Division BAT 72 In order to increase the energy efficiency of IGCC and gasification units, BAT is to use one or a combination of the techniques given in BAT 12 and below.
United Kingdom
| Technique | Description | Applicability | |
|---|---|---|---|
| a. | Heat recovery from the gasification process | As the syngas needs to be cooled down to be cleaned further, energy can be recovered for producing additional steam to be added to the steam turbine cycle, enabling additional electrical power to be produced | Only applicable to IGCC units and to gasification units directly associated to boilers with syngas pretreatment that requires cooling down of the syngas |
| b. | Integration of gasification and combustion processes | The unit can be designed with full integration of the air supply unit (ASU) and the gas turbine, with all the air fed to the ASU being supplied (extracted) from the gas turbine compressor | The applicability is limited to IGCC units by the flexibility needs of the integrated plant to quickly provide the grid with electricity when renewable power plants are not available |
| c. | Dry feedstock feeding system | Use of a dry system for feeding the fuel to the gasifier, in order to improve the energy efficiency of the gasification process | Only applicable to new units |
| d. | High-temperature and -pressure gasification | Use of gasification technique with high-temperature and -pressure operating parameters, in order to maximise the efficiency of energy conversion | Only applicable to new units |
| e. | Design improvements | Design improvements, such as:
| Generally applicable to IGCC units |
Table 42
BAT-associated energy efficiency levels (BAT-AEELs) for gasification and IGCC units
| Type of combustion unit configuration | BAT-AEELs | ||
|---|---|---|---|
| Net electrical efficiency (%) of an IGCC unit | Net total fuel utilisation (%) of a new or existing gasification unit | ||
| New unit | Existing unit | ||
| Gasification unit directly associated to a boiler without prior syngas treatment | No BAT-AEEL | > 98 | |
| Gasification unit directly associated to a boiler with prior syngas treatment | No BAT-AEEL | > 91 | |
| IGCC unit | No BAT-AEEL | 34–46 | > 91 |