A final investment decision has been taken to move forward with the world’s first carbon-negative hydrogen commercial pilot project — which uses an innovative process that could undercut conventional methods of producing green and blue H2.

Australian technology company Hazer will convert biogas derived from sewage at a wastewater treatment plant in Western Australia into hydrogen and graphite using its proprietary Hazer process.

By splitting the biogas (mainly CH4) into hydrogen (H2) and graphite (C) using an iron-ore catalyst, carbon that would otherwise be emitted as CO2 as the sewage decomposed is stored in the form of solid graphite, making it a carbon-negative process.

The company previously told Recharge that the graphite can be sold to industry for a profit, effectively offsetting the cost of the hydrogen to the point where it becomes cheaper than other forms of clean H2.

The Hazer process is also far more energy efficient than water electrolysis, requiring only 15-30kWh per kilogram of hydrogen, compared to the latter’s 65kWh — producing 2-4 times as much H2 for the same energy, further reducing the relative cost of the Hazer hydrogen compared to traditional green H2.

The $17m pilot at the Woodman Point Wastewater Treatment Plant, known as Commercial Demonstration Project (CDP), will produce 100 tonnes of hydrogen and 380 tonnes of graphite per year. Some of the hydrogen produced will be converted to electricity via a fuel cell, allowing the project to produce its own renewable power. Woodman Point already produces biogas at its facility inside large tanks known as anaerobic digesters.

It has taken more than a decade for the company to get to this stage of development. Work on the Hazer process — which originally stood for hydrogen and zero-emission research — began in 2007 at the University of Western Australia in Perth, with the Hazer company established in 2010.

The pilot — which is set to be fully commissioned in mid-2021 — is being part-funded to the tune of A$9.4m ($6.75m) by the federal government’s Australian Renewable Energy Agency.

“The Hazer CDP is a key step in demonstrating the commercial readiness of our technology to the growing national, and international, low-emission hydrogen market,” said Hazer managing director Geoff Ward.

“It will increase the utilisation of waste resources, improve civic infrastructure and offer new economic opportunities through the development of graphite-manufacturing opportunities and hydrogen for transport or clean energy.”