The production of future transportation fuels and chemicals requires the deployment of new catalytic processes that transform biomass into valuable products under competitive conditions. Furfural has been identified as one of the most promising chemical platforms directly derived from biomass. With an annual production close to 300 kTon, furfural is currently a commodity chemical, and the technology for its production is largely established. The aim of this review is to discuss the most relevant chemical routes for converting furfural to chemicals, biofuels, and additives. This review focuses not only on industrially produced chemicals derived from furfural, but also on other not yet commercialised products that have a high potential for commercialisation as commodities. Other chemicals that are currently produced from oil but can also be derived from furfural are also reviewed. The chemical and engineering aspects such as the reaction conditions and mechanisms, as well as the main achievements and the challenges still to come in the pursuit of advancing the furfural-based industry, are highlighted.

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Furfural: a renewable and versatile platform molecule for the synthesis of chemicals and fuels

https://onlinelibrary.wiley.com/doi/pdf/10.1002/est2.35

Hydrogen storage in carbon materials—A review

Ultra-lightweight cellulose aerogels can be obtained inthree steps: (1) preparation of a cellulose solution inmolten N -methylmorpholine- N -oxide monohydrate(NMMOOH 2 O) at 110–1208C and casting of the viscousmass into moulds; (2) extraction of the solidified castingswith ethanol to initiate cellulose aggregation and toremove NMMOOH 2 O so that the fragile, fine-porous tex-ture of cellulose II is largely retained; and (3) drying ofthe lyogel using supercritical carbon dioxide (scCO 2 ).According to this approach, cellulosic aerogels were pre-pared from eight commercial cellulosic materials andpulps and analysed for selected chemical, physicochem-ical and mechanical parameters. The results reveal thatall aerogels obtained from 3% cellulose containingNMMOOH 2 O melts had a largely uniform mesoporousstructure with an average pore size of ;9–12 nm, sur-face area of 190–310 m 2 g -1 , and specific density of0.046–0.069 g cm -3 , but rather low mechanical stabilityexpressed as compressive yield strain of 2.9–5.5%. Allsamples showed viscoelastic behaviour, with Young’smodulus ranging from ;5to10Nmm

Cellulosic aerogels as ultra-lightweight materials. Part 2: Synthesis and properties.

https://hal.archives-ouvertes.fr/hal-00265722/document

Hydrogen storage by adsorption on activated carbon: Investigation of the thermal effects during the charging process

An overview of the synthesis conditions and mechanisms for the fabrication of different types of carbon aerogels, as well as the structural and functional properties of these materials, is presented here. In this overview, carbon aerogels are classified into three major categories: (i) conventional pyrolyzed organic-based carbon aerogels, which are products of the pyrolysis process of organic aerogels; (ii) self-assembled carbon aerogels, which are products of a reduction process; and (iii) nanocomposite carbon aerogels. Synthesis mechanisms for the sol–gel process of organic aerogels are reviewed using different mechanisms suggested in the literature. Moreover, the overall fabrication process of self-assembled carbon aerogels (graphene and carbon nanotube aerogels) is covered and the suggested mechanism for the gelation process of self-assembled carbon aerogels during the reduction process is investigated using reported mechanisms. The structural performance and functional properties (electrochemical and thermal properties) of different types of carbon aerogels are covered in detail. Moreover, different structural features of carbon aerogels and the influence of synthesis conditions on these structural characteristics are assessed and compared. Based on the literature results covered in this review paper, carbon aerogels are perfect candidates for the fabrication of ultra-low density supercapacitors, as well as thermal insulating materials.

Self-assembled and pyrolyzed carbon aerogels: an overview of their preparation mechanisms, properties and applications

Carbon aerogels were prepared by sol-gel polymerization of phenolic novolak and furfural followed by supercritical drying and pyrolysis. The porosity and morphologies of carbon aerogels were characterized by nitrogen adsorption, apparent density, He- pycnometer method, and transmission electronic microscopy (TEM). Effect of ratios of phenolic novolak to furfural (Ra) and total concentration of reactants (C) in sol-gel step on porosity and morphologies of carbon aerogels was investigated. The carbon aerogels synthesized are rich in meso- and macropores. The Ra determines the cross-linking density of polymers, thereby the compatibility of the polymers, and ultimately the shrinkage of gels in the drying and pyrolysis. The network sizes and the porosity of organic and carbon aerogels are mainly determined by Ra. The C has no effect on volume shrinkage of gels in drying and pyrolysis and has only dilute effect in determining bulk density of organic and carbon aerogels, and ultimately the porosity of carbon aerogels. Conversion of mesopores to micro- and macropores is observed, which is related to combination of C and Ra, and determines the partition of micro-, meso- and macropores.

On Porosity of Carbon Aerogels from Sol-Gel Polymerization of Phenolic Novolak and Furfural

Hydrogels (HG) were prepared by the sol-gel polymerization of phenolic resole, m-cresol resole and methylolated melamine mixtures with different recipes in basic aqueous solution at 85 degreesC for 5 days Water in the HG was displaced by acetone to obtain acetone gels (AG) Organic aerogels (OA) were obtained by drying of AG under supercritical carbon dioxide Small angle X-ray scattering (SAXS) using synchrotron radiation as X-ray source was employed to investigate microstructure of HG, AG and OA It is found that physical cross-linking is dominant in HG and supercritical drying of the physically dominant cross-linked gels cause the following microstructure changes: (1) random growth of large scatterers that "bury" the scattering peak; (2) shrinking of gels; (3) deswelling of gel network and (4) evolution of gel structure from tangled or rough interface to smooth or flat interface (C) 2003 Elsevier BV All rights reserved

Small angle X-ray scattering study of microstructure changes of organic hydrogels from supercritical carbon dioxide drying

A Linear Comprehensive Adsorption Model of Hydrogen on Super Activated Carbon under Supercritical Conditions

A shaped activated carbon electrode with high specific capacitance for capacitor is prepared from the Mn and Co carried activated carbon powder with high specific surface area (more than 3000 sq.m/g)and binder through proportional mixing, die pressing at 120-150 deg.c and 5-20 MPa for 10 min, and high temp charrging at 700-900 deg.C. Its advantages are high yield (60-80%) and high specific capacitance (200-265 F/g).

Method for mfg. high specific capacitance formed active carbon electrode

A process for increasing the specific capacitance of mesoporous activated carbon by doping cheap metal includes such steps as proportionally mixing phenolic resin, Cu (CH3COO)2 or Ni(CH3COO)2, ferrocene, hexamethinetetraamine and methanol, solidifying at 150-180 deg.C for 3-5 hr, carbonizing at 700-900 deg.c and activating with steam for 0.5-2 hr. Its advantages are high specific capacitance (130F/g), high charge-discharge efficiency up to 99% or more, and high stability.

Meng Qinghan

Papers

On Porosity of Carbon Aerogels from Sol-Gel Polymerization of Phenolic Novolak and Furfural

Small angle X-ray scattering study of microstructure changes of organic hydrogels from supercritical carbon dioxide drying

A Linear Comprehensive Adsorption Model of Hydrogen on Super Activated Carbon under Supercritical Conditions

Method for mfg. high specific capacitance formed active carbon electrode

Method of increasing mesopore actire carbon specific capacitance by mixing with cheap metal