A New Methodology and Validations of Precise Hydrogen and Natural Gas Blending in Pipelines

Using hydrogen (H2) and natural gas (NG) blends allows the current infrastructure for gas transmission and distribution to be employed with a lower carbon footprint. Proper blending, where the amount of hydrogen is controlled to the required set point for different conditions, is an important part of the process. This study focuses on operating a newly developed blender and experimentally validating the new proposed protocol in a large-scale facility. The proposed methodology measures the mass flow rate of natural gas and the corresponding hydrogen mass flow rate to achieve a desired blend. It also uses additional analytical equipment to verify the final hydrogen content. The H2NG blender system has been built and tested in the multiphase flow facility of the University of Tulsa. Oklahoma Natural Gas (ONG) NG is blended with H2 stored in cylinders. Different H2 concentrations have been considered for different NG flow rates. The results show that the final blending follows the desired concentrations at different flow rates. The system can react quickly to different flow rate changes, keeping the H2 concentration within specifications. Additionally, traditional analytical tools (GCs) utilized for sampling NG are too slow to control H2 injection. Therefore, a mass flow meter at the H2 inlet and an H2 analyzer at the outlet are required to ensure proper blending.