Turning tree bark and compost into aircraft wings and plastic bags

Researchers have developed ways to make biodegradable food waste bags and food packaging from municipal food and garden waste.

Thomas Dietrich, an engineer in biotechnology at Spain's TECNALIA, a research and technological development center said, You are transforming organic waste to make a waste bag, which is biodegradable. So you are closing the cycle, you don't use other materials to make the (plastic) bag.

Dietrich is the project manager of a project called VOLATILE, which has developed a technology that can be integrated into existing municipal anaerobic digestion and composting plants. It uses microorganisms to break down organic waste into volatile fatty acids, which are the building blocks of the PHB and PHBV plastics used to make plastic bags and food packaging.

The main by-product is a residue that can be used to make compost. Hydrogen gas is another by-product, and it can be used to make electricity.

Normally the big (industries) selling (biodegradable plastics) on the market use food-grade agricultural materials. Using biowaste to produce biodegradable plastics could help solve a major challenge caused by the majority of biodegradable plastics currently being used. Because of the volumes needed, it will not be possible to use agricultural products to replace petroleum-based packaging without competing with food crops or biofuels for agricultural land.

So Dietrich and the team have to try to keep organic carbon in the economy without falling back on agriculture.

Plastic bags and packaging made with VOLATILE's technology would end up in household biowaste and in theory, could be used once more to produce volatile fatty acids although this has not yet been tested by the VOLATILE team. One of the main challenges to this type of system is the lack of composting plants in most regions of the world, including Europe.

Whether plastics are biodegradable or not is due to their chemical composition, not their origins. So petroleum-based plastics can be biodegradable, and plant-based ones can be non-biodegradable.

However, a shift to biopolymers would help reduce greenhouse gas emissions produced to make the plastics even if the end product is not biodegradable.

Vincent Placet, a research engineer at the FEMTO-ST Institute in France said, We need to achieve this (shift) in 10, or a maximum of 15, years because the climate stakes are so high. The quantity of CO2 emitted to produce wood and plants is very low. they also absorb atmospheric CO2 during growth. He coordinates a project called SSUCHY, which is developing load-bearing bio-based composites for use in the automotive and aerospace industries.