Resources

Energy and Chemical Savings in Boiler Operation

Energy Savings:

Reduced blowdown: By removing dissolved minerals in boiler feedwater, a boiler can operate at much higher “cycles of concentration”, resulting in markedly less blowdown of heated water to the drain. For example, utilization of reverse osmosis treatment of the boiler feedwater in a food processing plant allowed increase in cycles from 10 to 100, reducing blowdown by more than 80% and achieving annual natural gas savings of $299,000.

Chemical Savings:

Reduced chemical consumption in Demineralizers: High pressure boilers typically require demineralization of the boiler feedwater to remove minerals that carry over with the steam and plate on turbines (e.g., silica). Demineralizers are typically regenerated with sulfuric acid and liquid caustic. Both chemicals are currently in short supply, subject to unpredictable and rapidly escalating price increases (150% to 300% over 6 months). Some plants and power generating facilities have recently had to purchase on the spot market or have had to utilize emergency mobile DI trailers to bridge between uncertain deliveries.

Utilization of reverse osmosis upstream of the Demineralizers reduces dissolved minerals by 98%, reducing acid and caustic consumption by 90% or more. This list shows typical annual savings, as a function of boiler make-up flow, based on current chemical costs:

100 gpm >$140,000 annually
300 gpm >$260,000 annually
450 gpm >$345,000 annually
These savings typically result in a payback of <15 months.

ANCILLARY SAVINGS:

By removing dissolved minerals in the feedwater instead of relying on chemicals to minimize scaling in the boiler, boiler tubes remain cleaner, resulting in better energy transfer and chemical costs are significantly reduced. Reduced gas or oil consumption, resulting in significant carbon dioxide reduction.

Energy and Water Savings

Water Treatment Design Considerations

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