Eksergi
Not a member yet
261 research outputs found
Sort by
Effect of Temperature and N-Doping on the Distribution of Bamboo Waste Pyrolysis Products Using Quartz Tube Furnace
Full text linkThis study investigates the effect of temperature and nitrogen doping (N-Doping) on the pyrolysis of bamboo waste to optimize the distribution of biochar, bio-oil, and gas products. Bamboo waste as raw material was applied to pyrolysis in a quartz tube furnace reactor at temperatures of 300°C, 400°C, 500°C, and 600°C under two atmospheric conditions: pyrolysis with nitrogen (PN) and pyrolysis without nitrogen (PWN). Results reveal that temperature significantly influences product distribution, with bio-oil yield peaking at 500°C (52% in PN) and decreasing at higher temperatures due to secondary cracking. Nitrogen doping enhances bio-oil production by preventing oxidation and reducing secondary reactions, leading to a bio-oil yield increase from 16.52% in PWN to 55.32% in PN at 500°C. Conversely, PWN conditions resulted in higher biochar yield due to partial oxidation. Gas yield increased at elevated temperatures in both conditions, attributed to thermal cracking and reformation processes. These findings emphasize the importance of controlled temperature and atmospheric conditions in maximizing the efficiency and product quality of bamboo waste pyrolysis. The results provide valuable insights into sustainable biomass conversion strategies, contributing to renewable energy development and bamboo waste valorization
The Effect of Ammonium Sulfate Concentrations on The Size Distributions of NPK-Fertilizer Granules in a Rotating Drum Granulator
No full textThe granulation process is important in pharmaceuticals, detergents, and fertilizers. It consists of enlarging the particle size to create granules with specific properties. This study examined the wet granulation process for NPK fertilizers and investigated the effect of binder solutions, particularly ammonium sulfate (ZA) concentrations, on the distribution of granule sizes. The granulation process was conducted in a rotating drum granulator with varied NPK ratios (28-6-6, 20-20-8, 18-16-20, and 15-15-15) with amounts of binder (10 ml or 20 ml of 15% ZA solution or pure water). Granule sizes were analyzed using Image Pro Plus software, and Stoke’s number was calculated to establish a correlation between the average granule radius and Stoke’s number. The results showed that ammonium sulfate improved granulation, leading to larger granule size and more consistent size distribution in various NPK formulations than water-bond granules. Furthermore, a higher liquid-to-solid ratio generally increases granule size, resulting in a broader size distribution. The study demonstrated a robust correlation (R² = 0.95) between Stoke\u27s number and the average granule radius, indicating that Stoke\u27s number served as a generalized parameter of the granulation process for various NPK formulations and binder types
Mechanistic Modeling of a Spiral-Wound Nanofiltration Module using DSPM-DE for High-Purity Salt Recovery from Desalination Brine
Full text linkRejected brine is a concentrated NaCl stream whose elevated Ca²⁺, Mg²⁺, and SO₄²⁻ depress the quality of industrial salt. We built a mechanistic model of a spiral-wound KeenSen NF1-4040F nanofiltration (NF) element using the Donnan–Steric Pore Model with Dielectric Exclusion coupled to the Extended Nernst–Planck equations. Radial transport is coupled to axial mass balances and solved at steady, isothermal conditions over bar and . Water flux increases almost linearly with ; along the module falls and rises nearly linearly. Recovery increases with but decreases with . Flux decomposition shows cations are convection-dominated, whereas anions carry larger shares of diffusion and electromigration. Predicted end-of-module rejections are ≈ 99.0-99.3%, ≈ 97.6-98.1%, ≈ 96.0-96.6%, ≈ 88-89%, and ≈ 74-75%, confirming divalent ≫ monovalent selectivity. Linking to product quality, the simulated permeate at bar and yields a conservative dry-salt purity of ~96.9 wt% NaCl when all non-halite salts co-precipitate. Under halite-first crystallization with a gypsum pre-step and bittern purge, only a minor fraction co-crystallizes, giving ≥98.5 wt% (≈99.5 wt% for a 20% co-crystallization assumption). Thus, operating at moderate-to-high with moderate cross-flow not only maximizes recovery and divalent rejection but also supplies a permeate that can be crystallized to SNI-compliant high-purity salt
Enhancing Biodiesel Yield from Castor Seed Oil through Co-Solvent-Assisted Transesterification Using n-Hexane
Full text linkThe growing demand for sustainable energy sources has increased interest in biodiesel as a renewable alternative to petroleum-based fuels. This study explored the effect of reaction time, molar ratio of methanol to oil, and catalyst concentration with the addition of co-solvent on the transesterification of castor seed oil, aiming to increase methyl ester yield. n-Hexane was chosen as the co-solvent due to its physical compatibility with methanol, thus facilitating reactant solubility and product separation. Using response surface methodology (RSM) with Minitab software, process parameters such as co-solvent ratio, reaction duration, and temperature were optimized. The optimized conditions (1:5 co-solvent ratio, 55°C, 20 min) resulted in a biodiesel yield of 98.86%, with GC-MS confirming a methyl ester content of 99.79%. The resulting biodiesel yield met the requirements of the Indonesian National Standard (SNI) as well as viscosity but had a heating value that was slightly below the standard range. These findings highlight the effectiveness of co-solvent integration in improving biodiesel production from vegetable oil feedstocks
Adsorption of Rhodamine B by Coconut Shell Activated Carbon
Full text linkPollution caused by dye waste from the textile industry, specifically Rhodamine B, poses significant risks to human health. Furthermore, large-scale discharge of Rhodamine B into aquatic environments can alter water pH, thereby adversely affecting aquatic ecosystems. Environmental pollution caused by this dye can be prevented through adsorption using activated carbon. In this study aims to evaluate the efficiency of Rhodamine B dye removal from synthetic wastewater by varying the mass of activated carbon from coconut shell carbon and to determine the appropriate adsorption isotherm model based on the adsorption capacity of Rhodamine B on the adsorbent. The experiment was conducted by activating coconut shell carbon physically using a furnace at a temperature of 700℃ for 2 hours and chemically using 2.5 M KOH and soaked for 20 hours with a ratio of 1: 3 (m/v). The results of the study based on variations in adsorbent mass showed the best mass of 3 g with the smallest final concentration of 2.1717 ppm, an equilibrium time of 120 minutes, and an adsorption effectiveness of 86.13%. The appropriate adsorption isotherm model is the Langmuir isotherm
Optimization of Rotation Speed, Disc Diameter, and Lighting Time in Batik Waste Treatment Using Rotary Algae Biofilm Reactor (RABR) with Ulva sp.
Full text linkBatik is one of the cultural heritages in Indonesia that must be maintained and preserved. The batik industry process itself produces liquid waste that comes from the coloring processing, washing, wax removing, also rinsing. Batik waste, if not treated properly, can harm the environment. Various studies have shown that effluent treatment using the Rotary Algae Biofilm Reactor (RABR) method is promising. This research focuses on improving the RABR design and optimal conditions for treating batik wastewater, as well as utilizing the synergy between batik production and Ulva sp. The variables used in this research are the rotation speed of 20, 30, and 40 rpm, the lightning time for 0, 6, and 12 hours, and the disk diameter size of 9, 11, and 13 cm. The parameters that analyzed are BOD, COD, and pH levels. Waste treatment optimization in this research uses the RSM with a combination of Design Expert 13 software. Based on the results, the most optimal batik wastewater treatment variable is when the disk diameter is 10.306 mm, the rotation speed is 20 rpm, and the lightning time is 7.805 hours, yielding response values of 55.673 mg/L for BOD, 25.538 mg/L for COD, and 10.406 for pH
Production of Healthy Sugar by Adding Winter Melon [Benincasa hipsida (Thunb.) Cogn.] From Coconut Sap
Full text linkThe increasing prevalence of health issues such as diabetes, obesity, and hypertension due to excessive sugar consumption has prompted the need for healthier sugar alternatives. This study investigates the production of healthy sugar using coconut sap enriched with winter melon (Benincasa hispida) extract, which offers various health benefits, including anti-diabetic properties. The production process employed a vacuum rotary evaporator at controlled temperatures (50–80°C) to preserve the nutritional and physical qualities of the sugar while minimizing adverse effects of traditional methods. The study assessed sugar composition, crystallization behavior, and product yield. Results showed that the addition of winter melon extract enhanced antioxidant properties and functional value, while varying sugar seed concentrations improved crystallization, yield (up to 10.48%), and color stability. This research contributes to developing low-glycemic, nutritious sugar alternatives, meeting the increasing demand for healthier sweeteners
Production of Fragrance Tag (Paper-Based Air Fresheners) from Agarwood Powder Waste (Aquilaria malaccensis)
Full text linkAgarwood is a non-timber forest product known for its distinctive fragrance. Its processing generates powder waste that is often undervalued and underutilized, despite containing aromatic compounds with potential for value-added products such as fragrance tags. This study aimed to determine the optimal composition of agarwood powder and waste paper, assess the effects of NaOH treatment on product characteristics, and evaluate economic feasibility. The process involved preparing agarwood and HVS paper waste, treating with or without NaOH, producing pulp at ratios of 75:25, 50:50, and 25:75 (% w/w), and adding essential oil. Results showed that NaOH treatment significantly improved physical and sensory properties such as color brightness, grammage, and tensile strength but reduced thickness, absorbency, and aroma retention. Material ratio also influenced performance: 25:75 (% w/w) with NaOH yielded the best color and tensile strength, while 75:25 without NaOH showed the highest thickness, absorbency, and aroma stability up to day 5. Economic analysis indicated feasibility, with a break-even point of 181 units, a return cost ratio (RCR) of 1.44, and a payback period of 2.27 months
A Critical Review of Carbonization Hydrothermal and Pyrolysis for Adsorbent Production and the Application in Industrial Dye Removal
Full text linkBiochar is increasingly recognised as a low-cost and efficient adsorbent for removing organic dyes from wastewater. This review outlines recent developments in biochar production, particularly comparing biochars produced via pyrolysis and hydrothermal carbonisation (HTC). While pyrolysis biochar often exhibits a higher surface area, HTC biochar offers improved oxygen-containing functional groups, contributing to enhanced dye affinity. Studies indicate that biochar can achieve adsorption capacities ranging from 2 to 1353.09 mg/g for dyes such as methylene blue and crystal violet, comparable to or exceeding that of pyrolysis-derived biochars. The review also highlights characterisation techniques such as XRD, FTIR spectroscopy, and SEM to evaluate surface functionality, porosity, and morphology, which directly influence adsorption performance. Practical implications include the suitability of HTC biochar for low-energy, decentralised wastewater treatment systems, particularly in textile and dyeing industries. By connecting production parameters with biochar properties, this review provides insights into optimizing biochar as an adsorbent, particularly for the treatment of dye-contaminated wastewater
Production of Liquid Fuel from Motorcycle Used Tire via Pyrolysis: Effect of Temperature on Yield and Calorific Value
Full text linkThe continuous accumulation of used tires has raised serious environmental concerns due to their non-biodegradable nature. Pyrolysis offers a promising thermal conversion method to transform used tires into alternative energy sources. This study investigates the pyrolysis of used motorcycle tires, cut into 1 x 1 cm pieces, under atmospheric pressure at various temperatures ranging from 400°C to 750°C, using 500 grams of tire material for each run. The tar and char yields were collected, and the calorific values of the liquid product were analyzed. The optimum operating condition was found at 700°C, yielding 276.56 g of tar and 184.55 g of char after 2 hours and 35 minutes of reaction. The highest calorific value obtained was 39.98 MJ/kg. Although the liquid fuel produced exhibits significant energy content, its calorific value remains lower than that of conventional fuels used in vehicles. This indicates the potential of tire-derived oil as a supplementary fuel, with further improvement needed in quality and performance