This project aims at a compact version of a gasifier by integrating the fluidized bed steam gasification of biomass and the hot gas cleaning and conditioning system into one reactor vessel. This can be obtained by placing a bundle of catalytic ceramic candles that will operate at a temperature as high as the gasification temperature (800-850°C) in the gasifier freeboard; furthermore, by using a catalytically active mineral substance for primary tar reforming and by optimising the addition of sorbents into the bed for removal of detrimental trace elements.
The main objective is to develop an innovative technology for the production of syngas with the specifications required for use in fuel cells in a cost-effective way. The activity of catalysts and sorbents is increased, while keeping high the thermal efficiency of the whole conversion process as no cooling step is included, and avoiding particle entrainment in the producer gas at the reactor outlet.
As a result, some major advantages of traditional primary and secondary hot gas treatments are combined together, without their well known respective drawbacks (catalyst clogging by solid particles, loss of gas chemical and thermal energy, etc.). In addition, a remarkable process simplification and intensification is obtained:
- the use of a catalytic filter instead of a filter followed by a catalytic bed or a monolith followed by a filter saves equipment;
- housing the whole gas conditioning system in the gasifier reduces thermal losses and allows for a very compact unit.
This arrangement will guarantee the conversion of tar, elimination of trace elements and an efficient abatement of the particulate, delivering high purity syngas, suitable to assure a high share of power generation even in small- to medium-scale (few MWth) CHP and power plants, and to increase the overall economic revenue. It is expected that this innovation will provide a concrete contribution to the target fixed in the work programme, of reducing the cost of electricity obtained by means of advanced gasification systems below 0.04 €/kWh in 2020.