(206d) Strategies in Optimizing Condensate Return

Optimizing condensate return for reuse as boiler feedwater is often a viable means of reducing fuel costs and improving boiler system efficiency. Condensate that is contaminated with corrosion products or process chemicals, however, is ill fit for reuse; and steam or condensate that leaks from piping, valves, traps and connections cannot be recovered. A document published by the US Department of Energy estimated that for all pulp and paper, chemical manufacturing, and petroleum refining industry plants1, approximately:

*66% could realize typical fuel savings of 3 to 7% with an effective steam trap management program

*6.5% could realize typical fuel savings of 2.9% by minimizing vented steam

*24% could realize typical fuel savings of 2% by optimizing condensate return

*16% could realize typical fuel savings of 1.4% by repairing steam leaks

*7.8% could realize typical fuel savings of 0.9% by isolating steam from unused lines

As more condensate is returned, less makeup is required, saving on water and makeup water treatment costs. The high purity of the condensate allows for greater boiler cycles of concentration, thus reducing water and energy losses to blowdown. The high heat content (typically in excess of 180°F) can provide substantial energy savings. Additional savings will also be noted in reduced water treatment chemicals, water and sewer costs. Effective chemical treatment, in conjunction with mechanical system improvements, condensate polishers, and automatic dump systems can assure that condensate can be safely returned and valuable energy recovered.

1U.S. Department of Energy, ?Steam System Opportunity Assessment for the Pulp and Paper, Chemical Manufacturing, and Petroleum Refining Industries,? DOE/GO-102002-1639, September 2002.