| # | Country | Total Patents | |
|---|---|---|---|
| #1 | France | 20 |
| # | Industry | |
|---|---|---|
| #1 | Thermal processes | |
| #2 | Machines | |
| #3 | Basic materials chemistry | |
| #4 | Chemical engineering | |
| #5 | Environmental technology |
| # | Technology | |
|---|---|---|
| #1 | Milling | |
| #2 | Feeding fuel to combustion device | |
| #3 | Fluid fuel combustion | |
| #4 | Burners | |
| #5 | Combustion residues removal | |
| #6 | Separation | |
| #7 | Controlling combustion | |
| #8 | Furnaces | |
| #9 | Producer gas production |