coal, such as for power generation, gives rise to a variety of wastes which must be controlled or at least accounted for.

Coal cleaning by 'washing' has been standard practice in developed countries for some time. It reduces emissions of ash and sulfur dioxide when the coal is burned.

• Electrostatic precipitators and fabric filters can remove 99% of the fly ash from the flue gases - these technologies are in widespread use.
• Flue gas desulfurization reduces the output of sulfur dioxide to the atmosphere by up to 97%, the task depending on the level of sulfur in the coal and the extent of the reduction. It is widely used where needed in developed countries.
• Low-NOx burners allow coal-fired plants to reduce nitrogen oxide emissions by up to 40%. Coupled with re-burning techniques NOx can be reduced 70% and selective catalytic reduction can clean up 90% of NOx emissions.
• Increased efficiency of plant - up to 45% thermal efficiency now (and 50% expected in future) means that newer plants create less emission per kWh than older ones.
• Advanced technologies such as Integrated Gasification Combined Cycle (IGCC) and Pressurized Fluidized Bed Combustion (PFBC) will enable higher thermal efficiencies still - up to 50% in the future.
• Ultra-clean coal from new processing technologies which reduce ash below 0.25% and sulfur to very low levels mean that pulverized coal might be fed directly into gas turbines with combined cycle and burned at high thermal efficiency.
• Gasification, including underground gasification in situ, uses steam and oxygen to turn the coal into carbon monoxide and hydrogen.
• Sequestration refers to disposal of liquid carbon dioxide, once captured, into deep geological strata.

From the above description quoted by pro coal lobbies, surely they are no clean coal technology but devices yes. But TNB and SESB continue to sell their idea of clean coal technology.

Electrostatic Precipitators (ESP)

Manjung and Tanjung Bin are using British/French Electrostatic precipitators (ESP) whereas Sejingkat is using Chinese made ESP to remove ash from the flue gas. The proposed ESP system for Sabah will be using Chinese technology, similar to Sejingkat Power Plant. The fly ash in Sejingkat is carried to slurry pond or lagoon and stored permanently by water. Coal Ash is considered a schedule waste, meaning it contains toxic material. Wonder why they propose to use it for other purposes.

Flue Gas Desulfurization (FGD)

Manjung and Tanjung Bin plant have installed the FDG but not Sejingkat plant. The reason being Sejingkat plant is using locally mined sub-bituminous coal which contained very low sulphur. Manjung and Tanjung Bin are using bituminous coal from Kalimantan with sulphur content of less than one per cent (1%).

Both the Manjung and Tanjung Bin plant are using the seawater scrubber FGD system.

Seawater Scrubber FDG System

The hot flue gas from the dust collectors is transported via a quencher to the scrubber. The scrubber is a packed tower where the gas is contacted with seawater in a countercurrent operation. The seawater very efficiently absorbs the SO₂ in the flue gas.

The main supply of seawater for the process is split up into two streams. One passes through the scrubber for the absorption of SO₂, where upon the now acidic seawater flows further by gravity from the scrubber bottom to a water treatment plant. In order to achieve optimum conditions for the reaction taking place in the water treatment plant, the acidic seawater is premixed with the other split stream of fresh water. The water treatment plant basically consists of aeration basins. Air is supplied to convert the absorbed SO₂ into harmless sulphate ions. Sulphate ions are a major constituent of ordinary seawater. The treated seawater is then discharged into the sea.

In this system everything including micro ash particles, mercury, heavy metal, nitrogen oxide and others along with sulphur dioxide(SO₂) in the flue gas are discharged into the sea . The system claimed that the soluble Sulphate has no harm to the marine environment as the sea water itself contained sulphate.

Even though it is true the sea water contained sulphate and maybe good for the ‘fishes’, but millions of tons of Sulphate discharge outside the plant over the next 25 to 30 years will definitely create harmful effect on the marine environment. Moreover in the case of Sabah’s waters there are plentiful of corals that made up of calcium materials, and a large quantity of Sulphate discharged into our sea will definitely create a marine environment disaster. Not to mention the toxic materials that are discharged with will eventually reach us through the marine life that we eat.

Most countries use the lime scrubber FDG method, whereby the waste is collected and stored in land filled for eternity.

Seawater discharge point

2 PPM Sodium Hypochlorite (Chlorine)

Coal-fired power plants need of seawater for cooling their condenser (turbine), but our seawater is rich in marine life that will stick and built up itself on the condenser plates. Hence preventing good heat transfer and reduce efficiency in heat removal.

To prevent these marine life from damaging the condenser or heat exchanger, seawater will be treated with 2 ppm of sodium hypochlorite. Chlorine from hypochlorite is very toxic to marine life and we use them to treat our drinking water.

Coal-fired power plants use billions of tonnes of seawater over their life span and thousands of tonnes of chlorine-based chemical are used and flushed into our sea. Just imagine the harmful effect on our marine ecosystem in our sea.

Carbon Dioxide (CO₂)

Everybody now knows that coal-fired power plants produce the most pollution of CO₂ thereby causing climate change, and the world is trying to reduce this pollutant. How can TNB and SESB continue to promote clean coal technology whereby the existing plant has not done anything on CO₂, knowing that all their plants are producing millions of tons of CO₂ per year.

When everyone talks about clean coal technology, the first thing in their mind is about removing CO₂ and not just SO₂ and Ash. Therefore TNB and SESB should not qualify themselves to use CCT in their argument to propose a coal-fired power plant in Sabah.

In conclusion, as much as we want electricity to light up our home yet we cannot be so selfish as to allow the pollution that destroy our air, land and sea environment for our present comfort and not to think for our generation to come. Go for alternative.

SEPA TAWAU