Flexibility is Key to Solving Air Pollution Abatement Challenges


Trevor Lawton, Managing Director, AirProtekt Tel: + 44 (0) 1223 872933 Email: sales@airprotekt.co.uk


Modern air pollution regulations increasingly demand the deployment of more flexible abatement systems to address the growing complexity of air pollution regulations, which have to address a multi-tiered array of local authority, national and international requirements. The ever increasing pressure to reduce volatile organic compounds (VOCs) is making it more


difficult for plant operators to determine the most suitable pollution system for their process.


Many air pollution applications call for highly flexible abatement systems to be designed and deployed, especially where there is a requirement for batch based production runs. Low running costs together with the ability to run the abatement system at low process flowrates are vital. A quick start up system is also a major benefit.


a combination of precious metals that enables the oxidation reaction to occur at a low temperature. Additional heat exchangers are also incorporated into the system to reduce energy consumption.


Diagram of a Catalytic Oxidation system


The thermal oxidation process often occurs at a higher temperature compared with the catalytic oxidation method, so to minimise the energy requirements a heat exchanger is incorporated into the system. The most cost effective system is a Regenerative Thermal Oxidiser (RTO) which utilises a ceramic heat recovery system to reduce the additional energy required.


Once the pollution regulator establishes and confirms what emission limits have to be achieved for a specific plant then a plan can be formulated to establish the plant’s exact emissions which need to be known in order to set about designing a suitable abatement system.


The kind of information that is required includes: •Exhaust flow rate and temperature.


•The concentration of pollutants or VOCs and any variations during operating hours. •Number of operating hours of the process.


Once the plant data has been measured and confirmed then it can be assessed to help determine the most appropriate pollution control system solution.


Oxidation system alternatives


The most effective method of destroying VOCs is oxidation. By adding the required amounts of heat and oxygen it is possible to transform hydrocarbon compounds to harmless CO2 and H2O.


The oxidation reaction is exothermic which means that any calorific value in the hydrocarbons located in the exhaust gases is released into the exhaust gases. The result offers a significant benefit in terms of energy and cost savings.


The oxidation reaction completely destroys the hydrocarbons with no secondary pollution formed. There are two oxidation systems which are principally used for removal of VOCs: •Catalytic Oxidation Systems •Thermal Oxidation Systems


Both of these oxidation systems are able to meet the most arduous emission limits from a large number of industrial manufacturing processes.


In catalytic oxidation systems the hydrocarbon compounds react with a catalyst which is coated with Diagram of Regenerative Thermal Oxidiser system


For the majority of abatement applications catalytic oxidation is more cost effective than thermal oxidation at low flow rates. However, the reverse is often the case for high flow rates. Thermal oxidation abatement solutions tend to be more economical at very high VOC concentrations whereas catalytic oxidation is typically more economical at moderate VOC concentrations.


Being an air pollution control specialist that has built up a wealth of market knowledge, technical expertise and practical skills gained from working for more than thirty years in the global air pollution control industry, AirProtekt recognises that no two applications are the same. Each application requires careful assessment before a value for money solution can be implemented. For example, although an alternative solution to a catalytic oxidation could be the use of a thermal oxidation system this may result in high running costs because natural gas would have to be brought into the factory area.


A thermal oxidation approach in certain cases can prove inflexible because if production demand


18


www.pollutionsolutions-online.com • February / March 2011


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36