Low cost and compact solution for recycling PFCs by the continuous gas chromatography

We propose a new capture/recovery technology to reduce emissions of perfluorocompounds (PFCs) from semiconductor industry. The conventional capture/recovery technology has some problems in its repurification step. The cryogenic distillation needs a huge distillation tower and much power for refrigeration. On-site capture/recovery is not viable by the cryogenic distillation, because the system is economically feasible only with a large-scale operation. The continuous gas chromatography technology is a compact alternative to the conventional repurification method. The system is composed of the series of separation columns, vacuum pumps and automatic valves. The mixed PFCs are separated by the difference of the affinity for the column. Only the perfectly separated PFCs are output and the others are injected to the next column. By recycling the PFC mixture, which was not separated by the single column, the continuous gas chromatography outputs the pure PFCs continuously. The system is compact and it can operate with low energy consumption. Moreover, it can separate CF/sub 4/ and NF/sub 3/, which can not be separated by a cryogenic distillation.