Search results for "Raw material"

Cellulose Nanocrystals from Lignocellulosic Raw Materials, for Oxygen Barrier Coatings on Food Packaging Films

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…

Recycling of high density polyethylene containers

1997

The recycling of homogeneous high density polyethylene from containers for liquids gives rise to materials having mechanical properties that are strongly dependent on the reprocessing apparatus and the processing conditions. The thermomechanical degradation during processing gives rise to different modifications of the structure depending on the temperature, residence time and applied stress. In general, it is possible to say that if the reprocessing operations are carried out in apparatus with low residence time, the mechanical and rheological properties of the raw materials are only slightly influenced by the recycling operations. Significant degradation phenomena and reduction of some me…

Technological development and functional properties of an apple snack rich in flavonoid from mandarin juice

2012

Abstract The development of functional foods has evolved considerably over the years. The technological ability to produce a food with enhanced physiologically active compounds has grown significantly. The aim of this work was to study the incorporation of the beneficial compounds from mandarin low pulp juice into an apple snack using vacuum impregnation technology and to test if the final product exhibited the functional properties and components of both raw materials. Forty grams of the final product made using mandarin juice homogenized at 15 MPa could provide the same quantity of hesperidin as 250 mL of fresh mandarin juice. We also performed a chromatographic determination of the compo…

Behavior of carbohydrate-based material in black liquor during heating

2004

One industrial softwood Kraft black liquor was heat-treated (at 175 ?C and 190 ?C for 15-60 min) together with laboratory-made soda-AQ (wheat straw and reed canary grass) and Kraft (reed canary grass) black liquors (at 190 ?C for 30 min). The feedstock black liquors were characterized with respect to their polysaccharide (mainly xylem) and aliphatic carboxylic acid contents before and after the heat treatments. It was noted that, due to the higher amount of polysaccharides in the non-wood black liquors (8.2-16.6% of d.s) compared to that in the softwood black liquor (1.4% of d.s), the heat treatment in the former case resulted in a 5-30% increase in the amount of aliphatic acids formed by v…

Carbon Dioxide as Chemical Feedstock. Edited by Michele Aresta.

2010

TiO2-Based Photocatalysis for Organic Synthesis

2010

A major aim of the contemporary chemistry is to replace old environmentally hazardous processes with new, energy efficient routes allowing to reduce or totally avoid the use and production of harmful chemicals and to maximise the quantity of raw material that ends up in the final product. This chapter gives an account of TiO2-based selective photocatalysis as a green synthetic tool for the production of organics. Some case studies of the most common transformations carried out by means of photocatalytic reactions are illustrated in a midway perspective between photochemistry and organic chemistry.

Comprehensive valorisation of technically relevant organosolv lignins via anodic oxidation

2021

Lignin represents the largest renewable feedstock of aromatic moieties in nature. However, its valorisation towards organic chemicals poses a challenging task. We herein report the selective electrochemical depolymerisation of several technically relevant organosolv lignins to aromatic fine chemicals with a simple two-electrode arrangement using caustic soda as electrolyte. Vanillin, syringaldehyde, the corresponding ketones and guaiacol were obtained with a combined maximum of 7.8 wt% isolated yield. Deeper insight in the process was provided by FT-IR, HSQC NMR and 31P NMR analyses of the lignins.

Selection of novel geopolymeric mortars for sustainable construction applications using fuzzy topsis approach

2020

Construction is recognized as one of the most polluting and energy consuming industries worldwide, especially in developing countries. Therefore, Research and Development (R&amp

Współczesna wojna - model klasyfikacyjny surowców krytycznych

2016

The paper adresses the problem of the list of critical raw materials for the European Union. The theoretical model of classification of the critical raw materials was presented. The presented model is based on two variables: index of the compatibility (substitutability index) and recycling index.

Microwave-Assisted Esterification of Tall Oil Fatty Acids with Methanol Using Lignin-Based Solid Catalyst

2016

During alkaline pulping significant amounts of lignin, carbohydrates (mostly hemicelluloses), and extractives (tall oil soap and turpentine) are removed from wood feedstock. In this study, the catalytic esterification of fatty acids in tall oil with methanol to produce fatty acid methyl esters under microwave irradiation was performed at 100 °C for 10–60 min. A novel heterogeneous acid catalyst tested for this purpose was synthesized from the hardwood alkali lignin that was precipitated by acidification from the black liquor from soda-AQ pulping. The comparative reaction data were obtained by using other solid catalysts, Amberlyst 15, and p-toluenesulfonic acid. The results showed the highe…