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Published By Institute Of Research And Community Services Diponegoro University (Lppm Undip)

2407-5973, 0852-0798

REAKTOR ◽  
2021 ◽  
Vol 21 (2) ◽  
pp. 74-93
Author(s):  
Indra Riadi ◽  
Zulfan Adi Putra ◽  
Heri Cahyono

Pinch analysis for a sugar plant production capacity 4000 TCD has been carried out to reduce its energy consumptions. The plant has ten evaporators that can be configured to several multiple effect evaporators. It has been running with five-effect evaporator (quintuple) scheme. To maximize energy utilization within the plant, three multiple effect evaporator schemes were evaluated. They are triple effect evaporator, quadruple effect evaporator, and quintuple effect evaporator as the benchmark. The result shows that the quintuple effect evaporator yields the highest energy efficiency by about 10%. Options to achieve such target is to use low pressure steam only for the first effect and to use steam bleeding from the first effect to heat a tertiary juice heater. With this proposed scenario, sugar dryer, wash water RVF unit and wash water HGF unit no longer need external steam for its operation.


REAKTOR ◽  
2021 ◽  
Vol 21 (2) ◽  
pp. 65-73
Author(s):  
Agam Duma Kalista Wibowo ◽  
Pina Tiani ◽  
Lisa Aditya ◽  
Aniek Sri Handayani ◽  
Marcelinus Christwardana

Surfactants for enhanced oil recovery are generally made from non-renewable petroleum sulfonates and their prices are relatively expensive, so it is necessary to synthesis the bio-based surfactants that are renewable and ecofriendly. The surfactant solution can reduce the interfacial tension (IFT) between oil and water while vinyl acetate monomer has an ability to increase the viscosity as a mobility control. Therefore, polymeric surfactant has both combination properties in reducing the oil/water IFT and increasing the viscosity of the aqueous solution simultaneously. Based on the study, the Critical Micelle Concentration (CMC) of Polymeric Surfactant was at 0.5% concentration with an IFT of 7.72x10-2 mN/m. The best mole ratio of methyl ester sulfonate to vinyl acetate for polymeric surfactant synthesis was 1:0.5 with an IFT of 6.7x10-3 mN/m. Characterization of the product using FTIR and HNMR has proven the creation of polymeric surfactant. Based on the wettability alteration study, it confirmed that the product has an ability to alter from the initial oil-wet to water-wet quartz surface. In conclusion, the polymeric surfactant has ultralow IFT and could be an alternative surfactant for chemical flooding because the IFT value met with the required standard for chemical flooding ranges from 10-2 to 10-3 mN/m.Keywords: Enhanced Oil recovery, Interfacial Tension, Methyl Ester Sulfonate, Polymeric surfactant, vinyl acetate


REAKTOR ◽  
2021 ◽  
Vol 21 (2) ◽  
pp. 59-64
Author(s):  
Enny Ratnaningsih ◽  
Sulistiya Nirta Sunaryo ◽  
Idris Idris ◽  
Rindia Maharani Putri

In recent years we have witnessed the emergence of organohalogen utilization in various chemical-based industries, particularly polymer-based, agricultural, and pharmaceutical sectors. Despite this, organohalogen compounds are actually very dangerous to the environment, as they are difficult to be naturally degraded and generally toxic to organisms. A green and biocompatible method to overcome this issue is by employing enzymes that could convert organohalogens into non-toxic compounds, such as the class of enzymes known as haloacid dehalogenases. To enhance the activity of haloacid dehalogenase isolated from local strains of Bacillus cereus IndB1, we have developed a recombinant expression system using pET-bcfd1 plasmid in E. coli BL21 (DE3) host cells. Following enzyme production, we also demonstrated a one-pot purification system for the expressed dehalogenase, harnessing the presence of His-tag in the recombinant clones. Purification was carried out using Ni-NTA affinity column chromatography, using imidazole eluent with a concentration gradient of 10 mM to 500 mM. The enzyme activity was tested against the monochloroacetic acid (MCA) substrate according to the Bergmann and Sanik method, and the protein content in the solution was measured using the Bradford method. The purity of the enzyme after one-pot purification was confirmed by SDS-PAGE analyses, showing a single band of 40 kDa in size. Remarkably, the purified haloacid dehalogenase specific activity was increased by 12-fold compared to its crude enzyme extract. Therefore, the expression and purification system developed in this study allow further exploration of dehalogenases from local strains as an efficient catalyst for MCA biodegradation.Keywords: recombinant expression, haloacid dehalogenase, monochloroacetic acid, enzyme purification


REAKTOR ◽  
2021 ◽  
Vol 21 (2) ◽  
pp. 52-58
Author(s):  
Marcelinus Christwardana ◽  
Linda Aliffia Yoshi ◽  
J. Joelianingsih

This study demonstrates the feasibility of producing bioelectricity utilizing yeast microbial fuel cell (MFC) technology with sugarcane bagasse juice as a substrate. Yeast Saccharomyces cerevisiae was employed as a bio-catalyst in the production of electrical energy. Sugarcane bagasse juice can be used as a substrate in MFC yeast because of its relatively high sugar content. When yeast was used as a biocatalyst, and Yeast Extract, Peptone, D-Glucose (YPD) Medium was used as a substrate in the MFC in the acclimatization process, current density increased over time to reach 171.43 mA/m2 in closed circuit voltage (CCV), maximum power density (MPD) reached 13.38 mW/m2 after 21 days of the acclimatization process. When using sugarcane bagasse juice as a substrate, MPD reached 6.44 mW/m2 with a sugar concentration of about 5230 ppm. Whereas the sensitivity, maximum current density (Jmax), and apparent Michaelis-Menten constant (𝐾𝑚𝑎𝑝𝑝) from the Michaelis-Menten plot were 0.01474 mA/(m2.ppm), 263.76 mA/m2, and 13594 ppm, respectively. These results indicate that bioelectricity can be produced from sugarcane bagasse juice by Saccharomyces cerevisiae.Keywords: biomass valorization, biofuel cell, acclimatization, maximum power density, Michaelis-Menten constant


REAKTOR ◽  
2021 ◽  
Vol 21 (2) ◽  
pp. 45-51
Author(s):  
Novita Andarini ◽  
Ria Sherly Farida ◽  
Tanti Haryati

Calcium oxide nanoparticles was prepared by coprecipitation method using calcium acetate as precursor and calcined at 800 °C for 6 hours. This work studied the effect of different precursor concentrations on the size of calcium oxide obtained and its applicated for palm oil transesterification catalysis. Characteristics of samples were measured by XRD and SEM et al techniques. The results showed that the diffraction pattern of CaO has the same diffraction pattern as the XRD standard diffraction pattern from the Joint Committee on Powder Diffraction Standard (JCPDS). Calcium oxide analysis using SEM shows the morphology of particles that agglomerate almost all variations in precursor concentration. The particle size increases with increasing precursor concentration. The smallest particle size of 55.758 nm was produced on solid CaO from the lowest precursor concentration of 0.05 M. The catalytic activity of activated calcium oxide nanoparticle compound was tested in the production of methyl esters. The conversion of triglycerides in palm oil into methyl esters was 90.34%.Keywords: nanoparticles, calcium oxide, coprecipitation, precursor, catalys, metyl ester 


REAKTOR ◽  
2021 ◽  
Vol 21 (1) ◽  
pp. 1-10
Author(s):  
Putri Ramadhany ◽  
Abigail Fern Pramana ◽  
Arabella Febiola ◽  
Tony Handoko

Tomato is a seasonal horticultural product that has beneficial effects on human health. It contains a high concentration of lycopene and vitamin C. However, tomato production, which continues to increase in Indonesia, is not balanced with its consumption. Due to its high moisture content, harvested tomato relatively has a short shelf-life. Resultantly, the unconsumed tomato will end up being wasted. One way to prolong tomato’s shelf-life is by converting it into powder form. In this research, the tomato was shifted into tomato powder using a foam mat drying method. The weight ratio of GMS to tomato juice was varied: (1) 4%-w/w, (2) 5%-w/w, and (3) 6%-w/w. Tomato powder was then stored in two types of materials (sealed brown glass bottle and laminated aluminium foil (LAF) resealable zipper) and three conditions (refrigerator ( ± 4 ℃), room temperature (± 25.2 ℃) and sun-exposed  (± 30 ℃)). According to the results, foam mat drying could maintain the nutrients of the tomato powder. Increasing GMS larger than 5%-w/w had no big impact on reserving lycopene and vitamin C. At 5%-w/w GMS, tomato powder consisted of 1.09%/w/w moisture, 42.58 mg/100 g lycopene, and 123.28 mg/100 g vitamin C. It was found that moisture and vitamin C on tomato powder content was influenced by storage conditions, while lycopene content was influenced by storage material. Moisture content and vitamin C were best maintained at the sun-exposed condition and room temperature, respectively. While lycopene was best stored in the laminated aluminium foil (LAF) resealable zipper.


REAKTOR ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Dessy Ariyanti

REAKTOR ◽  
2021 ◽  
Vol 21 (1) ◽  
pp. 35-43
Author(s):  
Dianika Lestari ◽  
Khalisa Putri Aqilah ◽  
Salsafia Putri ◽  
Ardiyan Harimawan ◽  
Diky Mudhakir ◽  
...  

Vitamin E concentrate was produced through saponification of palm fatty acid distillates (PFAD) and magnesium oxide to form Mg-PFAD, followed by three-stages vitamin E extraction with isopropanol, hexane, or ethanol. The vitamin E-rich extracts were evaporated to remove solvent and produced vitamin E concentrate. The objectives of this research were to investigate the effect of organic solvent’s types and solvent to Mg-PFAD mass ratios on vitamin E concentration, solvent selectivity, and antioxidant activity of the vitamin E concentrate. Vitamin E concentrates obtained after isopropanol extraction had vitamin E concentration of 784 ppm with vitamin E recovery of 16 mg tocopherol/100 mg tocopherol in Mg-PFAD, while vitamin E concentrates obtained after hexane extraction had vitamin E concentration of 574 ppm with vitamin E recovery of 35 mg tocopherol/100 mg tocopherol in Mg-PFAD. Isopropanol extraction produced vitamin E concentrate with the highest selectivity for vitamin E and the highest antioxidant activity of 79% IC. It was found that vitamin E concentration was not proportional to the antioxidant activity of the vitamin E concentrate.Keywords: Direct solvent extraction, palm fatty acid distillate, saponification, vitamin E, unsaponifiable matter 


REAKTOR ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Dessy Ariyanti

REAKTOR ◽  
2021 ◽  
Vol 21 (1) ◽  
pp. 15-26
Author(s):  
Wilbur Donald Raymond Pokatong ◽  
Tiffany Nathalie

Avocado (Persea americana) is known to have high dietary fiber and monounsaturated fatty acids which can reduce low density lipoprotein (LDL); thus, reduced risk of heart attack. The research objective was to partially substitute margarine with avocado puree in the preparation of pound cakes to reduce the saturated fat and increase the nutritional values. The pound cakes were prepared with five different ratios of avocado puree to margarine which were 0:1, 1:3, 1:1, 3:1, and 1:0 using three types of flour (all-purpose, cake, or bread flour) and baked using two methods (oven and microwave baking). Results showed that avocado contains 81.37±1.38 (%, wb), 53.09±3.64 (%, db), 6,98±0.49 (%, db), 34.57±3.63 (%, db), and 5.36±0.49 (%, db) of moisture, fat, protein, carbohydrate, and ash, respectively. From each type of flour, one pound-cake was selected based on its physical properties i.e. firmness, volume expansion, L* value, and ohue. Selected pound cakes were further evaluated with scoring and hedonic tests by 70 panelists to observe its consumer acceptance and selected the best pound cake from each type of baking methods (oven and microwave baking). The results showed that oven-baked pound cake with avocado puree to margarine ratio 1:1 prepared with cake flour and microwave-oven-baked pound cake with avocado puree to margarine ratio 1:1 prepared with bread flour exhibited the highest acceptance with overall hedonic values of 4.96±1.18 and 4.83±1.09, respectively. However, considering the time needed for baking and that the microwave baked pound cakes exhibiting higher protein, the pound cake baked in the microwave oven is more preferrable for further commercial manufacture.Keywords: avocado;baking; fat-substitution;flour types, pound-cake


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