Jurnal Rekayasa Kimia & Lingkungan
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Acetylation of Glycerol Catalyzed by CaO as Octane Booster in Gasoline Fuel
Full text linkGlycerol, a byproduct of biodiesel production, can be transformed into value-added compounds such as triacetin, which serves as an effective octane booster in gasoline. This study investigates the acetylation of glycerol with acetic acid using calcium oxide (CaO) as a heterogeneous catalyst. Catalyst concentrations of 1%, 2.5%, 5%, 7.5%, and 10% were tested under reaction conditions of 100C for 180 minutes. The resulting products were analyzed using gas chromatographymass spectrometry (GC-MS) to identify acetylated derivatives. Among the tested conditions, 5% CaO yielded the highest triacetin content. The acetylated product was then blended into gasoline at a 5% concentration. Fuel testing showed an increase in the Research Octane Number (RON) from 84 (pure gasoline) to 93 with the addition of triacetin, along with slight increases in fuel density and viscosity. These findings highlight the potential of CaO-catalyzed glycerol acetylation for producing high-performance fuel additives
Effect of Glycerol Concentration and Filler Addition on the Properties of Bioplastics Derived from Kepok Banana Corm Starch
Full text linkThe waste from kepok banana corms and stems has not been well utilized, even as banana production continues to rise, increasing the volume of such waste. In Indonesia, banana production in 2023 reached 9.75 million tons, up from 7.2 million tons the previous year, leading to a corresponding increase in banana waste. This research investigates the effects of glycerol and banana stem filler on the properties of bioplastics made from kepok banana corm starch, aiming to develop a sustainable alternative to conventional plastics. Starch was extracted from kepok banana corms through grinding, filtering, and drying at 80C for 15 minutes. Cellulose filler was produced from banana stems using bleaching with NaOH and H2O2, followed by neutralization and drying to a constant weight. Bioplastics were then produced with filler concentrations of 0%, 2%, 4%, and 6% and glycerol volumes of 1-4 mL per 10 grams of starch, on mixing conducted at 70C in distilled water. Characterizations and tests of the bioplastics included for cristallinity, functional groups, surface morphology, yield, density, water absorption, tensile strength, and elongation. Bioplastics with addition filler performed better than those without filler, with the 6% filler and 2 mL glycerol variation showing the most favorable properties, including a yield of 25.92%, density of 1.14 g/mL, water absorption of 0.24%, tensile strength of 5.49 MPa, elongation of 8%, and a homogeneous surface with well-distributed filler. These findings demonstrate the potential of kepok banana waste-based bioplastics as an environmentally friendly alternative
Analyzing And Mapping of Sound Pressure Level in The Packing Plant Unit of PT Semen Padang Teluk Bayur
Full text linkThe cement industry is one of the strategic industries that has positive and negative impacts. One of the negative impacts is noise pollution. This research aimed to compare the sound pressure level (SPL) to the standard, analyzed the meteorological influence on SPL, and conducted noise level mapping. The noise measurement according to SNI 7231 of 2009. The SPL data was collected by using a Sound Level Meter at 36 points. Additionally, questionnaires were distributed to workers at the PT Semen Padang Teluk Bayur Packing Plant Unit. Measurement of noise used the grid method with sampling points spaced 20-40 meters apart, then analyzed the correlation and influence of meteorological on SPL, and noise mapping with Surfer 27. The results showed that the highest SPL came from the compressor engine at 85.7 dBA, and the lowest SPL was in the office area at 58.1 dBA. The SPL in this study was influenced by meteorological conditions such as temperature, air humidity, wind speed, and air pressure. There was a correlation between temperature and SPL with a value (r) of 0.9936 (very strong) and a correlation between air humidity and SPL with a value (r) of 0.9962 (very strong)
Techno-Economic Analysis of Electricity Generation From Rice Husk Based On Demand For Electric Vehicle: A Case Study In Surabaya City, Indonesia
Full text linkOn August 5, 2019, the President of the Republic of Indonesia issued a Presidential Regulation (Perpres) concerning the acceleration of the battery-based electric motorized vehicle program for road transportation. However, fossil energy sources such as coal, oil and natural gas used in conventional power plants are increasingly limited, so alternative energy that is more sustainable and environmentally friendly is needed. One source of sustainable electrical energy is biomass wastes such as rice husks, which have a potential CO2emission reduction of 142,610.51 tCO2/year. The method used for technical analysis by simulating the process of processing biomass waste into electrical energy using the gasification process with Aspen Plus software as a tool to obtain optimum operating conditions. Biomass with flow 32,906.9 kg/h is fed into the gasification process area and then produces 1,538 kmol/h of syngas which reacted with airflow 9,779 kmol/h. The selling target for electric products is to supply the electricity needs of electric vehicle users in Surabaya. This research is possible to do with the consideration that East Java is the province with the largest rice production in Indonesia, Surabaya is a metropolitan city and is the economic center of the province of East Java so it is possible to developments related to the infrastructure of electric vehicles and the electric vehicle itself. Based on the economic feasibility analysis, the biomass power plant has an NPV of Rp.163 million, an IRR is 15.01%, WACC 7.34%, LCOE 4.063 Rupiah/kWh and a payback period of 6 years
Improving Carrageenan Extraction Efficiency and Stability Using KOH, NaOH, and Anti-Caking Agents
Full text linkThis study investigates the impact of varying concentrations of potassium hydroxide (KOH) and sodium hydroxide (NaOH), along with anti-caking agents, on the quality of carrageenan extracted from Eucheuma cottonii seaweed. FTIR analysis revealed that KOH-extracted carrageenan retained key functional groups, including sulfate esters and glycosidic bonds, essential for its classification as kappa-carrageenan. KOH also proved more effective than NaOH in reducing moisture content, preserving structural integrity, and meeting the Indonesian National Standards (SNI) for carrageenan quality. The addition of anti-caking agents further optimized product stability, particularly in moisture control. The result shows that KOH was more effective than NaOH in improving carrageenan yield, with a yield of 46% achieved using 12% KOH and 4 g TCP. Anti-caking agents like tricalcium phosphate improved the products moisture control and stability. Future research should focus on refining extraction methods to enhance both product quality and yield
Assessment of Sail River Water Quality in Pekanbaru City Using the STORET and Pollution Index (IP) Methods
Full text linkThe Sail River acts as the main drainage in Pekanbaru City. Several community activities around the Sail River, such as residential areas, plantations, livestock, shops, markets, and schools, cause decreasing in water quality in the Sail River. For this reason, it is necessary to analyze the water quality of the Sail River using the STORET method and the Pollution Index. The physical (temperature, TSS, TDS), chemical (pH, COD, DO, Pb), and biological (total coliform) parameters were analyzed. The results of the water quality analysis obtained were compared with Class II Water Quality Standards based on PP No. 22 of 2021. The results of the analysis of the quality status of the Sail River downstream based on the STORET method over the last five years show a "heavily polluted" condition, while the results of the IP method analysis show a "moderately polluted" condition. Based on the STORET and Pollution Index methods results, sail river needs a pollution control policy and management to overcome the pollution
Comparative Evaluation of Poly Aluminum Chloride (PAC) and Aluminum Chlorohydrate (ACH) in Pre Treatment of Boiler Feed Water
Full text linkIndustrial boiler feed water from rivers and groundwater requires treatment to remove impurities causing scaling and corrosion. In this study, water treatment was carried out using the coagulationflocculation method with Poly Aluminum Chloride (PAC) and Aluminum Chlorohydrate (ACH) as coagulants, with the aim of comparing their performance and cost-effectiveness. Jar tests were performed with coagulant dosages of 40, 60, and 80 ppm and rapid mixing speeds of 90, 120, and 150 rpm. Metal reduction experiments were conducted by adding Fe and Cu at concentrations of 1, 3, and 5 ppm. The results showed that the optimum dosages for turbidity and metal removal were 80 ppm for PAC and 40 ppm for ACH, while the optimum dosages for COD reduction were 60 ppm for PAC and 40 ppm for ACH. Rapid mixing at 90 rpm was most effective for turbidity reduction, whereas 120 rpm was optimal for metal and COD removal. Overall, ACH was found to be more effective and more cost-efficient than PAC for the pretreatment of boiler feed wate
Estimation of Critical Properties of Eucalyptol, Alpha-Terpineol, Limonene, and Caryophyllene in Eucalyptus Oil (Melaleuca leucadendra) Using the Group Contribution Method
Full text linkCritical property estimation of compounds in eucalyptus oil has been conducted using the Group Contribution method to improve the accuracy of calculations of critical temperature (Tc), critical volume (Vc), critical pressure (Pc), and normal boiling point (Tb). This study updates the previous research by adding a comparative analysis of estimation errors between methods. Eucalyptus oil was extracted using microwave hydrodistillation followed by vacuum distillation to determine experimental data, then estimated using the Joback, Constantinou-Gani (CG), Wilson-Japerson (WJ), and Marrero-Pardillo (MP) methods. The results show that the Wilson-Japerson method provides the most accurate Pc estimation with %AAE of 12.7819%, the Marrero-Pardillo method is best for Vc with %AAE of 5.3393%, the Marrero-Pardillo method provides the most accurate Tc estimation with %AAE of 2.7143%. The Joback method is most suitable for Tb with a %AAE of 20.0828%. The application of the results of this study in the essential oil industry is crucial in optimizing the extraction and distillation process, increasing the efficiency of separation units, developing refining technology, and formulating essential oil-based products. The method with the best accuracy can be used in the design of distillation equipment and thermodynamic reactors, thereby improving production efficiency and product quality in the pharmaceutical, cosmetic, and natural chemical industries
Properties of Recycled Polyethylene Terephthalate (rPET)/Stearic Acid/Green Mussel Shell (GMS) Composite
Full text linkThe increasing accumulation of plastic waste, particularly polyethylene terephthalate (PET), presents significant environmental challenges. This study explores the incorporation of green mussel shell (GMS) as a bio-filler in recycled polyethylene terephthalate (rPET) composites to promote sustainability and circular economy practices. rPET/SA/GMS composites were fabricated using injection molding, with GMS compositions of 0%, 5%, 10%, and 15% and a fixed 1% stearic acid (SA) content as a coupling agent. The effects of GMS on thermal, mechanical, rheological, and morphology properties were analyzed using differential scanning calorimetry (DSC), universal testing machine (UTM), melt flow index (MFI) testing, and scanning electron microscopy (SEM). The results indicate that 10% GMS exhibited the highest melting temperature (249.5C) due to enhanced interfacial interactions, despite a decrease in crystallinity. However, tensile strength decreased significantly at 5% GMS (8.52 MPa) due to weak interfacial bonding, whereas 10% GMS (12.91 MPa) showed slight improvement due to better SA-assisted dispersion. Rheological analysis revealed the highest melt flow rate (162.87 g/10 min) at 5% GMS, but higher GMS concentrations reduced flowability due to increased CaCO content and filler agglomeration. Morphological analysis confirmed that GMS addition increased surface roughness, induced void formation, and disrupted stress transfer, weakening composite integrity. These findings highlight the potential of GMS as a functional bio-filler in rPET composites, emphasizing the need for optimized filler concentration and interfacial modifications to develop sustainable high-performance materials
Characterization and Effect of NaOH/ZnCl2 Chemical Activation on Nickel-Impregnated Activated Carbon for Biofuel
Full text linkThe global energy crisis, driven by dwindling fossil fuel reserves and surging energy demand, necessitates a sustainable solution. Therefore, this research aimed to develop sugarcane molasses-based activated carbon as a support for nickel (Ni) catalysts to increase the efficiency of bio-oil conversion into biofuels. In these processes, activated carbon was produced by the dehydrogenation process of sugarcane molasses followed by the wet impregnation method using sodium hydroxide (NaOH) and zinc chloride (ZnCl2) activating agents. The analysis results showed that sugarcane molasses was effectively converted into activated carbon with optimal catalyst-loading properties. Based on the results of SEM-EDS and BET analysis, the activated carbon has a surface area with type III (IUPAC) indicating the presence of mesopores. Additionally, the use of the reflux process with Ni catalyst successfully converted coffee shell pyrolysis oil into hydrazine-based biofuel on the SMNa sample and heptadecane on the SMZn sample. The highest yield, 73.6% was found on SMZn. This research shows the great potential of sugarcane molasses as a raw material for the production of environmentally friendly biofuels while providing economic added value to biomass waste. These results will contribute to biomass energy conversion efforts in Indonesia