Thermal Oxidiser to destroy VOC's from Solvent and Fuel Oil recovery plant

In late December 2006 we began the commissioning phase for the regenerative thermal oxidiser at Avonmouth. The plant is capable of destroying up to 4000 m3 an hour of air contaminated with solvents, paints, petrols and other waste VOC's (volatile organic compounds) from our recovery and fuel blending plants.

The expected effect of the plant will be to reduce our VOC emissions by over 90% from over 30 tonnes per annum to less than 3 tonnes.

What is a Thermal Oxidiser?

A thermal oxidiser is an item of plant that removes pollutants from a waste gas stream by burning the pollutants in a controlled manner.. Typical pollutants that can be treated by thermal oxidisers are hydrocarbons, other solvents and waste gases. These are often collectively termed VOC's

How are pollutants destroyed?

The treatment carried out by the thermal oxidiser is simply a controlled form of burning (combustion). The polluted gaseous waste stream requiring treatment is fed into the process space (combustion chamber) of the plant. Here there is a powerful naked flame running on the supplementary fuel, in our case natural gas with an option to run on Biogas at a later date, which incinerates the pollutants in the gas stream. Burning or incineration involves the chemical process of oxidation.

The incineration of pollutants in a thermal oxidiser usually requires high temperatures in the presence of excess oxygen (air) to achieve complete oxidation. When hydrocarbon VOC pollutants are completely oxidised the only products formed are carbon dioxide and water. Other VOC's will be oxidised to other less polluting compounds (predominantly CO2 and water)

A thermal oxidiser is designed to burn, as completely as possible, all the combustible components within the gaseous waste stream being treated. For this to be effective the pollutants in the waste stream need to be mixed with oxygen/air at a sufficiently high temperature and for a sufficient length of time.

How will we demonstrate compliance?

Our Oxidiser has been supplied by EIS Ltd and is process controlled to hold temperature Above 760 °C and further has temperature and LEL alarms to manage safe shutdown in the event of a problem.

As part of our open policy on our Environmental impact we are to publish all the data on the Oxidiser on our website to demonstrate compliance in meeting the standards under our IPPC Authorisation. This will include a facility to view live data and will be available early February 2007.

View our Oxidiser Data