A Membrane Preconcentrator for Portable Trace VOC Detectors

The sensitivity of low-cost, portable volatile organic compound (VOC) detectors currently in use is low, which limits their application in many situations. More sensitive detectors are more expensive and less robust and not suitable for field use. This Phase I project involves the development of a membrane-based preconcentrator able to concentrate trace amounts of VOC contaminants to levels that can be measured easily by existing portable detectors. The membrane concentrator is simple, compact, and lightweight. Only a small vacuum pump and blower are required to power the unit. In the Phase I project, a prototype preconcentrator based on a new type of membrane will be constructed. The device will be operated with model VOC/air mixtures to demonstrate the overall feasibility of the approach. The system will be considered successful if it can concentrate parts per billion levels of VOCs in air streams at least 100-fold. In Phase II, an integrated system consisting of the membrane preconcentrator and a suitable detector will be built and demonstrated. If successfully developed, the portable system will be used widely to determine VOC concentrations for environmental monitoring and for process control in chemical plants. The membrane concentrator component cost is not expected to be more the $5,000, so the improvement in performance of existing detectors will be achieved with only a small increase in total instrument cost.