Industrial air compressors are estimated to consume more than 12 percent of California’s manufacturing electricity consumption annually yet estimates show that only 10 to 15 percent of the energy used to compress air translates to useful output. Carnot Compression Inc. (Carnot) developed, tested, and demonstrated an isothermal compression technology intended to improve the energy efficiency of compressed air systems. Increasing the percentage of useful work output of compressed air systems by managing these inefficiencies can decrease demand for electricity in California’s industrial sector as well as in the agricultural, water, and commercial business sectors, thereby supporting state mandates to reduce planet-warming emissions 40 percent below 1990 levels by 2030 and achieve carbon neutrality by 2045.
A detailed engineering design process informed fabrication of Carnot’s first fully integrated prototype, which was tested in a laboratory setting and subsequently installed and monitored at a field test location.
Flow rates during lab testing were below the targeted capacity and consequently below the monitoring system’s flow cutoff, prompting a change in the measurement approach for field testing.
More than 115.5 and 155.6 hours of compressor run-time in the lab and the field, respectively, produced a significant volume of data, from which 571 compression events were selected, with flow rates of 0.63 actual cubic feet per minute at inlet conditions. Specific power was measured to be 3,091 kilowatts per 100 actual cubic feet per minute at inlet conditions, and isentropic efficiency was measured to be approximately 0.31 percent.
Although the alpha version compressor did not meet the efficiency levels of currently available commercial products, opportunities for improving system performance were identified and are being incorporated into the beta version compressor. Performance results of the prototype, environmental data for wastewater composition, sound levels, and vibration are also provided to inform future design considerations for commercialization.
Author(s)
Luke Bingham, Carlos Ortiz, Rob Kamisky, Jason Stair - Gas Technology Institute; Todd Thompson, Chris Finley, Hans Shillinger, Christophe Duchateau - Carnot Compression, Inc.
