As nations around the globe search for new ways of handling waste following China’s decision to stop processing the world’s rubbish, a South Australian man is searching for investors to help build a commercial system that converts waste plastic into biogas.
The extension of China’s ‘Operation Green Fence’ policy came into effect in January, banning the importation of 24 categories of contaminated solid waste including paper, plastics, textiles and some metals.
This caused prices for recyclable materials to crash, and left waste management companies in the United States, Europe, Japan and Australia with vast amounts of unsaleable waste.
Before the ban, China imported almost 30 million tonnes of waste paper and 7 million tonnes of “recyclable” plastic a year – including about 30 per cent of Australia’s waste paper and plastic. This is on top of the estimated 1 million tonnes of contaminated plastic that is deemed unfit for recycling and sent to landfill in Australia each year.
Scientist David Thompson is aiming to tackle this building problem head-on, and will file an application for patent protection for his Polymer Organic Energy Treatment (POET) System, which uses anaerobic digestion bacterial technology to turn a range of plastics, including polyethylene, polypropylene, polystyrene and expanded polystyrene, into methane.
The process also produces inert, organic by-products that can be used as garden fertiliser and mulch.
Thompson is looking for an investor to help it build a demonstration plant capable of processing, initially, 5000 tonnes of plastic a year.
He said there had been significant global interest in his invention but potential buyers generally wanted to see a working demonstration plant rather than just certified test results before committing.
“Everyone wants to be the first to be the second in line” Thompson said.
“The frustration has been in finding the person or company prepared to ‘take a punt’ and allow us to move forward.”
The startup company is based in the South Australian capital Adelaide and is looking for an investment of about AU$2.5 million to help it build the 100-tonne a week plant. However, Thompson said this capital investment could be significantly reduced if the investor already had access to appropriate land and certain infrastructure.
Thompson said the plant could be running six months after funding was secured, and that the system was ideally suited to operate alongside other anaerobic digestion systems such as a wastewater treatment plant.
“The nice thing about the POET system is that it’s a really ‘soft’ system because, although there are some mechanical processes at the beginning to make plastics attractive to the bacteria that digest it, it’s the bacteria that do all the work.”
Thompson said he has had the technology academically reviewed to prove that the science stacks up and the system is scalable.
He said the modelling on a 5000-tonne-a-year system in Australia based on waste disposal gate fees and electricity feed-in tariffs, showed a payback period of less than three years.
“We know what we need to do, we’re confident, we’ve done all the independent testing and all that can be put on the table with investors – real data, real results.”