Review: Sintesis Carbon Nanotubes (CNT) dari Bahan Terbarukan untuk Komposit Carbon Nanotube-Polyaniline

<p>Artikel ini berisi tentang sintesis <em>carbon nanotubes</em> (CNT) dari material tanaman sebagai upaya untuk mengurangi penggunaan bahan kimia dan pemanfaatan bahan terbarukan. CNT telah berhasil disintesis dari prekursor tanaman seperti cangkang sawit, minyak sawit, bambu, kayu karet, jerami padi, batok kelapa, serat kelapa dan minyak kelapa. Sifat unik dari CNT menyebabkan penelitiannya terus dilakukan dan banyak diterapkan dalam berbagai aplikasi salah satunya material komposit. CNT yang telah disintesis dapat dikompositkan dengan <em>polyaniline</em> (PANI) untuk memperoleh konduktivitas, sifat optik, dan kekuatan mekanik yang lebih unggul. </p><p><strong><em>Review: Synthesis of Carbon Nanotubes (CNT) from Renewable Materials for Carbon Nanotube-Polyaniline Composites. </em></strong>This article contains the synthesis of carbon nanotubes (CNT) from plant materials in an effort to reduce the use of chemicals and the use of renewable materials. CNT has been successfully synthesized from plant precursors such as palm kernel shells, palm oil, bamboo, rubberwood, rice straw, coconut shells, coconut fiber, and coconut oil. The unique properties of CNT have led to continuous research and many applications in various applications, one of which is composite materials. The synthesized CNTs can be composite with polyaniline (PANI) to obtain superior conductivity, optical properties, and mechanical strength.</p>

Utilization of Modified Zeolite as Catalyst for Steam Gasification of Palm Kernel Shell

Syngas from biomass gasification is being developed for alternative feedstock in the chemical industry. Palm kernel shell which is generated from palm oil industry can be potentially used as raw material for gasification process. The purpose of this study was to investigate the use of modified natural zeolite catalysts in steam gasification of palm kernel shells. Mordenite type zeolite was modified by acid leaching to be used as a tar cracking catalyst. Steam gasification was conducted at the temperature range of 750–850 °C and the steam to biomass ratio was in the range of 0–2.25. The result showed that steam gasification of palm kernel shell with the addition of zeolite catalyst at 750 °C and steam to biomass ratio 2.25 could reduce tar content up to 98% or became 0.7 g/Nm3. In this study, gasification of palm kernel shells produced syngas with the hydrogen concentration in the range of 52–64% and H2/CO ratio of 2.7–5.7. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Mechanical Properties of Concrete with Agricultural Waste as a Partial Substitute for Granite as Coarse Aggregate

The paper investigated the effect of using Palm Kernel Shell (PKS) as a partial substitute for granite as coarse aggregate in concrete production, aimed at developing an alternative form of construction material without compromising structural integrity. Randomly sourced dried and undried palm kernel shells, were used to replace coarse aggregate by weight to a standard mix ratio of 1:2:4:0.54. The dried shells were obtained by heating in an improvised oven at 800C. The physical and geotechnical properties of the aggregates were determined. Results showed that the aggregate impact value of granite and PKS used were 0.228 and 0.104 respectively. The substitution of the coarse aggregate was varied from 0% to 20%. A slump test was used to determine the workability of the fresh concrete. A total of 108 concrete cubes measuring 100mm×100mm×100mm were investigated at 7days, 14days, 21days and 28days. The control mix gave compressive strengths of 25.67 N/mm2, 29.83 N/mm2, 31.33 N/mm2 and 35.67 N/mm2 at 7, 14, 21 and 28days respectively. The compressive strengths of undried PKS cement blended concrete and dried PKS substitute at 5% were 23.17 N/mm2, 27.00 N/mm2, 28.00 N/mm2, 26.00 N/mm2 and 17.50 N/mm2, 16.17 N/mm2, 18.16 N/mm2, 20.00 N/mm2 respectively for 7, 14, 21 and 28days curing periods. The highest compressive strength of 28.00 N/mm2 decreased by 21.50% from the control of 35.67 N/mm2. This compressive strength is adequate for light weight construction works as specified by BS EN 206:2013.

Production of Bio-fuels by microwave-assisted Rapid Hydrothermal Liquefaction of Palm Kernel Shells Biomass

Hydrothermal Liquefaction (HTL) process is an alternative way for converting biomass to bio-fuels product. The aim of this study was to determine the effect of sample’s mass and heating time on the product yield (wt%) from palm kernel shells (PKS) and to characterize the bio-oil as produced. PKS which is one kind of biomass efficiently converted to bio-oil, bi-char and bio-gas by HTL associated with modified microwave oven. A modified household microwave oven with 800W was employed in this process. The product yield was increased proportionally with the sample mass from 31.16 wt% to 41.92 wt% for bio-oil at constant time of 15 minutes. However, a vice versa trend was observed for bio char. Furthermore, it was exhibited that the highest value of 66.51 wt% and then it reduced to 42.17 wt%. The last product, bio gas shows an increasing trend from 2.32wt% to 15.90wt%. For the second parameter, the production of bio oil decreases with the increasing of heating time while bio char and bio gas increases with the increases of time. For the highest product yield, the calorific value is 37.68 MJ/kg for 15g sample and 22.32 MJ/kg for 35g sample at 15 minutes heating time. Fourier Transform Infrared Spectroscopy (FTIR) result reveals that multiple functional groups i.e. alcohol, aldehydes, carboxylic acid and ketones is present in the PKS bio oil. Additionally, the pH value of the bio oil was in the range of 2-3.

Yield Enhancement of Activated Carbon Palm Kernel Shells Based through Carbonization Solidification Process

Utilization of palm oil waste in palm kernel shells as activated carbon, the activated carbon manufacturing goes through several processes, including dehydration, carbonization, and activation. Palm shell particle size was controlled during the activated carbon synthesis process through the temperature of the milling time and carbonization processes. The carbonization process was carried out using an electric furnace at carbonization temperatures 400, 600, and 800 °C, respectively. A carbonization time was 1 hour under vacuum condition to produce initial values of particle and grain sizes that had a neat structure and had absorption capacity. The particle size of formed activated carbon was measured by PSA (particle size analyzer) type Coulter LS 100Q micron scale. The particle size of active carbon was dependent on the carbonization temperature at 400, 600, and 800 °C was obtained particle size 19,90, 9,507, and 6,264 μm, respectively. Several characterizations are required to determine the properties of activated carbon was obtained. FTIR Spectrophotometer was used to observe activated carbon’s molecule structure before and after dehydration and carbonization process. It was found that the specific fingerprint at 2913,91 cm-1 and 2923,56 cm-1 for the carbon chain of activated carbon. Other physical and chemical properties were conducted to investigate moisture content, thermal property, yield enhancement, and formed product appearance.

KELAYAKAN USAHATANI TEMBAKAU VIRGINIA: STUDI KOMPARASI PADA PROSES PENGOVENAN DI KABUPATEN LOMBOK TIMUR

There are two methods of flue curing process used in virginia tobacco farmers in East Lombok, which are curing with fossil fuel and curing with local (alternative) fuels (candlenut shell, palm kernel shells, wood, and corn cobs). Now days, due to increasing fossil fuels price, farmer tend to use local fuels. The research objective was to compare the costs, income, and feasibility level of virginia tobacco farming on the use of various alternative fuels in the oven process in East Lombok Regency. The method used is descriptive survey method to 40 farmers. The cost of farming virginia tobacco using candlenut shell as fuel is Rp. 44,788,057/ha/planting season with an R/C ratio of 1.6 palm kernel shells of 45,081,109/ha/planting season with an R/C ratio of 1.5 wood of Rp. 49,498,452/ha/planting season with an R/C ratio of 1.4 and corn cobs of Rp. 39,184,196/ha/planting season with an R/C ratio of 1.8. The highest income is obtained from farmers who use corn cobs as fuel of Rp. 30,037,854/ha/planting season, the income of the farmers who use hazelnut shell and palm shell as fuel each is Rp. 25,938,788/ha/planting season and Rp. 23,757,891/ha/planting season. The lowest income using wood fuel is Rp. 16,883,748/ha/planting season. Because the R/C value is more than 1, it means that virginia tobacco farming using various alternative materials in the oven process in East Lombok Regency is feasible.