Inverurie Energy Recovery Facility

Central to the Inverurie Energy Park, is the development of a state of the art, Energy Recovery Facility (ERF). The ERF would receive up to 200,000 tonnes of municipal and industrial residual waste, that is waste that cannot be recycled and would otherwise be sent to landfill.

Existing Scottish Government legislation will ban the landfilling of biodegradable (food, paper and garden) waste from 2025. It has been estimated that 1.2 million tonnes of residual waste will have to be landfilled, managed or exported outside of Scotland if new projects do not come onstream by this time. In order to make up this shortfall, it will be necessary to develop more residual waste facilities within Scotland, including the one proposed at the Inverurie Energy Park.

As well as meeting these targets and diverting waste from landfill, the ERF will be able to export circa 30MW of electricity (enough to power approximately 62,000 homes). The facility would also have the potential to supply heat to at least 32,000 local homes as well as businesses through a district heat network and distribution of heat batteries. It will also provide the catalyst to implement Agile Energy’s wider vision for the Inverurie Energy Park.

Inverurie Energy Park

Situated on the site of the former Inverurie Paper Mill, the Inverurie Energy Park is Agile Energy’s vision to create a sustainable, low carbon energy hub right in the heart of the North East of Scotland. By utilising proven, state-of-the-art energy from waste technology, the Inverurie Energy Park has the potential to create new business and employment opportunities. These include: district heating, hydrogen production and distribution, advanced horticulture and aquaculture, along with carbon capture and utilisation.

Process Flow Diagram

  1. Mixed residual waste is delivered to the site and taken into the material recovery and waste processing hall. Equipment in this part of the plant shreds the delivered materials and maximises the recovery of recyclable materials and removal of any inert elements such as bricks/stones and metals. Heavy plastics are also separated as much as possible and sent for recycling. The biodegradable waste (fuel)that remains is then processed and sent to the storage silos. The waste processing hall is operated in a negative air pressure environment in order to prevent escape of any  odour. The air extracted to in this way is sent to the furnace as a part of the combustion process.
  2. The fuel is transported by conveyor to the fuel storage silos. These have a special design that mixes and homogenises the fuel that is delivered to them over several days, thus achieving a fuel uniformity at any one time that is essential for optimum furnace operation.
  3. Fuel is delivered to the furnace and combusted under controlled conditions using proven Energy from Waste Recovery technology to generate heat and raise steam in the boiler. The process applies ‘best available technology’ (BAT) to ensure residence times and temperature are at the required levels to prevent the formation of dioxins/furans. The combustion process design also minimises the formation of nitrous oxides (NOx) and carbon monoxide (CO).
  4. Bottom ash from the furnace will be treated and an aggregate produced utilising some of the CO2 from the flue gas. Air pollution Control Residues (APCR) are treated in the same way.
  5. The heat generated, makes steam to drive a steam turbine powering a generator to produce electricity.   The remaining heat is collected by the surface condenser through a process of heat exchange with the cooling water.
  6. The combustion process produces flue gasses, mainly nitrogen and carbon dioxide that are carefully cleaned prior to release. This process is continually monitored to ensure adherence to the Pollution Prevention Control Regulations and the plant Permit conditions set by the Scottish Environment Protection Agency (SEPA).
  7. Treated flue gas is delivered to a heat recovery and scrubbing facility which includes water treatment processing equipment to recover remaining heat energy, water and any small particulates.
  8. Clean, low temperature flue gas is vented through the stack and released to the atmosphere. This process is continually monitored to ensure compliance with SEPA requirements and the plant license conditions.
  9. Electricity from the generator is taken to the main power transformer for onward export to customers.
  10. Heat energy is captured at a number of locations along the process and used to enhance the efficiency of the combustion process and to provide district heating.
  11. When district heating demand is low, additional cooling for the steam turbine is provided by the cooler units. The design of the coolers the project will use prevent the formation of a visible plume.
  12. Treated process water and recovered rainwater are retained and stored to allow water re-use; minimising the plants impact on local resources.