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Framergy purifies methane from natural gas streams using MOFs and Coriolis mass flow meters
Co-written by Alicat and Framergy. Funding for this research was provided by the Environmental Protection Agency (EPA) under contract number 68HERC20C0007.
Metal organic frameworks (MOFs) are a novel class of nanomaterials that are highly effective as a solid adsorbent and utilize their unique “cage-like” structure to trap molecules. Because of these properties, MOFs have been studied for numerous fluid storage, separation, and purification applications. The company, Framergy, was the first group to focus solely on providing high-volume, high-quality, and low-cost MOFs with the goal of revolutionizing clean energy.
The AYRSORB™ line of MOFs from Framergy feature ultra-high surface area and permanent porosity to maximize molecule trapping. These features make it an ideal adsorbent for the modification and purification of natural gas streams. By purifying methane from a natural gas stream, less carbon is generated during the combustion process leading to a smaller emissions footprint.
To evaluate the performance of their product for natural gas purification, Framergy had to set up a pilot test – with quite a few demanding process requirements.
Problem: Find a mass flow meter capable of meeting the demanding requirements of the pilot test
- High operating pressure – 800 PSIG (MOF efficiency increases with pressure)
- High ambient temperatures (pilot station outside in Texas with highs of 70-105°F)
- Low-flow rates of gas (due to scale of adsorbent column and adsorption kinetics)
- Flow gas of unknown composition (exact molecular composition of natural gas unknown & inconsistent)
- Insensitivity to vibrations (due to nearby compressors)
Solution: Alicat Scientific’s CODA Coriolis mass flow meter
Figure Framergy field test diagram
- Precise measurement of low-flow fluids even with unknown fluid composition
- Able to withstand high pressure and temperature requirements
- Insensitive to external vibrations without the need for mass block
- Totalizer function to easily track total gas flowed over time
Pilot test setup
Framergy’s natural gas purification pilot test
Engineering lead Mr. Carlos Ybanez led the pilot test to evaluate AYRSORB™ F250’s natural gas liquid (NGL) adsorption capability, with the goal of selectively purifying methane from a natural gas stream. The testing system consisted of a knockout pot to drop liquid and two adsorption columns in series filled up with AYRSORB™ F250. Upstream of the system, an Alicat CODA Coriolis mass flow meter was utilized to measure the total gas treated by the system before saturation.
Results: Framergy MOFs deliver a 100% clean methane stream
- Engineers obtained stable, high-accuracy readings for the amounts of natural gas adsorbed over time.
- Readings were unaffected by the nearby vibrations and by changing gas mixture composition.
- Results demonstrated that Framergy MOFs delivered a 100% clean methane stream.
- Engineers were able to conduct further selectivity testing by successfully creating and flowing custom mixtures of gas through their test setup. Mixtures comprised of different weight percentages of methane, ethane, propane, and butane.
Conclusion
Framergy was able to use Alicat’s CODA line of mass flow meters to meet their process requirements, allowing them to offer robust MOF solutions with greater certainty of success.