Low temperature microwave-assisted vs conventional pyrolysis of various biomass feedstocks

A comparison between conventional pyrolysis and a novel developed low-temperature microwave-assisted pyrolysis methodology has been performed for the valorisation of a range of biomass feedstocks including waste residues. Microwave pyrolysis was found to efficiently deliver comparable evolution of bio-gases in the system as compared with conventional pyrolysis at significantly reduced temperatures （120-180 ℃vs 250-400 ℃）. The gas obtained from microwave-assisted pyrolysis was found to contain CO2, CH4 and CO as major components as well

绿色化学——化学工业走向可持续发展和具有竞争力的有效途径

绿色化学是化学工业走向可持续发展和具有竞争性的有效途径,并日益为政府、工业界及公众接受为社会、经济及环境发展的必要目标。本文对绿色化学的概念、进展及实践作了评介。

Electrochemical Biorefinery toward Chemicals Synthesis and Bio-Oil Upgrading from Lignin

Recalcitrance and the inherent heterogeneity of lignin structure are the major bottlenecks to impede the popularization of lignin-based chemicals production processes.Recent works suggested a promising pathway for lignin depolymerization and lignin-derived bio-oil upgrading via an electrochemical biorefinery(a process in which lignin valorization is performed via electrochemical oxidation or reduction).This review presents the progress on chemicals synthesis and bio-oil upgrading from lignin by an electrochemical biorefinery,relating to the lignin biosynthesis pathway,reaction pathway of lignin electrochemical conversion,inner-sphere and outer-sphere electron transfer mechanism,basic kinetics and thermodynamics in electrochemistry,and the recent embodiments analysis with the emphasis on the respective feature and limitation for lignin electrochemical oxidative and reductive conversion.Lastly,the challenge and perspective associated with lignin electrochemical biorefinery are discussed.Present-day results indicate that more work should be performed to promote efficiency,selectivity,and stability in pursuing a lignin electrochemical biorefinery.One of the most promising developing directions appears to be integrating various types of lignin electrochemical conversion strategies and other existing or evolving lignin valorization technologies.This review aims to provide more references and discussion on the development for lignin electrochemical biorefinery.

Highly efficient NHC-iridium-catalyzedβ-methylation of alcohols with methanol at low catalyst loadings

The methylation of alcohols is of great importance since a broad number of bioactive and pharmaceutical alcohols contain methyl groups.Here,a highly efficientβ-methylation of primary and secondary alcohols with methanol has been achieved by using bis-N-heterocyclic carbene iridium(bis-NHC-Ir)complexes.Broad substrate scope and up to quantitative yields were achieved at low catalyst loadings with only hydrogen and water as by-products.The protocol was readily extended to theβ-alkylation of alcohols with several primary alcohols.Control experiments,along with DFT calculations and crystallographic studies,revealed that the ligand effect is critical to their excellent catalytic performance,shedding light on more challenging Guerbet reactions with simple alcohols.

Textile waste-an opportunity as well as a threat

Clothing and textiles are very challenging to recycle due to the fact that they are nearly always a blend of fibres from different types of polymers.There are some promising early indications that new green solvents including CyreneTM and TMO as well as some simple ionic liquids can be used to aid recycling of complex fabrics by selective dissolution of one of the component polymers.A viable process for the future valorisation of many waste fabrics should be designed to maximise the creation of valuable product streams while also minimising any waste.

Urgently reveal longly hidden toxicant in a familiar fabrication process of biomass-derived environment carbon material

Biomass-derived N-doped carbon(BNC)is an important environmental material and widely used in the fields of water purification and soil remediation.However,the toxicant in the commonly used synthesis process of BNC materials have been largely ignored.Herein,we firstly report the presence of a highly toxic by-product(KCN)in the activation process of BNC materials consequential of the carbothermal reduction reaction.Because this carbothermal reduction reaction also regulates the N-doping and pore development of BNC materials,the KCN content directly relates with the properties of BNC material properties.Accordingly,a high KCN content(-611 mg)can occur in the production process of per g BNC material with high specific surface area(-3600 m^2/g).Because the application performance of BNC material is determined by the surface area and available N doping,therefore,production of a BNC material with high performance entails high risk.Undoubtedly,this study proves a completely new risk recognition on a familiar synthesis process of biomass-based material.And,strict protective device should be taken in fabrication process of biomass-derived carbon material.

Phosphine ligands featuring C-N chiral axis applicable to tetra-ortho-substituted biaryl synthesis

Asymmetric catalysis has been one of the most effective strategies for building up a chirality in the favored stereoisomer. Over the past decades, various sophisticated chiral ligands and catalysts have been well-designed, which enable great advances in enantioselective chemical transformations, for achieving excellent selectivity and activity.