Fuel cell power plant having a reduced free water volume

The present invention relates to fuel cell power plants that are suited for usage in transportation vehicles, portable power plants, or as stationary power plants, and the invention especially relates to a fuel cell power plant that minimizes free water within one or more fuel cells of the plant and eliminates free water within support systems of the plant so that the plant is freeze tolerant during shut down, start-up and steady-state operation in below freezing ambient temperatures. The invention reduces free water volume in a fuel cell power plant so support systems of the plant are freeze tolerant. The fuel cell power plant includes a coolant system having a sealed cooler plate that circulates an antifreeze coolant in heat exchange with a fuel cell and that collects fuel cell water; a water vapor removal system that removes water vapor from the antifreeze coolant to regulate the antifreeze concentration; and a start-up system having a start-up heat exchanger and a start-up valve that selectively direct heated antifreeze coolant into the cooler plate for a start-up procedure. The plant may also include a fuel processing system that utilizes the removed water vapor, and that is in heat exchange with the start-up heat exchanger. The antifreeze coolant is a low vapor pressure solution, such as an alkanetriol or polyethylene glycol.