Phenindione

In recent years, biomass oxy-fuel gasification has prompted increased interest for its ability to produce a gas with low tar content and to assist in carbon reductionIt is noteworthy that the type of atm. is a crucial factor influencing the devolatilization process in biomass gasification and the specific mechanisms by which an oxy-fuel atm. influences the devolatilization process remain inadequately explored.This work aimed to investigate the effect of various reaction atmospheres on devolatilization behavior, reaction kinetics, intermediate product formation, and biochar functional groups (BFGs) evolution.In comparison to an inert atm., the oxy-fuel atm. facilitated the release of volatiles, and enhanced energy self-sustainability within the devolatilization system.The presence of O₂ and CO₂ promoted the generation of potential anhydrosugars while suppressing the formation of phenolic compoundsThe synergistic effect present in the oxy-fuel atm. augments the exothermic effect and promotes the release of volatile and alkane gases during the devolatilization process.Furthermore, as oxygen concentrations increased in the reaction atm., the sequential response of BFGs primarily followed the order: C-O → aromatic ring → C-OH/C-H/COO- → C=O.Moreover, advanced characterization analyses revealed that the oxy-fuel environment was more effective in promoting the aromatization and pore structure of biochar than an inert atm.Collectively, these findings have substantial implications for reaction modeling in biomass fixed-bed gasification under real gas atmospheres and guide future research on tar control strategies.

We present here a new method for the synthesis of 2-substituted-3-aryl benzoheterocycles through a more challenging constrained [1,5]-type Friedel-Crafts reaction/rearrangement and aromatization process. By using the readily available 2-aryoxy-1,3-indandiones and 2-arylamino-1,3-indandiones, a range of 2-substituted-3-aryl benzofurans and indoles were prepared in good to excellent yields (yields up to 86%) under the catalysis of CF₃SO₃H or Sm(OTf)₃. Compared with previous methods for constructing similar structures, this approach offers several advantages, including the use of easily accessible starting materials, mild reaction conditions, high yield, excellent regio- and diastereoselectivity, and a broad substrate scope.