Technology companies want to capture carbon in paper mills and sewage treatment plants

Google, Salesforce, H&M and other brands have turned to unlikely allies to help them clean up their carbon pollution: sewage treatment plants and paper mills. The companies signed on to an $80 million plan to remove CO2 from the atmosphere, although the strategies they use have yet to demonstrate whether they can have a meaningful impact on climate change.

They are paying $32.1 million to a startup called CREW, which aims to combat carbon dioxide emissions produced at wastewater treatment plants. And $48 million will go to another startup called CO280, which equips pulp and paper mills with controversial carbon capture technologies. The two agreements were made possible by a carbon removal initiative called Frontier led by Stripe, Google, Shopify and McKinsey Sustainability on behalf of the founders and other brands trying to achieve their own sustainability goals.

Companies are increasingly looking for ways to undo the damage caused by their greenhouse gas emissions

Companies are increasingly looking for ways to undo the damage caused by their greenhouse gas emissions. They have funneled millions into startups building newfangled industrial plants that filter CO2 from ambient air or seawater. Frontier’s latest announcement shows that they are also open to even more new tactics to reduce carbon dioxide.

“We need to look at a lot of different types of approaches,” said Wil Burns, co-director of the Institute for Responsible Carbon Removal at American University, who is also part of a review committee for Frontier. “Some of these approaches still remain extremely expensive, particularly direct air capture, so we are looking for approaches that are potentially cheaper.”

The first generation of industrial facilities built over the past decade to filter CO2 from the air – called direct air capture – cost companies including Microsoft more than $600 per ton of carbon captured. The deals Frontier just closed equate to approximately $447 per ton of CO2 removal by CREW (for a total of 71,878 tons), and $214 per ton for CO280’s services (for a total of 224,500 tons).

That is still well above the $100 per tonne that industry leaders often say they are aiming for. And for a company like Google that was responsible for that 14.3 million tons from last year’s CO2 pollution you can see how unaffordable the technology still is.

Carbon dioxide removal involves a range of strategies to remove carbon dioxide from the atmosphere. These technologies could potentially help slow climate change by capturing some of the pollution that fossil fuels have already caused over the years. There are still concerns about costs, safetyand potential postpone a transition from fossil fuels to carbon-free energy. Experts say removing carbon is no substitute for preventing greenhouse gas emissions.

Although CREW’s strategy is more expensive, Burns says he’s mostly excited about its potential. The idea is to capture carbon dioxide that would otherwise have been released by microbes breaking down organic waste in water treatment tanks. To do this, CREW adds alkaline minerals to the tanks. These minerals react with the CO2 that microbes produce, trapping it in the water in the form of bicarbonate. Ultimately, the bicarbonate travels with the treated wastewater to the oceans, which are natural sinks that keep CO2 out of the atmosphere.

CO280, on the other hand, uses technologies initially developed by the fossil fuel industry to capture CO2 emissions from smokestacks before they can escape into the atmosphere. These types of devices have been added to industrial facilities and power plants in the past and can collect CO2 that companies can then shoot back into the ground to expel hard-to-reach oil reserves.

CO280 takes a different approach by adding carbon capture equipment to facilities that burn “black liquor,” a byproduct of pulp production used to generate heat and power. The devices are intended to capture the CO2 from the combustion of black liquor so that it can be permanently stored in underground wells. Because the fuel is made from trees, the process essentially stores the CO2 that these trees have absorbed through photosynthesis during their lifetime.

Sure, there are still big ones to assure about how effective carbon capture technologies are as a way to limit climate change. They use a lot of energy, which generates its own greenhouse gas emissions. There are also additional emissions from felling trees and transporting timber for paper mills, and it can be difficult to ensure that tree plantations are managed sustainably.

Companies that purchase carbon removal services also face criticism from environmentalists concerned it’s a distraction from more critical efforts to the transition from fossil fuels to clean energy. Ultimately, the only surefire way to stop climate change is to prevent the greenhouse gas emissions from fossil fuels that are causing the crisis in the first place.