Hydrogen-resistant control valve for refinery in Schwedt, Germany

Hydrosulfurization and hydrocracking in refineries

Especially in the petroleum industry, which produces gas oils such as diesel or heating oil or processes them further, processes of desulfurization (hydrosulfurization) and hydrocracking are quite central. Hydrogen is an important byproduct in both processes.

In hydrocracking, large quantities of hydrogen are added to the feedstock (e.g. crude kerosene) under a pressure of up to 200 bar and at temperatures of up to 480 degrees Celsius. In the process, the hydrocarbon compounds split and are converted into intermediate products. These are very pure, largely olefin-free and contain hardly any sulfur or nitrogen compounds.

The challenge: Special steel for control valve

PCK had to meet several requirements for the control valve: In the hydrocracking process, the hydrogen can penetrate the materials of the plant more easily due to the high pressure and high temperatures. Special steels must therefore be used that have sufficient high-temperature strength and toughness to withstand attack by pressurized hydrogen.

In addition, hydrogen is a gas that can easily enter various materials and cause them to become brittle. To avoid this, proper material selection and quality, among other factors, is critical to the selection of the hydrogen valve.

Learn more about hydrogen and hydrogen embrittlement!

The result: perfectly matched hydrogen valve!

For this challenging environment, A. Hock has provided a perfectly tuned hydrogen valve: a globe valve 2" 1500 lbs RTJ with control and quick-closing function (SIL 1). The control valve meets the highest safety standards by being certified with SIL 1.

In the choice of materials, heat-resistant steel 1.7357 (17CrMo55) was used and grade C was considered for the housing. This makes the valve ideal both against hydrogen embrittlement and for the demanding conditions of hydrocracking.