Minimizing the potential for leaks by applying proper design and material-selection standards is the first step in emission prevention.
First of Two Parts Operators in refineries or chemical/petrochemical plants must keep greenhouse gas (GHG) and environmental regulations for fugitive emissions in mind. One area in which this is extremely important is the processing of oil sands in Canada. Fugitive emissions are any chemical in physical form that can leak unanticipated within an installation. Knowing how to select valves that will meet or exceed volatile organic compound fugitive emission limits is critical. The costs are exorbitantly high if an operator fails to meet the requirements. End users should obtain test data that will allow for direct comparisons between valve packing, gaskets and other sealing components. Without data, end users are guessing which options are best for their applications. The operations/field data, including past experience, helps analyze the valve and packing options. Most companies require real-time testing, which will provide comparable fugitive emissions in parts per million (ppm) of hydrocarbons and chemicals. These tests include multiple test cycles that represent the plant conditions within a laboratory. These tests can be conducted at reasonable costs and within a reasonable timeframe. A few laboratories in North America are qualified and have developed a simple test procedure that can be adjusted to accommodate any off-the-shelf valve and provide the fugitive emissions in ppm, which is needed to understand how a valve will perform once it is in service. Part One of this series discusses how to eliminate fugitive emissions in valves already in service. Part Two will cover the current standards and testing procedures to ensure compliance with these standards.
Why Focus on the Fugitive Emissions of Valves?The industry statistics indicate the importance of discussing the fugitive emissions of valves specifically. Valves account for more than 51 percent of fugitive emissions, and GHGs are part of this (see Figure 1).
Figure 1. Sources of fugitive emissionsCompliance standards should be created by valve manufacturers that minimally include the following:
- Design of sealing components
- Selection of materials
- Prototype qualification of valves
- Production test of valves
- Fugitive emission compliance onsite
Control StrategiesThe key elements for effective, long-term control of fugitive emissions are:
- The application of the best available technology and standards, including the development of monitoring programs, operating procedures and performance objectives for controlling fugitive emissions Implementation of management systems
- Corporate commitment to the implementation and maintenance of a directed inspection & maintenance (DI&M) program to detect and prevent leaks
- The first step in controlling fugitive equipment leaks should always be to minimize the potential for leaks at the beginning by applying proper design and material-selection standards, following the manufacturer’s specifications for the installation, using and maintaining the components, and implementing practical control technologies (such as reduction, recovery and treatment systems).