CNG Transmission Corp., Clarksburg, C W.Va., is installing $10 million in new combustion control technology and engine management services on as many as 53 compressor station engines in Pennsylvania and New York.
The technology, called the INOX system by developer and supplier ENOX Technologies Inc., Natick, Mass., aims at significantly reducing nitrogen oxide (NOx) emissions from natural-gas compressor stations and other internal combustion engines. Lng Filling Machine
Such reductions are intended to bring these engines into compliance with the Clean Air Act Amendements of 1990 that require NO, emissions from such sources be reduced by May of next year.
The INOX system reduces NOx emissions by ensuring lean bum combustion, says ENOX. It is a tripartite system consisting of the patented PlasmIgnition System, auxiliary system modifications, and turbo charging to provide the excess air necessary to complete low-NO, operation.
Key to the product is its plasma technology. Instead of a conventional 50-usec spark within the gap of the spark plug, the PlasmIgnition System produces a continuous electrical plasma discharge much like the flame of a pilot light.
This long-duration ignition source enables engines to burn leaner air/fuel mixtures (that is, greater proportions of air to fuel) which are difficult to ignite using traditional spark ignition. Burning leaner mixtures results in lowered NO, emissions.
The Plasmignition System consists of individual electronic ignition circuits for each spark plug. The circuits consist of an ignition control module, ignition coil, spark plug, and primary lead.
The microprocessor-based timing control module allows operators to adjust ignition timing and monitor functions.
Independent tests by CNG and other pipeline companies indicated that the INOX System, with appropriate air flow, reduced NOx emissions to levels that meet or exceed the CAA NOx-reduction requirements of many states. In the test, the system also reduced NO, emissions to less than the 15 g/bhp-hr produced by typical natural-gas compressor station engines.
Additionally, the system virtually eliminated engine misfires, which can significantly reduce engine repair and maintenance.
ENOX says that until the availability of the INOX system, traditional NOx-reduction solutions offered by original-equipment manufacturers of natural gas compressor-station engines used Clean Bum kits or precombustion chambers.
These require replacement or extensive modification of engine cylinder heads to accommodate precombustion chambers. A turnkey system using this solution costs between $500,000 and $1.2 million, says ENOX to bring an engine into compliance with CAA permit-level requirements. Necessary modifications and installation can require up to 48 weeks for parts lead time and 6-12 weeks of engine down time.
The electronic INOX system works in conjunction with the. existing engine with no cylinder head modification or replacement and is installed in 3-5 days. Engine operators can meet CAA permit levels for up to 50% less than the total of the conventional solution.
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