Issued Patents All Time
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 9339760 | Methods and apparatuses for removal of hydrogen sulfide and carbon dioxide from biogas | Nicholas Kennedy, Quan-Bao Zhao, Craig Frear, Stephen W. Dvorak | 2016-05-17 |
| 7909995 | Combined nutrient recovery and biogas scrubbing system integrated in series with animal manure anaerobic digester | Tianxi Zhang, Craig Frear, Shulin Chen | 2011-03-22 |