Lowering the Cost of a Cryogenic Gas Plant

Lowering the Cost of a Cryogenic Gas Plant

Jan 19, 2016 | Cryogenic Gas, Modularization, NGL Recovery & Fractionation

In the world of natural gas liquids (NGL) recovery, small incremental changes in plant design are occurring all the time. Those innovations are sometimes shared across the entire industry and other times confined to one company. As a collective whole, however, the result tends to be improved NGL recovery and lower construction and operating costs across the industry. But what innovations in particular are lowering the overall costs associated with a cryogenic gas plant?

Modularity and prefabrication have contributed significant cost savings to the construction of a cryogenic gas plant industry-wide. Making process systems modular has been an increasing overall trend in a wide variety of industries, and hydrocarbon processing is no exception. When coupled with strongly backed national or global standards, a modular process tends to be easier and more cost-effective to implement, maintain, and quality test.

In some cases the improvements are more localized, however. Companies like Costain have attempted to lower the energy costs of the cryogenic nitrogen removal process for NGL-produced sales gas by integrating nitrogen exclusion with NGL extraction. Traditionally these have been separate energy-intensive processes, one heating and the other again cooling the gas. However, the company claims its improved process configuration allows a nearly 10 percent cost savings over the traditional method.

Sometimes innovation is fast-tracked due to new feed stocks and how they are acquired. Wet shale gas represents a modern example, which is known to vary in composition — sometimes significantly — over time. This has required a more flexible process that can adapt to variances in ethane and propane content in the feed stock. Companies like Opero Energy have recognized this and applied innovations (such as an improved turbo-expander configuration) to the cryogenic gas plant to not only provide this process flexibility but also lower compression and energy requirements.