Shaun Ossinger and Patricia Gill, Denmark Bulletin

A Wilson Inlet Catchment Committee project, Green waste towards net zero, will target the conversion of Denmark’s green waste into biochar.

The project has received the Department of Primary Industry and Regional Development’s Future Carbon funding of $52,000, plus $20,000 from other sources.

This will also help explore the on-farm use of biochar to sequester carbon and to improve farm productivity.

Biochar reduces the need for fertiliser by promoting the soil’s biological activity and enables it to hold more moisture.

Instead of burning the green waste at Denmark’s Waste Transfer Station or transporting it to Albany’s Hanrahan Road tip, WICC is seeking solutions that benefit farmers and the community.

They include a local supply of quality biochar, reduced costs to the Shire for green waste processing and transportation, plus reduced carbon emissions.

The on-farm use of biochar for economic and ecological purposes is being researched globally and has been used with success combined in the soil in horticulture.

WICC and partners will work on about 800 tonnes a year of green waste.

As a not-for-profit organisation, WICC hopes that after the feasibility stage the production of biochar will pay for itself, plus turn a profit to be invested in landcare.

This could involve selling the product to horticultural and agricultural enterprises at a reasonable cost.

The feasibility stage is expected to get underway this month.

“We need to make sure it makes financial sense before going operational,” WICC executive officer Shaun Ossinger said.

Biochar – charcoal – has been used for thousands of years in agriculture to improve water retention, nutrient efficiency, soil biology and more.

Rich in carbon, biochar can be stored in the soil for thousands of years but a steady supply of quality biochar is not available in the South West.

Dr Xiangpeng Gao from Murdoch University is leading the research, process design, and techno-economic analysis of the project.

The research team has the experience to assess if the concept is technically and economically achievable.

This means meeting safety and carbon sequestration standards while reducing costs of waste disposal.

Uses of biochar include binding more fertiliser to paddocks, rather than in waterways, fed in milker rations to improve dairy production and better pasture and tree growth.

Mr Ossinger said biochar combined with feed rations had been shown, apart from improving the animal’s gut health, to lift milk production by 1.4l a day for each cow.

Dr Gao said there were also opportunities for reducing pollution (carbon emission) in the Denmark project.

An example was the coproduction of biochar and heavy bio-oil pellets, which ultimately could be used in the manufacture of green hydrogen.

This is achieved through making biochar and heavy bio-oil pellets alongside green chemicals extracted from light bio-oils from pyrolysis (partial burning under low oxygen conditions) of the green waste.

The biochar-based pellets can also be used to make green hydrogen via higher temperature gasifi cation because of their high energy density and low mineral content.

But at this stage the focus will be on making solid biochar.

“We will investigate what is most suitable for the Denmark region and the Wilson Inlet,” Dr Gao said.

Project partners are Murdoch University’s Dr Gao, Professor Parisa A. Bahri, and Dr Gloria Rupf from Engineering and Energy at the College of Science, Health, Engineering and Education.

“This project is an excellent example of collaboration between universities and communities to help translate the creative and novel research ideas into real life and practical applications,” Prof. Bahri said.

The article appeared in the Denmark Bulletin, 19 May 2022.