A fugitive emission is an emission of the process fluid, usually a hydrocarbon in gaseous form, from any plant component which relies on a seal to separate the process fluid or hydrocarbon from the environment. The major 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 recent years the general topic of fugitive emissions from chemical and hydrocarbon processing plants has received increased attention, driven by environmental and legislative pressure introduction in industries of specific legislation for the monitoring and control of these emissions.
In areas where prescriptive legislation exists, chemical and hydrocarbon plant operators have no alternative but to comply with the legislation, and efforts have been focused on cost effective ways of achieving compliance.
This paper is split into two parts. The first part describes the techniques available for estimating, measuring and controlling fugitive emissions, and concentrates on emissions from valve glands, flanged joints and pump seals.
The second part of the paper addresses the techniques that can be used to minimize emissions from plant components. Making use of real plant data and practical operating and maintenance experience, the paper presents methods for minimizing fugitive emissions directed individually at valve glands, flanged joints and pump seals.