Coconut Carbon Research Articles

Studies on Properties of the Coconut Carbon Fiber and Yarn

A new health care fiber-coconut carbon fiber, and yarn use coconut carbon fiber and cotton blended into are introduced in this paper. And a series of performance testing and analysis about scanning electron microscopy, infrared spectrum, strength, hairiness, moisture content and acid and alkali resistance are done to the carbon fiber and coconut yam.

Research about the Wearability of Coconut Carbon Fiber Knitted Fabric

This article focuses on the performance test of coconut carbon fiber knitted fabric, like air permeability, moisture permeability, thermal insulation, fastness and deodorant, release negative ions, etc. use the fuzzy comprehensive evaluation method to analyze and evaluate the coconut carbon fiber knitted fabric.

Coconut Carbon Fiber Interwoven Fabric Development and Adsorption Study

In this paper, we use pure cotton yarn and cotton/coconut carbon blended yarn to develope interwoven fabric of different weave and different coconut carbon fiber content. We set up the experiment device which can test the adsorption performance of formaldehyde and use it to test the fabric, discuss influence of the time, weave and coconut carbon fiber content on the fabric's adsorption performance .

ヤシ殻活性炭を用いた固体捕集法におけるケトンの保存安定性の経時変化

The storage stability for six ketones was studied on four activated coconut carbons commonly used for air sampling in Japan. As the ratios of the enol form of cyclohexanone and methyl ethyl ketone are high, the ketones showed drastic losses during storage (storage stability), which could be attributed to catalytic oxidation and chemisorption. Moreover, adsorbed water caused a further decrease in recoveries of the ketones from the carbons. Because keto-enol tautomerism and hydration are catalyzed by acid or base, the relationships between the recoveries of the ketones from the carbons and pH in the aqueous solution of the carbons and the ignition residue of the carbons were investigated. As a result, the intensity of acidity or basicity of the carbons correlated with the loss of the ketones during storage, but the ignition residue of the carbons did not. Therefore, these results lead us to the conclusion that a more neutral coconut carbon is more suitable for the collection of aliphatic ketones, and activated coconut carbons are not suitable for cyclohexanone.

Analysis of Coconut Carbon Fibers for Gas Diffusion Layer Material

The main compound of natural fibers is a hydrocarbon. The heating of hydrocarbon in inert gas produces charcoal or carbon. Carbon materials are widely used for several purposes depending on the physical and electric properties, for example for hydrogen storage, conductive or reinforced plastics, catalyst supports, batteries and fuel cells. The main raw material of Gas diffusion Layer (GDL) of the Proton Exchange Membrane Fuel Cell (PEMFC) is a carbon. The properties of GDL are porous and electron-conductive material, because of the function of GDL is to distribute the gas as fuel and electricity conductors. This study aims to analyze the carbon fibers made from coconut fibers for the application of GDL materials. The carbon fiber was made using pyrolysis process in the inert gas (nitrogen) at a certain temperature according to the analysis of Differential Thermal Analysis (DTA) 3000C, 4000C, 5000C, 6000C, and 9000C. The crystalstructure, carbon content, powder density and morphology of carbon fibers were observed using X-Ray Diffraction (XRD), fixed carbon according to ASTM D 1762-64, Archimedes method (BS 19202 Part 1A), and Scanning Electron Microscope (SEM), respectively. The results showed that the structure of carbon was amorphous, and content of 51% ̶ 71%, powder density of 0.42g/cm3 ̶ 0.71g/cm3. The morphology having many parallel hollows like a tube that are close to each other with diameters of 2m ̶ 10m, and in the wall of tube there are some porous with sizes around 1m. According to this analysis, the coconut carbon fiber enables to be applied as candidate for a basic material of GDL.

Catalytic activity in hydrogenation processes of catalysts containing nanodimensional palladium on carbon support. Concentration effect of palladium and precursor

We showed earlier that catalysts obtained by depositing nanodimensional palladium on various nanocarbon materials: fullerenes, nanotubes, fullerene soot, and also activated coconut carbon [1, 2] possessed substantially higher catalytic activity in alkene hydrogenation in comparison with industrial catalysts, where palladium was deposited on activated carbon. At the same time, we found that the nature of nanocarbon material has no essential effect upon catalytic activity. The obtained catalysts posses a pronounced affinity towards hydrogen absorption. The dependence of the absorbed hydrogen amount on the palladium content in the catalyst is of extremal character. The absorption maximum is achieved at comparatively low palladium content in the catalyst (0.1 wt %) and equals to 30– 35 mol of Н2 per 1 mol of Pd.

Cost effective activated carbon treatment process for removing free chlorine from water

AbstractExperiments of batch treatment and column breakthrough were conducted to compare the dechlorination effectiveness of five activated carbons: three made from coal (of different activation) and one each from coconut shell and fruit nut/shell. The removal of free chlorine was accomplished by physical adsorption and chemical reaction; adsorption was the main removal mechanism initially while chemical reaction by catalytic reduction was responsible for continued removal of free chlorine. Removal of free chlorine was enhanced by a longer contact time, a lower pH, and a higher initial/influent free chlorine concentration. Using < 180 mesh particles of activated carbon in mixed batch reactors, the carbon's adsorptive capacity for free chlorine was established in 2 h; the carbons' adsorptive capacities for free chlorine were in the same order as their phenol numbers, the indicator of small micropores. The coconut carbon had the highest adsorptive capacity but was much less reactive relative to the commercial coal and fruit shell carbons. Much more free chlorine was removed in the lab carbon columns than the carbons' adsorptive capacities due to catalytic reduction of the adsorbed free chlorine on carbon surface. The free chlorine removal capacities of the two spent carbons were similar to the respective new carbons. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd.

Coconut Carbon Sequestration Part 1 / Highlights on Carbon Cycle in Coconut Plantations

This article reviews scientific information in order to prepare application of coconut plantations to the Clean Development Mechanism CDM of the Kyoto Protocol. It sums up some theories for describing the C cycle within a given plantation, separating the coconut trees, the under-storey and the soil. It synthesizes recent reports about the C cycle (stocks and fluxes) of a chronosequence of coconut plantations, considered to be a reference for productivity (high level of fertility, no drought). It gives figures for the potential C balance of a coconut plantation and compares them to other tropical humid evergreen forests. Although the results should not be extrapolated without caution, they highlight some main traits of this peculiar crop, such as a high productivity and a large C allocation into organs displaying rapid turnover (bunches of fruits, fine roots, leaves, peduncle and spikelets), the fate of which is to be turned into litter. Moreover, results bring new insights into the physiology of this plant, which is of high interest for understanding the components of yield, such as reserve dynamics. They also confirm that litter management is crucial for the C fixation and the sustainability of coconut cultivation, especially when the levels of inputs are low.

Coconut Carbon Sequestration Part 2 / Strategies for the Carbon Market & Simulating Potential Incomes for Coconut CDM Projects

The following article is a review of possible strategies of the coconut sector facing the carbon market, through the Clean Development Mechanism (CDM) of the Protocol of Kyoto, but also through Non-Kyoto (voluntary) initiatives. It sums up the conditions for certifying plantations, together with recent statistics of similar projects accepted by UNFCCC, which are currently displaying a rapid growth rate. It stresses the complexity of the CDM, but also the accessibility for coconut energy & afforestation + reforestation (A/R) projects, considering that coconut plantations do actually correspond to the definition of “forest”.
 Using recent scientific information on C cycle of coconut plantations and coconut oil, it proposes also a simulation of the expected potential profitability of coconut energetic and A/R projects. From the point of view of the farmer and of the oil mill, in absence of any CDM project (the reference here), the value-added comes mainly from local processing of the copra into coconut oil. When implementing a short-term A/R project (t-CER), the value-added by C fixation in the ecosystem would be ca. +15 to +19%, as compared to the copra and oil references. When implementing a long-term project (l-CER), the value-added would reach +40 to +52%. When implementing an energy-oil project solely, the value-added by C fixation in the coconut oil would be only +5% (this not including other benefits at national scale, however). When implementing a dual A/R + energy-oil project, the value-added by C fixation would be +19% for t-CER, and +45% for l-CER with respect to the copra and oil references. These results are just potential values given for example, suspected to vary much according to the actual conditions of coconut plantation productivity, management and also C market conditions. However, the simulation clearly supports every APCC initiative in this direction.

Interaction forces between waterborne bacteria and activated carbon particles

Activated carbons remove waterborne bacteria from potable water systems through attractive Lifshitz–van der Waals forces despite electrostatic repulsion between negatively charged cells and carbon surfaces. In this paper we quantify the interaction forces between bacteria with negatively and positively charged, mesoporous wood-based carbons, as well as with a microporous coconut carbon. To this end, we glued carbon particles to the cantilever of an atomic force microscope and measured the interaction forces upon approach and retraction of thus made tips. Waterborne Raoultella terrigena and Escherichia coli adhered weakly (1–2 nN) to different activated carbon particles, and the main difference between the activated carbons was the percentage of curves with attractive sites revealed upon traversing of a carbon particle through the bacterial EPS layer. The percentage of curves showing adhesion forces upon retraction varied between 21% and 69%, and was highest for R. terrigena with positively charged carbon (66%) and a coconut carbon (69%). Macroscopic bacterial removal by the mesoporous carbon particles increased with increasing percentages of attractive sites revealed upon traversing a carbon particle through the outer bacterial surface layer.

Adsorción de Cromo (VI) en Solución Acuosa sobre Fibra de Carbón Activado

The adsorption of Cr(VI) from aqueous solution on an activated carbon fiber of felt type, was studied. The adsorption equilibrium data of Cr(VI) on the fiber were obtained in a batch adsorber and the concentration of Cr(VI) was determined by a colorimetric method. The Freundlich isotherm fitted reasonably well the experimental data. The Cr(VI) adsorption capacity of the fiber decreased considerably while increasing the solution pH from 4 to 10 but slightly increased as the temperature increased from 15 to 35°C. The effect of the pH was due to the electrostatic interactions between the surface of the fiber and the Cr(VI) anions in solution. The adsorption capacity of the fiber was compared to those of granular activated carbons made from hazelnut shell and from coconut shell. The adsorption capacity of the fiber was twice that of the hazelnut carbon and half of that of the coconut carbon.

Adsorção de cobre por carvões ativados de endocarpo de noz macadâmia e de semente de goiaba

Visando a tratar efluentes com cobre (poluentes de grande relevância ambiental), produziram-se carvões ativados a partir de endocarpo de noz de macadâmia e semente de goiaba, resíduos gerados em larga escala pela agroindústria. Esses carvões foram comparados com carvão ativo convencional, de endocarpo de coco. A ativação foi feita com ZnCl2, na proporção de 1 parte do cloreto para 2 de material. Carbonização a 720°C e em nitrogênio resultou área superficial de 487,0 m²/g, para o carvão de macadâmia, e de 396,7 m²/g, para o carvão de semente de goiaba (contra 668,3 m²/g do carvão industrial). A depleção, em 24 h, de Cu2+ de uma solução mostrou-se efetiva, com capacidade adsortiva de 4,84 mg/g, para o carvão industrial padrão, de 3,48 mg/g, para o carvão do endocarpo da macadâmia carbonizado, e de 1,23 mg/g, para aquele de semente de goiaba carbonizada. Os resultados acenam para a utilização desses materiais no tratamento de efluentes contendo cobre, o que daria destinação nobre ao resíduo industrial.

Removal of Two Waterborne Pathogenic Bacterial Strains by Activated Carbon Particles Prior to and after Charge Modification

Waterborne diseases constitute a threat to public health despite costly treatment measures aimed at removing pathogenic microorganisms from potable water supplies. This paper compared the removal of Raoultella terrigena ATCC 33257 and Escherichia coli ATCC 25922 by negatively and positively charged types of activated carbon particles. Both strains display bimodal negative zeta-potential distributions in stabilized water. Carbon particles were suspended to an equivalent external geometric surface area of 700 cm2 in 250 mL of a bacterial suspension, with shaking. Samples were taken after different durations for plate counting. Initial removal rates were less elevated for the positively charged carbon particle than expected, yielding the conclusion that bacterial adhesion under shaking is mass-transport limited. After 360 min, however, the log-reduction of the more negatively charged R. terrigena in suspension was largest for the positively charged carbon particles as compared with the negatively charged ones, although conditioning in ultrapure or tap water of positively charged carbon particles for 21 days eliminated the favorable effect of the positive charge due to counterion adsorption from the water. Removal of the less negatively charged E. coli was less affected by aging of the (positively charged) carbon particles, confirming the role of electrostatic interactions in bacterial removal by activated carbon particles. The microporous, negatively charged coconut carbon performed less than the mesoporous, positively charged carbon particle prior to conditioning but did not suffer from loss of effect after conditioning in ultrapure or tap water.

Storage stability of ketones on carbon adsorbents

Activated coconut carbon constitutes the more widely used sorbent for preconcentration of volatile organic compounds in sampling workplace air. Water vapour is always present in the air and its adsorption on the activated carbon surface is a serious drawback, mainly when sampling polar organic compounds, such as ketones. In this case, the recovery of the compounds diminishes; moreover, ketones can be decomposed during storage. Synthetic carbons contain less inorganic impurities and have a lower capacity for water adsorption than coconut charcoal. The aim of this work was to evaluate the storage stability of various ketones (acetone, 2-butanone, 4-methyl-2-pentanone and cyclohexanone) on different activated carbons and to study the effect of adsorbed water vapour under different storage conditions. The effect of storage temperature on extraction efficiencies was significant for each ketone in all the studied sorbents. Recovery was higher when samples were stored at 4 °C. The results obtained for storage stability of the studied ketones showed that the performance of synthetic carbons was better than for the coconut charcoals. The water adsorption and the ash content of the carbons can be a measure of the reactive sites that may chemisorb ketones or catalize their decomposition. Anasorb 747 showed good ketone stability at least for 7 days, except for cyclohexanone. After 30-days storage, the stability of the studied ketones was excellent on Carboxen 564. This sorbent had a nearly negligible ash content and the adsorbed water was much lower than for the other sorbents tested.

Study of the Purifying Capacity of the Coconut Carbon from Fibrous Mesocarpe

Study of the Purifying Capacity of the Coconut Carbon from Fibrous Mesocarpe

Gold stripping by hydro-alcoholic solutions from activated carbon: Experimental results and data analysis by a semi-empirical model

The aim of this work was to study gold stripping from activated carbon using a range of different alcohols (isopropanol, ethanol and ethylene glycol). The experimental work was carried out on a laboratory scale, using activated coconut carbon, at 40 to 80 °C and up to 8 h extraction time. Isopropanol was the most rapid eluent with > 98% Au eluted after 1 h at 80 °C, ethylene glycol had a similar extraction after 2 h, ethanol was the least effective with 5 h required for > 95% extraction. Interestingly, 77% Au extraction was obtained at 40 °C using ethylene glycol. A second order semi-empirical model was used to successfully describe the stripping. The activation energies were > 57 kJ/mol, indicating that desorption was rate determining. The following order of the estimated kinetic constants has been observed at any investigated temperature: K isopropanol > K ethylene glycol > K ethanol indicating that isopropanol was the best organic compound for the gold stripping process among the selected compounds investigated in this work. From a practical viewpoint, the non-flammability of ethylene glycol makes it the most attractive.

Activated carbon porosity tailoring by cyclic sorption/decomposition of molecular oxygen

Activated-carbon pore size tailoring is usually achieved by pore size reduction, pore size widening or more rarely by direct activation. Successive widening cycles composed of an initial molecular oxygen sorption step, followed by a carbonization step under nitrogen, have been applied to three different materials in order to study their gradual pore size modifications. For years, the whole microporosity obtained after several cycles is known to present better pore size distribution than those inherited from conventional activations. Moreover, as shown in the present paper, the gradual obtained microporosities cover a wide and valuable range of porous textures highly dependent on the initial material origin and initial activation. Gradual mean pore size evolutions of 1 or 2 Å per cycle were observed linked to a simultaneous increase in microporous specific volume in the case of pitch-based and coconut activated carbons, respectively. Comparatively, the microporous specific volume of a commercial coconut carbon molecular sieve was increased by 26% without modification of its mean pore size and therefore of its sieving effect. Those results have been used to test a simple textural model of activated carbon porosity proposed in the recent literature.

Catalytic oxidation of NO to NO 2 on activated carbon

Catalytic oxidation of NO to NO 2 over activated carbons PAN-ACF, pitch-ACF and coconut-AC at room temperature (30°C) were studied to develop a method based on oxidative removal of NO from flue gases. For a dry gas, under the conditions of a gas space flow rate 1500 h −1 in the presence of oxygen of 2–20% in volume concentration, the activated coconut carbon with a surface area 1200 m 2/g converted about 81–94% of NO with increasing oxygen concentration, the pitch based activated carbon fiber with a surface area 1000 m 2/g about 44–75%, and the polyacrylonitriale-based activated carbon fiber with a surface area 1810 m 2/g about 25–68%. The order of activity of the activated carbons was PAN-ACF<pitch-ACF<coconut-AC. However, NO conversion markedly decreased with the increases in temperature and humidity. For the dry gas, the apparent reaction rate was expressed by an equation: R= k c P NO P O 2 β ( F/ W), where β is 0.042, 0.16, 0.31 for the coconut-AC, the pitch-ACF and the PAN-ACF respectively, and k c is 0.94 at 30°C.

Promotion effect of carbon on the oxidation of ferrous ions by oxygen in the presence of sodium nitrite

The effect of carbons was studied on the course of ferrous sulfate oxidation with oxygen catalyzed by sodium nitrite. Activated coconut carbon AR2, pyrolytic carbon Sibunit and carbon black Elftex 285 were used for this purpose. An enhanced initial rate of oxidation was observed when sodium nitrite catalyst was used in combination with carbon. The Fe II conversion within 30 min was substantially increased by carbon in some cases and decreased in others. The carbon effect on the initial rate and Fe II conversion was controlled by three factors, namely, quantity, surface area and surface functionality of the carbon. Previously used samples showed a higher promotion effect than the original carbons. In agreement with experimental data, the process under study is described by a complex mechanism, in which at least three steps involve participation of carbon: (i) oxidation of the active catalyst in the rate-determining reaction of Fe II nitroso complexes with oxygen, (ii) oxidative transformation of the active catalyst to inactive nitrate ions, (iii) the catalyst regeneration from nitrate ions.

Evaluation of five biocarriers as supports for immobilized bacteria: Comparative performance during high chemical loading, acid shocking, drying and heat shocking

AbstractImmobilized bacteria technology (IBT) utilizes inert biocarriers to support high concentrations of chemical‐degrading bacteria in reactors designed to provide optimal conditions for microbial activity. This study evaluated IBT performance in packed bed reactors (PBRs) using a porous inorganic biocarrier (diatomaceous earth), nonporous biocarriers (glass beads), and organic biocarriers having carbon adsorption properties (granular activated carbon) with different porosity. Each reactor was challenged with high chemical loading, acid, dryness, and heat shock conditions. Benchtop PBRs inoculated with ap‐nitrophenol‐ (PNP)‐ degrading Pseudomonas sp. and fed a synthetic waste containing 100 to 1,300 mg/L of PNP showed removal of PNP from effluents within 24 h of start‐up. Chemical loading studies showed maximum PNP removal rates of 6.45 to 7.35 kg/m3/d for bacteria in PBRs containing diatomaceous earth beads, glass beads, and activated coconut carbon. A lower PNP removal rate of 1.47 kg/m3/d was determined for the activated anthracite carbon, and this PBR responded more slowly to increases in chemical loading. The PBR containing bacteria immobilized on activated coconut carbon showed exceptional tolerance to acid shocking, drying, and heat shocking by maintaining PNP removal rates &gt; 85% throughout the entire study. The other biocarriers showed nearly complete loss of PNP degradation during the perturbations (except for drying), but all recovered high rates of PNP degradation (&gt; 98% removal) within 48 h after an acid shock at pH 2, within 8 d after an acid shock at pH 1.0, within 24 h after drying for 72 h, and within 48 h of heat shocking. The resiliency and high chemical removal efficiency demonstrated by immobilized bacteria in this study support the concept of using IBT for the biotreatment of industrial wastes.