Use of smoke from factories in papermaking and wastewater treatment industries

Google and other large companies have signed multi-million dollar contracts to capture carbon dioxide from wastewater treatment plants and paper mills.

According to the scientific service of Tekna Technology News Media, Google, SalesforceH&M and other brands have turned to unexpected partners to help clean up their carbon footprint: wastewater treatment plants and paper mills. These companies have joined an $80 million program to remove CO2 from the atmosphere, although the strategies they use have yet to show whether they can have a significant impact on climate change.

They are paying $32.1 million to a startup called CREW that aims to capture carbon dioxide emissions produced in wastewater treatment facilities. And another $48 million goes to another startup called CO280, which retrofits pulp and paper mills with controversial carbon capture technologies. The two agreements are facilitated by a carbon offset initiative called Frontier, led by Stripe, Google, Shopify and McKinsey Sustainability on behalf of those founding companies and other brands trying to achieve their sustainability goals.

Companies are increasingly looking for ways to offset their greenhouse gas emissions. They have invested millions of dollars in startups that build new industrial plants that filter CO2 from ambient air or seawater. they do Frontier’s latest announcement shows they are also open to supporting more innovative tactics to reduce carbon dioxide.

“We need to look at different approaches,” says Will Burns, director of the Institute for Responsible Carbon Removal at American University, who is also part of the Frontier Assessment Committee. “Some of these approaches are still very expensive, particularly direct air absorption, so we are looking at approaches that have the potential to be less expensive.

The first generation of industrial facilities built over the past decade to filter CO2 from the air—called direct air absorption—cost companies like Microsoft more than $600 per ton of carbon absorbed. Frontier’s recent deals yield about $447 per ton of CO2 removed by CREW (for a total of 71,878 tons) and $214 for CO280 services (for a total of 224,500 tons).

That’s still well above the $100 that industry leaders often say they’re aiming for. And for a company like Google, which was responsible for 14.3 million tons of carbon dioxide last year, you can see how expensive this technology still is.

While CREW’s strategy is more expensive, Burns says he’s particularly excited about its potential. The idea is to absorb carbon dioxide that would otherwise be released by microbes breaking down organic matter in water treatment tanks. To do this, CREW adds alkaline minerals to the tanks. These minerals react with the CO2 produced by the microbes and trap it in the water as bicarbonate. Finally, the bicarbonate ends up with the treated wastewater in the oceans, which are natural sinks that remove CO2 from the atmosphere.

CO280, on the other hand, uses technologies originally developed by the fossil fuel industry to capture CO2 emissions from smokestacks before they enter the atmosphere. These types of devices have been added to industrial facilities and power plants in the past and can capture CO2, which companies may inject into the ground to drive out harder oil deposits.

CO280 takes a different approach by adding carbon capture devices to facilities that burn “black liquor,” a byproduct of pulp production that is used to generate heat and electricity. These devices are supposed to absorb CO2 from burning black liquor so that it can be permanently stored in underground wells. Since the fuel is made from trees, this process essentially stores the CO2 that those trees absorbed through photosynthesis over their lifetime for a long time.

Of course, there are major concerns about the effectiveness of carbon sequestration technologies as a way to mitigate climate change. They use a lot of energy, which itself causes the production of greenhouse gases. There are also additional emissions from cutting trees and transporting wood for paper mills, and it can be difficult to ensure sustainable management of plantations.

Companies that buy carbon removal services are also criticized by environmentalists who worry that it distracts from more important efforts to transition from fossil fuels to clean energy. Ultimately, the only sure way to stop climate change is to stop the greenhouse gas emissions from the fossil fuels that have caused this crisis.