Pongsert Sriprom¹, Warawut Krusong², Pornsawan Assawasaengrat^3,*

Journal of Renewable Materials, Vol.9, No.2, pp. 311-324, 2021, DOI:10.32604/jrm.2021.012560

Abstract Durian rind wastes are an important raw material for activated carbon production due to their renewable sources and low-cost materials. The efficiency of increasing surface area and the quantity of oxygen groups on the surface of activated carbon were studied for the preparation of activated carbon. The preparation of activated carbon has been studied with the different methods as follows: activation by acid, activation by base, hydrothermal and activation by acid, and hydrothermal and activation by base. The results showed that hydrothermal and activation by acid had high iodine number which was chosen to determine the optimum condition for activated… More >

Dexby de Guzman, Rizalinda de Leon^*

Journal of Renewable Materials, Vol.9, No.1, pp. 145-162, 2021, DOI:10.32604/jrm.2021.011646

Abstract Levulinic acid (LA) is a platform biorefinery chemical from biomass which can be converted to green solvents, plasticizers, polymer precursors, bio-based cleaning agents, fuels and fuel additives. This study assessed the potential of SnCl₂-based mixed acid systems as catalyst in the hydrothermal conversion of microcrystalline cellulose to levulinic acid. Maximum LA yield of 36.2 mol% was achieved using 0.2 M SnCl₂ concentration at test conditions of 3 h, 180°C and 1% w/v cellulose loading. To reduce precipitate formation and further improve LA yield, the strategy employed was to combine SnCl₂ (a Lewis acid) with conventional mineral acids (Bronsted acids). Evaluation… More >

Riina Syivarulli^1,2, Nugroho Agung Pambudi^2,*, Mochamad Syamsiro³, Lip Huat Saw⁴

Energy Engineering, Vol.118, No.1, pp. 189-197, 2021, DOI:10.32604/EE.2020.010493

Abstract One of the major problems faced in managing biomass waste to higher quality products is choosing the right technology. Wastes are used as an alternative fuel, with increase in the calorific value. Hydrothermal carbonization (HTC) is a biomass conversion technology, used to obtain solid fuel. This study aims to utilize of Calophyllum inophyllum as an alternative solid fuel through HTC. The calorific value and proximate of the hydrochar will be determined and analyzed to find out its quality. The experiments were carried out at temperature variations of 160°C, 190°C, and 220°C and holding times of 30 and 60 minutes. The… More >

Lixia Gao¹, Sheng Shi^1,2,*, Wensheng Hou¹, Shuhua Wang¹, Zhifeng Yan¹, Chao Ge¹

Journal of Renewable Materials, Vol.8, No.6, pp. 703-713, 2020, DOI:10.32604/jrm.2020.09055

Abstract In this study, waste cotton fabric was used as cellulose raw material and pretreated in aqueous NaOH/urea solution system to investigate the effect of NaOH/urea pretreatment solution on the hydrolysis of cotton fiber. The cotton fiber was pretreated with different conditions of aqueous NaOH/urea solution, and the pretreated cotton fiber was hydrolyzed under the same conditions as the original cotton fiber. The results of characterization analysis showed that water retention value of pretreated cotton fiber was higher than that of unpretreated sample. Moreover, the cotton fiber presented both a convoluted structure and a coarser surface, XRD results suggested that the… More >

Yongfang Zhang^1,2, Wensheng Hou¹, Hong Guo¹, Sheng Shi¹, Jinming Dai^1,2,*

Journal of Renewable Materials, Vol.7, No.12, pp. 1309-1319, 2019, DOI:10.32604/jrm.2019.07884

Abstract Carbon microspheres were prepared from waste cotton fibers by hydrothermal carbonization (HTC) with the addition of copper sulphate in this work. The important influence factors, temperature, concentration of copper sulphate, resident time were explored here. The smooth and regular carbon microspheres could be formed at 330°C with 0.15 wt% copper sulphate after 6 h from waste cotton fibers. The crystal structures of cotton fibers were destructed in a short resident time with 0.15 wt% copper sulphate from SEM images and XRD patterns of solid products. This strategy provides a new, mild and efficient method to prepare carbon microspheres from waste… More >

Mahmoud MOUSTAFA^{1, 2}, Saad ALAMRI¹, Mohamed ELNOUBY³, Tarek TAHA⁴, M. A. ABU-SAIED⁵, Ali SHATI¹, Mohamed AL-KAHTANI¹, Sulaiman ALRUMMAN¹

BIOCELL, Vol.42, No.3, pp. 93-98, 2018, DOI:10.32604/biocell.2018.07014

Abstract Water contaminated with pathogenic microbes is considered as one of the most common routes for transmitting diseases in human beings. Different methods have been applied for the decontamination of microbes in contaminated water. In the current study, an easy to do hydrothermal method has been used for the preparation of TiO₂-Ag nanoparticles. The obtained material was characterised using a scanning electron microscope (SEM) and fourier transform infra-red spectroscopy (FTIR). The morphological appearance of the obtained nanoparticles was in the shape of a sphere with a size range of 60-90 nm. The antimicrobial activity of the prepared nanoparticles was tested against… More >

Marcelo M. Oliveira^1,2, Antônio A. S. Curvelo^2,3, Carlos Driemeier^1*

Journal of Renewable Materials, Vol.6, No.2, pp. 152-159, 2018, DOI:10.7569/JRM.2017.6341576

Abstract Lignocellulose conversion into cellulosic ethanol and coproducts starts with a pretreatment step. Most current industrial plants of cellulosic ethanol use thermochemical pretreatments under hydrothermal conditions, with or without addition of acid catalyst. Such pretreatments modify biomass chemistry and morphology, particularly at the nanoscale. In this work, we use X-ray diffraction, dynamic vapor sorption and calorimetric thermoporometry to investigate the biomass nanostructural changes promoted by hydrothermal conditions. We compare and differentiate the rind and pith fractions of sugarcane stalks in order to contribute to the understanding of rind-pith contrasting recalcitrance. Moreover, for both cane fractions our results point consistently to cellulose… More >

V. Shevtsova¹, A. Mialdun¹, H. Kawamura², I. Ueno², K. Nishino³, M. Lappa⁴

FDMP-Fluid Dynamics & Materials Processing, Vol.7, No.1, pp. 1-28, 2011, DOI:10.3970/fdmp.2011.007.001

Abstract The experimental results from nine benchmark test cases conducted by five different groups are presented. The goal of this study is to build an experimental database for validation of numerical models in liquid bridge geometry. The need arises as comparison of numerical results with a single experiment can lead to a large discrepancy due to specific experimental conditions. Perfectly conducting rigid walls and, especially, idealized boundary conditions at the free surface employed in numerical studies are not always realized in experiments. The experimental benchmark has emphasized strong sensitivity of the threshold of instability to the liquid bridge shape. A clear… More >

D.E. Melnikov¹, V.M. Shevtsova²

FDMP-Fluid Dynamics & Materials Processing, Vol.3, No.4, pp. 329-338, 2007, DOI:10.3970/fdmp.2007.003.329

Abstract Thermocapillary convection in a long vertical liquid column (called liquid bridge) subjected to heating from above is considered for a three-dimensional Boussinesq fluid. The problem is solved numerically via finite-volume method. Full system of three dimensional Navier-Stokes equations coupled with the energy equation is solved for an incompressible fluid. Instability sets in through a wave propagating in axial direction with zero azimuthal wave number, which is a unique stable solution over a wide range of supercritical heating. Further increasing the applied temperature difference results in bifurcation of a second wave traveling azimuthally with a slightly higher frequency. The two waves… More >