Optimizing Steam & Condensate System: A Case Study

Abstract

Optimization of Steam & Condensate systems in any process plant results in substantial reduction of purchased energy cost. During periods of natural gas price hikes, this would benefit the plant in controlling their fuel budget significantly, irrespective of the plant's size. This paper highlights the efforts taken by the management of a medium sized specialty chemicals plant in North East Louisiana. This site spent over $19 million in 2007 ($13.7 million for natural gas & $5.6 million for electricity). The site generates steam for its process operation from 3 gas fired boilers at 525-psig pressure. The steam is consumed at 5 process areas; Acid, Basics, Crystals, Derivatives & Hydrogen plants. All of the process areas recover condensate inside their area, utilize it partially, and drain the rest into the sewer. Boiler Feed Water (BFW) is supplied from the water treatment plant located at the Boiler House. The optimization study was conducted at this site, between Jul - Sep 2008, to identify opportunities to reduce the energy cost and to improve the steam system's reliability. The study identified 5 energy cost optimization opportunities that would result in a total cost savings of $1,181,000 annually. The initial estimates indicated that all the 5 projects recommended by the study would have simple payback periods of less than 2 years. This case study is a good example and motivation for all engineers and managers who are responsible for maintaining the efficiency and reliability of small and medium sized steam systems.