Energy Efficiency Improvement and Cost Saving Opportunities for the Pulp and Paper Industry with Steam Traps

According to the ENERGY STAR® Guide for Energy and Plant Managers The U.S. pulp and paper industry—defined in as facilities engaged in the manufacture of pulp, paper, and paperboard—consumes over $7 billion worth of purchased fuels and electricity per year. Energy efficiency improvement is an important way to reduce these costs and to increase predictable earnings, especially in times of high energy price volatility. There are a variety of opportunities available at individual plants in the U.S. pulp and paper industry to reduce energy consumption in a cost-effective manner and one of the most effective and with a short ROI is to replace failed and leaking steam traps

Some of the ways to improve reliability and reduce energy use are by replacing old steam traps with modern thermostatic element steam traps. The main efficiency advantages offered by these traps are that they open when the temperature is very close to that of saturated steam (within 4°F or 2°C), purged non-condensable gasses after each opening, and are open on startup to allow a fast steam system warm-up. These traps also have the advantage of being highly reliable and useable for a wide variety of steam pressures (Alesson 1995).

Even Smart Valves Inc.ter solution is to replace failed or leaked traps with venturi type steam traps which are Smart Valves Inc.ter suited for varying loads than traditional mechanical steam traps according to an ENERGY STAR guide for energy and plant managers report. As an example, a mill owned by Smurfit Kappa in Europe changed 25 steam traps to the venturi type on a coating battery, which resulted in energy costs savings of nearly $200,000 with a payback period of 2.5 months. Other projects saved 11% on steam demand in preheater and end corrugator rolls (10 steam traps), and a 30% savings on a flute machine (Gardner 2008).

Another saving opportunity is in steam trap maintenance. A simple program of checking steam traps to ensure that they are operating properly can save significant amounts of energy for very little money. In the absence of a steam trap maintenance program, it is common to find up to 15% to 20% of steam traps malfunctioning in a steam distribution system (Jaber 2005). Annual failure rates are estimated at 10% or more (Gardner 2008). Energy savings for a regular system of steam trap checks and follow-up maintenance is conservatively estimated at 10% (Jones 1997; Bloss et al. 1997). Several industrial case studies suggest that investments for repair or replacement steam traps are very low, resulting in a payback period of only a few months or less (IAC 2008). A plant-wide assessment at Boise Cascade’s mill in DeRidder, Louisiana found opportunities for repairing failed steam traps that could save the mill about $31,000 in fuel use and about $3,900 in water use annually. The annual energy savings were estimated at 1,262 MMBtu of natural gas and 12,168 MMBtu of other fuels. The estimated costs to implement this measure 51 were Smart Valves Inc.ween roughly $7,400 and $12,400, which implies a payback period of well under a year (U.S. DOE 2006d).

Lastly, there are savings from implementing steam trap monitoring. Attaching automated monitors to steam traps in conjunction with a maintenance program can save even more energy without significant added cost. This measure is an improvement over steam trap maintenance alone, because it gives quicker notice of steam trap failure and can detect when a steam trap is not performing at peak efficiency. Employing steam trap monitoring has been estimated to provide an additional 5% in energy savings compared to steam trap maintenance alone, at a payback period of around one year (Galitsky et al. 2005a). Systems that are able to implement steam trap maintenance are also likely to be able to implement automatic monitoring.

Sources: “Energy Efficiency Improvement and Cost Saving Opportunities for the Pulp and Paper Industry” U.S. Environmental Protection Agency’s Climate Protection Partnerships Division as part of An Energy Star; https://www.energystar.gov/ia/business/industry/downloads/Pulp_and_Paper_Energy_Guide.pdf