7 minute read
Two Sides To Every Story
Aiden Neary, Clean Coal Technologies,
Inc., USA, weighs the pros and cons of the coal industry and how it can address the issue of dust.
Figure 1. Risk of combustion prohibits coal being covered during transportation. The recurrent mantra that ‘coal is dead’ is now met with a louder than ever response of ‘long live coal’.
Coal provided approximately 40% of the global energy requirement in 2021 with a record 8 billion t of coal consumed, an increase of 6% over 2020. Global sea-borne trade in 2021 reached 1.2 billion t, an increase of 100 million t from 2020. Coal is found in 70 different countries around
the world, and is actively mined in 50 of them; with the top three countries (Indonesia, Australia, and Russia) accounting for 70% of the global coal export market. China and India combined account for over 67% of the global coal use, and their annual consumption continues to rise each year. As these countries lift their citizens out of energy poverty using coal, as it is a more reliable and affordable energy source, the standard of living and life expectancy continues to increase. Few can dispute the need for coal; coal is constantly being mined and transported via truck, rail, and sea and will be for the foreseeable future.
There are two main disadvantages for the use of coal: Carbon dioxide emissions and the belief that it contributes to climate change. Coal dust loss during transportation causing environmental and air pollution.
The focus of this article is on the tangible and observable impact that coal dust has on air, land, and water pollution.
Coal mining
Coal is a brittle sedimentary rock that, when mined, handled and transported, creates a fugitive dust that has a negative impact on the health of the environment and humans. Despite somewhat creative, but nevertheless limited, advancements in suppressing and mitigating coal dust, it remains one of the most common issues for groups advocating for the cessation of coal.
The coal industry has not done enough to alleviate the legitimate concern about coal dust, and only though technological advancements will this issue be fully addressed. Coal dust comprises of a number of toxic substances, including: lead, tin, mercury, cadmium, nickel, and arsenic. It also includes radio isotopes of thorium and strontium. All in all, coal dust is a complex composition of elements that require meaningful consideration and effective solutions when it comes to managing its loss through transportation.
Managing coal dust
Coal is the second largest dry bulk commodity shipped globally by volume. In any year, in excess of 1.1 billion t of coal is moved via sea freight. In all but a few exceptional scenarios, coal is mined at the coal mine and then transported to the power station by trucks, rail, and/or sea barges.
Several studies have been performed on coal dust loss during transportation; although results may differ between findings, largely due to different seams of coal being prone to having higher levels of dust, the overall results prove that too much coal dust is lost during the transportation process. Rail companies have taken the lead in a number of these studies, with legal actions having been brought against companies, including BNSF. Their own studies show a loss of between 500 lbs – 1 t of coal dust can escape from a single loaded rail car, whereas other studies show as high as 3% of the coal loaded is lost during transportation.
Possible solutions
The obvious solution is to simply cover the rail cars with the necessary protective covering, thereby preventing any dust loss. However, this is unfortunately not a viable option due to the chemical composition of coal. Coal dust is highly combustible and covering it increases the risk of the coal combusting, so alternative solutions have been employed. The primary solution currently used is applying a chemical spray (surfactant) over the top of the coal load to stabilise the dust. This process does not eliminate coal dust loss, although it has been proven to be effective in reducing the loss by as much as 80%.
Coal dust suppressants
Challenges with coal dust suppressant applications include: The first and most important challenge regarding the application of coal dust suppressant is enforcement. Some countries, such as the US, are very thorough with ensuring this is done prior to rail transportation, but many other countries are less than rigid with its compliance. Secondly, the cost of this process can be high.
It varies from mine to mine, but costs as high as
US$1/t are incurred. Not only does this have a negative impact on profitability, it can, in some cases, be cost prohibitive when moving coal. Finally, the use of any chemical spray can have a negative environmental impact both in production and also disposal of coal.
When coal dust is lost during transportation, it can negatively impact a multitude of areas: Environmental: Coal dust lost during transportation can enter the waterways which can have a poisonous effect on not only agricultural animals, but also in some cases on humans who rely on these streams for their water. Human: Respirable coal dust has been proven to cause a number of serious illness amongst those exposed to it for prolonged periods of time. Chronic obstructive pulmonary disease along with back lung disease (pneumoconiosis) has been linked to as many as 77 000 coal miner’s deaths since the 1970s. It is also widely reported in studies that families living close to rail tacks transporting coal have a
higher than average case of asthma and other respiratory issues. Financial: The cost of coal dust suppressant application can be as high as 10% of the total production cost (US$1.00) in some of the lower cost mining operations in the US (primarily in Powder River Basin region). There are also additional costs, including: environmental cleanup as the coal dust enters waterways, unclogging coal dust from rail cars, and workers compensation costs.
While progress has most certainly been made in addressing this challenge, the coal industry, rail providers, and power facilities can still do more. It would be-hoof the coal industry overall to show that it recognises, acknowledges, and is committed to finding a solution. A global coal transportation standard should be implemented using defined acceptable practices. Investments in technology that can better and more economically address the problem should be made. Governments should encourage, support, sponsor, and, in some cases, mandate initiatives to address this problem.
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Aiming for dust free
Technologies, such as Pristine technologies, owned by Clean Coal Technologies, Inc., produce a dust free end product as part of its coal beneficiation process. This process increases the Btu (heating value) of the coal by as much as 33%, and ‘coats’ the coal with heavy hydrocarbons from a slip stream of the same DNA coal that produces a clean dust free, stable coal ready for transportation.
Conclusion
The most effective solution-driven approach one can take is to firstly acknowledge and recognise both sides of any issue. For the foreseeable future, coal will play a critical role in global energy production with record consumption expected again in 2022, subsequently causing record levels of coal transportation.
It also needs to be understood that coal use in developing economies (e.g. India and China) have brought hundreds of millions of people out of poverty and has increased not only life expectancy levels, but also significantly improved the quality of life.
That said, there are also challenges with using coal. The global coal industry needs to join forces and not only address these issues but, once addressed, effectively inform the public of their success.
The easy and lazy approach is to simply demonise and criticise coal – the constructive approach is to find workable and economical solutions.
