During the cold winters, many households make use of different heating systems which include boilers or water heaters, fireplaces or wood stoves. These systems make use of a fuel which is burnt in the combustion chambers producing gases including both visible smoke and various invisible gases. Every system is designed to vent out gases to the outdoors through chimneys or vent pipes, however in some instances, they may escape into a home, where they could raise a number of health issues and this is called combustion spillage. Every year major and long-term incidences of combustion spillage do occur. They have a direct impact on the environment with serious or tragic results. Of critical concern are the combustion gases are produced on a larger scale in industries and manufacturing companies. These are emitted through the stacks or pipes, the gases are called flue gases. These have much more effects to the environment and human health. By causing air pollution chances of global warming increase and workers as well as people who live in close proximity to high emitting companies are at risk of respiratory diseases.
Flue gases have been defined as gases that exit into the atmosphere via a flue, which is a pipe or channel for conveying combustion gases. Efforts to monitor the concentrations of the gases were made hence the introduction of Flue Gas Analysis. The process used to be time consuming and expensive. However, modern advancements in technology have made it cheaper and easier to conduct. Besides monitoring the emitted gas concentrations, large companies also do the analysis so as to know the performance of their plants. Regular flue gas analysis is a great way of ensuring that the plant is achieving optimal efficiency at all times. It is also important for companies to monitor their gases for compliance with set emission regulations. The Environmental Management Agency is the statutory body responsible for ensuring the sustainable management of natural resources and protection of the environmental in Zimbabwe. According to Statutory Instrument 72 of 2009, the chimney of the air polluter is supposed to have a height of fifty metres so as to provide adequate dispersion of the pollutants. Furthermore, the Agency made it mandatory for companies to do emission analysis on every polluting appliance quarterly (after every 3 months) as a measure to monitor the polluting gases concentrations. Companies are mandated to comply with this Statutory Instrument.
Flue gases are a mixture of combustion products which depend largely on what is being burnt and how. These include water vapour, carbon dioxide (CO2), Nitrogen (N2), Carbon Monoxide (CO), Sulphur Dioxides (SO2), Hydrogen Sulphides (H2S) and Oxygen (O2). Of these gases, carbon dioxide and nitrogen are the most harmful to humans and to the environment. As greenhouse gases they contribute to climate change, ocean acidification and global warming.
The flue gas analyser needed will depend on the type of emitter to be studied. Different devices come with a variety of different features. Due to forever advancing technologies, first world countries make use of Continuous Environmental Monitoring Systems where real time values of gas concentrations are captured continuously, recorded and monitored. Unfortunately, this has not yet been brought home due to the high financial costs in purchasing the systems. In Zimbabwe, it is required to measure emissions quarterly as per Environmental Management Agency requirements so it might not seem necessary to advance to continuous monitoring, when in actual fact, Continuous Environmental Monitoring Systems is much more effective when it comes to monitoring gas emissions. There is a greater need to invest in advanced equipment to trace compliance with companies with the vision of reducing Greenhouse Gas Emissions to 40% by 2030.
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