ASEAN Journal of Chemical Engineering

Green tea drying in a closed cycle continuous vibro fluidized bed dryer with dehumidified air

Tue, 30 Apr 2024 15:23:37 +0700

There is potential for the development of zeolite as an adsorbent material for drying high-value items. This study aims to compare the green tea drying characteristic utilizing vibro-fluidized bed dryers that operate without dehumidification and with dehumidification. The research was carried out experimentally. The drying chamber was set at temperatures of 50^oC, 60^oC, and 70^oC. In the drying with dehumidification setup, zeolite was placed in a dehumidifier with a weight-to-tea leaf ratio of 1:2.86, 1:3.33, 1:4, and 1:5. The results showed that zeolite's impact on decreasing drying time is effective at a specific temperature, in this case is 60^oC. The effect is negligible at low temperatures (50^oC), while at high temperatures (70^oC) it is minor and drying time is primarily influenced by temperature. Utilizing zeolite for dehumidification can enhance the rate of drying during the falling rate period.

Investigation on The Effect of Low Frequency Ultrasound on The Crystallization of a Pharmaceutical Compound L+ Ascorbic Acid

Sarra Guilane, Manel Nedjoua — Tue, 30 Apr 2024 15:24:35 +0700

One of the most crucial processes in the chemical processing industry is crystallization, which has the major challenge of producing solid products with the required purity and properties. The standard crystallization methods have various processing limitations; hence, research into alternative methods like ultrasonic-assisted crystallization has been at the forefront. The present work investigates the application of low-frequency ultrasound irradiation (40 kHz) for improving the cooling crystallization of ascorbic acid. The impact of ultrasonic irradiation on crystal size, shape, and induction time has been studied, and a comparison with the conventional method has been made. The standing time had a minor effect on particle size on average, while the initial temperature had a far more significant impact. Photographic analysis using image-analysis software indicated that when ultrasound was applied to the saturated solutions, the resulting crystals were smaller and more uniform in size and shape. The resultant crystal grows predominantly in a single direction, resembling thin prisms. The use of ultrasound was also shown to reduce the induction time significantly. This ultrasonic impact is stronger at lower initial temperatures. Indeed, the smallest induction time of 300 s was obtained for sonicated solutions at an initial temperature of 65°C and ultrasonic power of 250 w. When different levels of ultrasonic power dissipation were tested, it was established that the time required for the first nuclei to appear decreased as the power increased. There was, nevertheless, a marginal impact on average crystal size.

Dehydration Impact on Antioxidant Potential and Phenolic content of Backhousia citrodora leaves

Ainaa Abdul Kahar, Sze-Pheng Ong, Nicholas J. Watson, Chung-Lim Law — Tue, 30 Apr 2024 15:25:11 +0700

The most popular method for food preservation is dehydration. In order to enhance the overall quality and prolong the longevity of herbal products, it is imperative to carefully choose optimal dehydration conditions. The dehydration of Backhousia citriodora, also known as lemon myrtle leaves (LML), was conducted via three distinct techniques: conventional dehydration at temperatures of 40, 50, and 60°C (referred to as CD40, CD50, and CD60, respectively); vacuum dehydration at the same temperature as conventional dehydration with a pressure of 50 mbar; and heat pump dehydration at a constant temperature of 45°C. The antioxidant capacities, specifically the radical scavenging activity (DPPH) and ferric reducing antioxidant power (FRAP), along with the total phenolic content (TPC), were evaluated. HPD samples came up second to VD samples in terms of TPC retention, DPPH activity, and FRAP test, whereas CD samples had the lowest biochemical content across all dehydration conditions. The TPC and antioxidant activity in the CD sample exhibited a substantial reduction as the dehydration temperature increased. After dehydration, the CD60 sample had the largest reduction in TPC, DPPH, and FRAP values. Maximising the retention of biochemical content is of utmost importance in post-harvest processing as it serves as an indicator of greater retention. Therefore, the selection of appropriate dehydration techniques and conditions is critical in achieving this objective.

Catalytic Cracking of Oily Sludge using Nickel Metal Catalyst Embedded in Silica Derived from Adsorbent in a Gas Process Plant

Novita Jayanti, Nazarudin, Panut Mulyono — Tue, 30 Apr 2024 15:25:43 +0700

Abstract. One of the Oily Sludge (OS) recycling methods is through catalytic cracking. This process involves the reaction breaking down large molecules into smaller ones with the help of a catalyst. Nickel (Ni) metal is often used as a catalyst because it can increase fuel liquid yield while reducing the coke formation. To enhance its performance, Ni metal can be embedded in a carrier material like Silica to form the Ni-Silica catalyst. In this research, OS sourced from a Gas Process Plant is treated with catalytic cracking using Ni-Silica, where the Silica used is derived from an Adsorbent activated with NaOH. Optimization of the cracking conditions is carried out using Response Surface Methodology (RSM) with a Box-Behnken design. The optimized cracking reaction conditions include temperature (713 K, 723 K, and 733 K), time (50 min, 60 min, and 70 min), and catalyst-to-OS ratio of 1:5, 1:6, and 1:7. Statistical analysis indicates that the relationship between the reaction condition variables and the Oil Liquid Product (OLP) falls into the moderate category, as shown by the coefficient of determination (R²) of 0.5. The calculated F-value for the deviation from the mathematical model is smaller than the F-Table value (9.2) at both 5% and 1% significance levels, with a value of 0.6. This indicates that the mathematical model generated can be accepted as the mathematical model within the range of reaction conditions in this study. Calculus analysis reveals that the optimum reaction conditions are a temperature of 717.34 K, a time of 58.58 min, and a catalyst-to-OS ratio of 1:6, 15. Canonical analysis indicates that for OLP, λ₁= [-12.38], λ₂= [-2.27], and λ₃= [4.50], where lambda values indicate that the most sensitive response surface parameter for OLP is temperature, followed by the catalyst-to-sample ratio, and the least sensitive is reaction time.

Keywords: Catalytic Cracking, Ni Metal, OS, RSM, Silica

Quality Improvement of Kesambi-Seed Oil using Free Fatty Acids and Hydrogen Cyanide Adsorption

Dwi Ardiana Setyawardhani, Diah Sri Umpati, Yudi Eka Fahroni — Tue, 30 Apr 2024 15:26:19 +0700

Kesambi-seed (Schleichera oleosa) is an Indonesian potential feedstock to produce vegetable oil for energy resources and oleochemicals. Crude Kesambi-seed oil (KSO) contains 8.43% free fatty acids (FFA) and 128 ppm hydrogen cyanide (HCN), which exceeds the Indonesian National Standard (SNI) for refined oil. Purification process is needed for crude KSO to be high quality vegetable oil. This study aimed to improve the quality of KSO by reducing the FFA and HCN contents using adsorption. The adsorption equilibrium is also determined to obtain the equilibrium constants. The purification process was developed in 2 steps, i.e., degumming and adsorption. Degumming was developed using 2.5% v/v H₃PO₄ to separate phospholipids/phosphatides in the crude oil, while adsorption using activated carbon was introduced to reduce the FFA and HCN contents. Kesambi-seed oil purification using activated carbon adsorption could be used as one-step refining for bleaching and reducing FFA and HCN. More adsorbent is needed to reach the FFA standard for the shorter adsorption time. Adsorption using 10% activated carbon for 24 hours reduced hydrogen cyanide up to 36 mg/kg oil, lightened the oil color, and achieved the highest yield (74.62%). Meanwhile, the activated carbon concentration of 40% w/w for 96 hours obtained 0.16% FFA. All three parameters have fulfilled the Indonesian National Standard for refined vegetable oil. Furthermore, the Freundlich model best fits equilibrium adsorption of FFA in the KSO.

Enhanced Copper Ion Adsorption by Rice Husk and Sugarcane Bagasse-based Magnetic Nanoparticles Biocomposites

Tue, 30 Apr 2024 15:27:30 +0700

Rice husk and sugarcane bagasse are biomass waste by-products of agriculture activities. High cellulose content makes them a potential material to develop. Biomass utilization is more interesting to develop due to its high cellulose content and nature abundance. Cellulose from rice husk and sugarcane bagasse is utilized as fiber in producing magnetic biocomposites. The Biocomposites can adsorb Cu(II) ions in aqueous solutions. A one-step solvothermal reaction was used to synthesize biocomposites. The amine functionalization on biocomposites was also studied for adsorption performance. The magnetic particle was generated on the surface of fiber and verified by XRD as Fe₃O₄. Amine group on biocomposites is also found on 570 cm^-1 and 1636 cm⁻¹ peaks for Fe-O bonds and N-H bending, respectively. Batch isothermal adsorption employing magnetic biocomposites has optimal conditions for Cu(II) ions adsorption at pH 5 for 60 minutes, with an adsorption capacity of 118.26 mg/g. The reusability of biocomposites for the next run showed a good performance at 3^rd repetitions with only a decrease in adsorption capacity of 8.81%. The rice husk and sugarcane bagasse-based magnetic nanoparticles biocomposites can adsorb Cu(II) ions and potential material to develop for wastewater treatment.

Facilitating Ulvan Extraction from Ulva lactuca via Deep Eutectic Solvent and Peracetic Acid Treatment

Tue, 30 Apr 2024 15:27:58 +0700

Ulva lactuca is a green seaweed and commonly referred to as sea lettuce and contains sulphated polysaccharides that have biological activity. Strong acids (HCl) and strong bases (NaOH) are commonly used as solvents in the conventional extraction process for ulvan, despite its lack of ecological sustainability. Deep Eutectic Solvent (DES) is an alternative to ulvan extraction solvent which is more environmentally friendly and has low toxicity. Ulvan extraction using DES with a temperature of 85-95ºC for 1 hour, and adding 2% peracetic acid pretreatment, 0.1%, 0.5%, and 2% peracetic acid posttreatment were conducted. Peracetic acid pre- and post-treatment (PAA) was carried out with a 1:10 (w/v) ratio at room temperature for 30 minutes. This study aims to optimize the use of DES in ulvan extraction with pre- and post-treatment of ulvan quality. The analysis performed included moisture content, yield, functional groups, sulphate content, and color. The test results revealed that ulvan treated with 2% PAA pretreatment had the highest moisture content and sulphate content, at 18.71% and 33.39%, respectively, while ulvan treated with 0.1% PAA posttreatment had the highest yield, at 41.96%. The addition of peracetic acid concentration can increase the color quality of the ulvan. PAA pre- and post-treatment had a significant effect on all ulvan quality parameters.

Studies on Encapsulation of Gas Releasing Agent in Ca-Alginate Beads and Controlled Release Pattern of the Beads

Yee Ming Peh, Boon Beng Lee, Nguyen Thi Le Lien — Tue, 30 Apr 2024 15:28:30 +0700

Calcium alginate beads have been used to control release gases and volatile compounds for agricultural applications, drug delivery, waste treatment, and food product enhancement. The release rate of the gas and vapor depends on the diffusion of gas and vapor through the Ca-alginate gel matrix. However, the knowledge about the effect of process variables on the diffusion rate of gas and vapor still needs to be improved. Therefore, this study aims to investigate the effect of alginate concentration, gas release agent concentration, and bead size on the concentration of gas released from Ca-alginate beads. In this study, calcium carbonate was used as the model gas release agent, encapsulated in Ca-alginate beads to release carbon dioxide when the beads reacted with an acetic acid solution. The results showed that the concentration of carbon dioxide released by the beads depended on the bead diameter. The gas release rate was increased when the diameter of the beads was increased. The total amount of gas produced by the large beads was observed to be higher than that of small beads. Compared to small beads, large beads take longer to react completely to produce carbon dioxide gas. It was also found that the amount of carbon dioxide produced by the Ca-alginate beads was inversely proportional to alginate concentration but directly proportional to calcium carbonate concentration. The results indicated that the gas diffusion rate of the Ca-alginate beads can be tailored by adjusting the process variables of the Ca-alginate bead encapsulation process.

Biotechnological Biosuccinic acid (Bio-SA) production from green microalgae Chlorella sp. hydrolysate: Synergistic effect of agitation and substrate concentration assessment using RSM

Tue, 30 Apr 2024 15:28:57 +0700

This paper evaluates the potential of Chlorella sp. microalgae biomass as a feedstock for biosuccinic acid (bio-SA) production via the fermentation process. In this study, the biomass was pretreated and hydrolyzed using a mild acid before being fermented with Actinobacillus succinogenes. The influence of the initial biomass concentration and agitation rate on bio-SA production during batch fermentation was evaluated using a Response Surface Methodology (RSM) design. The results of the study indicated that Chlorella sp. microalgae biomass contained various types of sugars, with glucose identified as the dominant reducing sugar in the Chlorella sp. hydrolysate. According to the RSM analysis, the study showed that changes in the initial biomass concentration and agitation rate could significantly affect bio-SA production from Chlorella sp. hydrolysate. The highest bio-SA concentration of 14.56 g/L with a yield of 0.62 g/g was achieved when fermentation was performed using 10% (w/v) biomass at 150 rpm. Therefore, this study suggests that Chlorella sp. hydrolysate can be an alternative and renewable feedstock for efficient bio-SA production.

Pigment Extraction Method for Anthocyanin Natural Resources in Indonesia: A Review

Yuyun Yuniati, Kejora Handarini, Mahfud Mahfud — Tue, 30 Apr 2024 15:26:56 +0700

Anthocyanin is the pigment that still attracts attention from food industries because of its abundance in Indonesian plants. Anthocyanins are produced in a variety of colors with unique stability properties. Through a systematic review, this review studied 40 scientific reports conducted in Indonesia over the last 10 years. The research objects included fruits, flowers, seeds, peels, and roots from the islands of Java, Sumatra, Kalimantan, Sulawesi, and Nusa Tenggara. Several methods are used to extract solvent-based anthocyanin compounds, including maceration, microwave, and reflux-soxhlet extraction. Microwave extraction, including ultrasonic extraction, is recommended for anthocyanin extraction. Spectrophotometry with the pH differential method was chosen as the anthocyanin quantification procedure, using 500 and 700 nm wavelenghts.