Sujan Chowdhury

A Review of Bio-Oil Upgrading by Catalytic Hydrodeoxygenation

Fast pyrolysis is an attractive thermal conversion process to generate the alternative liquid fuel. However, the bio-oil obtained from biomass pyrolysis has polarity, instability and low energy density due to contained oxygenated compound. Hydrodeoxygenation (HDO) process is the most promising route for bio-oil upgrading through oxygen elimination. The products are suitable for co-feeding into the existing refineries. Metal catalyst and operating conditions play an important role in HDO efficiency. A summary of HDO process has been conducted with various metal catalysts, type of reactors, and reaction mechanisms. It also raises some challenges in improving catalyst efficiency, reducing hydrogen consumption, and effort to understand the HDO kinetics.

Removal of Phosphate and Fluoride from Industrial Wastewater – A Short Review

Industries producing fertilizers, aluminium, steel, bricks, glass, and semiconductor discharge several thousand tons of phosphate and fluoride per year into the open atmosphere in the form of wastewater which cause many environmental issues as well as loss of drinking water. The objective of this review is to select the suitable method for the removal of phosphate and fluoride from industrial wastewater which is highly hazardous and acidic in nature. So that treated water can be reused for agricultural and industrial purposes. Industries discharge several thousand tons of phosphate and fluoride per year in the form of wastewater which cause many environmental issues and loss of drinking water. This review is provided with aimed a precise and accurate knowledge for the removal of phosphate and fluoride from industrial wastewater. A lot of technologies are available for the treatment of industrial wastewater treatment including chemical precipitation, crystallization, ion exchange, adsorption, reverse osmosis and nanofiltration methods. The selection of most suitable treatment technology is based on retention time, principle of operation, applications, chemicals and maintenance cost.

Effect of Acetone on Physical Properties of PES Membrane

In the present study, polyethersulfone (PES) dope solution were prepared from mixtures of two solvents containing dimethylformamide (DMF) as core solvent, and acetone as co-solvent (CS), deionized water was used as coagulant bath. The amount of PES was kept at 20 wt% and the weight ratios of acetone were varied 20-24 wt.% to DMF and the dope solutions were prepared under closed heating system Results revealed the complete miscibility of PES with the fixed mixture of acetone and DMF under atmospheric pressure. The relationships between degree of adsorption, relative water absorption, were investigated. The results revealed that the interaction of DMF and acetone is strongest when their mole ratio is unity, which exhibit the phenomenon of true cosolvency for PES membrane. Keywords: polyethersulfone, solvent mixture, characterization.

Hydrogen and Syngas Generation from Gasification of Coal in an Integrated Fuel Processor

Hydrogen is a clean and new energy carrier to generate power and effectively turned out through the gasification of organic material such as coal. The main objective of this manuscript is to present an analysis of the coal gasification for the generation of high-purity hydrogen in a lab-scale fixed-bed downdraft gasifier. Better understanding of the rank, formation, structure, composition and calorific value and method of analysis of the material is crucial for the proper utilization of these resources requires. Traditionally the quality of the Coal samples has been determined by their physical and proximate analysis, such as, bulk density, free swelling index, gross calorific value, sulfur, moisture, fixed carbon, volatile matter and ash content. In this study, coal is partially oxidized and ultimately converts into hydrogen rich syngas (CO and H2). As well, approximately 220 kg h−1 of coal would be gasified at 673–1073 K and 46.2 atm with the reactor volume 0.27m3 to obtain approximately 3.8×105 kcal h−1 of thermal energy during over 67% syngas generation with the generation of 110kW electrical powers.

Kinetic Studies on Gold Nanoparticle Formation in Aqueous Medium

Extensive research data were published in the last decade on synthesis, characterization and application of AuNP for drug delivery and protein conjugation. Gold nanoparticles were synthesized by the well-known citrate reduction (Turkevitch) method. Precursor concentrations were measured by UV-Vis spectroscopy and iodometric estimation methods. During reaction surface plasmon resonance (SPR) peaks of the reaction medium decreased from 556.5 nm to 527.2 nm in about 300s. Experimental data on time-concentration profiles of the precursor in the reaction medium were used to calculate pseudo-first order rate constant (0.0178± 0.002 s-1). Atomic Force Microscopy (AFM) was used for morphological characterization of the nanoparticles.

Application of Micro- or Small-Scale Biomass-Derived Fuel System for Power Generation

Biomass being world’s largest renewable fuel source is now considered as the best alternate for fossil fuels owing to the CO2 saving nature as well as more economical as compared to fossil fuels. Although, some pretreatment process is required in order to utilize the raw biomass for power generation. There are various systems to generate power but combined heat and power (CHP) generation has proved to be the most beneficial method to generate electricity as well as heat by recovering the surplus heat to make an overall efficiency of up to 90 %. Various types of CHP systems have been discussed and compared for their working and efficiency along with their applications in different dwellings depending upon their power capacities. Moreover, biomass CHP systems have been thoroughly overviewed for their economic, energy, and environmental aspects.

Comparison of Image Processing Methods for the Detection of Particle from Digital Hologram

Two image processing methods for the detection of particle based on digital holography are presented and compared. The image processing methods are developed based on edge detection and threshold based segmentation. The proposed methods have been applied on reconstructed images of holograms of ceramic beads and certified microspheres. Particle size distribution obtained for both methods are found to be in good agreement with the actual size, but the processing speed for threshold based detection has found to be faster in compared to the edge detection method.

Development of Morphology Dependent Titania Nanomaterial for Photo Degradation of Dyes

Titania nanomaterial flower structure is synthesized through the ionothermal route and is used for the degradation of sulfan blue (SB) through the photo catalysis process. The ionic liquid used is 1-butyl-3-methypyridium dicyanamide ([Bmpm]DCN). The particle sizes and surface morphologies are characterized by field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and Brunauer–Emmett–Teller (BET). Three types of titania have been compared for their degradation performance, namely commercial titania (TP), titania nanotube (TN), and titania flower (TF). The size of the particle is found to be approximately 33 nm from the FE–SEM analysis. The BET measures the highest surface area of 220 m2 g-1 and pore volume of 0.15 cm3 g-1 for the TF. The degradation of binary dye is more favorable in alkaline solution with pH 14 while varying the dosage of the commercial TiO2 from 0.025–0.2 g reveals an increase in the rate of degradation with optimum dosage is found to be 0.2 g. Results show that TF degradation rate is higher as compared to TP and TN.

Fine Structural Analysis of Solvent Activated Cu-BTC for Carbon Dioxide Capture

Metal organic frameworks (MOFs) are presently under substantial investigation due to their properties and high potential as new class of porous material for carbon dioxide (CO2) capture. Experimentally, Cu-BTC crystalline frameworks with diameter of approximately 6-13 μm were found. The washing method of Cu-BTC was examined using three different solvent, (a) ethanol and water (1:1), (b) water, and (c) acetone to improve the BET surface area. These materials display approximately type I isotherms with no hysteresis and saturation. CO2 adsorption capacities study shows that acetone wash material can store about 5.98 mmolg-1of CO2 at 25oC and 1.2 bar.

An Equation of State for the Liquid Phase

Developments in Equation of State for gases have enabled estimation of properties of gases with reasonable accuracy. Equation of State for liquid phase is developed in this note to explain dependence of density of liquid on temperature through latent heat vaporization and specific heat of the liquid. The model is validated with data on some common liquids.