Bioenergy pilot aims to slash emissions
A bioenergy plant soon to be built in Nelson Tasman is hoped to eventually unlock the ability to reduce national emissions.
The project will be the end of multiple years of work by Alimentary Systems to get to this point. “Nelson takes our patent from lab to pilot,” said co-founder Matthew Jackson. “The purpose of the project is to show that we can do zero waste, zero liquid discharge, zero emissions, and reduce ratepayers’ costs.”
The Bioenergy Resource Recovery Plant (BRRP, pronounced “burp”) is hoped to be commissioned on Bell Island, adjacent to the wastewater treatment plant, by mid2026. The BRRP is a circular system that combines the carbon in organic waste and the nitrogen in wastewater sludge to create methane gas and a synthetic fertiliser replacement. The methane is then used to power the plant, with the fertiliser and any remaining gas able to be sold for a profit.
“We’re trying to figure out a way where the system can extract so much value that we can change the behaviour,” Jackson said.
Alimentary Systems’ patented technology was brought to New Zealand by co-founder Harmaan Madon under the Edmund Hillary Fellowship. He worked with Dr Nitant Mate to patent similar technology, which has since been established in India on a much larger scale.
Jackson added that the Bell Island project, which will only take 10 tonnes of waste per day, is hoped to validate the methodology in a New Zealand context to unlock benefits for the entire country. The technology could delay the need to build costly new landfills by diverting organic waste and sludge into the BRRP facilities.
A new landfill for Nelson Tasman is currently budgeted to cost $42 million, though the existing landfill sites in the region have another 80 years of capacity at the current rate of waste collection. Organic waste also decomposes in landfills, releasing methane into the air, and significantly contributes to regional emissions.
About 59% of the Tasman District Council’s emissions come from landfill, though landfill emissions from Nelson Tasman’s York Valley Landfill are captured or flared.
Diverting organic waste into BRRP facilities would remove new methane sources from landfills.
Jackson said that nationally, councils send 9000 tonnes of organic waste to land-fills each day, and industry generates 363,000 tonnes of organic waste that must be managed in line with strict environmental standards.
If BRRP facilities were set up around the country for this waste, he estimated New Zealand’s total emissions would decrease by 5%. The fertiliser by-product could then be sold to horticulturalists to decrease the country’s reliance on imported fertilisers.
The project could also bring financial benefits, Jackson said.
New Zealand is currently on track to overshoot its 2030 climate emissions targets with billions likely needing to be spent on offshore carbon credits to compensate.
Jackson suggested the emission reductions achieved through widespread adoption of the technology would help reduce that shortfall and save the country funds that would otherwise be spent on additional credits. Locals might also save a few extra dollars too. The average Tasman resident with a rubbish bag service uses one and a half rubbish bags a week.
Jackson pointed to an independent council report that said if residents diverted their kitchen waste away from general rubbish and reduced their rubbish bag use to just one a week, they could save about $125 a year in bag costs.
That collected kitchen waste could then enter the BRRP facility and save it from decomposing in landfill, he suggested.
The BRRP project on Bell Island has secured a three-year licence from the Nelson Regional Sewerage Business Unit (NRSBU) to take sludge from the island’s wastewater treatment plant.
General manager Nathan Clarke confirmed that the NRSBU had agreed to a non-exclusive licence to occupy a small part of Bell Island adjacent to the wastewater treatment plant. The plant will provide the BRRP with small volume of untreated sludge so Alimentary Systems can carry out its trial over the next three years.
“We were open to giving them access to the land as their goals around reusing resources like wastewater sludge are the same as ours,” Clarke said.
“It can be hard to find land that is suitably zoned and located so we were happy to help them out as the results of the trial will be useful for the industry as a whole.”
All the sludge from the Bell Island plant is converted into biosolids, “an excellent fertiliser”, which are beneficially re-used.
Alimentary Systems has applied for a grant from the Ministry for the Environment’s Waste Minimisation Fund for up to $3.7 million. The result of their application is expected by July. If granted, the funding will go towards the $8 million cost of setting up the BRRP with the remaining cost being covered by private investors.
“Our ultimate aim … is to have zero emissions to the environment,” Jackson said.