SoCal Gas tests methane capture system

OREANDA-NEWS. September 23, 2016. SoCal Gas has tested a system to capture methane gas from an abandoned pipeline, gas that previously would have been vented to the atmosphere.

SoCal crews recently decommissioned a 2.5 mile (4km) section of pipeline in the city of Atascadero so that it could be replaced by a new pipeline. The work required that about 150,000 cf (4,200 m3) of gas be removed from the pipe. Instead of venting the gas, SoCal compressed most of the gas and pumped it into three large tanks.

In total, about 108,000 cf was captured, an amount that SoCal said could supply about 533 US homes.

Capturing the methane "not only reduces noise or smells neighbors might notice, but also minimizes impacts to the environment," said Rick Phillips, senior director of SoCal's pipeline safety enhancement plan. "We will continue testing this new innovation in hopes of expanding its use" when suitable.

The methane capture test was part of SoCal' Pipeline Safety Enhancement Plan (PSEP), a multi-billion dollar program that identifies sections of high-pressure pipeline on the company's southern California system to be pressure-tested or replaced.

Nationally, SoCal said emissions from gas distribution systems represent less than 1pc of greenhouse gas emissions.

In January, SoCal proposed installation of a system to capture and burn a portion of leaking gas from a damaged well at the Aliso Canyon gas storage field, but SoCal and state air regulators decided not to proceed because of safety concerns.

Methane leaks from oil and gas operations are the focus of new regulations under development by the US Environmental Protection Agency (EPA) which said methane has a warming effect that is more potent than CO2 over a 20-year period. Methane accounts for about 10.6pc of US greenhouse gas emissions, according to the EPA, and about a third of methane emissions come from the oil and gas sector. President Barack Obama set a goal to cut oil and gas sector emission of methane by 45pc by 2025.

The oil and gas industry is working to block the new methane rules which would require companies to limit methane emissions from new and modified equipment and regularly check for leaks.

In the wake of the massive gas leak at Aliso Canyon, SoCal is working with California regulators to develop a portfolio of projects to mitigate the harm from the methane that escaped from late October 2015 until mid-February.

Earlier this week, California governor Jerry Brown (D) signed legislation to restrict three short-lived but potent greenhouse gases, including methane, from waste streams like landfills and dairy farms in the state.

The new law requires a 40pc reduction in methane and hydroflourocarbon gases, along with a 50pc reduction in black carbon, from 2013 levels by 2030. This law represents the most aggressive restrictions on short-lived climate pollutants in the US.