Novel Material for Natural Gas Purification

Physical Sciences : Materials and Compounds

Available for licensing

Inventors

  • Adam Heller, Ph.D. , Chemical Engineering
  • Keith Friedman, Ph.D. , Chemical Engineering
  • Sheryl Coffman , Chemical Eng
  • David Eisenberg, Ph.D.
  • Joo-Woon Lee, Ph.D. , Chemical Engineering

Background/unmet need

Nitrogen is sorbed in gas separation processes on special carbons, used as such or in membranes. Important carbon utilizing gas separation processes include the de-nitrogenation of wellhead natural gas and the stripping of nitrogen from liquefied natural gas (LNG). Both wellhead natural gas and LNG consist mostly of methane.

Nitrogen is parasitic; it lowers the caloric (BTU) value per unit volume and increases the all-important costs of transportation and storage. Consequently, natural gas is rejected by pipelines and gas turbine electrical power generating plants unless it contains less than 4 to 6 volume % N2; LNG is rejected for shipping if it contains more than 1% N2.

Invention Description

Researchers at The University of Texas at Austin have developed a method to tailor a carbon surface such that it chemisorbs (reactively absorbs) nitrogen. This reactive sorption provides the highest-ever nitrogen sorption capacity, even at elevated temperatures, where little nitrogen is sorbed on most carbons and where sorption/desorption rates can be rapid, providing high throughput. They reversibly sorb at 40°C and at 1 bar nitrogen pressure 1.1 mmol/g nitrogen (3.2 weight %), five times more than the best nitrogen sorbing molecular sieve carbon. Desorption of the nitrogen is complete at only 160°C.

Benefits/Advantages

    Opens the door to much smaller and higher throughput de-nitrogenators of natural gas

Features

  • The novel nitrogen-doped carbons are rare-earth oxide (e.g. lanthanum oxide) templated.  
  • Formed by pyrolyzing at 710°C crystallographically well defined, phase-pure, lanthanum nitrilotriacetate monohydrate (LaNTA·H2O) and acid-extracting the co-formed lanthanum oxide
  • Different surfaces from those of other carbons by their exceptionally high content of nitrogen bound mostly within pyrrolic (five-membered) rings

Market potential/applications

Companies supplying specialty carbons to the gas separation industry; companies producing gas separators

Development Stage

Lab/bench prototype

IP Status

  • 1 PCT patent application filed