How a Chemical Processing Plant Saved $350K/year with a Heat-of-Compression Air Dryer
Heat-of-Compression Air Dryer Generates $350,000 Annual Energy Savings
Site: Chemical Process Plant – Indiana Instrument Air / Plant Air Supply
System: 15,000 CFM Oil-Free Centrifugal Air Compressor with Two 7,500 CFM Heatless Regenerative Air Dryers
Overview
A Heat-of-Compression (HOC) Air Dryer is the most energy-efficient air dryer available. In the case of this chemical process plant, existing heatless regenerative air dryers were consuming over 2,800 CFM of compressed air (purge air) to regenerate the desiccant beds, which is the equivalent air capacity of a 700 Hp air compressor.
Air Systems identified the high operating cost of this air-drying system and proposed a 15,000 CFM HOC air dryer that would eliminate the high volume of purge air associated with the heatless regenerative air dryers. An HOC air dryer makes use of the already available (free) discharge heat from the upstream air compressor. This heat is the byproduct of air compression and can be used to regenerate an HOC dryer’s desiccant.
The plant went forward with the HOC dryer project and was able to shut down a 900 Hp air compressor to realize an annual energy savings of $350,000. In addition, the improved overall system redundancy allowed the plant to remove older and less reliable air compressors from the air compressor rotation, thereby reducing maintenance costs. Furthermore, the project qualified for a $600,000 utility rebate on the merits of reduced energy consumption.
