Circular Glasgow: growing into a greener economy

Glasgow - 2012
 
Domain of aplication: Local
Status: Existing 
Stakeholders: 
  • Glasgow Chamber of Commerce
  • Zero Waste Scotland
  • Glasgow City Council
 
The City of Glasgow is on the road to becoming one of the world’s first circular cities. The city has taken its first steps in creating  a stronger more sustainable economy by completing the Circle City Scan. 
 
The pioneering study of Glasgow’s economy, identified leading industries through which the city’s economy can become more ‘circular’ and defined implementation strategies and opportunities for the region’s business community. The goal of the Circle City Scan is to pinpoint areas in which the city of Glasgow can benefit from new collaborations, create market opportunities and increase profits, while reducing the city’s environmental impact. 
The real benefits of the circular economy, recognised by Glasgow, is that it allows economic growth, prosperity and security by reducing the city’s unhealthy and harmful dependency on scarce natural resources. Circular thinking will inspire companies to increase their raw material efficiency by keeping the resources they use in circulation for as long as possible and to recover products when they are no longer being used by the consumer to act as inputs in a new cycle. By mapping the city’s resource flows from consumption to waste, the food and beverage sector was identified as having the greatest circular potential. 
 
 Circular Vision. Food & Beverage
 
Practical examples illustrated in the Circle City Scan include the implementation of heat recovery methods of local bakeries and breweries, resulting in a reduction of resource use. The food and beverage sector uses over 34.000 tons of biomass every year and generates over 2.000 trucks of waste. By valorising the city’s waste streams additional revenue streams are added to Glasgow’s economy and CO2 emissions are reduced. A practical example of this is the use of bread waste, a staggering 200.000 slices of bread are wasted daily in Glasgow, to create green gas, compost or even beer. Applying circular strategies in the city’s food and beverage sectors creates income, jobs and ultimately reduces carbon emissions.
 
There are four pilot projects that will identify the key participants required to build a working circular economy model. Initially, small in scale to make this practical and able to implement in a short period of time. After this, there is potential to scale up the pilot projects enabling a cascade into other sectors.
 
  • Heat recovery. In a bakery, nearly 20% of the toal energy consumption is from the boilers to heat process water and produce steam. This water and steam is used for: area heating, whasing and proofing the bread before it is baked. Heat from bakery ovens can be recovered and redirected to the boilers by using heat exchangers saving 15% to 30% of the energy currently used in the baking process. The payback period for such an investment is typically 18-27 months. The potential energy savings in Glasgow could total up to £300.000 in energy costs per year, an equivalent of 700 tonners of CO2 per year. One of the bottlenecks is the initial investments costs, which can be resolved via an Energy Service Company (ESCO). 

  • Aquaponics is a very promising technology in which the growing of fish is combined with the growing of biomass, leading to substantial savings in water use (90%) in comparison to traditional farming. The pilot project would include a small scale system (15m2) managed by a local restaurant. The restaurant would benefit from the production of locally grown and sustainable fisch (+/- 250 kg), vegetables (+/- 600 kg) and herbs (+/- 150 kg) per year. 

  • Bread to beer is an innovative technology which utilises bread waste in the beer brewing process. Over 200.000 slices of bread are wasted every day in Glasgow, and at the same time hundreds of tons of barley is being used for brewing beer. By using this bread to beer technology, over one third of the resources utilised in the brewing process can be saved while also reducing food waste, by using the wasted bread in the beer brewing process. A pilot would require 500 kg (13.000 slices) of unsold bread to be used in the production of 4.000 litres of beer. When piloted successfully, this technology has potential to use 70 million slice of wasted bread, produce 20 million litres of beer and save over 200 tones of biomass annually in Glasgow. 

  • High value cascading. Residual streams from beer brewing (spent grain) can be used to replace up to 50% of the flour needed to produce bread in the baking industry. Over 4.000 tonnes of residual spent grain is produced every year in Glasgow and can be used to make over 12.000.000 loaves of bread, reducing the amount of food waste throughout the city, thus lowering the city's waste treatment costs and resource needs. Additionally, the spent grain can be used in a plethora of other ways including the production of flapjacks, beer snacks, or to grow mushrooms on. After the mushrooms are grown, the mushroom grounds can be deposited into a composter, aiding in the realisation of a circular process. 

 

Links to relevant references: 

Circular Glasgow: A Vision and Action Plan for the City of Glasgow

Zero Waste Scotland