Fugitive emissions from mixing equipment

Abstract

During process plant development and preliminary design stages emissions resulting from the daily manufacturing operations are identified and measures are taken to control them in order to prevent possible adverse impacts on people and the environment. Process industry experiences not only emissions resulting from the daily manufacturing operations but also emissions which are fugitive or unanticipated. Fugitive emissions during process plant operation stage are often monitored because they are an occupational health concern. However the attention on fugitive emissions during the plant design stage is lacking. During this stage the equipment that involves large fugitive emissions could be identified and avoided. For this, methods to estimate fugitive emissions from various equipment used in the process industry are required. This work proposes a methodology to estimate the amount of potential fugitive emissions resulting from a mixing vessel used in the mixing operation. The distribution of those emissions in the environment which are essential to identify the impacts on the environment and human well-being is also looked at. Two designs of mixing vessels are studied for fugitive emissions. Firs t is a closed design where fugitive emissions are assumed to occur under well controlled conditions. The second is an open design where emission from surface evaporation occurs from an open mixing vessel. The method is applied on a paint mixing vessel in the paint manufacturing industry during early design stage and potential fugitive emission quantities are estimated. The results indicate that the fugitive emission estimates from closed design mixing vessel have lower environmental concentrations compared to that of the open design.