Diageo installs bio-energy plant at Scottish site

Cameronbridge, UK – Drinks manufacturing group Diageo has completed a £105-million investment programme at its Cameronbridge distillery – the largest grain distillery in Scotland.

Part of this improvement plan included the installation of a £65-milllion bio-energy plant, using the expertise of Veolia and BCI Process, who were responsible for the manufacture and installation of the mechanical services and support structures.

The whole project incorporates several different processes including anaerobic digestion, biomass conversion, reverse osmosis and ultra-filtration, all of which are contributing to a greatly improved environmental impact.

Veolia designed the plant with BCI being responsible for the stainless steel pipework linking the process plant packages and vessels, as well as providing the design and construction of the support structures and gangways etc.

The objective was to deliver a neat and functional installation which met the requirements for overall access and maintenance. Part of this contract, worth in excess of £2 million, was to provide on-site commissioning and then support following the completion of the project.

Using its new Solidworks facility, BCI was able to produce a detailed 3D layout of the stainless steel pipework, which was up to 1000mm in diameter, as well as the galvanized supports, to ensure that the design provided sufficient support and the most efficient layout.

The distillery produces approximately 90,000 tonnes of waste products per year which will be used to generate 5.5MW of electricity.

The distillery effluent, a mixture of wheat, malted barley, yeast and water, is processed through a belt press to remove the biomass, which will be burned to generate heat and energy for the distillery.

The extracted aqueous liquid will then be treated in an anaerobic digester, which will produce biogas to provide a second fuel for the boilers.

The boilers use the renewable fuel to produce superheated steam at approximately 60bar pressure, which drives the first stage of the steam turbine to produce electricity. The steam, now at a reduced pressure of 16bar, goes on to drive the second stage of the steam turbine but is also tapped off and sent into the main plant, where it is used in the distillation process.

The project is expected to generate approximately 80% of the electricity and 98% of the steam needed to run the distillery as well as clean up the effluent discharge from the production process.

In addition, by re-using the waste products rather than having them transported away from site by lorry, the overall CO2 levels are also reduced.

The company has said the use of the biomass plant to generate energy could reduce CO2 emissions at the distillery by 56,000 tonnes a year.

Scotland’s distilleries have been leading the way recently with considerable investment in renewable energy and using their by-products to produce heat and electricity both for their own use as well as for local communities.

In addition, a pilot scheme is under way which converts the waste products into an advanced biofuel which could be used in petrol or diesel vehicles.

All of these enterprises are supporting the Scottish Government’s target of reducing carbon emissions by 42% by 2020 as well as contributing to the EU mandated biofuel target of 10% by 2020.