MINNEAPOLIS (AP) — Minnesota regulators voted Thursday to proceed with an environmental review for part of a proposed but disputed pipeline network that would carry planet-warming carbon dioxide from Midwest ethanol plants to a permanent underground storage site.

Iowa-based Summit Carbon Solutions wants to build a $5.5 billion, 2,000-mile (3,200 kilometer) pipeline network across five states so that carbon dioxide from more than 30 ethanol plants could be permanently locked underground in central North Dakota instead of being released into the atmosphere as it is now.

But the project has run into resistance.

North Dakota regulators on Aug. 5 denied Summit’s application for key permits. Landowners in South Dakota concerned about the risks of a pipeline rupture and property rights have objected to the company’s use of eminent domain along the route. Iowa regulators recently opened a several-week hearing, while South Dakota regulators will open a hearing next month. The network would also cross parts of Nebraska, where counties will be the regulators.

Other similar projects are proposed around the country as industries try to reduce their carbon footprints. Supporters say carbon capture will combat climate change. Governments and companies are making big investments in it. But opponents say the technology isn’t proven at scale and could require huge investments at the expense of alternative energy sources such as solar and wind power.

The question before the Minnesota Public Utilities Commission on Thursday was narrow: whether to approve a draft plan laying out the scope of a formal environmental review for one small part of the proposed project, a 28-mile segment in Minnesota that would connect an ethanol plant in Fergus Falls to the North Dakota border, where it would connect with Summit’s network. Commissioners approved it unanimously.

The Minnesota-based rural environmental advocacy group CURE had asked the PUC to defer any decision indefinitely because of the decision by the North Dakota Public Service Commission to reject a certificate of need and route permit for the project. North Dakota regulators cited several issues that they said Summit didn’t appropriately address, such as cultural resource impacts, geologic instability and landowner concerns.

CURE said proceeding with the environmental review in Minnesota would be a waste of state resources – that the project would be a “pipeline to nowhere” without the crucial North Dakota approvals.

But Summit recently petitioned North Dakota regulators to reconsider. Company attorney Christina Brusven told the Minnesota regulators that Summit expects it will be able to address North Dakota’s concerns in the coming months, so Minnesota should not wait to start its review process.

PUC staff told commissioners ahead of Thursday’s hearing that they expected the review would lead to completion of a draft environmental impact this winter, followed by a public comment process. If the commission determines that the final review meets the legal requirements, the PUC could decide whether to issue a route permit for the project as early as next summer.

Summit is planning to file additional permit applications in the coming months for a longer and physically separate part of its proposed network that would connect several ethanol plants in southern Minnesota with its proposed main line in Iowa.