The goal of this project is to develop and demonstrate a Methane Mitigator (M²) system, which aims to economically reduce methane and other emissions across the natural gas supply chain while improving fuel consumption for prime-mover engines. Research will focus on four major objectives over approximately three phases that correlate with annual budget periods (BPs).

These objectives include:

1. complete a thorough review of recent studies and previous collaborations to identify data gaps in methane mass emissions and activity rates and subsequently collect additional data from in-use well sites to address these gaps (BP 1),
2. develop and demonstrate within a certification-grade laboratory an M² system that is capable of receiving emissions from engine crankcase vents, reciprocating compressor seal vents, pneumatic controller vent manifolds, and tank battery vent manifolds to offset fuel consumption without negatively impact engine performance (BP 2),
3. complete in-field demonstrations (active duty cycle >90%) with industry partners to highlight the benefits of the system while disseminating technical and economic data (BP 3), and
4. develop a full system model, capable of addressing varying engine types and site configurations, for use as a design tool for industry to enable widespread technology adoption (BP 1-3).

West Virginia University Research Corporation – Morgantown, WV 26506
Caterpillar, Inc. – Peoria, IL 61656

Natural gas production in the United States (US) is at 2.7 trillion cubic feet per year (EIA). It is estimated that up to 2.3% is lost to the atmosphere. Harnessing even a fraction of this lost gas, possibly 60 billion cubic feet, represents a substantial greenhouse gas (GHG) and economic impact. The M² system will target a reduction in vented methane emissions from four primary components that include:

1. crankcase vents of the prime-mover engines,
2. reciprocating compressor packing vents,
3. pneumatic controller manifold vents, and
4. tank battery vents.

The basis of the system will build upon technology approaches of dual fuel conversion systems that have been deployed across the automotive transportation and off-road engine sectors. Such retrofit systems have the capability to monitor engine operating parameters and supply low-pressure fumigated natural gas to the intake system through a basic air fuel mixer. Since natural gas compressor engines typically operate at fixed speed and fuel is controlled by a fuel governor, the engine’s electronic control unit (ECU) or mechanical governor will automatically reduce primary fuel consumption due to the increased energy content of the incoming charge. The research team has worked with technology developers to optimize, characterize, and certify such dual fuel systems for a variety of on-road and non-road diesel engines. This approach becomes straight forward when both fuel energy sources are the same; however, the system and design approach must be capable of managing at least four additional fuel energy streams that have varying mass flow rates and compositions.

The "Methane Mitigator" technology will reduce fugitive methane emissions from natural gas well sites, decreasing environmental impact and ensuring that well sites remain compliant with emerging emissions restrictions. Once successfully demonstrated, the approach could be applied to other downstream facilities. The technology will also permit the continued use of existing equipment and gas-operated control systems without loss to the atmosphere, avoiding unnecessary capital investment for GHG-sensitive upgrades and replacements. It will also make positive use of the previously lost methane, thereby increasing the overall energy efficiency of US natural gas production. At the present time, well sites, compressor stations, midstream facilities and gas storage systems release methane directly to the atmosphere or lose the value of additional methane which is sent to combustors. The technology will build upon safe and proven existing gas collector and crankcase vent closing technology, could capture and use 5 to 10 billion cubic feet per year of US gas per year within a decade. The technology has international applications and will promote a new domestic design and manufacturing industry, enabling the US to lead worldwide.

• Technical Advisory Panel (TAP) was created and includes members from WVU, CAT, a representative from an industry leader in gas compression, a site owner, and operators (energy company and service company), an independent environmental scientist, and a Lead mechanical engineer – regional contractor for NG industry.
• Extensive literature and data review was completed which primarily found a general lack of information on the temporal emissions from pneumatic controllers (PCs) and tank emission flow rates to control devices (combustors). A detailed Scope of Work was developed and submitted to industrial partners to fill missing data gaps.  The Scope of Work also included safety analyses for various measurement approaches.
• Surveyed local companies on well pad engines commonly used, which showed the power rating varied substantially from ~100 hp to well over ~1000 hp
• Selected the CAT G3508J engine as the research platform for use in laboratory R&D, which arrived February 2021.  Associated equipment was identified and procured for the dedicated research laboratory and included a S4 generator end, a load bank, SCAC (radiator system), and frames for laboratory installations.
• Initial site audits completed for methane quantification of engine crankcases and compressor vents completed for fivelarge engine sites.
  • Crankcase summary results
    • 43.9 to 64.2 CFH of methane
    • Estimated total flow range – 784 to 1326
    • Expected range – 220 to 1380
  • Compressor vent summary results
    • 3.7 to 32.3 CFH of methane
    • Estimated total flow range – 3.9 to 34.0 CFH
    • Expected range - ~0 to 180 CFH
• Modeling effort to incorporate emissions data from journal publications to inform a Monte Carlo simulation for overall site emissions and potential to offset fuel consumption.
  • 81 model scenarios ran
    • 3 engine sizes (3306, 3508, 3520)
    • 3 liquid production rates (40, 380, 900 bbl/day)
    • 3 well counts (2, 8, 15)
• Extended data collection campaigns (multi-week) were completed at two unconventional dry gas production sites.
• CAT G3508J engine platform was installed along with ancillary equipment at new dedicated off-campus laboratory space in partnership with Energy Environmental Analytics (EEA).
• Walker Engineering closed crankcase retrofit system was obtained for initial evaluation and to serve as starting point for M² system designs.

Due to prior pandemic and laboratory delays, the CAT G3508J research platform operation has been delayed. A dedicated off-campus research space has been developed and the engine along with ancillary equipment has been installed. Final checks are being completed awaiting review and approval from Caterpillar. The engine will be operated at two or three load points to very operation (fuel consumption, power production, and emissions) by comparison to manufacturer data. The engine will also be instrumented to obtain detailed crankcase data during normal operation and compared to Caterpillar data along with field data collected from G3508 engines. The Walker Engineering closed crankcase retrofit system will then be installed and evaluated for impacts on fuel consumption, power, and emissions along with oil removal capabilities. These results will serve to guide the design of the M2 system.

$1,498,405

$433,093

NETL – Gary Covatch (Gary.Covatch@netl.doe.gov or 304-285-4589)
West Virginia University Research Corporation – Dr. Derek Johnson (Derek.Johnson@mail.wvu.edu or 304-293-5725)