Mayo Renewable Power in Killala was designed to be Ireland’s largest independent 42.5MW biomass-powered combined heat and power (CHP) plant. The project when constructed would have had capacity to provide enough electricity to power the equivalent of 68,000 homes. The project site covered an area of approximately 21.7ha and straddles the former Asahi Business Park.

The main components of the plant included a boiler house, a main stack, a turbine hall, a water treatment plant integrating reverse osmosis system, fire-fighting pump house storage tanks, an auxiliary transformer, a step-up transformer, a generator, a 2,500 kilo-volt-ampere (kVA) back-up generator, fuel storage domes, belt dryers and a fuel processing plant adjacent to the power plant. A dryer system was also envisaged to pre-dry the feedstock before it was combusted. The boiler system, integrating stoker grate technology when constructed would constantly produce 204,953kg/h of 116.18 bar steam at a temperature of 510ºC. The power plant’s boiler system was also to be equipped with a selective catalytic reduction (SCR) system to control nitrogen oxide emissions, and a multi-cyclone dust collector and electrostatic precipitator (ESP) to control dust emissions.

PUNCH Consulting Engineers role was to design and specify the boiler frame to house the boiler and all the ancillary equipment. An in-depth knowledge of the workings of the boiler frame was required to ensure that the steelwork required to support the plant equipment and boiler were appropriately designed and set-out.

To achieve a coordinated steel frame PUNCH carried out the design of the 38m high by 28m square frame with ten floor levels and two external access stairs in Revit. This allowed the plant and pipework which were modelled by Amec Foser Wheeler to be incorporated into the steelwork frame. This highlighted any coordination issues and allowed them to be resolved prior to going into fabrication. The design of the boiler frame and fabrication drawings were completed prior to the project being put on hold.