Refineries face a new challenge in selling one of the by-products of crude oil refining, namely heavy crude oil. This black, viscous oil was widely deployed as a marine fuel up until 2020. However, a recent International Maritime Organization (IMO) agreement has significantly restricted its use. The reason for this move was that heavy oil produces considerable amounts of sulfur oxide and nitrogen oxide when combusted in a ship’s engine. Linde Engineering has developed a process technology called partial oxidation that allows oil companies to continue using this residue product. It involves heating heavy oil to temperatures of around 1,400 degrees Celsius and adding oxygen to support sub-stoichiometric (incomplete) combustion. This produces a hydrogen-rich synthesis gas – a mixture of hydrogen (H₂) and carbon monoxide (CO) that is purified in downstream steps. The H₂ fraction is extremely valuable to oil refining companies, which require large quantities of this gas especially to desulphurize fuel products. Our partial oxidation technology is a win-win for today’s refinery. On the one hand, they can turn a residue product into a useful commodity and, on the other, meet rising demand for H₂, which is on an upward path as stricter environmental legislation increasingly mandates lower-emission fuels.

Helium production is another showcase for the benefits of investing in new technologies. Our engineers came up with the idea of combining highly efficient and selective membranes with a pressure swing adsorption (PSA) unit. This not only results in a very high helium yield but also makes the new process cheaper and more energy-efficient by dispensing with the cryogenic gas separation step. Linde Engineering teamed up with chemicals specialist Evonik to deliver the high-performance membranes. These hollow fibers made of extremely efficient polymers are embedded in stainless steel cartridges. The pre-treated natural gas is fed into these cartridges under high pressure, with the gas fractions separating due to selective permeation. Simply put, this means that small molecules like helium can pass through the membrane faster than larger ones. Depending on the gas composition and the size of the plant, any number of cartridges can be combined in one or more membrane stages. Linde Engineering has installed this helium production technology at a plant in Mankota, Canada, which processes over 250,000 standard cubic meters of natural gas per day and achieves a helium yield above 95 percent at a purity level as high as 99.999 percent. Previously, this kind of quality could only be achieved with cryogenic methods.

Looking beyond process technology advances, Linde Engineering innovators are also constantly searching for ways to streamline production processes. Additive manufacturing, also known as 3D printing, is positioned at the heart of these efforts. This technology provides an innovative way to fabricate spare parts for plants. Its particular appeal lies in the fact that many plant components are complex in design and very costly to produce with conventional methods. Additive manufacturing (AM) on the other hand offers complete freedom of design. Using digital 3D design data, the AM powder or material gradually builds the final object, layer by layer. Our engineers are examining whether 3D printing can also be used for systems like heat exchangers – one of the key elements in natural gas liquefaction plants. 3D-printed parts could, for example, optimize heat transfer. This would reduce the surface area required for exchanging heat and thus the size of the components. Additive manufacturing is also a promising technology for complex process components with cavities, coils or catalytic structures as well as for tailor-made spare parts.