| Popis: |
Process intensification (PI) is an emerging field focused on reducing the size of chemical process equipment, such as distillation, which is particularly relevant for isotopic enrichment of noble gases including 39Ar and 136Xe. Micro channel distillation (MCD) is a new PI technology that has reduced the length of column needed for a separation stage to less than 0.5 cm compared to 2 cm for the best available laboratory structured packing from Sulzer. This reduces the column length for 10,000 separations stages from 200 meters to less than 50 meters. Furthermore, MCD columns can be operated horizontally, thereby mitigating the need for excessively tall columns. Data are presented for isotopic enrichment of methane, as well as other chemical separations, which are used in two case studies. The first case study is to produce 5 tons of 80% enriched 136Xe in 5–6 years for the next generation of 136Xe neutrinoless double beta decay experiments. The second is enrichment of germane to produce 1 tonne of 86% 76Ge in 4 years for a future Majorana dark matter experiment. In both cases, calculations were performed using estimated relative volatilities of isotopes which have not been measured. So far, 60 separation stages have been demonstrated in a single 25-cm-long device, and further development is required to improve performance, scale-up to larger devices, and to integrate systems. This presentation was used for the Low-Radioactivity Underground Argon Workshop held at Pacific Northwest National Laboratory in Richland, Washingtonon March 19 - 20, 2018. |
