Superselective Hydrogen Separation through a Mixed Conducting Graphene Oxide Membrane.

A cost-effective H separation method is required for the purification of gaseous mixtures containing H. Thus, in this study, we investigate the H separation properties of Ce ion-doped partially reduced graphene oxide (prGO) membranes. Pt/C-catalyst-coated, dense, micrometer-thick membranes are fabricated by stacking Ce-prGO nanosheets, followed by thermal annealing.

Selective Detection of CO Using Proton-Conducting Graphene Oxide Membranes with Pt-Doped SnO Electrocatalysts: Mechanistic Study by Operando DRIFTS.

To reduce the risk of carbon monoxide (CO) poisoning, there is a strong need for small, compact gas sensors to detect and monitor CO at ppm concentrations. In this study, we focused on detecting CO with electrochemical sensors based on proton-conducting graphene oxide (GO) nanosheets at room temperature. We found that a Ce-doped GO nanosheet membrane fitted with the sensing electrode composed of Pt (10 wt %)-doped SnO nanocrystals exhibits an excellent sensor response to CO at 25 °C.

Fast and selective production of quercetin and saccharides from rutin using microwave-assisted hydrothermal treatment in the presence of graphene oxide.

Rutin is a flavonoid glycoside, well-known for its antioxidant, anticarcinogenic, and cardioprotective properties. However, it exhibits lower bio absorptivity and bioactivity than its aglycon form, quercetin. Although liquid acid catalysts are conventionally utilized to obtain quercetin via rutin hydrolysis, the neutralization procedure is a major disadvantage owing to the added cost.

A review on potential of green solvents in hydrothermal liquefaction (HTL) of lignin.

One of the greatest challenges in biorefinery is to reduce biomass' recalcitrance and enable valorization of lignin into higher value compounds. Likewise, green solvents and hydrothermal liquefaction (HTL) with feasible economic viability, functionality, and environmental sustainability have been widely introduced in extraction and conversion of lignin. This review starts with the underscore of disadvantages and limitations of conventional pretreatment approaches and role of green solvents in lignin extraction.

Electrochemical Detection of Ethanol in Air Using Graphene Oxide Nanosheets Combined with Au-WO.

Detection, monitoring, and analysis of ethanol are important in various fields such as health care, food industries, and safety control. In this study, we report that a solid electrolyte gas sensor based on a proton-conducting membrane is promising for detecting ethanol in air. We focused on graphene oxide (GO) as a new solid electrolyte because it shows a high proton conductivity at room temperature.

Synergizing Sulfonated Hydrothermal Carbon and Microwave Irradiation for Intensified Esterification Reaction.

The synergy of sulfonated hydrothermal carbon and microwave (MW) irradiation was applied for the esterification of oleic acid with methanol (MeOH) to produce biodiesel. The effects of temperature, reaction time, ratio of oleic acid to methanol, and catalyst loading were investigated at a fixed MW power of 400 W. The addition of hexane, serving as a co-solvent and separator, was also investigated.

Biogasoline production from linoleic acid via catalytic cracking over nickel and copper-doped ZSM-5 catalysts.

Catalytic cracking of vegetable oil mainly processed over zeolites, and among all the zeolites particularly HZMS-5 has been investigated on wide range for renewable and clean gasoline production from various plant oils. Despite the fact that HZSM-5 offers a higher conversion degree and boost aromatics yield, the isomerate yield reduces due to high cracking activity and shape selectivity of HZSM-5. Hence, to overcome these problems, in this study the transition metals, such as nickel and copper doped over HZSM-5 were tested for its efficiencies to improve the isoparaffin compounds.

Carbocatalysed hydrolytic cleaving of the glycosidic bond in fucoidan under microwave irradiation.

Biomass valorization involves breaking down naturally occurring long chain polysaccharides into their constituent monomers. The polysaccharide chain consists of monomers adjoined C (carbon)-O (oxygen) glycosidic linkages that are typically cleaved hydrolytic scission. In this study, we aimed to recover fucose from the polysaccharide fucoidan, which can be extracted from seaweed biomass.

Recovery of cellulose fibers from oil palm empty fruit bunch for pulp and paper using green delignification approach.

The aim of this work was to recover the cellulose fibers from EFB using low-transition-temperature-mixtures (LTTMs) as a green delignification approach. The hydrogen bonding of LTTMs observed in H NMR tends to disrupt the three-dimensional structure of lignin and further remove the lignin from EFB. Delignification process of EFB strands and EFB powder were performed using standard l-malic acid and cactus malic acid-LTTMs.

Synthesis of Cu₂O/CuO Nanocrystals and Their Application to H₂S Sensing.

Semiconducting metal oxide nanocrystals are an important class of materials that have versatile applications because of their useful properties and high stability. Here, we developed a simple route to synthesize nanocrystals (NCs) of copper oxides such as Cu₂O and CuO using a hot-soap method, and applied them to H₂S sensing. Cu₂O NCs were synthesized by simply heating a copper precursor in oleylamine in the presence of diol at 160 °C under an Ar flow.

Production of gasoline range hydrocarbons from catalytic cracking of linoleic acid over various acidic zeolite catalysts.

Employment of edible oils as alternative green fuel for vehicles had raised debates on the sustainability of food supply especially in the third-world countries. The non-edible oil obtained from the abundantly available rubber seeds could mitigate this issue and at the same time reduce the environmental impact. Therefore, this paper investigates the catalytic cracking reaction of a model compound named linoleic acid that is enormously present in the rubber seed oil.

Utilization of rice husk to enhance calcium oxide-based sorbent prepared from waste cockle shells for cyclic CO capture in high-temperature condition.

The CO capture capacity and cyclic stability of calcium oxide (CaO) prepared from cockle shells (CS) were enhanced by incorporating rice husk (RH) and binder through wet-mixing method. The cyclic reaction of calcination and carbonation was demonstrated using thermal gravimetric analyzer (TGA) which the calcination was performed in a pure N environment at 850 °C for 20 min and carbonation at 650 °C for 30 min in 20 vol% of CO in N. The analysis using x-ray fluorescence (XRF) identified silica (Si) as the major elements in the sorbents.

Sustainable green pretreatment approach to biomass-to-energy conversion using natural hydro-low-transition-temperature mixtures.

Natural hydro-low-transition-temperature mixtures (NH-LTTMs) tend to be the most favorable next-generation green solvents for biomass pretreatment, as they are cheap and environmental friendly. The amount of water bound into the NH-LTTMs greatly affected their thermal stability, whereby the highest thermal stability was observed with the water content of 7.6 wt%.

Thermogravimetric analysis and kinetic modeling of low-transition-temperature mixtures pretreated oil palm empty fruit bunch for possible maximum yield of pyrolysis oil.

The impacts of low-transition-temperature mixtures (LTTMs) pretreatment on thermal decomposition and kinetics of empty fruit bunch (EFB) were investigated by thermogravimetric analysis. EFB was pretreated with the LTTMs under different duration of pretreatment which enabled various degrees of alteration to their structure. The TG-DTG curves showed that LTTMs pretreatment on EFB shifted the temperature and rate of decomposition to higher values.

Choline chloride (ChCl) and monosodium glutamate (MSG)-based green solvents from optimized cactus malic acid for biomass delignification.

This work aimed to develop an efficient microwave-hydrothermal (MH) extraction of malic acid from abundant natural cactus as hydrogen bond donor (HBD) whereby the concentration was optimized using response surface methodology. The ideal process conditions were found to be at a solvent-to-feed ratio of 0.008, 120°C and 20min with 1.

Characterization of natural low transition temperature mixtures (LTTMs): Green solvents for biomass delignification.

The aim of this work was to characterize the natural low transition temperature mixtures (LTTMs) as promising green solvents for biomass pretreatment with the critical characteristics of cheap, biodegradable and renewable, which overcome the limitations of ionic liquids (ILs). The LTTMs were derived from inexpensive commercially available hydrogen bond acceptor (HBA) and l-malic acid as the hydrogen bond donor (HBD) in distinct molar ratios of starting materials and water. The peaks involved in the H-bonding shifted and became broader for the OH groups.

Supercritical carbon dioxide extraction of fucoxanthin from Undaria pinnatifida.

Undaria pinnatifida, commonly known as wakame in Japan, is one species of brown seaweeds containing valuable bioactive organic compounds such as fucoxanthin, a carotenoid, which has numerous functional properties. However, most of the seaweeds that do not meet strict quality standards are normally discarded as wastes or returned to the sea, a situation which is becoming an environmental concern. In this research, supercritical carbon dioxide (SCCO₂) extraction was investigated for the isolation of fucoxanthin.

Polyphenolic contents and antioxidant activities of Lawsonia inermis leaf extracts obtained by microwave-assisted hydrothermal method.

Extracts obtained by microwave-assisted hydrothermal extraction of Lawsonia inermis leaves were evaluated for the presence of polyphenolic compounds and antioxidant activities. Extraction experiments were performed in temperature-controlled mode at a range of 100 to 200 degrees C, and extraction time of 5 to 30 min, and microwave-controlled mode at a power from 300-700 W, in irradiation time of 30 to 120 s. Polyphenolic contents were measured using Folin-Ciocalteau method, while antioxidant properties were analyzed using DPPH radical scavenging activities (RSA) expressed in BHA equivalents.

Recovery of oil components of okara by ethanol-modified supercritical carbon dioxide extraction.

Recovery of the oil components of okara by ethanol-modified supercritical carbon dioxide extraction was investigated at 40-80 degrees C temperature and 12-30 MPa pressure. In a typical run (holding period of 2 h, continuous flow extraction of 5 h), results indicated that the oil component could be best obtained with a recovery of 63.5% at relatively low temperature of 40 degrees C and mild pressure of 20 MPa in the presence of 10 mol% EtOH as entrainer.

Metal elution from Ni- and Fe-based alloy reactors under hydrothermal conditions.

Elution of metals from Ni- and Fe-based alloy (i.e. Inconel 625 and SUS 316) under hydrothermal conditions was investigated.

Qualitative investigation on hydrothermal treatment of Hinoki (Chamaecyparis obtusa) bark for production of useful chemicals.

Hydrothermal treatment of an outer layer of a bark of Hinoki (Chamaecyparis obtusa) tree was investigated qualitatively for the possibility of utilizing residual forest biomass to produce valuable chemicals. Experiments were carried out in a semibatch reactor apparatus that allows the study of the effect of reaction temperatures in a single run. Gas chromatography-mass spectrometry analyses show the presence of useful chemicals such as furfural, aromatic compounds (1,3-di-tert-butyl benzene and 2,4-di-tert-butyl phenol), and fatty acids (myristic acid, palmitic acid, and stearic acid) in the products.

Low-molecular-weight carboxylic acids produced from hydrothermal treatment of organic wastes.

This article reports production of low-molecular-weight carboxylic acids from the hydrothermal treatment of representative organic wastes and compounds (i.e. domestic sludge, proteinaceous, cellulosic and plastic wastes) with or without oxidant (H(2)O(2)).