Jurnal Rekayasa Proses

Techno-economic analysis of process for separating saturated and unsaturated fractions from palm fatty acid distillate

2025-04-26T09:23:05+07:00

Palm fatty acid distillate (PFAD) can be used as a raw material for two types of polyvinyl chloride (PVC) thermal stabilizers: organotin and mixed organometal. To produce high-quality thermal stabilizers, PFAD must first be separated into saturated and unsaturated fractions. This research aims to develop and analyze the techno-economics of separating these fractions from PFAD through solvent crystallization using methanol. The study began with the development of a process flow diagram, including the selection of unit operations and equipment. Mass and energy balances for the developed process were then calculated. Investment and production costs were estimated and used to determine economic indicators. These calculations were performed using Aspen Plus and Aspen Hysys software. Utility requirements were primarily driven by solvent evaporation and condensation. From an environmental perspective, higher crystallization temperatures are preferable due to reduced fuel consumption and lower CO₂ emissions. However, higher crystallization temperatures resulted in a less pure unsaturated fraction, despite producing a larger quantity. The estimated investment for constructing a separation plant with the studied capacity and crystallization temperature range was between 13.6 and 13.9 million USD. Among the equipment, fired heaters and refrigeration compressors contribute the most to costs. The separation process at temperatures of -15°C and 0°C was found to be economically viable, with internal rates of return (IRR) of 36% and 49%, respectively. In contrast, the separation process at 10°C was not economically feasible. The findings of this study are expected to serve as a reference for the development of commercial-scale processes.

Differences in the molecule structure of natural rubber and thermal coagulant process based on FTIR analysis

2025-04-26T13:45:12+07:00

Rubber is one of the most potential and abundant biological natural resources in Indonesia. This research was conducted to determine the content of compounds contained in rubber after coagulation by means of thermal coagulants. There are 2 (two) thermal coagulants used, traditional using firewood and modern using a laboratory oven. Variations in the weight of the latex used were 0.5 kg, 0.75 kg, 1 kg, 1.25 kg and 1.5 kg. Then the results of the thermal coagulant were subjected to the Fourier Transform Infrared (FTIR) test to see the compound content contained in the rubber. The results of the FTIR test on traditional thermal coagulants at high and medium heat and modern thermal coagulants in the oven showed the typical functional groups of rubber, namely the presence of C-H, C=C and C-C carbon bonds.

Filtration of Kutawaru Cilacap batik waste using fly ash activated by sulfuric acid

2025-04-26T09:23:43+07:00

The batik industry is one of the largest contributors to liquid waste. Batik liquid waste if not treated properly has the potential to increase disease and pollute the environment. Pollutant levels contained in the waste can be degraded by using fly ash as an adsorbent. Fly ash is obtained from Steam Power Plant waste. The purpose of this study was to determine the best concentration of sulfuric acid between 1M and 3M added to activate fly ash to reduce COD, BOD, TSS, color change and pH of Kutawaru batik waste. The research consisted of three stages: the first stage was the activation of fly ash by immersing it in a solution of 1M and 3M sulfuric acid with a ratio of 1:5 for 3 hours. Then, wash with water until the pH is neutral. Furthermore, the fly ash was dried using an oven at 105oC for 4 hours to a constant weight, resulting in sulfuric acid-activated fly ash. The second stage of the adsorption process, where batik waste was mixed with sulfuric acid-activated fly ash in a ratio of 5:1 for 3 hours, resulted in the waste after adsorption. In the last stage, testing of the waste before and after adsorption was carried out at the Cilacap Environmental Laboratory. The results showed that the best concentration of sulfuric acid for the activation of fly ash was 1M because it reduced COD, BOD and TSS by up to 90%. Changes in COD, BOD, TSS, color and pH of batik waste before and after adsorption using 1 M sulfuric acid-activated fly ash, namely COD 13678 mg/L to 1302 mg/L, BOD 8480 mg/L to 870 mg/L, TSS 460 mg /L becomes 47 mg/L, the color of the batik waste changes from black to yellow, and pH 9 becomes 7.

Thermogravimetric Analysis of Indonesian Low-Rank Coal: Optimization of Drying Temperature and Kinetic Modeling

2025-04-26T09:24:00+07:00

Drying high-moisture of low rank coal in the mining sector is essential for increasing energy efficiency and ensuring stability in its use as an energy source. This study aims to determine the optimal drying temperature and kinetic parameters for Indonesian low rank coal (i.e., lignite and sub-bituminous) using thermogravimetric analysis (TGA) under both isothermal and non-isothermal conditions. Coal samples were tested at three heating rates (5, 10, and 20°C/min) and three fixed temperatures (150, 200, and 250°C). Several drying kinetics models, including the Newton, Henderson and Pabis, Logarithmic, and Page models, were used to evaluate the drying characteristics of both coal types. The results indicate that the Page model provided the best fit, with the highest 𝑅² value and the lowest 𝜒² value, making it the most accurate model for describing coal drying rates under various conditions. The optimal drying temperature for lignite was 83.04°C, with an activation energy of 3224.04 J/mol, while for sub-bituminous coal, the optimal temperature was 109.65°C with an activation energy of 17972.83 J/mol. These findings support the optimization of the drying process in the industry, particularly for efficiently reducing coal moisture content without compromising energy quality.

Optimization of D-limonene and phenolic compounds extraction from local Indonesian orange peel using ultrasound-assisted extraction

2025-04-26T09:24:16+07:00

Malang Regency is one of the orange plantation centers in East Java, Indonesia, and has been named Indonesia’s orange agrotourism area. Orange peel waste in Indonesia has not been utilized, even though orange peel contains valuable compounds, such as D-limonene and polyphenols. To date, studies on the extraction of D-limonene and total phenolic compounds (TPC) from Baby Java Pacitan orange (Citrus sinensis L.) and Keprok Batu 55 oranges (Citrus reticulata Blanco) has not been investigated. In this work, several factors affecting the extraction of D-limonene and total phenolic compounds from local Indonesian orange peels with ultrasonic assistance were investigated and optimized. The results showed that drying using a vacuum oven and agitation significantly increased the yield of D-limonene and TPC. The optimum condition for extracting D-limonene was a solid-solvent ratio (SSR) of 1:10 with an ethanol concentration of 96% for 40 minutes. Meanwhile, the optimum condition for extracting polyphenol compounds was a solid-solvent ratio of 1:10 with an ethanol concentration of 96% for 80 minutes. Under optimum conditions, Baby Java Pacitan orange peel produced D-limonene of 130.5 mg/g dry biomass, which was 2.8 times higher than Keprok Batu 55 orange peel. Meanwhile, the TPC for Baby Java Pacitan orange peel and Keprok Batu 55 orange peel were 46.1 mgGAE/g dry biomass and 43.9 mgGAE/g dry biomass, respectively.

Extraction of manganese from Indonesian manganese ore using sugarcane bagasse-acid reductive leaching

2025-04-26T09:24:37+07:00

In this study, sugarcane bagasse was used as a reducing agent in manganese leaching from manganese ore from Way Kanan, Lampung under acidic conditions using sulfuric acid as a leaching reagent. Bagasse is an agricultural waste from the cane sugar manufacturing industry which is commonly found in Lampung Province. This agricultural waste has the potential to become a reducing agent in manganese leaching because it contains carbon in the form of cellulose and sugar. The optimization of the leaching conditions has been investigated with the parameters of H₂SO₄ concentration, temperature, and pulp density. The highest manganese leaching recovery was obtained under the following optimized conditions: 1 M H₂SO₄ concentration, 14 g sugarcane bagasse/20 g MnO₂, 50 g/L pulp density, 80 °C leaching temperature, 200 rpm stirring rate, and 4 hours of reaction time. The present process therefore deals with achieving the effective recovery of value-added products from low-grade manganese ore using agriculture waste as reducing agent.

Synthesis of hydroxyapatite from hard clams shell (Meretrix spp.) using hydrothermal method as a dental implant coating biomaterials

2025-04-26T09:28:04+07:00

Biomaterials that can be used as coatings on dental implants are hydroxyapatites. One of the natural substances used in the synthesis of hydroxyapatite is the ale-ale shell, which has a substantial calcium content of 93,444%. The hydroxyapatite synthetic was carried out using a hydrothermal method that uses the calcium precursor (Ca) of the ale-ale shell and phosphate precursors (P) derived from (NH₄)₂HPO₄, as well as NH₄OH as a pH regulator. This research uses the influence variables of CaO/(NH₄)₂HPO₄ concentration (0.67; 1.67; and 2.67) and pH (11, 12, and 13). The results of the FTIR analysis showed that the typical absorption peaks of hydroxyapatites are , OH^-, and group absorptions. XRD analysis results showed the formation of major HAp peaks that correspond to ICDD data 01-072- 1243, with the highest peaks in succession appearing at angles 31,74; 31,67; and 31,64°. The crystal size is 35,25; 123,39; and 55,81 nm with degrees of crystallinity in sequence of 87,28; 91,67; and 95,09° and has a hexagonal crystal shape. Hydroxyapatite synthesis with ale-ale shell waste raw materials by hydrothermal method gives the best results at a concentration of CaO/(NH₄)₂HPO₄ 2.67-pH 13.

Synergistic ultrasonic-microwave assisted extraction (UMAE) for enhanced fat extraction from nutmeg seeds

2025-04-26T13:07:18+07:00

Nutmeg seeds contain essential oils and fats, are widely used in the cosmetic and pharmaceutical industries. This research aims to determine the yield, physicochemical characteristics and fat composition of nutmeg seeds extracted from Ultrasonic-Microwave Extraction (UMAE). The research used a factorial completely randomized design (CRD) method with the independent variables, length of extraction time (45, 90, 135 minutes) and microwave power (300 and 450 watts). The dependent variables in this research are yield, melting point, specific gravity, acid number and saponification number. The results showed that the highest fat yield of nutmeg was 30.48% at 300 Watts and 135 minutes. The physicochemical characteristic of nutmeg fat was yellow with specific gravity, melting point, acid number and saponification number were 0.96, 52.4 °C, 16.69 mg KOH/g fat and 254.96 mg KOH/gram fat. GCMS results show that the fat composition is trichloromethyl, isopropyl phosphoranidothioic acid and lauric acid triglyceride which have potential as cosmetic raw materials.

Soluble phosphorus rich compost by aerobic solid-state fermentation of chicken bone-containing food waste with Aspergillus niger

2025-04-26T13:10:15+07:00

Food waste has become a concern in solid waste management due to its high bulk volume and production rate. Without good management, food waste piling may result in foul odor, global warming by methane emission and even an epidemic. Composting is a method usually employed to process food waste. However, this method often took a long period and selective to organic waste such as leafy materials or fruit waste. Bone is a food waste that is rich in phosphorus, a chemical substance that is required to make various useful products such as fertilizer, battery, detergent, etc. This study investigates the characteristics of food waste compost containing chicken bone and various domestic organic food waste that was processed through aerobic solid-state fermentation using Aspergillus niger. The composting process was monitored over a 28-day period at 28°C. The resulting compost was characterized under various physicochemical parameters, including pH and nutrient composition. The findings demonstrated that Aspergillus niger effectively released phosphorus from bone while degraded organic matter in just a week, resulting in significant reductions in unprocessed waste volume and the production of a stable, nutrient-rich compost in a short time. Additionally, the compost was successfully induced better growth on corn seed compared to the food waste pile and naturally composted food waste. These results suggest that Aspergillus niger-mediated aerobic solid-state fermentation is a viable and efficient method for converting food waste into high-quality compost, promoting sustainable waste management and agricultural practices.

Potential of polyphenol compounds in oil palm leaf extract for natural sunscreen gel products

2025-04-26T13:10:29+07:00

The bad effects of exposure to sunlights through the content of UltraViolet A (UVA) and UltraViolet B (UVB) in the long term can cause skin damage. One way of protection is through the using of sunscreen. This study aims to make a gel sunscreen from natural ingredients, polyphenolic compounds from oil palm leaf extract. The use of natural sunscreens has the advantage of the safety level of use when compared to synthetic sunscreens. The process of making sunscreen consists of several stages, namely raw material preparation (separating the leaves from the palm fornds, chopping, washing, and drying the palm leaves), extraction palm leaf by the maceration method (soaking and stirring powdered plam leaf with ethanol 96%) and making gel preparations by mixing palm leaf extract with methylparaben and a gel base, namely Hydroxy Propyl Methyl Cellulose (HPMC) and Carbopol. After the gel is made, the preparation is tested to obtain a sunscreen formulation that complies with SNI No 16-4399-1996. From the test results, several standard formulations were obtained, namely pH, spreadability, emulsion stability, antioxidant, viscosity, and SPF parameters. The best sunscreen gel product is the F2 (comparison of HPMC and Carbopol 70% : 30%) with a concentration of 1% palm leaf extract.