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In this paper, the performances of two iron-based syngas-fueled chemical looping (SCL) systems for hydrogen (H2) and electricity production, with carbon dioxide (CO2) capture, using different reactor configurations were evaluated and compared. The first investigated system was based on a moving bed reactor configuration (SCL-MB) while the second used a fluidized bed reactor configuration (SCL-FB). Two modes of operation of the SCL systems were considered, namely, the H2 production mode, when H2 was the desired product from the system, and the combustion mode, when only electricity was produced. The SCL systems were modeled and simulated using Aspen Plus software. The results showed that the SCL system based on a moving bed reactor configuration is more efficient than the looping system with a fluidized bed reactor configuration. The H2 production efficiency of the SCL-MB system was 11 % points higher than that achieved in the SCL-FB system (55.1 % compared to 44.0 %). When configured to produce only electricity, the net electrical efficiency of the SCL-MB system was 1.4 % points higher than that of the SCL-FB system (39.9 % compared to 38.5 %). Further, the results showed that the two chemical looping systems could achieve >99 % carbon capture efficiency and emit ~2 kg CO2/MWh, which is significantly lower than the emission rate of conventional coal gasification-based plants for H2 and/or electricity generation with CO2 capture.

Molinate (S-ethyl-azepane-1-carbothioate) is a thiocarbamate herbicide used in rice cultivation for the control of grass weeds. Environmental contamination with molinate is of major concern due to the adverse effects described both for humans and animals. Molinate hydrolase, a novel amidohydrolase previously characterized, is responsible for the initial breakdown of molinate, cleaving the thioester bond of molinate, releasing ethanethiol and azepane-1-carboxylate (ACA). Biotechnology is the key for sustainable farming. With advances in biotechnology, bioremediation has become one of the most rapidly developing fields of environmental restoration. Through the microencapsulation of molinate hydrolase, we are aiming to develop a bioremediation process for the effective molinate degradation in rice paddies. The purpose of this work was to develop and validate an UV method to effectively quantify the substrate (molinate) in further assays with free and microencapsulated molinate hydrolase. The analytical method was validated and the main parameters, as limit of detection, linearity range, precision and accuracy were determined, and compared to those obtained by HPLC (regarding free enzyme kinetics). Both methods show to be linear (r > 0.999) over the concentration range of 0.005-0.150 mM molinate. The global uncertainty, estimated accordingly to the bottom-up approach used by Eurachem, was estimated for both methods. The UV analytical method is effective and seems that it can be applied in future for the quantification of molinate breakdown by free and encapsulated molinate hydrolase.

We show that a simple ethanol (EtOH) refluxing treatment at mild temperature (120 °C) allows producing blue-colored and reduced titanium dioxide (TiO2-x) exhibiting improved visible-light (VIS) photocatalytic properties. The treatment causes an increase in the density of Ti(III) species and the appearance of two optical absorption features: a broad absorption band--responsible for the blue coloration--extending from the green region (~2.3 eV) up to the near-infrared and a subgap absorption tail close to the band gap energy. The experimental results combined with a computation of the density of states via hybrid Hartree-Fock density functional support the hypothesis that the EtOH reflux treatment leads to formation of surface and subsurface oxygen (O) vacancies. We also show that the excitation-resolved photoluminescence technique allows a high-contrast detection of a subgap optical excitation band peaked at about 430 nm (~2.9 eV), associated with anatase photoluminescence, whose intensity increases after the EtOH reflux treatment. This result gives a very direct support to the debated hypothesis identifying O vacancy states as the energy levels involved in the radiative transition of anatase TiO2. Improved photocatalytic degradation by the processed TiO2 under VIS illumination is demonstrated, and the possible mechanism involved in the formation of surface O vacancies is discussed. The method outlines a very simple, low-cost, and fast procedure to target the formation of O vacancies in the TiO2 surface region.

Sustainability of energy systems has a strategic role in the current energy-environmental policies as it involves key issues such as security of energy supply, mitigation of environmental impact (with special regard to air quality improvement) and energy affordability. In this framework modelling activities are more than ever a strategic issue in order to manage the large complexity of energy systems as well as to support the decision-making process at different stages and spatial scales (regional, national, Pan-European, etc.). The aim of this article is to present a new model for the Italian energy system implemented with a common effort in the framework of an integrated project under the Sixth Framework Programme. In particular, the main features of the common methodology are briefly recalled and the modelling structure, the main data and assumptions, sector by sector, are presented. Moreover the main results obtained for the baseline (BAU) scenario are fully descfibed.

Lignins from softwood, hardwood, grass and wheat straw were fractionated by selective extraction at ambient temperature using green solvents like acetone/water solutions of 10, 30, 50, 70 and 90% (v/v) acetone and ethyl acetate. A comparison between the isolated fractions and unfractionated lignins was made in terms of extraction yield, lignin solubility factor, molecular weight distribution and functional group composition. Low molecular weight (LMW) lignin fractions with narrow dispersity are obtained by extraction with ethyl acetate and acetone–water solution containing 30% acetone, with yields depending on the type and the functional group content of lignins. A significant amount (56%) of the organosolv hardwood lignin with low molecular weight (Mw = 1868 g/mol) and low dispersity was isolated from ethyl acetate. Insoluble fractions with very high molecular weight (Mw between 10 and 17 kg/mol) are obtained in low yield from acetone–water solutions with 50, 70 and 90% acetone. LMW lignins are in general less condensed and have lower aliphatic hydroxyl content than parent lignins while the HMW fractions have a higher content of condensed hydroxyls. Principal component analysis on the chemical composition of lignins and isolated fractions determined from 31P NMR data showed the high heterogeneity of the technical lignins. Partial least squares models based on FT-IR spectral data were developed to predict the functional group content determined by quantitative 31P NMR analysis of technical lignins and lignin fractions. This approach can be used to develop simple, rapid and accurate analytical tools to monitor and control the selective fractionation of lignin.

Butanol is considered a superior biofuel, as it is more energy dense and less hygroscopic than bioethanol, resulting in higher possible blending ratios with gasoline. However, the production cost of the acetone-butanol-ethanol (ABE) fermentation process is high, mainly due to the low butanol titer, yield, and productivity in bioprocesses. The classic recovery by distillation is an energy-intensive process that has largely restricted the economic production of biobutanol. Other methods based on gas stripping, liquid-liquid extraction, adsorption, and membranes are also energy intensive due to the bulk removal of water. This study proposes a novel process for the butanol recovery by enhanced distillation, using only several operating units in an optimized sequence to reduce costs. This work considers a plant capacity of 40 ktpy and purities of 99.4 %wt butanol, 99.4 %wt acetone and 91.4 %wt ethanol. The process was simulated and optimized using Aspen Plus as PSE tool. The enhanced process proposed here is cost effective and can be readily employed at large scale to improve the economics of biobutanol production.

In the present work, we report the successful extraction of high purity silica from the Algerian siliceous sand. We improved the chemical extraction process of silica using acid pretreatment before purification and studied the effect of sodium hydroxide (NaOH) solution molarity on the purity of as-obtained silica. X-ray diffraction, Energy-dispersive X-ray spectroscopy, and Scanning Electron Microscopy analyses were carried out on the samples before, during, and after chemical purification. The results show the improvement of the purity of the resulting powder with the change of the alkaline concentration. The results showed a decrease in the impurity concentration of the sand after acid leaching. The extracted silica has a purity of more than 99% and has an amorphous and mesoporous nature, confirmed by the mentioned analysis techniques, together with Fourier Transform Infrared Spectroscopy, thermogravimetric analysis, and the Physical Adsorption Analysis, which makes our chemical extraction method very promising, and the resulted silica is a good source to elaborate solar grade silicon used in photovoltaic applications.

Recently, the studies about vitamin B12 increased due to the high number of people who can develop vitamin B12 deficiency, namely: vegetarians, pregnant women or with vitamin B12 malabsorption. One solution to correct the low nutritional intake of vitamin B12 can be using food supplements or pharmaceuticals, based on the vitamin B12 microencapsulation. In the present research, the vitamin B12 microencapsulation and the controlled release of fresh and 4 months storage samples of vitamin B12 microcapsules were studied. The microcapsules were prepared using a spray-drying technique, and 7 biopolymers were used as encapsulating agents: arabic gum, sodium alginate, carrageenan, maltodextrin, modified starch, xanthan and pectin. The product yield of the spray-dryer ranged from 20 to 50%. The microparticles were also characterized in terms of size and morphology. The vitamin B12 release profiles from microcapsules were assessed by spectrophotometric analysis, at 361.4 nm, in deionized water at 22 C and simulated gastric fluid at 37 C. This study showed that the vitamin B12 microcapsules, with good stability properties, can be produced with several encapsulating agents and proved the possibility of releasing the vitamin in different periods of time.