Spirax and Dallol Partnership Helps Heat Scottish Homes
Spirax Sarco and Dallol Energy have came together in a partnership to provide boiler controls and steam systems for an innovative energy scheme. The project will use wet biomass boiler systems to hear approximately 200 Scottish homes through a district heating system and to delivery steam to a neighbouring distillery. The plant will be owned and operated by Ignis Wick, a subsidiary of Ignis Biomass.
After a procurement process, Ignis Wick took over the district heating scheme in Wick, Caithness, in 2012 from Highland Council, after they experienced various technical and commercial problems during the project.
With a lot of the old equipment removed from the energy centre building, the company engaged biomass steam specialist Dallol Energy, formally a team at KIV UK. They’ll deliver a 3.5 MW boiler and plant steam distribution system which will be used locally with clean woodchips as fuel.
Victor Buchanan, Director at Dallol Energy said:
“For this project we needed a reputable partner that could help us design, commission and install a whole new boiler house and steam distribution system,
“We knew we could trust Spirax Sarco’s knowledge and proven technology and they were happy to trust our biomass expertise.”
The biomass boiler will generate steam at 20 bar g. The plant steam system will reduce the pressure of the steam to 10 bar g before sending some of the steam to the neighbouring Pulteney Distillery, whilst the rest of it is passed through a steam to water heat exchanger that will generate hot water for the district heating. A steam accumulator vessel will act as the buffer between both biomass boiler and the rest of the steam circuit. This should make it easier for the system to cope with the demand of steam variations and help to maximise the productivity of the system to it’s full potential. It is said that there will be an additional two back-up oil fired boilers which will be on standby for when the biomass boiler is undergoing maintenance.
Spirax Sarco have provided all the steam distribution equipment, including the heat exchanger skids and the boiler house controls on the project, in addition with the boiler hot well and steam accumulator. The boiler house is housed with the latest supervisory control and monitoring system technology, and level controls, as well as an automated heat recovery blowdown system which will help to minimise any energy losses that will occur.
Normally for a wet biomass boiler, the main disadvantage would be to raise steam over it’s gas fired counterpart, which is the longer ramp up period that is required from start-up so that it is able to deliver the process steam. However, the innovative use of the stream accumulator specified by Ignis Wick for this application has completely eliminated any lag time, which will allow the plant to produce steam whenever it is needed.
Victor Buchannan has also added:
“This application can completely change the way that wet biomass steam systems are used in the future,
“Any distillery, food factory or commercial steam user that is run on fossil fuel can benefit from a massive reduction in energy costs, made even more attractive by the government in the shape of the Renewable Heat Incentive (RHI). Supply chain sustainability is also a big plus and there is certainly a marketing advantage to run off local forestry rather than gas or oil from goodness knows where! ”
Typically, the long term cost of running the system on something like wet biomass fuel, is much lower than a dried biomass, because any prior drying of the fuel is not required in the process. Furthermore, a wider market of fuel supply is available, that includes wood fuel that can be sustainably sourced from a local forestry supplier. The prices of such should follow the local wood market instead of international energy markets.
John Chappell, Ignis Wick Director noted:
“It’s taken a bit of sorting out to get the system set up exactly how we want it, but both companies have been responsive and helpful throughout,”
“This is the first renewable energy project in our pipeline of projects that we are developing and it won’t be the last. We’d certainly consider using both Dallol Energy and Spirax Sarco again where it’s appropriate in these future projects,”
Ignis Wick has since signed up for an ongoing service and support contract, as well as buying its spares inventory from Spirax Sarco.
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