Green Diesel Production from Oleic Acid Deoxygenation Using Subcritical Water under Hydrogen-Free Condition

Green diesel or bio-hydrogenated diesel (BHD) is a second generation renewable liquid fuel that can be produced from several types of renewable sources such as triglyceride in vegetable oils or animal fats, free fatty acid in waste from refining palm oil industry, and their derivatives via a catalytic reaction involving hydrogenation and deoxygenation provided n-alkanes as a main product. In this work, the aim was to investigate the effect of reaction time and catalyst type on green diesel production in a batch mode without H2 feed. The green diesel was produced from oleic acid using activated carbon and commercial catalyst at reaction temperature of 250 °C and total pressure of 40 bars under DI water as a hydrogen source. The results showed that 100% oleic acid conversion was obtained by using both type of catalysts. Pentadecane was the main product with 96% percentage at 3 h reaction time for commercial catalyst and 100% percentage at 5 h reaction time for activated carbon. In addition, the products in gas phase were CO2 and CO for both types of catalyst and CH4 only appeared when commercial catalysts were used.&nbsp

Production of Composite Fibers from Natural Rubber and Lignin

The interest of natural rubber (NR) product applications have been increased as natural rubber can be obtained from nature and it can be produce into sustainable products. It’s widely used in applications such as tires, wires, latex products, medical devices, and sport components. In this work, the use of electrospinning technique to produce fibers has been carried out because this technique has been proved to be a simple and effective technique for fiber production. This work aimed to study morphology, diameter, and functional group of natural rubber fibers, DPNR fibers, and different loadings of lignin in DPNR/lignin composite fibers produced by electrospinning technique. The condition for electrospun fibers were as following; needle-target distances of 15 cm and flow rate of 2.5 ml/h. The results of deproteinization by urea, SDS solution, and acetone showed protein in NR latex decreased. Moreover, increasing load of lignin resulted in an increase of the diameter of DPNR/lignin composite due to increasing of viscosity of the solution related to increasing of viscoelastic force. Characterizations of these fibers were reported using scanning electron microscopy to examine fibers surface and measure diameter of the fibers. Fourier transform infrared spectroscopy was used to examine the functional group of the fibers

CFD Simulation of Raschig Ring Packing Patterns in a Pilot Scale: Prediction of Mean Residence time

AbstractMean Residence Time (MRT) was determined numerically for the pilot packed bed reactor filled with the ceramic raschig rings. Three well-defined patterns and one randomly packed bed were studied, where a tube-to-particle ratio (N) was around 7. A case study of Dry Methane Reforming (DMR) was investigated at 600 °C, 1 atm. Reactant feeding rates were varied in the range of 0.985 to 2.957 L/min. The MRTs of four difference packing pattern, namely, vertical-staggered (pattern 1), chessboard-staggered (pattern 2), reciprocal-staggered (pattern 3), and randomly packed bed were conducted using finite-element based Computational Fluid Dynamics (CFD). The results were shown in terms of E(t) function where a higher value of the E(t) function means greater deviation from the ideal plug flow. Results showed that chessboard-staggered pattern had the lowest E(t) values compared with all patterns and all feeding rates. To deeply representative results for the system configurations, the discussion on non-ideal behaviors of each structured packing can be made systematically in this work

Effects of Raschig Ring Packing Patterns on Pressure Drop, Heat Transfer, Methane Conversion, and Coke Deposition on a Semi-pilot-scale Packed Bed Reformer

The effects of Raschig ring packing patterns on the efficiency of dry methane reforming reactions were investigated using computational fluid dynamics (CFD). The present study aims to understand the behavior of fluid flow in packed bed reactors, especially under low reactor-to-ring ratios between 4 and 8. Three packing patterns were studied: vertical staggered (VS), chessboard staggered (CS), and reciprocal staggered (RS). It was determined that packing pattern notably affected pressure drop across the reactor length. The VS pattern produced the lowest pressure drop of 223 mPa, while the CS and RS patterns produced pressure drops of 228 mPa and 308 mPa, respectively. The values of methane conversion can be increased by ca. 2 % by selecting a more suitable packing pattern (i.e., 76 % for the VS pattern and 74 % for the CS and RS patterns). This work is licensed under a Creative Commons Attribution 4.0 International License

Catalytic upgrading of bio-oils by esterification

Biomass is the term given to naturally-produced organic matter resulting from photosynthesis, and represents the most abundant organic polymers on Earth. Consequently, there has been great interest in the potential exploitation of lignocellulosic biomass as a renewable feedstock for energy, materials and chemicals production. The energy sector has largely focused on the direct thermochemical processing of lignocellulose via pyrolysis/gasification for heat generation, and the co-production of bio-oils and bio-gas which may be upgraded to produce drop-in transportation fuels. This mini-review describes recent advances in the design and application of solid acid catalysts for the energy efficient upgrading of pyrolysis biofuels