Question

Sulphur oxides which are responsible for major air pollution are caused by (a) burning of coal and refining of petroleum (b) burning of fuels in automobiles (c) combustion of fuels containing \(\mathrm{C}\) and \(\mathrm{H}\) (d) using indoor combustion devices like cooking gas.

Short answer

Sulphur oxides, responsible for major air pollution, are primarily caused by: (a) burning of coal and refining of petroleum, and (b) burning of fuels in automobiles.

Step-by-step solution

Understanding the Sources of Sulphur Oxides

Sulphur oxides (SOx), such as sulphur dioxide (SO2), are primarily produced from the combustion of fuels containing sulphur. When fuels that contain sulphur are burned, the sulphur is converted to SOx, which contributes to air pollution.

Analyzing the Given Options

Options (a), (b), (c), and (d) need to be analyzed based on whether sulphur is likely to be present in the fuels used in these processes which would lead to the emission of sulphur oxides when these fuels are burned.

Option (a): Burning of Coal and Refining of Petroleum

Coal often contains sulphur. When coal is burned, this sulphur is released as sulphur oxides. Similarly, the refining of petroleum can also release sulphur oxides.

Option (b): Burning of Fuels in Automobiles

Automobile fuels like petrol and diesel contain sulphur. The combustion of these fuels in the engine of an automobile leads to the emission of sulphur oxides.

Option (c): Combustion of Fuels Containing \(\mathrm{C}\) and \(\mathrm{H}\)

While the presence of carbon (C) and hydrogen (H) is a common feature of many fuels, this option does not necessarily imply the presence of sulphur. However, if these fuels do contain sulphur, their combustion would result in the emission of sulphur oxides.

Option (d): Using Indoor Combustion Devices like Cooking Gas

Cooking gas, such as liquefied petroleum gas (LPG), typically has a very low sulphur content. Therefore, the use of such indoor combustion devices contributes comparatively less to sulphur oxide pollution.

Determining the Correct Option(s)

Based on the information above, the major contributors to sulphur oxide pollution are the burning of fuels that contain sulphur. Therefore, options (a) burning of coal and refining of petroleum and (b) burning of fuels in automobiles are the most significant sources of sulphur oxide emissions.

Key concepts

Sources of Sulphur Oxides

Sulphur oxides (SOx), particularly sulphur dioxide (SO₂), pose notable concerns for air quality and the environment. The primary sources of sulphur oxides are human activities that involve burning materials containing sulphur.

For example, the combustion of coal, a process steeped in history for its role in electricity generation and industrial use, involves the release of sulphur contained within the coal itself. Likewise, when petroleum products are refined, sulphur oxides can be released into the atmosphere. These industrial processes contribute significantly to the global release of SOx.

Beyond industrial sources, everyday activities contribute to SOx emissions. The simple act of driving automobiles, which burn petrol or diesel, results in the production of sulphur oxides, making transportation a notable contributor too. Thus, understanding and controlling these sources are vital steps towards improving air quality.

Combustion of Fossil Fuels

Fossil fuels are the cornerstone of modern energy infrastructure, with coal, oil, and natural gas powering nations.

What are Fossil Fuels?

Fossil fuels are carbon-based materials that formed over millions of years from the remains of living organisms. When combusted, these fuels release energy, but they also emit a variety of pollutants, including sulphur oxides.

The presence of sulphur in these fuels depends on the origin and composition of the source material. The combustion of these sulphur-containing fossil fuels releases sulphur oxides into the air, contributing to pollution and a range of environmental concerns. The process of combustion, essentially, converts the energy stored in fossil fuels into usable power but at a cost to environmental health.

Environmental Impact of Fuel Combustion

The burning of fossil fuels has far-reaching impacts on the environment. It goes beyond immediate air pollution, influencing climate change, acid rain, and human health issues.

Sulphur oxides, for instance, contribute to the formation of fine particulate matter and ground-level ozone, which have a variety of health impacts including respiratory problems and heart diseases. Moreover, when sulphur oxides combine with water vapor in the atmosphere, they form sulphuric acid, a main component of acid rain.

This acid rain can drastically alter ecosystems, damaging forests, crops, and aquatic life in rivers and lakes. The decrease in pH levels can lead to soil degradation, affecting agriculture and wildlife. The broader impact also includes the potential for increased maintenance of infrastructure due to the corrosive nature of acid rain. A comprehensive understanding of these impacts is essential in forming strategies to combat air pollution.

Air Pollution from Burning Coal

Coal burning is one of the most significant sources of air pollution, contributing a substantial percentage of sulphur oxides emitted.

The Nature of Coal

Coal contains various impurities, sulphur being among the most environmentally concerning ones.

When coal is burned, these impurities are released into the air as pollutants. Along with SOx, coal combustion can emit harmful substances such as mercury, arsenic, and a slew of heavy metals.

The traditional reliance on coal for energy production has led to substantial atmospheric SOx levels, particularly in regions with heavy coal consumption. Cleaner technologies, including sulphur scrubbing and alternative energy sources, have been developed to tackle this issue, but the historical and ongoing use of coal remains a challenge to environmental health. Efforts to transition to cleaner energy sources continue to be important in the global drive for reduced air pollution.

Sulphur Emissions from Automobiles

Automobiles are among the most ubiquitous sources of sulphur oxides due to the widespread use of vehicles powered by internal combustion engines.

The Transportation Sector

Cars, trucks, buses, and motorcycles operate by burning petrol and diesel, which often contain sulphur.

Although the levels have been reduced in many places due to regulations, the sheer volume of vehicles means that collectively, they remain a significant source of SOx emissions.

Continuous improvements in fuel standards and vehicular technology, including catalytic converters and cleaner burning engines, aim to minimize the impact of these emissions. Additionally, the advent of electric vehicles and alternative fuels, like hydrogen, might be the turning point towards a more sustainable transportation ecosystem with drastically lowered sulphur emissions.