The Mineral Product Association (MPA) Waste Code of Practice has now been implemented at Tunstead Cement Plant. In the past, when a new alternative or waste derived fuel was ready to be used in the plant, a full permit variation had to be submitted to the Environment Agency; this process was time consuming and costly. Going forward a variation will not be required for any of the fuels listed within the Waste Code of Practice. There are over 100 different pre-approved wastes listed in the code, and although not all of them will be appropriate for every kiln, it greatly increases our choices and ability to be innovative while decreasing the dependency on traditional fossil fuels.
Previously, a permit variation would have cost £30,000 and take approximately 6 months to be processed by the Environment Agency. Now that the MPA Waste Code of Practice has been implemented there is no additional cost required to vary the permit and wastes can be trialled on site following the completion of a risk assessment and notification to the EA.
Tarmac aims to increase its waste derived and alternative fuel usage to 70% by 2020, as outlined in the Sustainability Strategy. This will reduce carbon emissions, divert wastes away from landfill and ensure sustainability into the future by becoming less reliant on conventional fossil fuels.
In order to achieve these targets, the Tunstead Cement Plant has already trialled new waste materials in the pyro and grinding processes. For example, using slip casting moulds from the pottery industry as a substitute for gypsum in the Cement Mill, although this material has all of the chemical properties required for the end product, the size and shapes of the moulds were not suitable for the system at Tunstead. In some cases, the material has been used in other Cement Plants in the Tarmac network and has a very good track record; MBA Polymer is an example of this. MBA Polymer is a plastic granulate generated from the recycling of cars and consumer appliances, it has been used in Tarmac’s Aberthaw Cement Plant in South Wales successfully due to the process benefits it offers; it has a very high calorific value and therefore allows a high substitution rate in the kiln.
Tunstead Cement Plant has a target of 60% fossil fuel substitution rate for at least one month during 2016. Possible future fuels and alternative raw materials to help us achieve this include; tyre fluff from tyre recycling, waste clays from mineral extraction and catalysts from the petrochemical industry.