Hydraulic fracturing and horizontal drilling have opened up vast new areas for low-cost natural gas production, and consequently have altered the energy landscape in the United States. The rush to develop this new resource via new techniques has resulted in numerous environmental challenges, including water and air quality concerns. Preventable emissions of methane, a potent greenhouse gas with approximately 30 times the heat trapping ability of CO2, are cited by some as among the easiest of those challenges to address. According to the U.S. Energy Information Administration, marketed production of natural gas increased from approximately 1,650,000 to 2,440,0000 million cubic feet between 2005 and 2017, as in projected to continue the rise.
Methane leaks occur during the production, processing, and transmission of natural gas. Pneumatic devices, powered by natural gas under pressure, regulate various aspects of the gas passing through them, including temperature, pressure, and flow rate. Many pneumatics are powered by natural gas under high pressure, and vent (or “bleed”) some of that gas to the atmosphere as part of normal operations. High-bleed pneumatic devices are a significant source of methane emissions throughout the supply chain. According to EPA Inventory data, in 2013, pneumatics emitted roughly 638,000 metric tons of methane, over 20 million metric tons of CO2 equivalent, or a full one-third of all methane emissions from the production sector. Other studies exist that suggest this might be underestimated by over 40 percent. Replacing or retrofitting a continuously or intermittently emitting high-bleed controller, defined as emitting an average of over six standard cubic feet (scf) per hour as part of normal operations, can make economic sense.
An alternative solution that eliminates methane emissions altogether is to replace gas-driven pneumatic devices with ones that rely on electricity instead – solenoid actuated valves. Solenoid valves can be purchased from manufactures such as Clark Cooper configured with certified explosion proof coils per UL-1203 and CSA C22.2 #30. Stainless steel valves are readily available in sizes 1/2” through 2” with maximum allowable inlet pressures of up to 1500 psi. Where a power grid is not available, DC coils are available that can be battery operated. External leakage is essentially zero. An expensive compressed air system is not required.