Instead of releasing the CO2 absorbed by the wood as it grew, the carbon will instead be trapped in the form of solid biochar, a substance similar to charcoal that can be used to enrich agricultural soil.
“We are carbon negative because we emit less than we sequester,” said Glenn Davies, chief executive of joint venture partner CAC-H2, a biomass-focused Singaporean technology company.
The Port Anthony Renewables Hub will initially produce 75,000 tonnes of green ammonia and about 1,000 tonnes of H2 per year by 2023 at Port Anthony in southeast Australia, as part of the Hydrogen Plus JV between CAC-H2 and clean-energy developer Port Anthony Renewables.
Production of both hydrogen and ammonia can be scaled up in future, according to demand, with the initial ammonia output being lined up for export to Japan, South Korea and Singapore, and the hydrogen being used locally.
Standard gasification is a combustion-free process that uses high temperature heat of more than 700°C and a small amount of oxygen and/or steam to break biomatter down into carbon dioxide and hydrogen. But CAC-H2’s gasification process creates solid carbon instead of CO2.
“Our process is unique as we are solving many problems along the way including waste, carbon removal, and clean energy production,” Davies tells Recharge.
“Our by-products are also great for the agricultural sector and construction industries who can use our biochar & wood vinegar [a so-called ‘superfood’ for plants with the chemical formula C5H4O2] for environmental purposes, or blend the biochar with cement for a ‘green’ building product.”
“And because we’re helping with a waste removal problem, avoiding landfills or incineration, we are often paid to remove this [woody biomass] feedstock.
These multiple revenue streams, including carbon credits, “allow us to have one of the most effective production costs for green hydrogen in the market today — at least a third of what it costs via electrolysis. Our internal commitment is to meet global demand for hydrogen at $2/kg by 2030.”
Standard green hydrogen — which uses renewable electricity to split water molecules into H2 and oxygen in a process called electrolysis — is said to cost $2.50-6 per kg, according to the International Energy Agency, with the price depending on a wide range of factors, including the cost of green power and electrolysers, the capacity factors of renewables projects, operating expenditure, interest rates, etc.
Climate think-tank Energy Transitions Commission believes that by 2030 the cost of standard electrolytic green hydrogen will fall to “below $2 per kilogram in most geographies and even lower in favorable geographies with very cheap renewables”.
Davies tells Recharge that the energy-intensive Haber-Bosch process — which combines nitrogen from the air with hydrogen to produce ammonia — will be powered by burning some of the syngas created during the gasification process. While this combustion results in a “small” amount of emissions, “the net effect is still carbon negative”, he explains.
The woody waste matter will be sourced locally, Davies adds.
“Some of our feedstock is residual wood chips and wood waste coming from sustainable sawmill activities, and a large part is removing forestry-floor fallen timber from sustainable forestry management practices.
“We are also talking to municipal waste and industrial waste partners to look at alternate feedstocks depending on the plant’s production objectives.”
CAC-H2 is also utilising its carbon-negative biomass-gasification technology at two other projects in Australia — in the Hunter region of New South Wales, where it aims to produce 800 tonnes of hydrogen per year; and in Bundaberg, Queensland, where it will manufacture 4,500 tonnes of green H2 and 27,000 tonnes of ammonia annually.