Could Mesaba Energy Project really ‘convert’ back to coal?

Earlier this week, we told you about the troubled Mesaba Energy Project, a proposed coal gasification plant in northern Minnesota that, after 10 years of planning, still doesn’t have a power purchase agreement or investors to begin construction.

A bill in the state legislature would allow the project to proceed as a natural gas plant, while still keeping the millions of dollars in “advanced energy” funds it has been awarded by the state.

Tom Osteraas, attorney for the developers, said this wouldn’t be a “bait-and-switch,” but would just allow one of two phases of the plant to go on hold:

Osteraas explained that the facility they proposed is a two-piece operation. The first is essentially a coal refinery, in which coal is converted into a synthetic gas. The second piece is a gas-burning power generator. If the current legislation passes, it would allow Excelsior to build the second component first and power it with natural gas. The coal-gasification element could be added later, “if and when” economic conditions dictate, Osteraas said.

That explanation makes intuitive sense, but may not make economic sense, at least not according to Ronald R. Rich, a Twin Cities-based engineer and president of Atmosphere Recovery, Inc. Rich, who testified against the project before the state PUC in 2007, had this to say in a comment posted this morning:

It would be prohibitively expensive for Excelsior to convert their proposed natural gas combined cycle (NGCC) plant to an integrated gasification combined cycle (IGCC) coal plant in the future. No matter what they claim.

Excelsior would have to purchase special and much more expensive combustion gas turbines that could use both the relatively clean and high energy content natural gas and also the much dirtier and lower energy content IGCC syngas at the time they constructed their NGCC plant.

And they would also need to install much more expensive steam tubes than NGCC requires if they ever wanted to generate steam from the combustion turbine exhaust of an IGCC plant.

Excelsior would never do this because installing “upgradeable” equipment would be cost-prohibitive and result in an unaffordable electric plant.

So in short, Excelsior’s plant would not be convertible. They may argue it is “technically possible” but will completely ignore economic facts. And will further minimize the additional massive extra expense needed for the syngas generation portion of the IGCC conversion also required.

Conversion would never happen.

So, a question that state legislators clearly need to ask is whether the turbines in the proposed plant will be able to operate on both coal syngas and natural gas. The two gases are chemically quite different and have different energy potential.

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