Conversion of Woody Biomass Materials by Chemical Looping Process—Kinetics, Light Tar Cracking, and Moving Bed Reactor Behavior

Abstract

In recent years, chemical looping has evolved into a promising technique for carbonaceous fuel conversion. The chemical looping technology using biomass material as feedstock could provide a process that is environmentally attractive and sustainable. The focus of this study is to examine the kinetics of biomass decomposition and to evaluate the feasibility of using biomass as a renewable source for chemical looping processes. A series of thermogravimetric experiments were carried out under inert and reactive gas environments to investigate the kinetics of the devolatilization and gasification stages of biomass decomposition. Since tar derived from biomass pyrolysis is a major concern for many biomass conversion techniques, the cracking of biomass derived light tar using iron oxide-based composites was also investigated in a fixed bed reactor. Furthermore, a bench scale moving bed reactor was used to study the feasibility of biomass chemical looping in both cocurrent and countercurrent gas–solid contact modes.

Evaluation of multi-functional iron-based carrier from bauxite residual for H2-rich syngas production via chemical-looping gasification

“…Chemical looping combustion (CLC) is a highly-efficient technology for fossil fuel combustion and CO 2 capture by avoiding the energy intensive gas separation step [1], and is considered to be one of the most advanced technologies for carbon sequestration according to the U.S. DOE Innovative CO 2 Control Technology Road Map [2]. The application of chemical looping to fuel conversion or syngas production could reduce the energy penalties for air separation or CO 2 capture.…”

“…The same reaction scheme can be used for solid fuels for syngas production. Interest in this technology, using coal and biomass, is currently increasing due to the abundance of these resources [2][3][10][11]. The gasification agent, usually H 2 O or a mix of CO 2 and H 2 O, has been used to fluidize bed materials in the fuel reactor (FR).…”

Biomass-based chemical looping technologies: the good, the bad and the future

“…109 Studies using iron-based oxygen carriers in a moving bed reactor have shown that these oxygen carriers can crack tar at high temperatures (900 1C). 154 Similar studies have shown that volatile biomass tars are effectively cracked over both oxidised and reduced Fe-based carriers (both supported and unsupported). Carbon deposition was found to be reversible and not to affect the cycling behaviour, 155 although it unfavourably affects the carbon capture by transferring carbon to the air reactor.…”

Investigations into the effects of volatile biomass tar on the performance of Fe-based CLC oxygen carrier materials

“…To date, research efforts have predominantly focused on the development of a CLC technology using fossil fuels such as natural gas [4,[8][9][10][11], coal [12][13][14][15][16][17] and pet coke [18][19][20]; however over the last few years there has been growing interest in the application of CLC technology for biomass utilisation [21][22][23][24][25]. Bioenergy-CCS (BECCS) processes are of particular interest as they have the potential to result in negative CO 2 emissions i.e.…”

“…A large proportion of biomass/CLC research has focused on the development of bio-syngas upgrading/ tar removal systems [24,30,31]. Larsson et al [32] studied ilmenite as a tar cracking catalyst to upgrade biosyngas from gasification of woody biomass in a 2-4 MW th interconnected fluidized bed system.…”