New study: compressed natural gas for automobile use

The goal of mass adoption of natural gas as an alternative fuel for vehicles is closer to realisation with the efforts of studies such as the one conducted by Oregon State University. A prototype engine, using a Modular Reed Valve (MRV) from Zahroof Corp. for the check valves, was designed, built and successfully tested to prove the concept of selectively repurposing one cylinder of an automobile engine running on compressed natural gas (CNG) to be used as a compressor. This would allow a CNG vehicle to refuel itself at home quickly and with low capital cost. Phase I of the ARPA-E MOVE project was successfully completed and Zahroof Corp is now providing the valve technology for Phase II of this project.

The study, headed by Christopher L. Hagen of OSU along with researchers from Czero Inc, is titled ‘Design and Analysis of a Self-Refuelling CNG Vehicle to Provide Home Refuelling’.

The study examines the limitations of current natural gas refuelling systems with their long refill times and proposes the repurposing of one cylinder of a vehicle's internal combustion engine (Cummins I6) as a compressor of CNG, at home, to allow the vehicle to refill more quickly and more cost effectively. By creating a quicker, more efficient way to refuel vehicles, CNG could overcome a major hurdle in its adoption. Natural gas at 1.22 bar is compressed to 3626 PSI through three stages of compression with the engine running at 1000 RPM. This is a very difficult application for a compressor valve as the same set of valves had to be used for all three stages of compression, with the final stage compressing gas from 614 PSI to 3626 PSI (a 3012 PSI pressure differential). The MRV was able to meet the challenge, resulting in the success of Phase I of this project.

"Innovation will be the key to adoption of compressed natural gas, and it is studies like this one that hold the most promise, says Zahroof Mohamed, President and CTO of Zahroof Valves. "The ability to refuel CNG at home would reduce or eliminate the need for a national infrastructure of CNG stations, often mentioned as a necessity for mass adoption. We are proud that our own innovative product could play a role in the prototype."

The project is currently in Phase II and is examining ways to increase the compression ratio to improve pumping efficiency, among other efforts.

The MRV is the core technology used in Zahroof Valve's flagship product, the ZVI StraightFlo Valve (SFV), which is a patented, revolutionary, reciprocating compressor valve technology that results in step improvements in valve key performance indicators through its unique design. The benefits are increased valve efficiency by up to 40% while significantly increasing run time between valve services. Zahroof Valves recently announced an industry leading 10 year warranty on its valve housings.

Adapted from press release by Rosalie Starling

Read the article online at: https://www.hydrocarbonengineering.com/gas-processing/27052015/new-study-compressed-natural-gas-for-automobile-use-851/