N.S. firm lands US$25 million to capture carbon by mixing limestone in rivers

A Halifax-based company says it expects to receive US$25.4 million for projects that reduce greenhouse gas emissions by mixing crushed limestone in rivers.

A Halifax-based company says it expects to receive US$25.4 million for projects that reduce greenhouse gas emissions by mixing crushed limestone in rivers in Canada and Scandinavia.

The first project by CarbonRun has already started, as lime is being added to the West River in Pictou County at a site about 45 kilometres east of Truro, N.S.

The firm says the lime combines with carbon dioxide in the water and is carried out to sea, where it will remain in that captured state for thousands of years.

In a news release today, the company says the investment has been arranged by Frontier, a U.S.-based fund that supports carbon-removal projects, with 13 companies planning to pay for carbon credits associated with the projects.

Eddie Halfyard, the chief technology officer at CarbonRun, says his company will get the money once it can verify that its limestone-mixing method has reduced carbon dioxide emissions from the rivers.

CarbonRun says that between 2025 and 2029 its river-liming projects are expected to prevent about 55,000 tonnes of carbon dioxide — roughly the equivalent of the annual emissions from 13,000 cars — from entering the atmosphere.

The company says the addition of limestone is also helping combat the long-term effects of acid rain — created by nitrogen oxide and sulphur dioxide emissions — and as a result is improving Atlantic salmon habitat.

Sensors along the river will measure whether the lime dosing is changing the chemical composition of the water as scientists have predicted.