Search results for "cellulosic"
showing 10 items of 52 documents
Microbial production of biopolymers from the renewable resource wheat straw.
2014
Aims Production of poly-s-hydroxybutyrate (PHB) and the chemical basic compound lactate from the agricultural crop ‘wheat straw’ as a renewable carbon resource. Methods and Results A thermal pressure hydrolysis procedure for the breakdown of wheat straw was applied. By this means, the wheat straw was converted into a partially solubilized hemicellulosic fraction, consisting of sugar monomers, and an insoluble cellulosic fraction, containing cellulose, lignin and a small portion of hemicellulose. The insoluble cellulosic fraction was further hydrolysed by commercial enzymes in monomers. The production of PHB from the sugar monomers originating from hemicellulose or cellulose was achieved by …
Production of ethyl lactate by activated carbon-supported Sn and Zn oxide catalysts utilizing lignocellulosic side streams
2021
Abstract In this study, activated carbon-supported Sn and Zn oxide catalysts were prepared from hydrolysis lignin and used for the conversion of model solutions of trioses, hexoses, and lignocellulosic biomass hydrolysates to ethyl lactate. Both catalysts, SnO2@AC and ZnO@AC, were able to produce ethyl lactate in high yields. SnO2@AC was a more active and selective catalyst in triose (dihydroxyacetone) conversion, providing 99% yield to ethyl lactate. ZnO@AC, by contrast, was more selective in glucose and hydrolysate conversion, with a yield of 60% and 85%, respectively. The ethyl lactate yields were significantly higher than those from the optimized model solution experiments when using Zn…
Economic evaluation of introduction of poplar as biomass crop in Italy
2014
Abstract Lignocellulosic biomass production deriving from agro forest species, as well as poplar ( Populus spp.), has denoted an increase in last years in UE also thanks to a series of policies aimed at reducing emissions of greenhouse gases and promoting renewable sources. In Italy poplar represents the main agro forest species and it is cultivated according to two different methods: very Short Rotation Coppice (vSRC) and Short Rotation Coppice (SRC). The aim of this paper has been to evaluate the economic feasibility of poplar as energy crop in the southern Italy and specifically to consider its competitiveness with respect to conventional crops. In particular, an economic analysis in a r…
La spettroscopia di risonanza magnetica nucleare in stato solido per lo studio dello stato di conservazione di materiali cellulosici
2013
This work shows the potentiality of the solid state nuclear magnetic resonance (ss-NMR) technique applied to characterize cellulosic materials and the possibility of analyze small amounts of starting material within reasonable experimental time using a modern equipment. The NMR analyses were performed to assess the conservation state of a material in order to plan appropriate conservative and restorative interventions. 13C {1H} Cross Polarization (CP) Magic Angle Spinning (MAS) NMR was used to identify the paper and wood components and the crystalline degree of the cellulose. Besides, in wood holocellulose/lignin ratio and the condensation degree of the lignin were determined.
Cellulose Nanocrystals from Lignocellulosic Raw Materials
2017
Cellulose nanocrystals (CNCs) are unique, renewable top-down nano particles from which coatings with improved gas barrier properties and new functionalities can be prepared. In this paper, the potential for obtaining such high performing nanocrystals from low-cost lignocellulosic by-products or raw materials is proved by a comparison study on CNCs obtained both from cotton linters and kraft pulp, by means of the ammonium persulfate (APS) process. Morphological and chemical characterization of the nanocrystals obtained, as well as the main functional properties of the poly(ethylene terephthalate) coated films, showed quite similar characteristics and performances of CNCs obtained from pure c…
Water absorption and hydrothermal performance of PHBV/sisal biocomposites
2014
[EN] The performance of biocomposites of poly(hydroxybutyrate-co-valerate) (PHBV) and sisal fibre subjected to hydrothermal tests at different temperatures above the glass transition of PHBV (TH ¿ 26, 36 and 46 C) was evaluated in this study. The influences of both the fibre content and presence of coupling agent were focused. The water absorption capability and water diffusion rate were considered for a statistical factorial analysis. Afterwards, the physico-chemical properties of water-saturated biocomposites were assessed by Fourier-Transform Infrared Analysis, Size Exclusion Chromatography, Differential Scanning Calorimetry and Scanning Electron Microscopy. It was found that the water d…
Reactivity of cellulose during hydrothermal carbonization of lignocellulosic biomass
2020
Abstract Hydrothermal carbonization (HTC) of pure cellulose (CE) and birchwood (BW) samples was carried out at temperatures between 160 and 280 °C, 0.5 h residence time and biomass-to-water ratio 1:5, to investigate the reactivity of cellulose in lignocellulosic biomass. Thermogravimetric analysis (TGA) and Fourier transform infrared spectroscopy (FTIR) showed that the CE samples remained unaltered at temperatures up to 220 °C, but were significantly decomposed at 230 °C producing a thermal recalcitrant aromatic and high energy-dense material. FTIR showed that dehydration and aromatization reactions occurred at temperature equal or higher than 230 °C for the CE samples while a similar incre…
Artichoke (Cynara cardunculus L.) fibres as potential reinforcement of composite structures
2011
Abstract The aim of this paper is to examine the use of artichoke fibres as potential reinforcement in polymer composites. The fibres are extracted from the stem of artichoke plant, which grows in Southern Sicily. In order to use these lignocellulosic fibres as potential reinforcement in polymer composites, it is fundamental to investigate their microstructure, chemical composition and mechanical properties. Therefore, the morphology of artichoke fibres was investigated through electron microscopy, the thermal behaviour through thermogravimetric analysis and the real density through a helium pycnometer. The chemical composition of the natural fibres in terms of cellulose, lignin, and ash co…
Solid state 13C-NMR methodology for the cellulose composition studies of the shells of Prunus dulcis and their derived cellulosic materials.
2020
Lignocellulosic fibers and microcellulose have been obtained by simple alkaline treatment from softwood al- mond shells. In particular, the Prunus dulcis Miller (D.A.) Webb. was considered as a agro industrial waste largely available in southern Italy. The materials before and after purification have been characterized by 13C CPMAS NMR spectroscopy methodology. A proper data analysis provided the relative composition of lignin and holo- cellulose at each purification step and the results were compared with thermogravimetric analysis and FT-IR. To value the possibility of using this material in a circular economy framework, the fibrous cellulosic material was used to manufacture a handmade c…
Influence of Elevated Pressure on the Torrefaction of Wood
2016
The use of pressurized reactors in industrial processes can improve efficiency and economics. Torrefaction is a partial pyrolysis of lignocellulosic biomass designed to result in a solid product with improved fuel properties for utilization in combustion and gasification. In this work, the influence of elevated pressure on the torrefaction of wood has been investigated. Wood samples were torrefied using a pressurized thermogravimetric reactor (PTGR) with pressures of 0.1 to 2.1 MPa. The results indicate that reactor pressure, particle size of feedstock, and wood species are all factors in torrefaction yield improvements. Torrefaction at 2.1 MPa pressure improved the higher heating value (ca…