High-pressure carbon dioxide/water pre-treatment of sugarcane bagasse and elephant grass: Assessment of the effect of biomass composition on process efficiency

AbstractThis mini-review assesses supercritical carbon dioxide (scCO2) extraction and high-pressure carbon dioxide pre-treatment technologies for valorisation of corn stover agricultural residues with particular focus on showing how these can aid in the creation of a holistic biorefineries. Corn stover is currently the largest source of agriculture residues in the USA, as such there is significant potential for exploitation to yield valuable chemicals. ScCO2 extraction could lead to the recovery of a variety of different chemicals which include flavonoids, sterols, steroid ketones, hydrocarbons, saturated fatty acids, unsaturated fatty acids, fatty alcohols, phenolics and triterpenoids. Importantly, recent studies have not only demonstrated that supercritical extraction can be utilized for the recovery of plant lipids for use in consumer products, including nutraceuticals and personal care, but the processing of treated biomass can lead to enhanced yields and recovery of other products from biorefinery processes. Despite the great potential and opportunities for using scCO2 and high-pressure systems in a biorefinery context their real-world application faces significant challenges to overcome before it is widely applied. Such challenges have also been discussed in the context of this mini-review.

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Experimental Studies Concerning the Semipermeable Membrane Separation Efficiency for 134Cs, 137Cs, 57Co, 58Co, 60Co, 54Mn in Liquid Radioactive Waste I. Treatment of secondary waste from POD decontamination procedure

Revista de Chimie ◽

10.37358/rc.08.5.1825 ◽

2008 ◽

Vol 59 (5) ◽

Cited By ~ 4

Author(s):

Mirela Dulama ◽

Nicoleta Deneanu ◽

Cristian Dulama ◽

Margarit Pavelescu

Keyword(s):

Membrane Separation ◽

Separation Efficiency ◽

Liquid Radioactive Waste ◽

Experimental Studies ◽

Experimental Tests ◽

Suspended Solid ◽

Process Efficiency ◽

Active Charcoal ◽

Precipitation Process ◽

Pre Treatment

The paper presents the experimental tests concerning the treatment by membrane techniques of radioactive aqueous waste. Solutions, which have been treated by using the bench-scale installation, were radioactive simulated secondary wastes from the decontamination process with modified POD. Generally, an increasing of the retention is observed for most of the contaminants in the reverse osmosis experiments with pre-treatment steps. The main reason for taking a chemical treatment approach was to selectively remove soluble contaminants from the waste. In the optimization part of the precipitation step, several precipitation processes were compared. Based on this comparison, mixed [Fe(CN)6]4-/Al3+/Fe2+ was selected as a precipitation process applicable for precipitation of radionuclides and flocculation of suspended solid. Increased efficiencies for cesium radionuclides removal were obtained in natural zeolite adsorption pre-treatment stages and this was due to the fact that volcanic tuff used has a special affinity for this element. Usually, the addition of powdered active charcoal serves as an advanced purifying method used to remove organic compounds and residual radionuclides; thus by analyzing the experimental data (for POD wastes) one can observe a decreasing of about 50% for cobalt isotopes subsequently to the active charcoal adsorption.. The semipermeable membranes were used, which were prepared by the researchers from the Research Center for Macromolecular Materials and Membranes, Bucharest. The process efficiency was monitored by gamma spectrometry.

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The degradation of cellulose in ionic mixture solutions under the high pressure of carbon dioxide

RSC Advances ◽

10.1039/d0ra07154d ◽

2021 ◽

Vol 11 (6) ◽

pp. 3484-3494

Author(s):

Sumarno ◽

Prida Novarita Trisanti ◽

Bramantyo Airlangga ◽

Novi Eka Mayangsari ◽

Agus Haryono

Keyword(s):

Carbon Dioxide ◽

High Pressure ◽

Hydrothermal Process ◽

Reducing Sugar

Cellulose processing by a hydrothermal process as well as in combination with a sonication pretreatment under a CO2 pressurization that affects the morphology and reducing sugar products.

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