Rare gas units Linde Engineering continuously enhances its plant technologies for the production of the rare gases krypton, xenon and neon, standardising and optimising processes and equipment to deliver plants with the highest performance levels for our Gases Division.

Rare gases such as krypton (Kr), xenon (Xe) and neon (Ne) are only present in air at concentrations below 20 ppm. Demand for these rare gases is rising, however, as they play a vital role in many different industries. As the world's largest manufacturer of rare gas mixtures for incandescent, fluorescent, and high intensity discharge (HID) lamps, Linde Engineering has developed innovative processes that boost the capture of rare gases from secondary streams in tonnage-size air separation plants.

Our multi-step enrichment process produces krypton and xenon gas mixtures with typical purities of over 99.9 percent. In a first enrichment step the concentration of krypton and xenon in liquid oxygen (LOX) is increased to levels below 1% using cryogenic rectification.

In the second enrichment step, our standardised plant design comprises supercritical crude Kr/Xe evaporation, demethanation, cryogenic rectification and product compression for storage and transport.

In a subsequent final purification step Kr and Xe are separated and purified with a combination of cryogenic rectification and reactive filter systems.

A high degree of modularisation and process automation enables short installation and commissioning times of Kr/Xe plants.

Neon and some amount of helium as byprodukt are extracted from the inert gas in the main condenser of air separation plants together with nitrogen and hydrogen. We have optimised existing processes to boost neon yield and operating range and to minimise utility consumption and maintenance effort.

The result is a highly efficient and automated process design for product delivery in gaseous or liquid phase. The plant components are condensed into a containerised package unit that can be easily transported and quickly set up and commissioned. The unit is delivered fully factory tested and can be directly embedded in the customer's plant infrastructure.

We continually monitor the construction, start-up and operation of our plants and channel new findings back into our research work to further optimise performance levels.