Synthesis and characterization of carbon microspheres from rubber wood by hydrothermal carbonization

Ahmed Khan, Tanveer,Kim, Hyun‐,Joong,Gupta, Arun,Jamari, Saidatul S,Jose, Rajan John WileySons, Ltd 2019 Journal of chemical technology and biotechnology Vol.94 No.5

<P><B>Abstract</B></P><P><B>BACKGROUND</B></P><P>Carbon is the raw material for many commercial products; conventionally their production is from non‐renewable sources such as petroleum coke, pitch and coal. Recently carbon has been obtained from bioresources because of their renewability and high lignocellulosic content. This article details the synthesis of carbon microspheres from rubber wood, which is one of the largest commodity plants, via hydrothermal carbonization (hydrothermal rubber wood carbon; HTRW carbon) and evaluation of their characteristics.</P><P><B>RESULTS</B></P><P>Two sets of carbon were synthesized: (i) in the first set, excess of water (20–40 × weight of biomass) was used in the hydrothermal process at 180–260 °C for 3–9 h; and (ii) in the second set, water ratio was 25–35 × weight of biomass and the hydrothermal carbonization (HTC) reaction temperature was fixed at 260 °C. The H/C and O/C ratios of starting rubber wood were ∼1.78 and ∼0.85, respectively, which upon processing through the first strategy resulted in H/C ∼0.78 and O/C ∼0.29; thereby suggesting increased condensation under HTC. On the other hand, the carbonization process was accelerated by water when the temperature was maintained at 260 °C; Fourier transform infrared (FTIR) studies show that this carbon has a different chemical structure from the starting rubber wood. Scanning electron microscopy (SEM) images showed that HTRW carbon was in the form of microspheres (size ∼1.5–5 µm).</P><P><B>CONCLUSION</B></P><P>HTRW carbon with carbon content as high as 68% was developed from rubber wood biomass by hydrothermal processing of a mixture containing 35 times more water than the solid raw biomass at a temperature of 260 °C for 7 h. © 2018 Society of Chemical Industry</P>

< 구두-E-10 > Synthesis of Carbon material and its application in medium density fiber (MDF) boards to enhance the thermal and mechanical properties

( Tanveer Ahmed Khan ),( Hyun-joong Kim ) 한국목재공학회 2018 한국목재공학회 학술발표논문집 Vol.2018 No.1

The medium density fiber boards(MDF) provide an alternative to structural materials from furniture to flooring to crown molding. It is made from a slurry containing wood fibers and a thermoset resin usually urea formaldehyde (UF) bonded under heat and pressure. An MDF board should have high dimensional stability and high mechanical strength under adverse atmospheric conditions of temperature and humidity; these requirements strongly depend on the board processing conditions. Wood fibers have low thermal conductivity thereby imposing severe inhomogeneity during the curing process and leads to low internal bonding, poor modulus of rupture and low dimensional stability. The thermal conductivity of the wood fiber could be increased by nano/micro structured fillers. It is hypothesized that carbon materials, such as carbon black, carbon nanotubes, carbon fibers would offer high thermal conductivity considering the carbon-carbon bonding between wood fibers and carbon materials. In this work, the carbon material was synthesized by pyrolysis of rubber wood fibers and characterized by CHNOS analyzer, X-ray diffraction (XRD), Brunauer, Emmett and Teller (BET) and scanning electron microscope (SEM). The prepared carbon materials were used as fillers in urea-formaldehyde adhesive in different weight concentration up to 5%. The dispersion of carbon materials into UF resin matrix were evaluated using Thermo gravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC), Fourier Transform Infrared (FTIR), X-ray diffraction (XRD) and solution rheology. The MDF was prepared by mixing of rubber wood fibers and UF/carbon material, resin at different weight percentages, i.e. 1, 2.5, 3.5 and 5. The mixing of carbon materials enhanced the heat transfer during the hot pressing of MDF. The core temperature reached 100 °C in 72 seconds on the board made using carbon material control board made without carbon material i.e., 84 seconds. The internal bonding (IB) strength and the modulus of rupture (MOR) estimated for the MDF is observed to have a maximum of 1 wt. % concentration of carbon material i.e., 0.71MPa and 37.63MPa respectively which are significantly higher than the boards made without carbon material i.e, IB and MOR values are 0.56 MPa and 32.31 MPa respectively.

< 구두-E-03 > 열수 탄화에 의한 탄소 미립자의 합성과 중 밀도 섬유 (MDF) 판재에 탄소 미립자가 충진제로서 복합재에 미치는 영향

칸탄비어아미드 ( Tanveer Ahmed Khan ),김현중 ( Hyun-joong Kim ) 한국목재공학회 2019 한국목재공학회 학술발표논문집 Vol.2019 No.1

This article details the syntheses of carbon microspheres from rubberwood, which is one of the largest commodity plants, via hydrothermal and evaluation of their characteristics. The syntheses were coordinated in excess of water (for water ratio was 25-35 × weight of biomass) and different operating time i.e., 5-7 hours at fixed temperature 260 °C. The carbon content as high as 68% was developed from rubber wood biomass by hydrothermal processing of a mixture containing 35 times more water than the solid raw biomass at a temperature of 260 °C for 7 hours. The prepared carbon microspheres were used as fillers in urea-formaldehyde adhesive in different weight concentration up to 5%. The dispersion of carbon materials into UF resin matrix were evaluated using Thermo gravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC), Fourier Transform Infrared (FTIR), X-ray diffraction (XRD) and solution rheology. The uniform dispersion of the carbon microspheres in the resin undertaken by mechanical stirring is confirmed on curing. The result from the curing reaction showed an increasing trend with the addition of carbon microspheres concentration. The X-ray-based measurement of CrI indicates that carbon microspheres increased the crystallinity of UF resin, whereas the maximum value was observed at CF-1 i.e., 87.3 %. The MDF was prepared by mixing of rubber wood fibers and UF/carbon microspheres, resin at different weight percentages, i.e. 1, 2.5, 3.5 and 5. The mixing of carbon microspheres enhanced the heat transfer during the hot pressing of MDF board composites. The core temperature reached 100 °C in 74 seconds on the board made using carbon microspheres. These values are on the lower side compared to the control board made without carbon material i.e., 84 seconds. The internal bonding (IB) strength and the modulus of rupture (MOR) estimated for the MDF is observed to have a maximum of 1 wt. % concentration of carbon microspheres prepared by HTC method. The IB and MOR values of boards made by 1 wt. % of carbon microspheres are 0.72MPa and 37.72MPa respectively which are significantly higher than the boards made without carbon microspheres i.e., IB and MOR values are 0.56 MPa and 32.31 MPa respectively.

Improving Dispersion and Mechanical Properties of PETG/Sepiolite Nanofiber Composites via Covalent Functionalization using Silane

김훈,신재호,Tanveer Ahmed Khan,김현중 한국고분자학회 2018 한국고분자학회 학술대회 연구논문 초록집 Vol.43 No.2

Spatial interpolation of geotechnical data: A case study for Multan City, Pakistan

Aziz, Mubashir,Khan, Tanveer A.,Ahmed, Tauqir Techno-Press 2017 Geomechanics & engineering Vol.13 No.3

Geotechnical data contributes substantially to the cost of engineering projects due to increasing cost of site investigations. Existing information in the form of soil maps can save considerable time and expenses while deciding the scope and extent of site exploration for a proposed project site. This paper presents spatial interpolation of data obtained from soil investigation reports of different construction sites and development of soil maps for geotechnical characterization of Multan area using ArcGIS. The subsurface conditions of the study area have been examined in terms of soil type and standard penetration resistance. The Inverse Distance Weighting method in the Spatial Analyst extension of ArcMap10 has been employed to develop zonation maps at different depths of the study area. Each depth level has been interpolated as a surface to create zonation maps for soil type and standard penetration resistance. Correlations have been presented based on linear regression of standard penetration resistance values with depth for quick estimation of strength and stiffness of soil during preliminary planning and design stage of a proposed project in the study area. Such information helps engineers to use data derived from nearby sites or sites of similar subsoils subjected to similar geological process to build a preliminary ground model for a new site. Moreover, reliable information on geometry and engineering properties of underground layers would make projects safer and economical.