Production Of Carbon Adsorbents Research Articles

Production of Carbon Adsorbents from Hydrolysis Industry Waste and Methods for their Modification

Production of Carbon Adsorbents from Hydrolysis Industry Waste and Methods for their Modification

Production of Carbon Adsorbents from Wheat Grain Processing Waste for Rhenium Adsorption

In the present work, activated carbons from wheat grain production waste (WGPW), modified by 3, 5 and 7 % wt. ammonium nitrate, were obtained by heat treatment in an inert argon atmosphere and subsequent activation with superheated water vapor. The temperature of 750 oС is the optimal temperature of carbonization (pyrolysis) and activation of the WGPW for obtaining a carbon-containing sorbent with the highest iodine adsorption value of 53.74% from the 0.7-mm-sized crude fiber of the WGPW. The impregnation of NH4NO3 in the amount of (3.0, 5.0 and 7.0%) into the composition of the initial charge of the WGPW, which is the optimal condition for the chemical modification of the obtaining carbon sorption material. Their main adsorption characteristics (specific surface area, adsorption activity of iodine and methylene blue), as well as surface morphology were studied using the scanning electron microscopy method. Activated carbon, based on the wheat grain production waste (WGPW) with 7% wt. NH4NO3 (Activated Carbon-7) — 213 m2/g, 53.74% and 138 mg/g respectively, has a high specific surface area, adsorption activity of iodine and methylene blue. The obtained photomicrographs of various sizes prove that the studied sorbing agents preserve the non-degraded body of the porous hackberry of plant tissue with a pore diameter of 1–10 μm. Cultural treatment of the initial charge with ammonium saltpeter (NH4NO3) improves the selectivity of the obtained sorbing agent for the rhenium sorption. The derived sorbing agents were studied in the processes of static sorption of rhenium from simulated solution. Activated carbon-7 showed a high degree of rhenium recovery from simulated solution — 99 %.

Synthesis of Carbon-Base Materials by Microwave Irradiation of Peat

The production of carbon adsorbents by carbonization of peat under the effect of microwave irradiation within the environment of own gases was studied. The optimization of conditions and parameters for carbonization of peat was conducted. By means of FTIP-spectroscopy, elemental analysis, thermographic analysis, nitrogen sorption-desorption and model indicators’ occlusion it was found that in consequence of carbonization the content of loaded surface sites is reduced due to the destruction of functional organic compounds, dispersion is decreased, adsorption properties of carbon-base materials are increased.

ФОРМИРОВАНИЕ АДСОРБЦИОННЫХ СВОЙСТВ НАНОПОРИСТЫХ МАТЕРИАЛОВ МЕТОДОМ ТЕРМОХИМИЧЕСКОЙ АКТИВАЦИИ

The results are shown studies on the use of hydrolytic lignin as a raw material for the production of carbon adsorbents. As method of activation of hydrolytic lignin was chosen thermochemical using sodium hydroxide as an activating agent. During experiment it was required to find out influence of condition parameters on an yield and properties of the received active coal. Synthesis of adsorbents was carried out on central composite rotatabelny uniforms plans of the second order for three variables varying at 5 levels. As changing the parameters there were temperature of preprocessings and pyrolysis, and also a dosage of the activating agent. For the samples of active carbon adsorption activity was investigated in three adsorbates: methylene blue (MG), iodine, hexane. Based on output parameters coefficients of the equations of regression were calculated and the assessment of their importance is carried out. By the absolute value and sign of the coefficients can be made at the conclusion of the power of the influence of factors, bending their study space. The influence of operating parameters on the yield and sorption activity of the obtained coal was studied by constructing of graphic dependences – response surfaces. As a result of analysis of the received data a conclusion was done about efficiency of in-use method for the synthesis of adsorbents, because obtained active coal has developed porous structure

Improving the pore structure and adsorption properties of industrial active carbons

The paper describes the possibility of improving the pore structure and adsorption properties of industrial active carbons (AC) by means of their modification with ɛ-caprolactam (CL). Application of ɛ-caprolactam (a product of large-scale organic synthesis) as a modifying substance allows the targeted regulation of the specific surface area and volume of AC mesopores, while the conditions of modification change the chemical composition of the surface of carbon adsorbents and, as a result, their adsorption properties. The process of modification includes three stages. The first is the adsorption of CL from aqueous solution and heating at 300°C in the presence of atmospheric oxygen. The second is carbonization in an argon flow at 900°C, and the third is the vapor-gas activation of the resultant adsorbents at 900°C. Each stage is followed by determining the parameters of the pore structure by N2 adsorption and the adsorption parameters with respect to benzene, iodine, aqueous solutions of ɛ-caprolactam, and copper sulfate (CuSO4). When modifying the carbonized samples with an initial ɛ-caprolactam content of 2%, we observe the growth of mesopores over 100% of volume, relative to AG-OV-1 original industrial activated carbon. Depending on the stage of modification, an increase in adsorption is observed, relative to the AG-OV-1 original carbon: benzene adsorption rises by 50%, the adsorption of iodine from aqueous solution rises by 20%, the adsorption of ɛ-caprolactam from aqueous solution grows by more than 30%, and the adsorption of copper(II) ions rises by more than 70%. The procedure for the production of the described modified adsorbent has no rivals abroad; it is protected by a patent and can be used in industry. It is possible to use inexpensive industrial carbons as the original material. The procedure allows the production of carbon adsorbents with predetermined structural and adsorption properties.

Utilization of Cotton Stalks-Biomass Waste in the Production of Carbon Adsorbents by KOH Activation for Removal of Dye-Contaminated Water

Four activated carbons were produced by two-stage process as followings; semi-carbonization of indigenous biomass waste, i.e. cotton stalks, followed by chemical activation with KOH under various activation temperatures and chemical ratios of KOH to semi-carbonized cotton stalks (CCS). The surface area, total pore volume and average pore diameter were evaluated by <TEX>$N_2$</TEX>-adsorption at 77 K. The surface morphology and oxygen functional groups were determined by SEM and FTIR, respectively. Batch equilibrium and kinetic studies were carried out by using a basic dye, methylene blue as a probe molecule to evaluate the adsorption capacity and mechanism over the produced carbons. The obtained activated carbon (CCS-1K800) exhibited highly microporous structure with high surface area of 950 <TEX>$m^2/g$</TEX>, total pore volume of 0.423 <TEX>$cm^3/g$</TEX> and average pore diameter of 17.8 <TEX>${\AA}$</TEX>. The isotherm data fitted well to the Langmuir isotherm with monolayer adsorption capacity of 222 mg/g for CCS-1K800. The kinetic data obtained at different concentrations were analyzed using a pseudo-first-order, pseudo-second-order and intraparticle diffusion equations. The pseudo-second-order model fitted better for kinetic removal of MB dye. The results indicate that such laboratory carbons could be employed as low cost alternative to commercial carbons in wastewater treatment.

Petroleum Asphaltites – a Highly Effective Additive in Production of Carbon Adsorbents

TIt is not possible to eliminate the acute shortage of carbon adsorbents by creating a scientifically substantiated assortment of sorbing materials with defined properties based on traditional stock bases alone. Petroleum residues with the most important natural resource can be used for this purpose. The number increases with the development of heavy, resinous, and medium‐sulfur crude oils [1‐3 ].

Asphaltene Concentrates as Bases for Carbon Adsorbents

The possibility of eliminating the shortage of binder for production of carbon adsorbents from crude oil cuts was demonstrated previously [1]. However, coal as a stock base prevents improving the sorption characteristics and expanding the assortment of adsorbents. Petroleum residues are also of great interest for manufacture of carbon adsorbents. They have an extensive stock base, are inexpensive, and are lyophilic with respect to the carbon stock materials and binder [2]. We investigate the possibility of using asphaltenes concentrates of broad group composition instead of coal for production of carbon materials.

96/05990 Production of carbon adsorbents from brown coal

96/05990 Production of carbon adsorbents from brown coal

95/00390 On the composition of volatiles evolved during the production of carbon adsorbents from vegetable wastes

95/00390 On the composition of volatiles evolved during the production of carbon adsorbents from vegetable wastes

On the composition of volatiles evolved during the production of carbon adsorbents from vegetable wastes

Gas and liquid products evolved in the process of carbon adsorbent production by steam pyrolysis of apricot stones and coconut shells are investigated. The oils are separated by an extrographic procedure, and the obtained fractions are analysed by gas chromatography-mass spectrometry (g.c.-m.s.). The basic part of the identified compounds are derivatives of phenol, guaiacol, veratrol, syringol, resorcinol, free fatty acids and esters of fatty acids. The comparative study of the pyrolysis products of apricot stones and coconut shells reveals some differences, referring mainly to the lipid parts of the raw materials.

UTILIZATION OF PETROLEUM RESIDUES FOR PRODUCTION OF CARBON ADSORBENTS

ABSTRACT This article presents ideas, and describes studies, on utilization of petroleum residua as binding agents during the production of carbon adsorbents from coal dust.

Utilization of tars from thermal cracking in the production of carbon adsorbents

The authors report on the production of carbon adsorbents from thermal cracking tars and investigate their properties. They present experimental data for various adsorbent grades on burn off in activation for differing compositions, pore volume for differing densities, and retention volume. They conclude that tar from thermal cracking can serve as a new type of raw material in the production of carbon adsorbents that may be used, depending on the degree of burnoff, as molecular sieves or as gas, recuperation, or clarifying carbons.