How to control fugitive emissions

Fugitive emission can be defined as a spurious emission of the process fluid. It’s usually hydrocarbon in gaseous form, from any plant component that depends on a seal to separate the process fluid from the environment. The primary sources of fugitive emissions are valve glands, pump seals, and flanged joints, and although emissions from individual components can be small, the cumulative effect can be very significant. In addition to the economic cost of lost commodities, fugitive emissions pollute the air and trigger climate change.

 As expected, there are a lot of rules and regulations that force oil & gas producers to stay in check when it comes to fugitive emissions. These rules are made by a variety of bodies such as the Environmental Production Agency (EPA) in the USA and TA Luft in the EU. In keeping with the rules and regulation on control of fugitive emissions, necessary measures are taken for compliance by affected industries. One of such control to reduce emission is using valves and safety system using HIPPS (high-integrity pressure protection system).

 HIPPS is part of SIS (Safety Instrumented System) designed to limit overpressure by shutting the source of emission and capturing the pressure on the upstream side of the system. Doing so provides a barrier between the High Pressure and Low-Pressure ends of the process plant, as the tight shutoff prevents loss of the containment and eliminate fugitive emissions. HIPPS is the last defense system to prevent fugitive emissions.

 It looks like an intelligent solution for controlling emissions althoug a variety of elements and parts have to play together to give users the best use of this system. The challenge for users as well as suppliers is to have the right certifications to meet the desired safety level.

 Different of efforts have been in place to find effective means of controlling fugitive emission and below are some ways to reduce emission and save the environment from avoidable pollution.

  1. Replace old, outdated valves. Fugitive emissions reduction efforts center on Valves. This is because valve leakage is responsible for over half of total fugitive emissions. But don’t be alarmed, because old valves not designed using the latest materials and technologies are mainly the problem.
  1. Ensure proper installation of your valves. Valve installation technicians are invited continuously to job sites for valve leakage diagnosis. Their findings point to valves installed incorrectly. Instances include valves installed horizontally, or overloading weight on the valve by discharge piping system.
  1. Stick with valve preventative maintenance plan. When new valves built with the latest technologies are installed correctly but still leaking, the reason is probably due to improper maintenance. When you adopt preventative maintenance, you can identify and avoid little problems before they grow bigger.
  1. Remember the “easy” solutions. It is evident that valves have a higher stake in fugitive emissions, but simple maintenance at other locations can improve the system. For example, flanges and pumps are responsible for 15% of fugitive emissions, so tightening pipe flanges can create smaller reductions. You can also meet emissions compliance by installing low emissions valve packing, which is flexible, doesn’t shrink, and won’t absorb moisture.
  1. Check the system for leakages. Leaks exist everywhere in a piping network; many methane leaks happen due to unpredictable factors such as a valve that gets stuck open. Currently, there is a lot of “guessing” about the cause and frequency of the leaks. You need new technologies with reliable methods of leak detection.
  1. Replace high-bleed pneumatic devices with low-bleed ones. Pneumatic tools are often used to operate valves and control liquid and pressure levels in the gas industry. The EPA suggests replacing as many as 80% of high-bleed devices. You can recoup the cost of the implementation usually within a year by reducing gas-bleed losses.
  1. Carryout a directed inspection and maintenance (DI&M) program at compressor stations. On gas pipelines, compressor stations are the primary source of fugitive emissions. A DI&M program involves conducting a baseline survey to identify and quantify leaks, then a cost-effective repair program follows. Within four months, EPA estimates gas savings from DI&M will pay for the costs of installation.

 How to control fugitive emissions

Fugitive emissions are posing a serious concern. Applying the above strategies will minimize the leaks by early detection and quick fixing. Although,  the various oil and gas producers, EPCs, valves and other flow control industry suppliers have essential roles to play in reducing or even preventing emissions to get that fresh air!