Claudia Antonetti

• University of Pisa

Alkyl levulinates (ALs) are strategic compounds for the development of sustainable energy transition. In this regard, the direct alcoholysis of fructose and inulin for the selective ethyl levulinate (EL) production was investigated with a One‐Factor‐At‐a‐Time (OFAT) approach employing diluted H2SO4 as catalyst to clarify the role of the main reacti...

Diphenolic acid, or 4,4-bis(4-hydroxyphenyl)pentanoic acid, represents one of the potentially most interesting bio-products obtainable from the levulinic acid supply-chain. It represents a valuable candidate for the replacement of bisphenol A, which is strongly questioned for its toxicological issues. Diphenolic acid synthesis involves the condensa...

Levulinic acid production by acid-catalyzed hydrothermal conversion of (ligno)cellulosic biomass generates significant amounts of carbonaceous hydrochar, which is currently considered a final waste. In this work, the hydrochar recovered after the levulinic acid production, was subjected to cascade pyrolysis and chemical activation treatments (by H3...

In this work, a three-step approach to isolate the main components of lignocellulosic cardoon, lignin and cellulose, was investigated. The raw defatted biomass, Cynara cardunculus, after steam explosion was subjected to a mild organosolv treatment to extract soluble lignin (L1). Then, enzymatic hydrolysis was performed to achieve decomposition of t...

The depletion of fossil resources makes the transition towards renewable ones more urgent. For this purpose, the synthesis of strategic platform-chemicals, such as 5-hydroxymethylfurfural (HMF), represents a fundamental challenge for the development of a feasible bio-refinery. HMF perfectly deals with this necessity, because it can be obtained from...

The transition from fossil resources to renewable ones represents a pressing need. The acidogenic fermentation of biomass-derived ethanol to carboxylic acids represents a novel and smart possibility, opening the way for the production of further value-added bio-products through cascade chemical approaches. In this work, the hydrogenation of commerc...

Commercial niobium and synthesized zirconium phosphates were tested as water-tolerant heterogeneous acid catalysts in the hydrothermal conversion of different bio-based substrates. Different acid-catalyzed reactions were performed using biomass-derived model compounds and more complex real lignocellulosic biomasses as the substrate. The conversion...

This work investigated the catalytic high‐pressure CO2 pretreatment of giant reed. CO2 is a renewable resource; its use does not generate chemical wastes and it can be easily removed and recycled. The effect of the addition of low concentrations of FeCl3 (0.16 wt %) and PEG 400 (1.0 wt %) on the hemicellulose hydrolysis to xylose and xylo‐oligosacc...

The cover feature image represents the role of carbon dioxide in the proposed biorefinery scheme based on CO2 capture by lignocellulosic biomass and the use of supercritical CO2 for the efficient pretreatment of giant reed under sustainable reaction conditions. The synergistic combination of supercritical CO2, FeCl3 and surfactant PEG400 allowed to...

The depletion of fossil resources is driving the research towards alternative renewable ones. Under this perspective, 5‐hydroxymethylfurfural (HMF) represents a key molecule deriving from biomass characterized by remarkable potential as platform chemical. In this work, for the first time, the hydrogenation of HMF in ethanol was selectively addresse...

Cutaneotrichosporon oleaginosus is an oleaginous yeast with several favourable qualities: It is fast growing, accumulates high amounts of lipids and has a very broad substrate spectrum. Its resistance to hydrolysis by-products makes it a promising biocatalyst for custom tailored microbial oils. C. oleaginosus can accumulate up to 60 wt.% of its bio...

Hydrolysis and butanolysis of lignocellulosic biomass are efficient routes to produce two valuable bio-based platform chemicals, levulinic acid and n-butyl levulinate, which find increasing applications in the field of biofuels and for the synthesis of intermediates for chemical and pharmaceutical industries, food additives, surfactants, solvents a...

5-hydroxymethylfurfural (HMF), accessible from various feedstocks, represents an important renewable platform-chemical, precursor for valuable biofuels and bio-based chemicals. In this work, the continuous hydrogenation of an aqueous solution of HMF to give strategic monomers, 2,5-bis(hydroxymethyl)furan(BHMF) and 2,5-bis(hydroxymethyl)tetrahydrofu...

p>In order to improve the lignin exploitation to added-value bioproducts, a mild chemical conversion route based on electrochemistry was investigated. For the first time, soda lignin Protobind™ 1000 (technical lignin from the pulp & paper industry) was studied by cyclic voltammetry to preliminarily investigate the effect of the main reaction parame...

Giant reed (Arundo donax L.) is a promising source of carbohydrates that can be converted into single cell oil (SCO) by oleaginous yeasts. Microbial conversion of both hemicellulose and cellulose fractions represents the key step for increasing the economic sustainability for SCO production. Lipomyces starkeyi DSM 70296 was cultivated in two xylose...

Alkyl levulinates (ALs) represent outstanding bio-fuels and strategic bio-products within the context of the marketing of levulinic acid derivatives. However, their synthesis by acid-catalyzed esterification of pure levulinic acid, or by acid-catalyzed alcoholysis of furfuryl alcohol, although relatively simple, is still economically disadvantageou...

Nowadays, the solvothermal conversion of biomass has reached a good level of development, and now it is necessary to improve the process intensification, in order to boost its further growth on the industrial scale. Otherwise, most of these processes would be limited to the pilot scale or, even worse, to exclusive academic investigations, intended...

Single cell oil (SCO) represents an outstanding alternative to both fossil sources and vegetable oils from food crops waste. In this work, an innovative two-step process for the conversion of cellulosic paper mill waste into SCO was proposed and optimised. Hydrolysates containing glucose and xylose were produced by enzymatic hydrolysis of the untre...

Since safety hazards can occur during the life of a Li-ion battery, understanding its behavior under abusive conditions is important for the development of a safe cell. In this work, overcharge tests on commercial Li-polymer cells were conducted in a climatic chamber, resulting in gas evolution. A comprehensive post-mortem analysis of the abused ce...

A two-step exploitation of the giant reed cellulose to glucose and levulinic acid, after the complete removal of the hemicellulose fraction, was investigated using FeCl3 as catalyst. In the first step, the microwave-assisted hydrolysis of cellulose to glucose was optimised by response surface methodology analysis, considering the effect of temperat...

The present investigation represents a concrete example of complete valorization of Eucalyptus nitens biomass, in the framework of the circular economy. Autohydrolyzed-delignified Eucalyptus nitens was employed as a cheap cellulose-rich feedstock in the direct alcoholysis to n-butyl levulinate, adopting n-butanol as green reagent/reaction medium, v...

Lignocellulosic biomass represents one of the most important feedstocks for future biorefineries, being a precursor of valuable bio-products, obtainable through both chemical and biological conversion routes. Lignocellulosic biomass has a complex matrix, which requires the careful development of multi-step approaches for its complete exploitation t...

The present work aimed to investigate and optimize the selective exploitation of hemicellulose and cellulose fractions of the energy crop Arundo donax L. (giant reed), to give xylose and levulinic acid, respectively. In order to improve the sustainability of this process, a microwave-assisted hydrolysis in the presence of FeCl3 was implemented usin...

Lignocellulosic biomass conversion to sugars represents the basis of future biorefineries, because sugars can be converted to valuable products through chemical or fermentative routes. In order to guarantee a sustainable bio-based economy, a multi-stage fractionation/conversion of biomass feedstock should be developed, in this way maximizing sugars...

In recent years, the replacement of fossil resources with renewable ones has received great interest, especially as regards the production of new valuable bio-products and bio-fuels, in order to replace the traditional petroleum-based ones. In this context, the exploitation of waste biomasses into added-value bio-chemicals is strongly encouraged. A...

5-hydroxymethylfurfural (HMF) is one of the most important renewable platform-chemicals, a very valuable precursor for the synthesis of bio-fuels and bio-products. In this work, the hydrogenation of HMF to two furan diols, 2,5-bis(hydroxymethyl)furan (BHMF) and 2,5-bis(hydroxymethyl)tetrahydrofuran (BHMTHF), both promising renewable monomers, was i...

5-hydroxymethyl-2-furaldehyde is one of the top 12 bio-based chemicals, precursor of renewable monomers and biofuels. This key molecule can be obtained from the dehydration of monosaccharides and polysaccharides. In this work, the synthesis of HMF from fructose and inulin was investigated in the presence of a wide range of metal salts adopting a tr...

Improvement of processes starting from renewable feedstocks to produce chemicals and biofuels up to now derived from fossil carbon feedstocks is paramount to creating environmentally sustainable industrial processes. Guerbet condensation of ethanol to give n-butanol represents a turning point not only respect to the traditional petrochemical “oxo”...

The ruthenium compounds [(η6-p-cymene)RuCl(κ2N-(HCNR)2)]NO3 (R = 4-C6H4Me, [1]NO3; 4-C6H4OH, [2]NO3; C6H11 = Cy, [3]NO3; 4-C6H10OH, [4]NO3; tBu, [5]NO3) were prepared in high yields from [(p-cymene)RuCl2]2, AgNO3 and the appropriate α-diimine. Compounds [2]PF6 and [4]PF6 were obtained by straightforward reaction of [(η6-p-cymene)RuCl(MeCN)0.66]PF6,...

A cascade strategy for the catalytic valorization of aqueous solutions of levulinic acid as well as of γ-valerolactone to 2-methyltetrahydrofuran or to monoalcohols, 2-butanol and 2-pentanol, has been studied and optimized. Only commercial catalytic systems have been employed, adopting sustainable reaction conditions. For the first time, the combin...

Nowadays, the transformation of lignocellulosic biomass into added-value products such as reducing sugars is attracting great attention. Pentose and hexose sugars are very important industrial intermediates because they represent a versatile platform for the synthesis of several valuable compounds through chemical or biotechnological approaches. Th...

In recent years, the replacement of fossil resources with renewable ones has focused great interest, expecially as regards the production of new valuable bio-products and bio-fuels, in progressive replacement of the traditional petroleum-based ones.The Waste Management Policy strongly encourages the valorization of waste biomasses into added-value...

Levulinic acid is a platform chemical obtained from acid-catalyzed hydrothermal conversion of cellulose-rich biomass. The low amounts of solid biomass which can be handled in the reactor limit the levulinic acid concentration in the aqueous stream, making the economic viability of the aqueous phase process unsuitable for large scale applications. N...

Eucalyptus globulus wood samples were subjected to preliminary aqueous processing to remove water-soluble extractives and hemicelluloses, and the resulting solid (mainly made up of cellulose and lignin) was employed as a substrate for converting the cellulosic fraction into mixtures of levulinic and formic acid through a sulfuric acid-catalyzed rea...

Furfural was produced in biphasic media using a microwave-heated reactor. Diverse substrates were considered: xylose (considered as a reference compound) or hemicellulosic saccharides from Eucalyptus globulus wood or corncobs. Operation was carried out at 170°C for the desired reaction time in the presence of an acidic catalyst (sulfuric acid or HC...

Up to now, on the industrial scale, the acid-catalysed hydrothermal conversion of lignocellulosic biomass has been targeted to the production of levulinic acid (LA), while the lignin fate has been neglected, and its use has been limited at most to the energy recovery. Now, an integrated investigation of the hydrothermal process for the synthesis of...

5-hydroxymethyl-2-furaldehyde (HMF) can be obtained from the hexose fraction of lignocellulosic biomass and its catalytic exploitation represents a big challenge for sustainability. Environmentally friendly oxidation of aqueous HMF to give 5-hydroxymethyl-2-furancarboxylic acid (HFCA) and 2,5-furandicarboxylic acid (FDCA) was now studied through he...

For the first time, the exploitation of hazelnut shells for the combined production of levulinic acid (LA) and hydrochar was investigated. The optimization of the catalytic hydrothermal treatment was performed both in autoclave and microwave reactor, approaching a maximum LA yield of∼9-12 wt%. Hydrochars recovered with high yield (∼43-47 wt%) were...

The chemical characterization of shell and cuticle from Tonda Gentile Romana hazelnut was carried out using analytical pyrolysis in the presence of hexamethyldisilazane followed by gas chromatography-mass spectrometry analysis (Py(HMDS)-GC/MS) and high-performance liquid chromatography with diode-array detection (HPLC-DAD). The aim was to acquire a...

Flexible polyurethane foams were prepared from solid waste residue derived from the hydrothermal acid treatment of the Arundo donax L. herbaceous biomass, which produced a very high yield of levulinic acid. An innovative, sustainable, and green liquefaction route was adopted to produce lignin-based flexible polyurethane foams by partially replacing...

5-Hydroxymethyl-2-furaldehyde (HMF) is a biomass-derived intermediate for the sustainable production of monomers and biofuels. However, most of its syntheses are performed under not environmentally and/or economically green conditions. In this work, the dehydration of fructose/inulin to HMF was optimized, employing aqueous medium, high substrate co...

5-hydroxymethyl-2-furaldehyde (HMF) is a key bio-based platform for the production of renewable monomers and bio-fuels. However, most of its syntheses are carried out under not sustainable conditions. In this work, the production of HMF from fructose and inulin was investigated following the Green Chemistry principles, adopting aqueous medium, appr...

Levulinic acid (LA) is one of the top bio-based platform molecules that can be converted into many valuable chemicals. It can be produced by acid catalysis from renewable resources, such as sugars, lignocellulosic biomass and waste materials, attractive candidates due to their abundance and environmentally benign nature. The LA transition from nich...

The removal of polychlorinated biphenyls (PCBs) both from siloxane transformer oil and hydrocarbon engine oil was investigated through the application of microwave (MW) irradiation and a reaction system based on polyethyleneglycol (PEG) and potassium hydroxide. The influence of the main reaction parameters (MW irradiation time, molecular weight of...

Recycled paper needs a lot of mechanical/chemical treatments for its re-use in the papermaking process. Some of these ones produce considerable rejected waste fractions, such as "screen rejects", which include both cellulose fibers and non-fibrous organic contaminants, or "stickies", these last representing a shortcoming both for the papermaking pr...

Background: Autohydrolysis of lignocellulosic biomass in liquid hot water has been widely studied owing to its high efficiency and relatively low cost. In the perspective of industrial applications, continuous or semi-continuous processes are more interesting than batch systems. Moreover, microwave heating of pretreatment systems has been proposed...

The characterization of the solid residue coming from the acid hydrolysis of giant reed (Arundo Donax L.) herbaceous biomass was performed and compared with the characteristics of two commercial technical lignins, i.e. a soda and a sulphate (kraft) one, in order to ascertain their differences, and thus better address their successive possible appli...

[PdCl2(dppb)] is highly active in the catalytic CO-ethene copolymerization in H2O-H(CH2)nCOOH (n = 0, 1 or 2). The influence on the productivity, the limiting viscosity number and the average viscosity molecular weight MW¯v of the following reaction conditions is investigated: (i) solvent composition; (ii) temperature; (iii) CO and ethene partial p...

The hydrothermal conversion of giant reed (Arundo donax L.) to furfural (FA) and levulinic acid (LA) was investigated in the presence of dilute hydrochloric acid. FA and LA yields were improved by univariate optimization of the main reaction parameters: concentration of the acid catalyst, solid/liquid ratio of the reaction mixture, hydrolysis tempe...

The acid-catalysed ketalization between ethyl levulinate and two different alkyl 1,2-diols (ethylene glycol and 1,2-dodecanediol) was investigated using different acid catalysts, e.g. p-toluensolfonic acid, Amberlyst 70, zeolite H-ZSM-5 and niobium phosphate. Good activity and recyclability were achieved in the reaction with ethylene glycol catalyz...

Today, the sustainable growth of the chemical and energy industries has become an indispensable benchmark of our society and the current development of the industrial sector based on fossil resources must be replaced by an alternative one, linked to renewable resources. By 2030, 30 % of the chemicals and materials production in Europe will be bio-...

An inductive measurement method was adopted to analyze the magnetic properties of magnetite nanopowders and the possibility to prepare samples having the same geometry is discussed from a macroscopic point of view. The influence of the chemical composition on magnetic and morphological characteristics of the samples was investigated by several meas...

This paper deals with the characterization of magnetic iron oxide nanoparticles. Pure magnetite (Fe3O4) and noble metal doped magnetite were synthesized following a new sustainable microwave-assisted method. Furthermore, an experimental analysis was carried out to investigate the chemical and magnetic properties of these new nanopowders. Morphologi...

La sostituzione delle materie prime fossili con quelle rinnovabili rappresenta una necessità sempre più stringente sia in ambito energetico sia della chimica degli intermedi e dei materiali. Si stima infatti che nel 2030 il 30 % della produzione di composti chimici sarà bio-based. La conversione catalitica dei rinnovabili è un argomento estremament...

A semiquantitative analysis by means of midinfrared FT-IR spectroscopy was tuned for the simultaneous determination of cellulose, hemicellulose, and lignin in industrial crops such as giant reed (Arundo donax L.) and switchgrass (Panicum virgatum L.). Ternary mixtures of pure cellulose, hemicellulose, and lignin were prepared and a direct correlati...

An organic-inorganic hybrid material, PK-SiO2 (PK = polyketone), was employed as support for Pd catalysts. Their synthesis was carried out by MW irradiation of an ethanol solution of Pd(OAc)2 in the presence of the support. The obtained systems were characterized by solid state NMR, SEM, TEM, ICP, XPS, BET, gas porosimetry and tested in two probe r...

A novel catalytic system based on palladium supported on chitosan was synthesized adopting a MW-assisted process. This synthetic approach results efficient under mild reaction conditions and very short microwave irradiation times. The prepared catalyst was employed in the hydrogenation of ethyl cinnamate (EC) to ethyl hydrocinnamate (EHC) adopting...

Lignocellulosic biomass can be converted by hydrothermal treatments into interesting platform chemicals, such as high energy furan liquids. This route represents a sustainable solution to the increasing demand of these compounds, allowing security of supply and economic advantage, in particular when cheap raw materials or agricultural residues are...

For the first time, copper nanoparticles were synthesized under microwave (MW) irradiation in the absence of any stabilizing agent. A 2-step synthetic approach was adopted working in basic ethanol solution and then ascorbic acid was added as a reducing reagent in the second step. The obtained copper nanoparticles were characterized by UV-vis spectr...

Magnetic iron oxide nanoparticles, in particular magnetite (Fe 3 O 4) and maghemite (γ-Fe 2 O 3), with a ferromag-netic behavior at room temperature, find many technological employments, not only as sensors, optical devices, medicine applications but also in the synthesis of magnetically separable catalysts [1]. In fact, catalysts separation and re...

The acid hydrothermal conversion of a non-food dedicated feedstock – giant reed (Arundo donax L.) – to levulinic acid (LA) was investigated. LA is a versatile intermediate for the production of biofuels and bio-based chemicals. LA was subsequently hydrogenated to γ-valerolactone (GVL), a sustainable liquid and valuable fuel additive and a precursor...

A novel catalytic system based on palladium supported on chitosan was synthesized adopting a MW-assisted process. This synthetic approach results efficient under mild reaction conditions and very short microwave irradiation times. The prepared catalyst was employed in the hydrogenation of ethyl cinna-mate (EC) to ethyl hydrocinnamate (EHC) adopting...

For the first time, copper nanoparticles were synthesized under microwave (MW) irradiation in the absence of any stabilizing agent. A 2-step synthetic approach was adopted working in basic ethanol solution and then ascorbic acid was added as a reducing reagent in the second step. The obtained copper nanoparticles were characterized by UV–vis spectr...

For the first time, polyketone (poly-3-oxotrimethylene, PK) has been employed as support for Pd nanoparticles. Three different approaches have been adopted: (i) reduction of Pd(OAc)2 in EtOH under microwave irradiation, (ii) hydrothermal reduction of the same precursor in EtOH or n-BuOH employing traditional heating and (iii) vaporization of Pd met...

Carbon nanotubes (CNTs) have been employed for the preparation of supported ruthenium nanoparticles using, for the first time, a low boiling alcohol or a mixture ethanol/water as solvent/reducing agent under microwave irradiation as heating source. These systems were employed as catalysts in the selective hydrogenation of p-chloronitrobenzene (p-CN...

Two analytical procedures based on gas chromatography and mass spectrometry were used to study the compositions of a wild population and a selected clone (Torviscosa) of giant reed (Arundo donax L.), one of the most promising biomass both in terms of energy and fine chemicals production. Gas chromatography/mass spectrometry (GC/MS) was used to char...

The hydrothermal conversion of waste biomass to levulinic acid was investigated in the presence of homogeneous acid catalysts. Different cheap raw materials (poplar sawdust, paper mill sludge, tobacco chops, wheat straw, olive tree pruning) were employed as substrates. The yields of levulinic acid were improved by optimization of the main reaction...

A sustainable process for the hydrogenation of levulinic acid (LA) to γ-valerolactone (GVL) is reported. GVL can be easily obtained in high yield, adopting very mild reaction conditions, by the hydrogenation of an aqueous solution of levulinic acid using a commercial ruthenium supported catalyst in combination with a heterogeneous acid co-catalyst,...

The hydrothermal conversion of waste biomass to levulinic acid was investigated in the presence of homogeneous acid catalysts. Different cheap raw materials (poplar sawdust, paper mill sludge, tobacco chops, wheat straw, olive tree pruning) were employed as substrates. The yields of levulinic acid were improved by optimization of the main reaction...

A variety of measurements indicates that Au nanoparticle- catalyzed Sonogashira coupling of iodobenzene and phenylacetylene is predominantly a heterogeneous process. Large gold particles are much more selective than small ones, which is consistent with this view. Substantial leaching of Au into the solution phase occurs during the reaction, but the...

An efficient and highly reproducible process for the microwave-assisted solvothermal synthesis of palladium nanoparticles has been carried out adopting mild reaction conditions and very short microwave irradiation times. Colloidal nanoparticles have straightforwardly been obtained by the direct irradiation of an ethanol solution of Pd(OAc)2 in the...

The development of greener chemical processes is becoming more and more important because this approach moves towards sustainable methods and products, minimizing pollution and risks for human health and environment. In these perspectives, microwaves seem to fulfil these requirements; in this context, we have tested a novel method both for the synt...

An efficient, reproducible process for the solvothermal synthesis of Ru/γ-Al2O3 nanocatalysts has been developed. This synthesis employs a low boiling point alcohol acting as solvent and reducing agent. The reaction is performed in autoclave under nitrogen overpressure, by heating the solution of metal precursor and stabilizing agent in the presenc...

An efficient, cheap and safe process for the solvothermal synthesis of ruthenium nanocatalysts has been developed: it involves the innovative use of a microwave (MW) applicator for the in situ activation of the reaction in a stirred glass vessel without resorting to an oven. The synthesis was carried out by direct MW irradiation of an alcohol or gl...