very low temperatures in our specialist sample environment (SE) equipment. However, helium is a finite resource in need of preservation. In order to reduce our helium consumption ISIS uses a Helium Recovery (HR) system. This allows us to recover helium used in experiments, store it, and reuse it later on, reducing our dependence on external sources.
This system has been in place for almost 6 years now. It began with a recovery rate of 50% but has become more efficient year on year and currently recovers over 90% of the Helium used at ISIS. This is fantastic news as it means we don’t need to obtain as much helium from the diminishing natural sources. However, for a sustainably goaled process helium recovery requires a lot of energy. In this new study, members of the ISIS SE Cryogenics team have calculated the carbon footprint of both our helium recovery process and the production process from the supplier.
To start with, this required piecing together the journey of the helium in both cases…
For the gas company the journey starts with the extraction of helium from natural wells in Qatar. From this, the helium needs to be separated from other gases via distillation. The gaseous helium then undergoes liquification so that it can be transported safely as a liquid. Finally, it is stored in containers and transported via boat and then lorry to the ISIS facility.
Once at ISIS we initially collect used helium in a large, low pressure gas balloon. Then the gas is compressed and stored in cylinders to await use. When required, the helium can be liquified for transportation through the experimental halls to the specific cryogenic equipment that requires it.
Taking into account the transportation and energy used in each process it was calculated that 500 g of CO2 is produced per liquid litre of helium (so the carbon footprint is 500g CO2/l He). In comparison, the carbon footprint of the gas suppliers process is 712g CO2/l He, making the output from our system 30% smaller. However, once the separation process from the supplier is taken into account their carbon footprint dramatically increases to the point where our HR system footprint seems negligible at 99.02% smaller than that of the supplier.
Regardless of the comparison, the team are always looking for ways to improve this carbon footprint. Implementation of a precooling system, which will double the helium production from the same energy usage, is already underway. Congratulations to the team for 6 years of successful growth on this project and we look forward to seeing its future steps!