Recent developments in catalyst synthesis using DBD plasma for reforming applications

The catalyst has a significant role in gas processing applications such as reforming technologies for H₂ and syngas production. The stable catalyst is requisite for any industrial catalysis application to make it commercially viable. Several methods are employed to synthesize the catalysts. However, there is still a challenge to achieve a controlled morphology and pure catalyst which majorly influences the catalytic activity in reforming applications. The conventional methods are expansive, and the removal of the impurities are major challenges. Nevertheless, it is not straightforward to achieve the desired structure and stability. Therefore, significant interest has been developed on the advanced techniques to take control of the physicochemical properties of the catalyst through non-thermal plasma (NTP) techniques. In this review, the systematic evolution of the catalyst synthesis using NTP technique is elucidated. The emerging DBD plasma to synthesized and effective surface treatment is reviewed. DBD plasma synthesized catalyst performance in reforming application for H₂ and syngas production is summarised. Furthermore, the status of DBD plasma for catalyst synthesis and proposed future avenues to design environmentally suitable and cost-effective synthesis techniques are discussed.     

The effect of ZIF-90 particle in Pebax/Psf composite membrane on the transport properties of CO2, CH4 and N2 gases by Molecular Dynamics Simulation method

Nowadays, mixed matrix membranes (MMMs) have considered by many researchers to overcome the problems of polymeric membranes. In addition, molecular dynamics (MD) and Monte Carlo (MC) simulation Methods are suitable tools for studying transport properties and morphology in MMMs. For this purpose, in this study using material studio 2017 (MS) software, the transport properties of CO₂, CH₄ and N₂ in Pebax, Psf neat Pebax/Psf composite and Pebax/Psf composite filled with ZIF-90 particles have been investigated. By adding Psf to Pebax matrix, the selectivity of CO₂/CH₄ and CO₂/N₂ gases has significantly increased. In addition, adding ZIF-90 particles to the Pebax/Psf composite increased the permeability of CO₂, CH₄ and N₂ compared to neat and composite membranes. The morphological properties of the membranes, such as the fractional free volume (FFV), radial distribution function (RDF), glass transition temperature (T_G), X-ray diffraction (XRD) and equilibrium density have calculated and acceptable results have obtained.     

The applications of nanotechnology in food industry

Nanotechnology has the potential of application in the food industry and processing as new tools for pathogen detection, disease treatment delivery systems, food packaging, and delivery of bioactive compounds to target sites. The application of nanotechnology in food systems will provide new methods to improve safety and the nutritional value of food products. This article will review the current advances of applications of nanotechnology in food science and technology. Also, it describes new current food laws for nanofood and novel articles in the field of risk assessment of using nanotechnology in the food industry.     

Life cycle GHG emissions from Malaysian oil palm bioenergy development: The impact on transportation sector's energy security

Malaysia's transportation sector accounts for 41% of the country's total energy use. The country is expected to become a net oil importer by the year 2011. To encourage renewable energy development and relieve the country's emerging oil dependence, in 2006 the government mandated blending 5% palm-oil biodiesel in petroleum diesel. Malaysia produced 16 million tonnes of palm oil in 2007, mainly for food use. This paper addresses maximizing bioenergy use from oil-palm to support Malaysia's energy initiative while minimizing greenhouse-gas emissions from land-use change. When converting primary and secondary forests to oil-palm plantations between 270–530 and 120–190 g CO₂-equivalent per MJ of biodiesel produced, respectively, is released. However, converting degraded lands results in the capture of between 23 and 85 g CO₂-equivalent per MJ of biodiesel produced. Using various combinations of land types, Malaysia could meet the 5% biodiesel target with a net GHG savings of about 1.03 million tonnes (4.9% of the transportation sector's diesel emissions) when accounting for the emissions savings from the diesel fuel displaced. These findings are used to recommend policies for mitigating GHG emissions impacts from the growth of palm oil use in the transportation sector.     

Clean hydrogen generation and storage strategies via CO2 utilization into chemicals and fuels: A review

Hydrogen becomes one of the most clean energy sources. The major issues on hydrogen are lack of practical clean and high‐temperature processes and possible practical storage of clean hydrogen. An energy intensive of clean hydrogen storage via chemical and liquid fuel production route is the current demand. This article reviewed the most recent research for hydrogen (H₂) production by using several methods, such as thermochemical process, thermal decomposition, biological approaches, electrolysis, and photocatalytic method. H₂ storage types, including physical and chemical approaches, were also reviewed. The produced H₂ was stored as valuable chemicals and fuels via CO₂ hydrogenation reaction. Reactor designs are the illustrated number of design ranging from the fixed bed to the continuous stirred tank reactor. Catalyst type, catalytic system, and the related mechanism of CO₂ hydrogenation reaction to form alcohol, alkanes, and carboxylic acid were also discussed in detail.     

Novel numerical solutions of nonlinear heat transfer problems using the linear barycentric rational interpolation

In this investigation, a numerical technique to obtain the approximate solutions of four well‐known nonlinear differential equations in the area of heat transfer is presented. This method is based on the operational matrix of derivative of linear barycentric rational interpolation. The main advantages of this approach are that it uses the Floater‐Hormann weights, which are very efficient in practice, and reduces the governing differential equation to a system of algebraic equations. The results are compared with the obtained numerical results of the fourth‐order Runge‐Kutta method along with the shooting method and some of the previously existing methods. The acquired results reveal that the derivative operational matrix method with barycentric rational basis functions is very efficient and can be implemented easily and fast.     

Analytical modeling of heat convection in magnetized micropolar fluid by using modified differential transform method

In this study, a new analytical method (DTM‐Padé) and the numerical method (by using a fourth‐order RungeBKutta and shooting method) were compared to solve convective heat transfer for a micropolar fluid in the presence of uniform magnetic field. It was shown that the differential transform method (DTM) solutions are only valid for small values of independent variables; therefore the DTM is not applicable for solving magnetohydrodynamic (MHD) boundary‐layer equations. The new method (DTM‐Padé) has removed this problem. Numerical comparisons between the DTM‐Padé and the numerical method revealed that the new method is a powerful method for solving MHD boundary‐layer equations. Finally, the analytical and numerical solutions of the problem for different values of the dimensionless parameters are shown simultaneously. © 2011 Wiley Periodicals, Inc. Heat Trans Asian Res; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/htj.20337     

Biohydrogen production from Imperata cylindrica bio-oil using non-stoichiometric and thermodynamic model

This paper presents a non-stoichiometric and thermodynamic model for steam reforming of Imperata cylindrica bio-oil for biohydrogen production. Thermodynamic analyses of major bio-oil components such as formic acid, propanoic acid, oleic acid, hexadecanoic acid and octanol produced from fast pyrolysis of I. cylindrica was examined. Sensitivity analyses of the operating conditions; temperature (100–1000 °C), pressure (1–10 atm) and steam to fuel ratio (1–10) were determined. The results showed an increase in biohydrogen yield with increasing temperature although the effect of pressure was negligible. Furthermore, increase in steam to fuel ratio favoured biohydrogen production. Maximum yield of 60 ± 10% at 500–810 °C temperature range and steam to fuel ratio 5–9 was obtained for formic acid, propanoic acid and octanol. The heavier components hexadecanoic and oleic acid maximum hydrogen yield are 40% (740 °C and S/F = 9) and 43% (810 °C and S/F = 8) respectively. However, the effect of pressure on biohydrogen yield at the selected reforming temperatures was negligible. Overall, the results of the study demonstrate that the non-stoichiometry and thermodynamic model can successfully predict biohydrogen yield as well as the composition of gas mixtures from the gasification and steam reforming of bio-oil from biomass resources. This will serve as a useful guide for further experimental works and process development.     

A novel analytical solution of mixed convection about an inclined flat plate embedded in a porous medium using the DTM-Padé

In this study, the problem of mixed convection about an inclined flat plate embedded in a porous medium is performed. The similarity transformations are applied to reduce governing partial differential equations (PDEs) to a set of nonlinear coupled ordinary differential equations (ODEs) in dimensionless form. An efficient mathematical technique, called the differential transform method (DTM), is used to solve the nonlinear differential equations governing the problem in the form of series with easily computable terms. Then, Padé approximant is applied to the solutions to increase the convergence of given series. It has been attempted to show the reliability and performance of the DTM in comparison with the numerical method (fourth-order Runge–Kutta) in solving this problem. The obtained solutions, in comparison with the numerical solutions admit a remarkable accuracy.     

Ethanol and lactic acid production using sap squeezed from old oil palm trunks felled for replanting

Old oil palm trunks that had been felled for replanting were found to contain large quantities of high glucose content sap. Notably, the sap in the inner part of the trunk accounted for more than 80% of the whole trunk weight. The glucose concentration of the sap from the inner part was 85.2 g/L and decreased towards the outer part. Other sugars found in relatively low concentrations were sucrose, fructose, galactose, xylose, and rhamnose. In addition, oil palm sap was found to be rich in various kinds of amino acids, organic acids, minerals and vitamins. Based on these findings, we fermented the sap to produce ethanol using the sake brewing yeast strain, Saccharomyces cerevisiae Kyokai no.7. Ethanol was produced from the sap without the addition of nutrients, at a comparable rate and yield to the reference fermentation on YPD medium with glucose as a carbon source. Likewise, we produced lactic acid, a promising material for bio-plastics, poly-lactate, from the sap using the homolactic acid bacterium Lactobacillus lactis ATCC19435. We confirmed that sugars contained in the sap were readily converted to lactic acid with almost the same efficiency as the reference fermentation on MSR medium with glucose as a substrate. These results indicate that oil palm trunks felled for replanting are a significant resource for the production of fuel ethanol and lactic acid in palm oil-producing countries such as Malaysia and Indonesia.