Fast pyrolysis of biomass is an attractive way to produce bio-oil since it can convert most of biomass components directly into liquid fuel. However, the bio-oils obtained from such a fast pyrolysis process always hav...Fast pyrolysis of biomass is an attractive way to produce bio-oil since it can convert most of biomass components directly into liquid fuel. However, the bio-oils obtained from such a fast pyrolysis process always have highly complex oxygenated compounds with high viscosity, serious corrosivity, and rather instability. Thus, before the raw bio-oils are used as fuel or chemical feedstock, they must be upgraded, especially deoxygenated. Cracking of bio-oils over porous solid catalysts such as zeolite-based catalysts at ambient pressure is considered one of effective ways for the bio-oil upgrading, especially in which hydrogen gas is not necessary. Herein, zeolite-based catalysts (mainly HZSM-5 based catalysts) for the upgrading of pyrolysis bio-oils are critically reviewed. The effects of porous structure, acidity and other parameters including biomass type, biomass/catalyst ratio and operation temperature on cracking activity, selectivity, stability and deactivation are summarized. While, the proposed mechanisms on the bio-oil upgrading over the zeolite-based catalysts and the possibility for the application of the developed catalysts in the industrial process are discussed. Furthermore, the main strategies including metal modification, construction of zeolites with a hierarchical structure and synthesis of special morphologies with hollow structure or core/shell structure and nanosheet structures for the improvement of deoxygenation property performance are introduced. It is expected to provide a guidance for the design and fabricate more excellent zeolite-based catalysts and their application for high-quality bio-oil production from fast biomass pyrolysis.展开更多
In this work,to efficiently utilize waste fruit and low-rank coal for the hydrogen(H_(2))-rich syngas production,steam co-gasification of banana peel(BP)and brown coal(BC)was studied in a fixed-bed reactor.The results...In this work,to efficiently utilize waste fruit and low-rank coal for the hydrogen(H_(2))-rich syngas production,steam co-gasification of banana peel(BP)and brown coal(BC)was studied in a fixed-bed reactor.The results showed that the gasification rate of BC was highly enhanced after mixing it with BP and the obvious synergistic effect was observed in all investigated three mixing weight ratios(i.e.,1:1,1:4,4:1),resulting in a higher carbon conversion as well as a H_(2)-rich gas production yield for the co-gasification.However,the extent of promotion by synergistic effect was affected by the reaction temperature,mixing ratio,and steam amount.It was found that the high potassium(K)species content in the BP provided the catalytic effect not only on water-gas shift reaction but also on tar reforming/cracking,thereby enhancing the gasification of BC.In addition,it is confirmed that steam should be an important factor to promote the synergistic effect and H_(2)-rich gas production.展开更多
文摘Fast pyrolysis of biomass is an attractive way to produce bio-oil since it can convert most of biomass components directly into liquid fuel. However, the bio-oils obtained from such a fast pyrolysis process always have highly complex oxygenated compounds with high viscosity, serious corrosivity, and rather instability. Thus, before the raw bio-oils are used as fuel or chemical feedstock, they must be upgraded, especially deoxygenated. Cracking of bio-oils over porous solid catalysts such as zeolite-based catalysts at ambient pressure is considered one of effective ways for the bio-oil upgrading, especially in which hydrogen gas is not necessary. Herein, zeolite-based catalysts (mainly HZSM-5 based catalysts) for the upgrading of pyrolysis bio-oils are critically reviewed. The effects of porous structure, acidity and other parameters including biomass type, biomass/catalyst ratio and operation temperature on cracking activity, selectivity, stability and deactivation are summarized. While, the proposed mechanisms on the bio-oil upgrading over the zeolite-based catalysts and the possibility for the application of the developed catalysts in the industrial process are discussed. Furthermore, the main strategies including metal modification, construction of zeolites with a hierarchical structure and synthesis of special morphologies with hollow structure or core/shell structure and nanosheet structures for the improvement of deoxygenation property performance are introduced. It is expected to provide a guidance for the design and fabricate more excellent zeolite-based catalysts and their application for high-quality bio-oil production from fast biomass pyrolysis.
基金supported by JST Grant Number JPMJPF2104 and Hirosaki University Fundthe scholarship from the Ministry of Education,Culture,Sport,Science and Technology(MEXT)of Japan.
文摘In this work,to efficiently utilize waste fruit and low-rank coal for the hydrogen(H_(2))-rich syngas production,steam co-gasification of banana peel(BP)and brown coal(BC)was studied in a fixed-bed reactor.The results showed that the gasification rate of BC was highly enhanced after mixing it with BP and the obvious synergistic effect was observed in all investigated three mixing weight ratios(i.e.,1:1,1:4,4:1),resulting in a higher carbon conversion as well as a H_(2)-rich gas production yield for the co-gasification.However,the extent of promotion by synergistic effect was affected by the reaction temperature,mixing ratio,and steam amount.It was found that the high potassium(K)species content in the BP provided the catalytic effect not only on water-gas shift reaction but also on tar reforming/cracking,thereby enhancing the gasification of BC.In addition,it is confirmed that steam should be an important factor to promote the synergistic effect and H_(2)-rich gas production.
