Search results for "cellulosic"
showing 10 items of 52 documents
Manufacturing Cellulosic Fibres for Making Paper: A Historical Perspective
2018
The manufacture of pulp and paper is an important branch of industry worldwide and is based on complex and multidisciplinary technology. The production and modification of cellulosic fibre, which created the foundation for this industrial sector, has had a rich and colourful history. It has gone through many eras and its development has been closely integrated with the growth of our fundamental knowledge of chemistry and other natural sciences. During the last two decades, modern pulp and paper technologies have undergone some significant developments, especially ones involving the creation of a wide range of new options for different feedstock materials. Nevertheless, the fundamental conce…
Catalytic treatment of rapeseed straw for enhanced production of furfural and glucose for bioethanol production
2021
Abstract Ethanol produced from renewable biomass, such as lignocellulosic feedstock, is one of the most promising future biofuels. In this paper, rapeseed straw was tested as an abundant and cost-effective renewable resource material for the production of cellulosic glucose. Pre-treatment of this material is an important step to improve the efficiency of subsequent cellulose hydrolysis. In this study, we used two pre-treatment methods – hydrothermochemical and ultrasound. Studies have shown that, in the initial hydrothermal pre-treatment of rapeseed straw, Al2(SO4)3 may be used as an efficient catalyst, at least in procedures for obtaining glucose. An increase in the amount of this catalyst…
Un contributo dell'agricoltura all'ambiente: le agroenergie
2009
La crisi energetica che si sta registrando negli ultimi anni a livello mondiale, determinata da un progressivo esaurimento delle scorte di petrolio e da una crescente richiesta di energia da parte dei Paesi e-mergenti (Cina ed India, in particolare), ha riproposto l’esigenza di ri-correre a fonti alternative. Recenti studi, condotti dalla comunità scientifica, hanno dimostrato che, nel medio-lungo periodo, l’impiego di fonti rinnovabili può af-fiancare l’uso di combustibili fossili o, addirittura, diventarne un’alternativa. Tra queste, particolare importanza per il settore energetico siciliano assumono le cosiddette “agroenergie”, espressione di un’agricoltura multifunzionale legata non sol…
Dielectric and mechanical assessment of cellulosic insulation during transformer manufacturing
2021
Due to the impact of cellulose of paper insulation on transformer life, it is imperatire to remove moisture from the oil and the solid insulation. Several techniques have been implemented during manufacturing of power transformers to reduce water content in transformers. These drying processes can involve different costs and time, and they can damage the insulation paper. In this work, a drying process has been implemented in the laboratory trying to simulate the most aggressive conditions that can be suffered by the paper in transformer manufacturing in a real industry. Once the moisture content of papers was lower than 0.5%, the effect of the drying process on paper degradation was evalua…
Hybrid biocomposites based on polylactic acid and natural fillers from Chamaerops humilis dwarf palm and Posidonia oceanica leaves
2022
AbstractPlatelet-like and fibrous lignocellulosic fillers were achieved from the leaves of Chamaerops humilis (CHL) and Posidonia oceanica (POL) and used as a hybrid reinforcement for a polylactic acid (PLA) matrix at three different loading levels (from 5 to 20%). The materials were fully characterized from a morphological, physicochemical, mechanical, and dynamic-thermomechanical point of view. When compared to their counterpart containing either CHL or POL only, the resulting hybrid biocomposites showed the highest mechanical properties, with strengthening and stiffening effects respectively up to 120% and 50% higher than those expected from the linear combination of the two, and higher …
Effective saccharification of lignocellulosic barley straw by mechanocatalytical pretreatment using potassium pyrosulfate as a catalyst
2017
The catalytic conversion of lignocellulosic biomass is attractive due to the feasible generation of valuable products such as reducing sugars which constitute the basic substrates for chemical and transportation fuel production, as well as the production of renewable hydrogen. This study shows the efficient conversion of lignocellulose, especially hemicellulose, into reducing sugars such as xylose and galactose, by mechanocatalysis using potassium pyrosulfate, K2S2O7, as an effective salt catalyst. Ball milling was performed, introducing a mechanical force which, combined with chemical pretreatment, leads to reducing sugar yields (40%) almost as high as when commonly used sulfuric acid was …
Biogas production and saccharification of Salix pretreated at different steam explosion conditions.
2011
Abstract Different steam explosion conditions were applied to Salix chips and the effect of this pretreatment was evaluated by running both enzymatic hydrolysis and biogas tests. Total enzymatic release of glucose and xylose increased with pretreatment harshness, with maximum values being obtained after pretreatment for 10 min at 210 °C. Harsher pretreatment conditions did not increase glucose release, led to degradation of xylose and to formation of furfurals. Samples pretreated at 220 and 230 °C initially showed low production of biogas, probably because of inhibitors produced during the pretreatment, but the microbial community was able to adapt and showed high final biogas production. I…
Semi-Continuous Lab-scale Plant for Hydrothermal or Organosolv Treatment of Lignocellulosic Biomass
2013
Lignocellulosic biomass is increasingly being considered as a potential alternative source for both fuels and goods production. In order to better address the starting material to higher conversion and selectivity in the desired products, the possibility to selectively control the dissolution of the three main constituents of the matrix (hemicellulose, cellulose and lignin) should be pursued. As the three biopolymers are intimately connected one another, a suitable pretreatment step could help the effectiveness of the whole process, by producing cleavage of the biomacromolecules interconnecting bonds and by starting their depolymerization . In this frame, we developed a semi-continuous lab-…
Enzyme recovery and fouling mitigation by ultrasound-enhanced ultrafiltration
2013
Abstract The development of second-generation biofuels from cellulosic/lignocellulosic biomass has advantages from energy and environmental aspects, but the overall cost of the process is mainly dependent on the cost of the enzymes. Enzyme recovery and recycling is one of the most important and effective means of increasing the efficiency of enzymatic hydrolysis processes by lowering the enzyme costs. The primary objective of this study was to investigate the possibilities of enzyme recovery by membrane separation. Ultrafiltration (UF) membranes with various cut-off values and materials were used to recycle cellulase and cellobiase in model solutions and cellulosic hydrolysates. The membran…
Chemo-enzymatic Conversion of Glucose in 5-Hydroxymethylfurfural: The Joint Effect of Ionic Liquids and Ultrasound
2020
For the valorization of lignocellulosic biomass, a key step is unlocking the conversion of glucose to suitable chemical platforms. To this aim, we herein describe the sequential chemo-enzymatic conversion of glucose into 5-hydroxymethylfurfural (5-HMF), in two steps: glucose isomerization to fructose, catalyzed by glucose isomerase (GI) and fructose dehydration to 5-HMF promoted by Amberlyst 15. The novelty of our approach lies in the use of crude cell extracts of Streptomyces coelicolor showing GI activity, as isomerization catalysts, along with a commercial immobilized GI. Under optimized reaction conditions, we obtained a conversion to 5-HMF (C5‑HMF) from glucose of 50% in the H2O/[bmim]…