Boiler upgrade captures waste heat, water vapor
A Midwest-based global provider of medical products and services required significant fuel and water resources to generate steam for water purification, sterilization, and other manufacturing processes. The company conducted routine energy assessments to identify energy-saving opportunities and implemented energy-conservation practices through a lean-energy program, one of the goals of which was a 3-percent-per-unit-of-production decrease in energy and water consumption in 2008.
To help reach that goal, the company initiated an upgrade of its bioscience facility that included boiler optimization and installation of steam economizers. The economizers feature an advanced heat-recovery system developed by Gas Technology Institute (GTI) that uses Transport Membrane Condenser (TMC) technology. The technology recovers both sensible and latent heat, as well as water from the exhaust stream, to co-generate additional steam for the manufacturing process. TMC technology increases fuel-to-steam energy efficiency by up to 15 percent (for up to 95-percent fuel-to-steam efficiency). Also, it increases the capture of water from flue gases by up to 20 percent. That water is used in a boiler without the need for further treatment.
TMC technology has increased the efficiency of the facility's natural-gas boiler from about 81 to 82 percent to 93 to 94 percent, saving the company more than 12 percent on fuel costs for the boiler while also reducing carbon emissions by more than 12 percent and reducing the need for fresh water.
TMC technology can be retrofitted on any clean-fuel boiler to raise fuel-to-steam efficiency to a level of almost 95 percent while allowing the return of environmentally clean water to the system. Applied in conjunction with an economizer, TMC technology has been shown to be a cost-competitive system that can be installed as a retrofit on existing high-pressure steam boilers in a range of sizes. TMC technology utilizes a porous ceramic membrane tube designed to condense water vapor and capture, recover, and re-use sensible and latent waste heat, along with water vapor from exhaust/flue gas.
GTI engineers have calculated that the nationwide application of TMC technology could save 600 trillion Btu and 62,000 tons of NOx annually. At a natural-gas price of $8 per million Btu, that would save U.S. industry $5.6 billion per year, in addition to lowering the amount of greenhouse gases emitted annually by 23 billion tons.
Cannon Boiler Works Inc. and GTI are developing the technology, branded “Ultramizer,” for commercial application in a standard range of boiler sizes for market availability by early fourth quarter 2010. As an upgrade to an existing boiler system, the Ultramizer can be implemented in stages. The Ultramizer also is adaptable to an economizer that already is installed and is packaged to accommodate limited floor space.
Information courtesy of Cannon Boiler Works Inc.