Cyanide in industrial wastewaters and its removal: A review on biotreatment

Around the world, there is a growing increase in biofuels consumption, mainly ethanol and biodiesel as well as their blends with diesel that reduce the cost impact of biofuels while retaining some of the advantages of the biofuels. This increase is due to several factors like decreasing the dependence on imported petroleum; providing a market for the excess production of vegetable oils and animal fats; using renewable and biodegradable fuels; reducing global warming due to its closed carbon cycle by CO2 recycling; increasing lubricity; and reducing substantially the exhaust emissions of carbon monoxide, unburned hydrocarbons, and particulate emissions from diesel engines. However, there are major drawbacks in the use of biofuel blends as NOx tends to be higher, the intervals of motor parts replacement such as fuel filters are reduced and degradation by chronic exposure of varnish deposits in fuel tanks and fuel lines, paint, concrete, and paving occurs as some materials are incompatible. Here, fuel additi...

The Role of Additives for Diesel and Diesel Blended (Ethanol or Biodiesel) Fuels: A Review

This paper reports the results of experimental investigations on the influence of the addition of cerium oxide in the nanoparticle form on the major physicochemical properties and the performance of biodiesel. The physicochemical properties of the base fuel and the modified fuel formed by dispersing the catalyst nanoparticles by ultrasonic agitation are measured using ASTM standard test methods. The effects of the additive nanoparticles on the individual fuel properties, the engine performance, and emissions are studied, and the dosing level of the additive is optimized. Comparisons of the performance of the fuel with and without the additive are also presented. The flash point and the viscosity of biodiesel were found to increase with the inclusion of the cerium oxide nanoparticles. The emission levels of hydrocarbon and NOx are appreciably reduced with the addition of cerium oxide nanoparticles.

https://journals.sagepub.com/doi/pdf/10.1155/2010/581407

Experimental Investigations on the Effects of Cerium Oxide Nanoparticle Fuel Additives on Biodiesel

Catalytic wet-air oxidation processes: A review

Conventional and emerging processes that require the application of multiphase reactors are reviewed with an emphasis on catalytic processes. In the past, catalyst discovery and development preceded and drove the selection and development of an appropriate multiphase reactor type. This sequential approach is increasingly being replaced by a parallel approach to catalyst and reactor selection. Either approach requires quantitative models for the flow patterns, phase contacting, and transport in various multiphase reactor types. This review focuses on these physical parameters for various multiphase reactors. First, fixed-bed reactors are reviewed for gas-phase catalyzed processes with an emphasis on unsteady state operation. Fixed-bed reactors with two-phase flow are treated next. The similarities and differences are outlined between trickle beds with cocurrent gas–liquid downflow, trickle-beds with countercurrent gas–liquid flow, and packed-bubble columns where gas and liquid are contacted in coc...

Multiphase catalytic reactors: a perspective on current knowledge and future trends

Improvement of Diesel fuel properties by using additives

An attempt has been made to prepare glucaric acid by oxidation of sugar beet molasses in packed beds. In the first part, a suitable oxidizing medium was sought. Experiments were performed in a cylindrical Pyrex-glass reactor with air–molasses cocurrent downflow. Spherical glass and cylindrical vanadium pentoxide particles were used as an inert packing and catalyst respectively. The addition of catalyst, sodium nitrite, nitric and sulfuric acids to the medium resulted in an improvement in glucaric acid yield. The presence of nitric acid in the oxidizing medium and the use of vanadium pentoxide catalyst were the most effective factors as regards the yield. In the second part, the effects of temperature, molasses concentration, amount of catalyst and air flow rate on the yield were studied; each of these variables increased the yield. The use of a longer catalyst bed, however, resulted in a decrease in the yield. The highest rate of conversion of glucose to glucaric acid was 63.9% at optimum conditions.

© 2001 Society of Chemical Industry

The preparation of D‐glucaric acid by oxidation of molasses in packed beds

Liquid holdup and wetting efficiency in packed columns were determined using a tracer method. A new model was developed considering axial dispersion, and analysis was made using the moment technique. The saturated solution of KG was used as an inert tracer and total liquid holdups were determined in the first part of experiments. As an adsorbable tracer, dioxane was utilized in the second part of the work and wetting efficiencies were obtained. Adsorption equilibrium constant was determined by the experiments conducted in a liquid full bed. A model proposed between liquid holdup and wetting efficiency gave good agreement with the experimental results. Axial dispersion effects were also taken into account during the work. It was also shown that axial dispersion of liquid phase should be considered especially in the small scale trickle bed reactors. @KEYWORDS:Packed beds,Wetting efficiency,Liquid holdup,Tracer method,Moment technique,Trickle bed reactors.

The relation between wetting efficiency and liquid holdup in packed columns

This study concerns with the preparation of flame retardant and hydrophobic cellulosic fabric by using hexagonal boron nitride nanosheets (h-BNNs). h-BNNs were prepared from hexagonal boron nitride (h-BN) using two different exfoliation methods. These methods include direct sonication (aq-BNNs) and sonication after pretreatment with Hummers method (Hum-BNNs) in aqueous medium. The characterization of h-BNNs was carried out by x-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), limited oxygen index (LOI), and water contact angle (WCA) analysis. The surface morphologies of h-BNNs were investigated via atomic force microscope (AFM). The coating with the h-BNNs was proved by scanning electron microscopy (SEM). Hummers method is considered to be more effective reaction by gained functionality to h-BN structure. In this way, it will easily provide physical or chemical interaction between the functionalized h-BN and cellulosic structure. A nanometric-sized ...

Cellulosic tent fabric coated with boron nitride nanosheets

At the first part of this work, three different textile dyes (disperse orange 11, 13 and 37) were separately doped (1% w/w) to the nematic liquid crystal (E7). Single‐walled nanotube and fullerene C60 in a small amount (0.05% w/w) were mixed to these solutions at the second stage. Order parameters, threshold voltages, textures and clearing temperatures for all of mixtures were determined. Co‐use of dyes and nanoparticles as dopant was resulted in notable increases in order parameters. While threshold voltages required for the change of order parameter decreased, an important change in the texture and clearing temperature of the liquid crystal was not observed.

Ahmet Alicilar

Papers

Improvement of Diesel fuel properties by using additives

The preparation of D‐glucaric acid by oxidation of molasses in packed beds

The relation between wetting efficiency and liquid holdup in packed columns

Cellulosic tent fabric coated with boron nitride nanosheets

Phase Transitions, Order Parameters and Threshold Voltages in Liquid Crystal Systems Doped with Disperse Orange Dye and Carbon Nanoparticles