Stuff Digital Edition

Hydrogen hope for thermal dryer

Christina Persico

The multimillion-dollar machine that will turn New Plymouth’s sewage into fertiliser is set to be powered by hydrogen – potentially hydrogen created from treated wastewater.

The $37 million project to upgrade the thermal dryer at the New Plymouth District Council Wastewater Treatment Plant is about two-and-a-half to three years away from completion, councillors were told at a strategic projects committee meeting this week.

The existing dryer runs on natural gas and produces approximately 2000 tonnes of carbon dioxide a year – the equivalent of about 432 passenger vehicles driven for one year.

There were a number of options for running the replacement dryer on hydrogen, a cleaner fuel, infrastructure manager David Langford said.

One of these was the plant itself producing the hydrogen, using treated effluent as the feedstock.

‘‘So we use our own wastewater into the electrolyser to create hydrogen for the thermal dryer,’’ Langford said.

Currently, sewage is pumped in and goes through several steps before the solid matter is separated out to the thermal dryer, which dries it out for use as fertiliser.

The remaining treated liquid is then sent out to sea.

But with an electrolyser the liquid could be used to create hydrogen by being separated from its oxygen components.

‘‘The intention is that when we commission the new facility we’re ready to operate on hydrogen,’’ Langford said.

Contracts are already in place for much of the project, and a contractor has prioritised Taranaki and then New Zealand-based supply chains ahead of its normal international channels, Langford said.

The total cost of the project, including addressing earthquake-prone buildings, staff welfare and expansion of the compliance testing laboratory, is estimated at $43m, including $6m of contingency funding.

This was signed off by council last October.

Central Government has given $37 million in shovel-ready funding.

News

en-nz

2021-06-18T07:00:00.0000000Z

2021-06-18T07:00:00.0000000Z

https://fairfaxmedia.pressreader.com/article/282239488580264

Stuff Limited