Food waste is an enormous problem worldwide. It’s estimated that anywhere between one-third to one-half of all food produced is wasted, contributing to food shortages or global greenhouse gas emissions when it ends up in our landfills. Some have proposed various solutions, from changing habits at home, to more interesting ideas like converting food waste into fuel, or into building materials, as multinational engineering and design firm Arup is proposing with its report, titled The Urban Bio-Loop.
The report suggests diverting discarded food by-products and transforming them into materials suitable for interior partitions, finishes, insulation and even envelope systems. The authors say:
Organic waste from our cities and the countryside, traditionally managed through landﬁll, incineration and composting could be diverted – at least in part – to become a resource for the creation of construction engineering and architecture products before being fed back in the biological cycle at the end of their service life.
© Arup Group / The linear consumption model
© Arup Group / The circular economy model
Items such as discarded peanut shells, leftover stalks from crops, corn cobs, waste from sunflower harvesting, potato peels, hemp, flax and rice husks can be processed in order to make them suitable for converting into bio-materials. For instance, organic waste like bagasse, cellulose, seeds, stalks, or peanut shells can be pressed with heat to form stiff but lightweight boards for use in walls. Washed potato peels or fibers from pineapples can be made into insulation. Rice husk ash can be used as a natural filler when mixed with cement.
© Arup Group
© Arup Group
The report notes that in the United Kingdom, 60 percent of raw materials are used for construction, while more than 40 million tons of dried organic waste was produced in European agriculture and forestry industries in 2014. There could be a big potential to transform that dried organic waste into something useful for such a big industry; and it could be quite profitable, as the report also points out that a kilogram of waste incinerated for energy recovery might only bring in €0.85 (USD $0.98), while the same kilogram of material converted into interior cladding might bring in €6 (USD $6.95), meaning there’s both economic and environmental benefits to this approach.
© Arup Group
© Arup Group
The idea is to take advantage of the increasing amount of organic waste that is coming from growing cities, which could be reused and re-incorporated back into the building industry, or shifting from a linear consumption model into a “circular economy” where the supply chain is a closed loop that reuses so-called waste:
Organic waste is not restricted to the countryside but it extends more significantly to the urban environment. Cities aggregate a large amount of resources. This includes both a high concentration of biological nutrients coming from rural areas as food – that rarely return to the agricultural system thus causing damage where they are discharged – as well as resources directly produced at urban level – as the biological waste coming from parks, trees, urban agricultural systems, community gardens, green roofs and facades.
© Margaret Badore
Arup itself has been experimenting with bio-materials for some years now. It recently created the world’s tallest compostable tower out of mushrooms in NYC, while its BIQ Hamburg project was the first in the world to use algae facade panels to generate heat and biomass as renewable energy sources.
So it’s a big deal that Arup is advocating such a “circular” approach to our waste streams: after all, as a company with over 14,000 staff, 90 offices and projects in 160 countries, Arup’s reach and size means that if such bio-materials gained more ground with both the private and public sectors, we could soon be building with food waste, literally. As Arup’s European materials consulting lead Guglielmo Carra explains:
As one of the world’s largest users of resources we need to move away from our ‘take, use, dispose’ mentality. There are already pockets of activity, with some producers making lower carbon building products from organic materials. What we need now is for the industry to come together to scale up this activity so that it enters the mainstream. An important first step is to work with government to rethink construction codes and regulations to consider waste as a resource, opening up the opportunity to repurpose it on an industrial-scale.
Read more over at The Urban Bio-Loop.