OREX technology and mixed collections

OREX technology and mixed collections

The Environment Act, which received royal assent in November 2021, contains proposals to roll out separate weekly household food waste collections across England by 2023, writes Simon Christian of Anaergia UK.

Plans include introducing legal guidance on new minimum service standards for refuse and recycling collections, and a minimum service standard for residual waste at least once a fortnight, alongside weekly waste collection organic.[1].

While this news has been welcomed by the anaerobic digestion (AD) industry, local authorities who currently provide mixed food and yard waste collection hope that this will not force a potentially costly dismantling of their infrastructure and current vehicle fleets.

Not least because a new technology from Anaergia, OREX, offers a solution that offers the best of both worlds. By extracting the food waste fraction from mixed waste streams, OREX has the potential to increase food waste recycling rates while allowing existing mixed collections to remain in place. The clean food waste fraction can then be sent for processing in a AD plant, helping to achieve the country’s ambitions for GHG reduction and renewable energy generation.

Stalling recycling rates

It is clear that the current fragmented system of household waste collection in England needs to be redesigned, not only to provide consistency for residents, but also to stem the decline in recycling rates. England has missed the government’s target of recycling 50% of household waste by 2020; indeed, in 2020, the recycling rate for “household waste” was 44.0%, compared to 45.5% in 2019. And while food waste collected separately increased by 11.0% in 2020, it did not represent only a small proportion of total “household waste”. ‘, only 2.2%[2].

This is largely because, according to 2018/19 figures from WRAP, almost half of England’s 326 local authorities (LAs) – 160 councils – provide no food waste collection at all. A total of 115 municipalities offer a separate food waste collection service, sending this valuable organic resource to AD factories where it is used to produce biogas and biofertiliser. A further 38 offer mixed food/garden waste collections, with both fractions going to in-vessel composting (IVC), while 13 councils offer a mix of both systems.[3].

Separate food waste from mixed streams

Anaergia’s OREX technology is a solution that allows municipalities to fulfill their obligations for the separate collection of food waste without replacing the existing infrastructure of vehicles and combined collection. Robust and efficient extrusion press, it reliably separates solid waste into wet and dry organic fractions. For mixed waste streams, it processes the dry fraction to recover up to 90% of putrescible, wet organics (i.e. food waste), maximizing the amount that can then be fed into a processing plant. AD.

OREX’s ability to separate food waste from the mixed waste stream in a way that makes it suitable for processing via wet AD is crucial as the Food and Beverage Waste Hierarchy has identified AD as the optimal technology to recycling of all inedible food waste. The hierarchy is used to inform council decisions on which technologies they should use to deal with collected food waste. By employing OREX, councils offering mixed collections can be confident that they are adhering to BAT (best available technology) guidelines.

Save cost and carbon

Author: Simon Christian, Business Development Manager for Anaergia UK

OREX can also help LAs overcome the additional environmental, financial and technological challenges posed by the potential removal of co-mingled collections as follows:

· By allowing mixed collections to remain in place, only one set of vehicles would be required to travel to a household, reducing emissions and capital/operating costs compared to the two sets of vehicles required for separate collections food and garden waste.

· Existing mixed vehicle and collection infrastructure would not need to be replaced, further reducing costs.

· Once the wet organic fraction has been removed from the mixed waste stream, the organic loading rate on the IVC is reduced, improving composting performance.

A sensible solution

As local authorities and the waste industry wait for government guidance on the environmental bill, it is hoped that common sense will prevail. Instead of eliminating existing mixed collections, allowing them to remain in place with the support of efficient technological solutions such as OREX can offer the best of both worlds: improving food waste recycling rates without the need to dismantle efficient collection systems.

[2] england-2020