The current “state of the art” is not to recycle any gases and take a single pass-through approach – this is promoted by the gas suppliers who have a vested interest in not promoting gas recycle and reuse.
There are a couple of options for site wide recovery and recycle of argon gas but none appear to be being used in the solar or semiconductor wafer fabrication markets – these are the big two uses for high purity argon. One of the problems with a central, site wide, system is that it is an all or nothing approach with a single point of failure that can close down a facility whereas a number of distributed point of use systems provides a much more robust solution.
The UK company's product has an internal recycle rate of ~98% and a factory recycle rate of ~95% - the customers typically waste some gas during their process. It delivers a gas purity of 99.9998% with a recycled gas flow of 320l/min – this flow capacity allows for one unit to multiplex across 4 silicon ingot process tools or multiple heat treatment furnaces. The product removes all combustive impurities e.g. CO, CO2, H2, H2O, non-methane hydrocarbons, volatile organic compounds, volatile sulphur compounds and will also remove O2, however, it does not remove nitrogen and methane.
The system is based around an innovative chemical looping combustive purification technology that the company invented that uniquely uses a solid state oxygen carrier for the combustive removal of the impurities and compressed air for regeneration of the reactor vessels. The unit contains two pairs of reactor vessels to allow 24/7 operation.
The company have also developed a different and complementary technology of sub-ambient temperature adsorption and can remove nitrogen and methane as well as other species but can't remove hydrogen. This product has a similar flow capacity to the argon-related product of ~320l/min and a recycle rate of 95%. This additional product can be applied to the removal of air gases e.g. glove boxes, 3D printed metals etc.
In addition both technologies can be applied to the removal of organo-sulphur/H2S and VOCs (volatile organic compounds) from biogas in a single step. Removal of these odorant compounds is a requirement for injection of the bio-methane into the gas grid and removal of the sulphur compounds is required if the biogas is to be burned in a electrical generator – the sulphur reacts to sulphuric acid and corrodes the engine from the inside out.
The UK company are seeking engineering or OEM (original equipment manufacturers) partners working in biogas or 3D metals printing to incorporate either or both technologies into their existing processes via commercial agreement with technical assistance or joint venture.
