The RES Kaidi High Efficiency Hydrothermal Reformer (HEHTR) is an indirectly fired gasifier, which combusts fuel gases in burners, external to helical process coils in which biomass, steam, char and syngas are flowing. This external heating provides the sensible and reaction heat necessary to achieve the desired conversion and gas quality.
This gasification technology is unique, due to the beneficial effects of fast or flash pyrolysis of the biomass, produced as a result of fast particle heating rates due to particle/wall contact, which provides for high carbon conversions. In addition, the unique helical coil geometry results in volatiles released from the biomass & char having to pass thru a layer of very hot char, which catalyzes volatile decomposition reactions, and results in a low tar content syngas and in particular very low heavy tar contents. Char catalyzed reactions also allow a high H2:CO syngas to be produced in the HEHTR, which is a unique feature of this technology.
The key design features of the HEHTR are:
- The ability to control heat flux along the length of the process coil, to achieve the desired skin wall temperature profile.
- Helical coil design which results in fast biomass/char heating and which results in a hot char layer up against the outside of the helical process coil, which catalyzes specific desirable decomposition reactions.
- A method of steam/Biomass mixing.