Papers by Keyword: Carbonization

Abstract: The cupric ion is toxic for humans and is contained in many industrial wastewater that should be effectively removed with adsorption before discharging into the natural water source. In this study, pineapple pulp was obtained from canned pineapple juice manufacturing for drying (DPP) and carbonization (CPP) for 2 h. at 400 °C as the fine biochar adsorbents. The specific surface area of DPP and CPP were 45.3 and 60.2 m²/g, respectively. A high surface area of the carbonized pineapple pulp as a fine adsorbent was found to effectively cupric ion adsorption capacity, the maximum cupric ion removal efficiency of 83.4% and 41.9 mg/g of adsorption capacity at a pH of 6.0 was attained after 30 minutes to equilibrium reach, initial feed concentration of copper (II) sulfate 5-hydrate (CuSO₄ ^. 5H₂O) 250 ppm and temperature 50 °C. From these results can be applied to remove the cupric ion from the wastewater treatment.

Abstract: This research was conducted to determine the morphology, dimensions, and structure of carbon-nanofibers, using polyvinyl alcohol (PVA) as a source of polymer fibers fabricated by electrospinning technique, and given variations in carbonization temperature. Variations in temperature during the carbonization process are carried out to see changes in the structure and morphology of the carbon nanofibers formed. characterization by conducting XRD and SEM tests to determine the structure and morphology of the carbon nanofibers produced, it is seen that the amorphous carbon structure of the nanofibers produced is in the shape of random fibers and tends to be straight without beads. The results obtained from the XRD test, it appears that the structure is amorphous with two peaks that appear during the test, the two peaks are typical of amorphous carbon peaks, so that the fiber that has been formed, then with the carbonization process changes its structure to carbon nanofiber. Unique results were obtained when PVA nanofibers were characterized by SEM, namely the diameter of the fibers formed before and after the carbonization process had sizes in the range of 40 to 50 nanometers, these results were influenced by the process of initial formation of nanofibers using an electrospinning system.

Abstract: Environmental contamination might result from sawdust waste that has not been adequately managed. However, waste has a high economic value. This study aimed to analyze the characteristic model of sawdust after the carbonization process. The research method used the L9(3)4 Orthogonal Array experiment. The research variables included: drying temperature (X₁), drying time (X₂), carbonization temperature (X₃), and carbonization time (X₄), each with three levels of factors. The research response variables were moisture content (Y₁), volatile matter (Y₂), ash (Y₃), and fixed carbon (Y₄) of sawdust charcoal. The results showed that the average moisture content was 0.9%, volatile matter 8.3%, ash content 8.29%, and fixed carbon content 82.51%. According to the outcomes of multiple linear regression analysis, the correlation coefficients (R) of the four were very significant for moisture content, volatile matter, ash, and fixed carbon of 0.865, 0.929, 0.987, and 0.935, respectively. The optimum conditions obtained were water content X_1-2X_2-3X_3-3X_4-3, volatile material X_1-1X_2-1X_3-1X_4-1, ash content X_1-1X_2-1X_3-1X_4-1, and carbon content X_1-2X_2-1X_3-1X_4-1. The outcomes of the sawdust charcoal proximate analysis model validation test were normally distributed, and there was no homoscedasticity, multicollinearity, or negative autocorrelation. Thus, the four models produced in this study were feasible and valid so that they could use them to predict the physical material characteristics of teak sawdust.

Abstract: Local date palm (Phoenix dactylifera) waste stems were used to prepare activated carbon (AC) using KOH, NaCl and ZnCl₂ as activation agents. Carbonization was conducted at 600 °C for 2hr under nitrogen flow, followed by activation at 750 °C for 2 hr under carbon dioxide flow. AC was characterized using a scanning electron microscope (SEM), Attenuated total reflectance Fourier transform infrared (ATR FT-IR), Thermogravimetric analysis (TGA), Iodine adsorption, BET, micropores, and mesopores surface areas at different carbon-to-activation-agent-ratios (1:1, 1:2, 1:3). FT-IR spectra results showed a reduction in AC-NaCl bands compared to other AC, which indicates less functional surface groups. At 750 °C, the TGA analysis showed the carbon yield as AC-ZnCl₂ > AC-NaCl > AC-KOH, however, among all samples, AC-NaCl at 1:2 ratio was the best in terms of iodine removal. This treated AC sample exhibited about 18.3 % maximum iodine removal, which indicates the high surface area and porosity with 550.4380 m²/g, 348.7432 m²/g, and 201.6947 m²/g BET, micropores and mesopores surface areas, respectively. In conclusion, the local Omani date palm waste stems can be used for AC production with a well porous structure using cheap and environmentally friendly salts as activation agents. In addition, the produced AC attained better adsorption characteristics among other alternatives.

Abstract: The abundance of waste coffee grounds led to an adverse effect in our environment. This study focuses on generating carbon with conventional microwave for energy efficiency. The carbon result of conventional microwave carbonization is being compared to furnace and microwave-furnace processes. Before the conversion, Thermogravimetric Analysis (TGA) was performed to determine the degradation temperature of the waste coffee grounds. In addition, Fourier Transform Infrared Spectroscopy (FTIR) was employed to elucidate the presence of organic functional groups in the samples. Absence of significant peaks from the carbonized coffees spectrum confirms degradation. X-ray Diffraction (XRD) analysis was also performed to monitor the effect of temperature as shifting, and formation of peaks are seen. Identified peaks with Miller indices of (002), (101), and (004) signifies the presence of carbon. Scanning Electron Microscopy (SEM) paired with Energy Dispersive X-ray spectroscopy (EDX), shows the difference in morphology for the dried coffee and the carbonized coffees as well as the strong presence of carbon from the microwave-assisted carbonization which is about 74%.

Abstract: Scientific research and the search for new technologies to increase the level of mechanical and high-temperature properties are ongoing. The article discusses the technology of using carbon materials, pyrolysis and impregnation with phenol-formaldehyde resins. It is shown that the proposed technology makes it possible to achieve a sufficient level of mechanical properties when using low-modulus carbon fabrics after pyrolytic treatment as a prepreg at a temperature treatment no higher than 900 K. Pillowcase and resole phenol-formaldehyde resins were used to impregnate the prepreg. The proposed technology also allows the introduction of alloying additives into the system to improve the properties. An example of the introduction of nitrogen into a composite by adding urotropine to a phenol-formaldehyde resin, which was used to impregnate the composite, is considered.

Abstract: This review article presents the usage of various animal bones such as chicken bone, fish bone, pig bone, camel bone, and cow bone as reliable biosorbent materials to remove heavy metals contained in contaminated water and wastewater. The sources and toxicity effects of heavy metal ions are also discussed properly. Then specific insights related to adsorption process and its influential factors along with the proven potentiality of selected biosorbents especially derived from animal bone are also explained. As the biosorbents are rich in particular organic and inorganic compounds and functional groups in nature, they play an important role in heavy metal removal from contaminated solutions. Overall, after conducting study reports on the literature, a brief conclusion can be drawn that animal bone waste has satisfactory efficacy as effective, efficient, and environmentally friendly sorbent material.

Abstract: In order to increase environmental safety and reduce the cost of production, a modified method of self-activation for the synthesis of activated carbon from plant wastes - cherry stones and wheat straw. A 5% solution of orthophosphate acid was used as an additional activator. Synthesis of activated carbon at temperatures of 600 °C, 700 °C and 800 °C was performed. It was found that coal from cherry stones has a production of 1.3-1.6 times higher than the production of activated carbon from wheat straw. The obtained coal was studied by electron microscopy and the method of isothermal adsorption / desorption of nitrogen. It is shown that all synthesized coal has a well-developed porous structure, which is determined mainly by micropores. An increase in the synthesis temperature leads to an increase in the specific surface area, the volume of micro-and mesopores and a decrease in the average pore radius. The reduction of the average pore radius for activated carbon from cherry stones occurs at lower temperatures compared to coal from wheat straw.

Abstract: The purpose of the study is to study the possibility of using secondary resources of metallurgical production, namely: steel-making slag and carbon dioxide in the production of vibropress products for construction purposes. The tests were carried out with the complete replacement of the coarse aggregate in the concrete mixture with steelmaking slag and varying the hardening processes. The optimal condition for strength gain is hardening in carbon dioxide at an increased pressure of 0,2 MPa.

Abstract: The solution to the problem of large industrial cities with a developed metallurgical industry is the creation of environmentally friendly conditions for the life of the population through the disposal of industrial waste. The studies carried out have shown that the developed technology makes it possible to widely use steel-making slags and carbon dioxide emitted into the atmosphere in the production of small-piece wall stones with high operational properties. It is shown that only slag is required to obtain wall material without the use of a hydraulic binder.