Tehnologii eficiente energetic pentru producerea etanolului Din biomasă lignocelulozică

ABSTRACT: Currently, biofuels are the most significant alternative fuel aiming to provide clean power for transport, in case sustainable production technologies are employed. Due to the increased tendency of turning over the existing agricultural land to biofuel production, lignocellulosic feedstock is gaining increasing support against the use of first generation feedstock such as sugar cane, corn, wheat or sweet potatoes. However, despite the existing pilot plants, energy intensive technological processes like pretreatment and distillation, as well as high cost of enzymes, still prevent market roll-out of production facilities, extensive researches being conducted in order to find economically feasible alternatives. New close to market techniques, with improved performance in terms of energy and resources, are discussed: the relatively recent SPORL pretreatment, reported as the most effective in size-reduction energy consumption; pretreatment by means of extrusion - a technique in which biomass undergoes continuous mixing, heating and shearing, thus suffering physicochemical disintegration; energy saving pass-through distillation that performs at room temperature, which also offers indirect advantages like the possibility of yeasts and enzymes recovery, and simplified exploitation and maintenance of the distillation equipment. The above mentioned subjects are selected based on their reported performances as well as on their market potential and estimated technical and economic feasibility.REZUMAT: În prezent biocombustibilii reprezintă categoria cea mai importantă de combustibili alternativi, cu impact pozitiv asupra mediului în cazul în care tehnologiile de producţie a acestora sunt sustenabile. Datorită tendinţelor accentuate de utilizare a terenurilor agricole pentru culturi energetice, biomasa lignocelulozică a devinit tot mai atractivă în raport cu resursele de prima generaţie precum porumbul, grâul, cartoful, trestia de zahăr etc. Cu toate acestea, deşi există staţii pilot funcţionale pentru producerea de bioetanol lignocelulozic, costul ridicat al enzimelor sau consumurile energetice ridicate aferente unor procese precum pretratarea şi distilarea împiedică pătrunderea pe piaţă a acestor tehnologii. În consecinţă, cercetările din acest domeniu se orientează către identificarea unor soluţii fezabile economic. Articolul prezintă trei procese noi, performante din punct de vedere al necesarului de resurse, cu un bun potenţial de piaţă: metoda de pretratare SPORL, raportată ca fiind cea mai eficientă din punct de vedere al energiei consumate pentru mărunţirea biomasei; pretratarea continuă prin extrudare, în cadrul căreia biomasa este dezintegrată fizico-chimic printr-un proces de amestecare, încălzire şi strivire/forfecare mecanică; distilarea “pass-through” la temperatura camerei, cu avantaje precum consumul redus de energie, posibilitatea de reutilizare a enzimelor şi drojdiilor, sau uşurinţa în exploatare. Subiectele au fost selectate pe baza rapoartelor privind performanţele, potenţialul de piaţă şi fezabilitatea tehnico-economică

Energy efficient technologies for lignocellulosic ethanol production

Currently, biofuels are the most significant alternative fuel aiming to provide clean power for transport, in case sustainable production technologies are employed. Due to the increased tendency of turning over the existing agricultural land to biofuel production, lignocellulosic feedstock is gaining increasing support against the use of first generation feedstock such as sugar cane, corn, wheat or sweet potatoes. However, despite the existing pilot plants, energy intensive technological processes like pretreatment and distillation, as well as high cost of enzymes, still prevent market roll-out of production facilities, extensive researches being conducted in order to find economically feasible alternatives. New close to market techniques, with improved performance in terms of energy and resources, are discussed: the relatively recent SPORL pretreatment, reported as the most effective in size-reduction energy consumption; pretreatment by means of extrusion - a technique in which biomass undergoes continuous mixing, heating and shearing, thus suffering physico-chemical disintegration; energy saving pass-through distillation that performs at room temperature, which also offers indirect advantages like the possibility of yeasts and enzymes recovery, and simplified exploitation and maintenance of the distillation equipment. The above mentioned subjects are selected based on their reported performances as well as on their market potential and estimated technical and economic feasibility.info:eu-repo/semantics/publishedVersio

Equilibrium and Kinetic Studies on the Biosorption of Cu(II) onto Aspergillus niger Biomass

The solid and liquid waste with heavy metal content that are discharged direct or indirect in environment determine negative effects for organisms, and environment. The main heavy metals found in wastewaters and solid wastes are cadmium, chromium, lead, nickel, zinc, copper, mercury, and arseni

Laccases—Versatile Enzymes Used to Reduce Environmental Pollution

The accumulation of waste and toxic compounds has become increasingly harmful to the environment and human health. In this context, the use of laccases has become a focus of interest, due to the properties of these versatile enzymes: low substrate specificity, and water formation as a non-toxic end product. Thus, we begin our study with a general overview of the importance of laccase for the environment and industry, starting with the sources of laccases (plant, bacterial and fungal laccases), the structure and mechanism of laccases, microbial biosynthesis, and the immobilization of laccases. Then, we continue with an overview of agro-waste treatment by laccases wherein we observe the importance of laccases for the biodisponibilization of substrates and the biodegradation of agro-industrial byproducts; we then show some aspects regarding the degradation of xenobiotic compounds, dyes, and pharmaceutical products. The objective of this research is to emphasize and fully investigate the effects of laccase action on the decomposition of lignocellulosic materials and on the removal of harmful compounds from soil and water, in order to provide a sustainable solution to reducing environmental pollution

Laccases—Versatile Enzymes Used to Reduce Environmental Pollution

The accumulation of waste and toxic compounds has become increasingly harmful to the environment and human health. In this context, the use of laccases has become a focus of interest, due to the properties of these versatile enzymes: low substrate specificity, and water formation as a non-toxic end product. Thus, we begin our study with a general overview of the importance of laccase for the environment and industry, starting with the sources of laccases (plant, bacterial and fungal laccases), the structure and mechanism of laccases, microbial biosynthesis, and the immobilization of laccases. Then, we continue with an overview of agro-waste treatment by laccases wherein we observe the importance of laccases for the biodisponibilization of substrates and the biodegradation of agro-industrial byproducts; we then show some aspects regarding the degradation of xenobiotic compounds, dyes, and pharmaceutical products. The objective of this research is to emphasize and fully investigate the effects of laccase action on the decomposition of lignocellulosic materials and on the removal of harmful compounds from soil and water, in order to provide a sustainable solution to reducing environmental pollution

REAL-TIME ANALYSIS OF QUERCETIN, RESVERATROL AND /OR DOXORUBICIN EFFECTS IN MCF-7 CELLS

Abstrac