Biomass gasification reactor design

All these chapters describe the smart use of reactor design and process integration to increase the efficiency and reduce the emissions when using fossil fuels as energy source. Of course, intensified systems can also be used for bio-based energy sources. Chapter 8 reports the possibility to convert biomass into substitute natural gas. The chapter describes how both packed beds and fluidized bed reactors can effectively be used to improve the methanation reaction so that the products of biomass gasification can be converted into a more sustainable methane stream. 

Similar to other thermochemical processes, gasification of biomass involves a series of interconnected chemical and physical processes which depend on the reaction conditions and the reactor design. The gasification process can be divided into three stages (Bridgwater, 2006 De Lasa et al., 2011 Balat et al., 2009) ... 

This process uses a fluid-bed unit that is especially designed for gasification of brown and hard coals, peat, and biomass. In the case of brown coal, predried feed at 12 wt % moisture is fed along with oxygen and steam to the reactor which operates at 750 to 800°C and 2.53 MPa. 

There are only limited reports on hydrothermal gasification in larger than laboratory scale. At PNNL bench-scale systems were developed as early as 1989 (Elliott et al., 1989). This work was used to design a scaled-up mobile reactor system, designed for up to 0.5 t of wet feed per day (Elliott et al., 1994). PNNL demonstrated successfully the continuous gasification of biomass to methane-rich product gas. Initially problems occurred with plugging of the catalyst bed by biomass which was solved by a two-step process where biomass was liquefied in a CSTR before HTG. The design... 

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