Cathodic Conversion of Pressurized CO at Silver Cathodes: What are the Optimal Values of Pressure and Current Density?

The cathodic reduction of pressurized CO (PrCOCR) at suitable cathodes can allow to produce various chemicals, such as formic acid/formate (FA) and carbon monoxide or synthesis gas, with high faradic efficiencies (FEs) and productivities. Here, we have performed the conversion of CO in an undivided pressurized electrochemical reactor using silver cathode in order to determine the optimal values of CO pressure and current density. It was found that the plot FE vs.

Oxidation of organics in water by active chlorine performed in microfluidic electrochemical reactors: a new way to improve the performances of the process.

Wastewater polluted by organics can be treated by using electro-generated active chlorine, even if this promising route presents some important drawbacks such as the production of chlorinated by-products. Here, for the first time, this process was studied in a microfluidic electrochemical reactor with a very small inter-electrode distance (145 μm) using a water solution of NaCl and phenol and a BDD anode. The potential production of chloroacetic acids, chlorophenols, carboxylic acids, chlorate and perchlorate was carefully evaluated.

Electrochemical remediation of synthetic and real marine sediments contaminated by PAHs, Hg and As under low electric field values.

To date, remediation, protection, and restoration of contaminated sites is a global concern. The current technologies to restore sediments characterized by heterogeneous characteristics, several pollutants, fine grains, and low hydraulic permeability are poorly effective; hence their remediation is still challenging. A promising approach for the sediment's remediation could be the electrochemical route since it is a not-expensive, effective and noninvasive in situ technology.

Development of a process for the treatment of synthetic wastewater without energy inputs using the salinity gradient of wastewaters and a reverse electrodialysis stack.

Electrochemical processes are considered very effective methods for the treatment of wastewater contaminated by organics resistant to conventional biological processes and various inorganic pollutants. Large sites that treat wastewaters usually deal with a large number of waters often characterized by different salinity contents, that could be potentially used to provide the energy necessary for the electrochemical remediation. Hence, in this work a reverse electrodialysis (RED) process for the treatment of synthetic wastewaters contaminated by organics, without energy inputs, using the salinity gradient of different wastewaters, was studied, for the first time.

Robust Mesoporous CoMo/γ-AlO Catalysts from Cyclodextrin-Based Supramolecular Assemblies for Hydrothermal Processing of Microalgae: Effect of the Preparation Method.

Hydrothermal liquefaction (HTL) is a promising technology for the production of biocrude oil from microalgae. Although this catalyst-free technology is efficient under high-temperature and high-pressure conditions, the biocrude yield and quality can be further improved by using heterogeneous catalysts. The design of robust catalysts that preserve their performance under hydrothermal conditions will be therefore very important in the development of biorefinery technologies.

Electrochemical treatment of aqueous solutions of organic pollutants by electro-Fenton with natural heterogeneous catalysts under pressure using Ti/IrO-TaO or BDD anodes.

The treatment of toxic organic pollutants by electro-Fenton (EF) presents some drawbacks such as the necessity to work at low pH and the low solubility of oxygen in water contacted with air or oxygen at room pressure that results often in slow and relatively low abatements. Here, the coupled adoption of natural heterogeneous catalysts and of relatively high pressure was proposed in order to improve the performances of EF for the treatment of organic pollutants. Caffeic acid (CA) and 3-chlorophenol were used as model resistant organic pollutants.

Reverse electrodialysis performed at pilot plant scale: Evaluation of redox processes and simultaneous generation of electric energy and treatment of wastewater.

This paper describes the experimental campaign carried out with a reverse electrodialysis (RED) demonstration plant (Marsala, Italy) with the main aims of: (i) evaluating the effect of various operating parameters, including the redox processes, on the system performances; (ii) using the plant for the simultaneous generation of electric energy and treatment of wastewater. The prototype (44 × 44 cm, 500 cell pairs) was tested using both real (brackish water and brine) and artificial solutions. Tests with two different electrode rinse solutions (with or without iron redox couples) were performed.

Autohydrolysis pretreatment of Arundo donax: a comparison between microwave-assisted batch and fast heating rate flow-through reaction systems.

Background: Autohydrolysis of lignocellulosic biomass in liquid hot water has been widely studied owing to its high efficiency and relatively low cost. In the perspective of industrial applications, continuous or semi-continuous processes are more interesting than batch systems. Moreover, microwave heating of pretreatment systems has been proposed to intensify the kinetics of the process.

A one-pot method to enhance dissolution rate of low solubility drug molecules using dispersion polymerization in supercritical carbon dioxide.

The surfactant assisted polymerization of 1-vinyl-2-pyrrolidone in supercritical carbon dioxide in the presence of Piroxicam, selected as a model of a low aqueous solubility drug, was studied in order to prepare in a single step a polymeric composite to enhance the rate of dissolution of the pharmaceutical compound. Reactive entrapping was carried out at 65 degrees C in the P range 21-38MPa. Under proper operative conditions we obtained the composite under the form of sub-micron spherical particles with relatively narrow particle size distribution.

Electrochemical oxidation of organics in water: role of operative parameters in the absence and in the presence of NaCl.

The electrochemical oxidation of organics in water was investigated theoretically and experimentally to determine the role of several operative parameters on the performances of the process in the presence and in the absence of sodium chloride. Theoretical considerations were used to design the experimental investigation and were confirmed by the results of the electrochemical oxidation of oxalic acid (OA) at boron doped diamond (BDD) or IrO(2)-Ta(2)O(5) (DSA-O(2)) anodes in a continuous batch recirculation reaction system equipped with a parallel plate undivided electrochemical cell. Polarization curves and chronoamperometric measurements indicated that, in the presence of chlorides, the anodic oxidation of OA is partially replaced by an indirect oxidation process.

Complexation of phosphine ligands with peracetylated beta-cyclodextrin in supercritical carbon dioxide: spectroscopic determination of equilibrium constants.

The interaction between peracetylated beta-cyclodextrin and several triphenyl phosphine derivatives was studied in supercritical carbon dioxide (scCO2) by UV-visible spectroscopy. The equilibrium constant for a 1:1 complexation reaction was obtained from titration spectra and calculated using two established mathematical models. The values of the equilibrium constants are 1-3 orders of magnitude smaller than those obtained in aqueous solution with analogous phosphines.

Electrocarboxylation of benzyl halides through redox catalysis on the preparative scale.

The electrocarboxylation of benzyl halides to the corresponding carboxylic acids through homogeneous charge-transfer catalysis was investigated both theoretically and experimentally to determine the influence of the operative parameters on the yield of the process and on the catalyst consumption. Theoretical considerations, based on fast kinetics of redox catalysis, were confirmed by the electrocarboxylation of 1-phenyl-1-chloroethane catalyzed by 1,3-benzenedicarboxylic acid dimethyl ester performed at a carbon cathode under different operative conditions. We obtained high yields of the target carboxylic acid and experienced a low catalyst consumption by operating with optimized [RX]bulk/[CO2]bulk and [RX]bulk/[catalyst] ratios.