Save energy, ecology and humanity

Dr Debapriya Mukherjee *

The quality of ambient air in urban cities of India has assumed alarming proportions. Any substance that is not part of the air’s gaseous make-up is regarded as a pollutant. Particulate Matter consists of materials that are directly emitted to the ambient air or results from the transformation of gaseous pollutants in atmosphere. Particles smaller than 2.5 micrometer in aerodynamic diameter on entering the deepest portions of the lungs cause the severity of chronic lung diseases, inflammation, irritation of lungs, increase susceptibility to viral and bacterial pathogens, changes of blood chemistry, causing carcinoma and heart attacks.

They come from natural sources or by human activities that are anthropogenic in character. Air pollution is not confined to a particular territory but is a trans-boundary phenomenon. In major urban cities and rural areas of India, the quality of air has been deteriorating rapidly over the past two decades. The -increasing population with their demand of energy is posing a serious problem.

Thick fogs, especially in colder weather, blanket the major cities in India. Emission from vehicles and biomass burning has been identified as the major environmental burden but fossil fuels are still the most dominant among the fuels and have provided about 85% of world energy in 2015. Their share in energy production in next 20 years is not expected to reduce very much.

Energy required for thermal power plant (TPP), cement industry, sponge iron, foundry and many other industries are obtained from burning of coal and these industries are emitting pollutants to the ambient air. Among all these industries TPP demands fresh water and coal and causes both air and water pollution.

Generally thermal power plant is established using coal as fuel with an assurance to protect vegetation and human health. To ensure prevention of adverse impact of this power plant on environment, world renowned consultants have been engaged. Dedications of the bureaucrats, technical experts, consultants (even internationally reputed experts) and political ruler and regulatory authorities have been highlighted focusing their concern to protect the environment and human health. In response to these arguments, counter arguments related to different environmental issues have been raised with reference to pollution problems of coal fired power plant.

The domination of coal consumption in TPP has already led to serious environmental damages in many places all over the world. The pressures on the environment caused by electricity generation are manifold, with local or global outreach, and quantifying the associated emissions (to air/water) and water consumption, along with their ensuing impacts. Increasing water demand for power production amid water shortages has raised concerns for the water-energy nexus in many parts of the world.

The main environmental issues are related to air pollution, the loss of biodiversity and the pollution of water resources. From the coal-ûred power plants, 30-40% of the PM pollution is secondary in nature, with the most coming from chemical conversion of gaseous SO2 (sulfur dioxide) to aerosol sulfate. Further occasional failure of dedicated flue gas desulfurization (FGD) system causes huge emission of the SO2 from coal combustion that ends up in respirable PM fraction, resulting in more health impacts.

The long-range transport of pollution from the stacks, as high as 275 m, and travelling the distances of more than 300 km in less than 24 hr causes the health and environment damages. Disposal of coal ash is another problem. The present situation is a long way from full utilization of ash.

There are large amounts of ûy ash either stored temporarily in stockpiles, disposed of in ash landûll or lagoon. The phase transformations that mineral matter in coal undergoes during high temperature combustion may render the trace elements particularly arsenic, lead and mercury in the original coal matrix susceptible to leaching from the storage/disposal/ application site when ash comes in contact with water. Also dumping of huge quantity of ash into the ash yard per day using open tippers and during the monsoon creates significant community pollution.

Though attempt has been made to cover the ash yard with ash slurry to reduce airborne pollution, but ultimately only a part of the yard is covered, and other areas remain open to erosion as observed during inspection of TPPs. Even winds at 1 m/s are capable of lifting them and blowing them away. Thereby the people residing in close proximity to the main plant and yards are regularly exposed to the dust throughout the year due to extensive, round-the-clock dumping and due to erosion.

Significant portion of dust emitted from the stack is smaller sized particles. The presence of high silica and alumina content in particular coal ash is another problem, as it increases ash resistivity and reduces the collection efficiency at the electrostatic precipitators (ESPs). In addition to these problems, thermal pollution causes severe damage to aquatic ecosystem.

In this context it is pertinent to mention that serious environmental issues such as energy consumption, air pollution, climate change, acidiûcation, and waste generation due to operation of Coal- fired thermal plant are raised not only by the local people and NGOs but also by the researchers all over the world. Adverse impact of coal-fired thermal plant on environment and human health are cited in many peer reviewed journals addressing lapses in Environmental impact studies (EIA) and environmental management system (EMS).

But bureaucrats, scientific and technical officers in environment sector cannot accept the adverse repercussions on the environment due to pollution from coal-fired thermal power plant and declare all these environmental issues as fabricated stories framed by the media and various eco-groups despite objective evidences (photographs, analytical results, suffering of people and many more).

They always claim all precautions and preventive measures have been taken to minimize environmental pollution. The output of regular environmental compliance study (monitoring of stack emission and monitoring of wastewater discharge) by regulatory authority does not reflect the actual environmental damages already taken place.

Regulatory authorities force the industry to adopt end-of-pipe treatment to mitigate environmental pollution but non-compliance is a common feature due to failure of the pollution control system very often. The regulatory agencies inspect the industries once or twice in a year but are unable to ensure consistent control of pollution.

It is not always feasible with limited trained/experienced personnel to continuously monitor the environmental performance over the time and thereby the ecological crisis and social problems remain unattended in the area closed to these industries. However, these industries are the backbone of the economic growth of the societies and provide a substantial part of the jobs and energy.

Reducing this pollution problem needs environmental improvement at the micro level, a goal which has been stubbornly elusive in many parts of the world. Environment Sustainability (ES) that is defined “development that meets the needs of the present without compromising the ability of future generations to meet their own needs” cannot be maintained and thereby the Sustainable Development (SD) is bound to be jeopardized.

To achieve ES, it is necessary to create changes in their production system through adoption of Cleaner Production (CP) principles and practices that could support economic and environmental beneûts. Only the cost effective CP can improve material utilization and reduce energy consumption and waste emission. The proper knowledge/understanding of these benefits among the owners’ of these industries and the employees in environmental sector could help them to invest in infrastructure, including clean technologies and environmental capacity, fostering CP implementation.

In this view, regulatory authority and owners of the industries must focus on providing preliminary insight into the barriers to ES and pointing out opportunities to overcome these barriers to implementing CP considering their size, technology adopted, type and quantity of raw materials used, intellectual capacity of the employees, overall management, capital cost and end-of–pipe treatment.

Due to the indispensable role of coal power, clean and efficient coal power development will be the priority of national energy policy by implementing comprehensive energy efficiency retroûtting in existing units employing measures including ûue gas residual heat recovery, turbine ûow passage retroûtting, boiler and fan retroûtting, pipe network optimization as well as assessment on water consumption and impacts on regional water scarcity, coal quality with reference to ash content and utilization of ash to prevent windblown dust and leaching of metal to surface /ground water.

The web of actions taken to improve the efficiency of existing older power plants can captivate mind of the local people and NGOs that coal fired thermal plant will not be the environmental burden in developing countries like India.