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1.
Artigo em Inglês | MEDLINE | ID: mdl-36360849

RESUMO

Plastic can be used for many things and at the same time is the most versatile material in our modern world. However, the uncontrolled and unprecedented use of plastic comes to its end. The global ban on plastic brings significant changes in technology but even more so in civil perception-changes taking place before our eyes. The aim of this study was to find answers to the questions about the readiness of consumers for a global ban on plastic. Within the research, the differences in consumer acceptance in countries in Europe, South and North America and Asia and the expression of social readiness to change attitudes towards plastic food packaging were analyzed. This work sketches the legal framework related to limiting the use of one-use food packaging made of fossil raw materials at the level of the European Union, Poland and Portugal but also at the level of the two largest economies in the world, China and the United States, as well as lower-income countries, e.g., Ukraine and Brazil. The survey results were analyzed using descriptive and inferential statistics. The performed study demonstrates that, in in all the surveyed countries, appropriate legal acts related to the reduction of plastic in everyday life are already in place. Furthermore, this work demonstrates the full understanding of plastic banning in all surveyed countries. Consumers are aware that every effort should be made to prevent the world from drowning in plastic waste. Society is, in general, open to the use of bioplastics produced from the second-generation resource if second-generation bioplastics contribute to environmental and pollution reduction targets.


Assuntos
Plásticos , Brasil , América do Norte , Europa (Continente) , China , Polônia
2.
Molecules ; 26(24)2021 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-34946673

RESUMO

Biomass pre-treatment is a key step in achieving the economic competitiveness of biomass conversion. In the present work, an imidazole pre-treatment process was performed and evaluated using wheat straw and eucalyptus residues as model feedstocks for agriculture and forest-origin biomasses, respectively. Results showed that imidazole is an efficient pre-treatment agent; however, better results were obtained for wheat straw due to the recalcitrant behavior of eucalyptus residues. The temperature had a stronger effect than time on wheat straw pre-treatment but at 160 °C and 4 h, similar results were obtained for cellulose and hemicellulose content from both biomasses (ca. 54% and 24%, respectively). Lignin content in the pre-treated solid was higher for eucalyptus residues (16% vs. 4%), as expected. Enzymatic hydrolysis, applied to both biomasses after different pre-treatments, revealed that results improved with increasing temperature/time for wheat straw. However, these conditions had no influence on the results for eucalyptus residues, with very low glucan to glucose enzymatic hydrolysis yield (93% for wheat straw vs. 40% for eucalyptus residues). Imidazole can therefore be considered as a suitable solvent for herbaceous biomass pre-treatment.


Assuntos
Biomassa , Celulase/química , Celulose/química , Eucalyptus/química , Imidazóis/química , Triticum/química
3.
Molecules ; 24(12)2019 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-31238569

RESUMO

l-3,4-dihydroxyphenylalanine (l-DOPA) is a medically relevant compound in Parkinson's disease therapy. Several extraction methods of l-DOPA from beans, including velvet and faba beans, have been described in the literature. However, these methods require the use of strong acids, long extraction times, or complex downstream processing, which makes the extraction of l-DOPA expensive and energy-demanding, limiting its industrial application. In addition, the stability of l-DOPA during the extraction process is critical, further complicating the extraction of adequate amounts of this amino acid. This work is the first report on a simple, rapid, greener, and robust extraction method of l-DOPA. The developed method consists of a quick homogenization step followed by a double extraction with 0.2% v/v acetic acid for 20 min and was applied to faba bean at a ratio of 1:25 with respect to the extracting solvent. This study also investigated the stability of l-DOPA during extraction and thermal treatment. The proposed method demonstrated to be robust and extraordinarily efficient for numerous cultivars of faba bean, velvet bean, and food products containing faba beans.


Assuntos
Fracionamento Químico , Levodopa/isolamento & purificação , Fracionamento Químico/métodos , Árvores de Decisões , Concentração de Íons de Hidrogênio , Levodopa/química , Estrutura Molecular , Reprodutibilidade dos Testes , Solventes , Fluxo de Trabalho
4.
Molecules ; 24(4)2019 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-30813398

RESUMO

Ionic liquids have been recognised as interesting solvents applicable in efficient lignocellulosic biomass valorisation, especially in biomass fractionation into individual polymeric components or direct hydrolysis of some biomass fractions. Considering the chemical character of ionic liquids, two different approaches paved the way for the fractionation of biomass. The first strategy integrated a pre-treatment, hydrolysis and conversion of biomass through the employment of hydrogen-bond acidic 1-ethyl-3-methyimidazolim hydrogen sulphate ionic liquid. The second strategy relied on the use of a three-step fractionation process with hydrogen-bond basic 1-ethyl-3-methylimidazolium acetate to produce high purity cellulose, hemicellulose and lignin fractions. The proposed approaches were scrutinised for wheat straw and eucalyptus residues. These different biomasses enabled an understanding that enzymatic hydrolysis yields are dependent on the crystallinity of the pre-treated biomass. The use of acetate based ionic liquid allowed crystalline cellulose I to change to cellulose II and consequently enhanced the glucan to glucose yield to 93.1 ± 4.1 mol% and 82.9 ± 1.2 mol% for wheat straw and eucalyptus, respectively. However, for hydrogen sulphate ionic liquid, the same enzymatic hydrolysis yields were 61.6 ± 0.2 mol% for wheat straw and only 7.9 ± 0.3 mol% for eucalyptus residues. These results demonstrate the importance of both ionic liquid character and biomass type for efficient biomass processing.


Assuntos
Biomassa , Líquidos Iônicos/química , Ácidos/química , Celulose/química , Fracionamento Químico , Eucalyptus/química , Glucose/química , Hidrólise , Imidazóis/química , Íons/química , Lignina/química , Polissacarídeos/química , Solventes/química , Triticum/química
5.
ChemSusChem ; 11(6): 1099-1107, 2018 03 22.
Artigo em Inglês | MEDLINE | ID: mdl-29400913

RESUMO

Biomass processing with ionic liquids (ILs) has been one of the most topical research areas in recent years. However, separation and recovery of biomass products and ILs are currently a challenge. Recovery of produced monosaccharides from an IL postreaction solution and the possibility to reuse the IL are strongly required to guarantee the sustainability of biomass processing. The present study demonstrates a novel approach that aims at separating a biomass hemicellulose-derived product, namely, xylose, and 1-ethyl-3-methylimidazolium hydrogensulfate ([emim][HSO4 ]). High polarity of a postreaction system composed of xylose, IL, and water is one of the major hindrances in the separation performance. A proposed solution is fine-tuning of the system polarity by the addition of moderately polar acetonitrile. To scrutinize the potential of xylose and IL separation, phase equilibria of a system constituted by [emim][HSO4 ], water, and acetonitrile were studied. Additionally, preparative chromatography experiments with alumina as a stationary phase were performed to determine the conditions required for efficient separation of the sugar and the IL by selective adsorption of xylose on alumina in detriment of IL. The amount and treatment of the stationary phase, eluent polarity, and amount of loaded sample were also scrutinized in this study. Treatment of alumina was considered as a necessary step to achieve recovery yields of 90.8 and 98.1 wt % for the IL and xylose, respectively, as separate fractions.

6.
Bioresour Technol ; 224: 639-647, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27955864

RESUMO

The performance of two lignocellulosic biomasses was studied in high-pressure carbon dioxide/water pre-treatment. Sugarcane bagasse and elephant grass were used to produce C5-sugars from hemicellulose and, simultaneously, to promote cellulose digestibility for enzymatic saccharification. Different pre-treatment conditions, with combined severity factor ranging from -1.17 to -0.04, were evaluated and maximal total xylan to xylose yields of 59.2wt.% (34.4wt.% xylooligomers) and 46.4wt.% (34.9wt.% xylooligomers) were attained for sugarcane bagasse and elephant grass, respectively. Furthermore, pre-treated biomasses were highly digestible, with glucan to glucose yields of 77.2mol% and 72.4mol% for sugarcane bagasse and elephant grass, respectively. High-pressure carbon dioxide/water pre-treatment provides high total C5-sugars and glucose recovery from both lignocellulosic biomasses; however it is highly influenced by composition and intrinsic features of each biomass. The obtained results confirm this approach as an effective and greener alternative to conventional pre-treatment processes.


Assuntos
Dióxido de Carbono/química , Celulose/química , Pennisetum/química , Saccharum/química , Água/química , Biocombustíveis , Biomassa , Carboidratos , Glucanos/química , Glucose/química , Hidrólise , Lignina/química , Pressão , Xilose/química
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