Natural gas is fully liquefied in a low energy sweet-spot using moderate compression (~ 90 Bar) and, conventional chilling (-50 Celsius). This can be attained with off-the-shelf equipment.
As the required temperature is not cryogenic, the gas does not have to be ‘stripped’ as does conventional LNG. Dehydration of the gas may be required. This major reduction of required pre-processing significantly reduces the cost of producing P-LNG.
A P-LNG production plant will also have a small footprint. A modular facility will cost approximately (US) $200/ MTPA (metric tonne per annum). In contrast, an LNG facility in Qatar will cost ~ $600/ MTPA. In the US ~ $850/ MTPA. In Canada ~ $1200 per MTPA, plus marine and other infrastructure.
The energy required to produce P-LNG will range from 100 kW/MT to 220 kW/MT depending on the compression and chilling required. In comparison. LNG requires ~ 240 kW/MT for a new facility and up to 400 kW/MT for an older facility.
Due to the relative ease to liquefy natural gas this way, small scale biogas is made easy and feasible in rural areas where there are no pipelines. Biogas may be feasibly produced from farms, feedlots, and forestry operations. Biogas from landfills and even sewage treatment facilities will require additional stripping.
