Coal emissions are those emissions most commonly coming from coal plants that result from the burning of coal for the purpose of generating electricity. These emissions often come in the form of chemical compounds, with the most prevalent being carbon dioxide, sulfur dioxide, and nitrogen oxide. To a lesser extent, coal emissions can also include carbon monoxide, mercury, arsenic, and heavy meals such as lead, cadmium and uranium. All of these have potentially negative impacts on the environment.
The most common of the coal emissions is carbon dioxide. This is an odorless, tasteless gas that is a natural occurrence in the Earth’s atmosphere, and makes up a small percentage of the air. In larger quantities, such as those produced at coal power plants, it is suspected the gas can tip the atmospheric balance, and lead to the trapping of additional heat in the atmosphere through the greenhouse effect.
Sulfur dioxide is another common emission from coal. This gas is not responsible for the greenhouse effect, at least not to a great extent, but can cause more localized problems. It is a major cause of acid rain, which can kill entire forests, and ruin the surfaces of buildings and vehicles. Though steps have been taken to reduce this gas from coal emissions in most countries, the problem is still a major one in some parts of the world, especially China.
The other major emission from the burning of coal is nitrogen oxide. This gas is responsible for the creation of ozone, which is helpful at upper levels of the atmosphere, but can be quite dangerous at lower levels where people live. At lower altitudes, ozone creates smog and can trigger asthma attacks in those prone to them. Thus, it is considered a public health hazard.
While these three gasses make up the bulk of coal emissions, there are others found in smaller quantities. Mercury, arsenic and heavy metals can poison entire water systems, making the water itself unsafe to drink, or fish unsafe for human and animal consumption. Carbon monoxide can also cause respiratory problems, or aggravate heart conditions. As with some of the gasses mentioned above, there are ways to reduce some of these hazards.
Scrubbers and cleaners can remove many of the coal emissions such as sulfur dioxide and nitrogen oxide commonly found in coal. Scrubbers often use limestone to soak up harmful gasses like a sponge, typically turning them into a paste or powder that will not be released into the atmosphere. Other harmful materials may also be removed through a similar process. Despite the advancements in clean coal technology, there is still no cost-effective way to remove carbon dioxide.