Coal and the environment

There is incontrovertible evidence that carbon emissions are having a significant effect on the environment. These emissions are in part due to the burning of fossil fuels by the world’s electrical power generators and the transport sector.

That said, the dilemma is that people in the economically–developed countries are not willing to cut the standards of living to which they have grown accustomed. By the same token, people in developing-economy countries expect their living standards to rise, which depends on greater availability of energy. While the message of global warming is well understood, almost all developed countries have turned their back on “clean” alternatives such as nuclear power generation. We cannot do without our cars and the capacity to produce electricity from renewable resources such as wind or solar is limited. Conservation is part of the solution. But the inescapable fact is that coal will become an increasingly important part of the developed world’s energy mix.

On the other side of the economic divide, people in many developing countries are motivated to seek the equivalent material benefits enjoyed by those in developed countries. A quarter of the world’s people do not have access to electricity. And calls by developed countries on developing nations to curb their hunger for motor vehicles and easily accessible energy fall on deaf ears. Why, the poor countries ask, should we accept anything less than the rich? Slowing, never mind halting or reversing, the growth in demand for energy will prove incredibly difficult.

Furthermore, virtually every one of the world’s nations is seeking as high a degree of energy autonomy as possible. Countries may not have oil or gas, but many have domestic coal resources.

Can the conflicting demands of increasing demand for energy and the effect on the environment of burning fossil fuels be settled? Yes, is the answer. And part of that answer lies with coal.

The technology already exists for reducing the amount of carbon dioxide emitted when coal is burned in power stations. Top of the list comes the introduction of existing technology that makes the generation process more efficient. As an example, China is busy replacing small, older power stations that only convert some 20% of the energy in a ton of coal into electrical energy with state–of–the–art power stations that can convert 40%. This results in a halving of the amount of coal needed to generate each megawatt of electricity and a direct halving of carbon dioxide emissions for each megawatt.

Just around the corner is carbon capture and storage (CCS), a technology that might appear to come directly from the realms of science fiction but that is already something of a reality. Essentially the process is to capture carbon dioxide from the atmosphere (or, at least, directly from power station and factory chimneys) and sequestrate it by pumping it into deep underground geological formations. The process is already being used on a small scale by Statoil, the Norwegian oil company, with carbon dioxide being pumped into oil–bearing rocks (old oil wells) under the North Sea. The process has a double advantage in that the carbon dioxide under pressure forces residual oil and natural gas that might not otherwise be extracted from the undersea oil wells.

CCS has a cost, but once a global pricing system for carbon and marketable carbon credits are in place, cost should not be a barrier.

Other environmentally–unfriendly by–products from the burning of fossil fuels can be removed. Scrubbers on factory or power station smokestacks can remove fly ash; fluidized bed combustion removes pollutants from coal as it is being burned and coal gasification converts coal into gas that is cleaner to burn than coal itself.

On a smaller scale, mining itself can affect the local environment. But, managed correctly, the longer–term effects can be minimised. Most countries insist that all mining land be reclaimed – that the waste rock removed to gain access to coal either be returned to the place from which it was taken or else stored in a way that neither creates an eyesore nor permanently damages the local environment. The effect on ground water and other water sources also needs to be carefully monitored and controlled.