| # | Country | Total Patents | |
|---|---|---|---|
| #1 | United States | 4 | |
| #2 | Canada | 3 | |
| #3 | Belgium | 1 | |
| #4 | France | 1 | |
| #5 | United Kingdom | 1 | |
| #6 | WIPO (World Intellectual Property Organization) | 1 |
| # | Industry | |
|---|---|---|
| #1 | Civil engineering | |
| #2 | Machines | |
| #3 | Engines, pumps and turbines | |
| #4 | Environmental technology |
| # | Technology | |
|---|---|---|
| #1 | Earth drilling | |
| #2 | Safety devices | |
| #3 | Unspecified technologies | |
| #4 | Reduction of greenhouse gas emissions | |
| #5 | Machines for liquids | |
| #6 | Gas-turbine plants |
| # | Name | Total Patents |
|---|---|---|
| #1 | Grupping Arnold W J | 8 |
| #2 | Van Eek Wouter H | 1 |
| Publication | Filing date | Title |
|---|---|---|
| WO9306367A1 | A system for subterranean storage of energy | |
| US5287926A | Method and system for underground gasification of coal or browncoal | |
| US4808029A | System for subterranean storage of energy | |
| US4441554A | Method for the underground gasification of coal or browncoal | |
| US4243101A | Coal gasification method |