ASEAN Journal of Chemical Engineering

Gelatinization Behavior, Morphological, and Chemical Properties of Flour of Cassava, Sago, and Wheat

Setya Budi Muhammad Abduh , Nurwantoro, Sri Mulyani, Sri Hestiningsih Widiyanti — Tue, 31 Dec 2024 13:12:45 +0700

Gelatinization is an important property tailoring the functionalities of starch present in flour. This study aimed to investigate the gelatinization properties of Indonesian cassava and sago flours, namely tapioca, modified cassava flour, modified cassava starch, sago starch, and from soft and hard wheat. The gelatinization properties were investigated based on pasting and thermal properties, which were analyzed by means of a rapid visco analyzer (RVA) and differential scanning calorimetry (DSC), respectively. In addition, the morphological property was investigated using polarized microscopy, and chemical properties, namely solid, protein, lipid, ash, and crude fiber, were analyzed respectively using thermogravimetry, Kjeldahl, solvent extraction, and acid hydrolysis. It is found that flours of cassava, wheat and sago show pasting temperature (°C) of 69 – 71, 83 – 85, and 74; peak viscosity (cp) of 5400 – 5800, 2400 – 2700, and 2065; breakdown viscosity (cp) of 2600 – 4000, 900 – 1200, and 1493, setback viscosity (cp) of 1000 – 1500, 1000 – 1100, and 1063, final viscosity (cp) of 2800 – 3100, 2500 – 2700, and 1635. For gelatinization temperature (°C), they show onset temperature of 66 – 69, 54 – 60, and 72.04; peak temperature of 70 – 74, 60 – 64, and 75.93; conclusion temperature of 78 – 81, 66 – 69, and 80.99; and enthalpy change (J/g) of 8 – 12, 3 – 6, and 9.78. It can be concluded that flour and starch of cassava show the highest pasting profile (temperature and viscosity), while sago shows the lowest among the samples. Sago shows the highest gelatinization temperatures but the lowest enthalpy among samples. Starches of cassava show a round granular shape, smaller than wheat, while sago shows an oval shape. Considering the chemical composition, higher protein leads to higher pasting temperatures, and higher amylopectin content leads to higher peak and breakdown viscosities that might influence the gelatinization properties of flours.

Optimizing Crystal Size Distribution Based on Different Cooling Strategies in Batch Crystallization Process

Siti Zubaidah Adnan, Noor Asma Fazli Abdul Samad — Tue, 31 Dec 2024 13:14:10 +0700

Crystal size distribution (CSD) is an essential criterion for determining the production of high-quality crystals since it influences the efficiency of the crystallization process. Producing specified CSD in the crystallization process represents a main challenge as it depends on temperature control, which indirectly regulates the solution’s concentration and affects the crystal’s evolution. Different temperature profiles may influence the distribution of crystal products, and a suitable optimization algorithm is required to produce an optimum temperature trajectory that produces the desired CSD. Thus, this study aims to maximize the CSD of the grown seed crystals while minimizing the nucleus-grown crystals by employing the best optimization algorithm for the potash alum crystallization process. The crystallization process was developed and simulated in Matlab software using a potash alum in the water system. Four optimization algorithms were proposed with different objective functions, such as maximizing mean crystal size (I), minimizing coefficient of variation (II), minimizing nucleus-grown crystals (III), and maximizing CSD (IV). Based on the simulation results, optimization IV, which maximizes CSD, performs best with a large mean crystal size of 490 µm. Furthermore, the number of fine crystals was among the lowest at a volume distribution of 0.00071 m³/m compared to the linear profile at 0.00191 m³/m. Optimization IV employs a dissolution strategy, which manipulates two quality specifications in one algorithm (size of crystals and number of fines), which is considered the best optimal cooling profile for seeded batch crystallization by maximizing CSD and minimizing the generation of nucleus-grown crystals.

Optimization of α-Amylase Extraction Parameters of Rice Bran Oil (RBO) by Response Surface Methodology

Tue, 31 Dec 2024 13:15:03 +0700

Rice bran oil (RBO) is known as a vegetable oil that has various health benefits; it is extracted from the outer layer (bran) of rice grains using an enzymatic extraction process (Aqueous Enzymatic Extraction, AEE) in the form of α-amylase. The research goals of this study are to determine the optimal processing condition for RBO extraction with α-amylase. The processing parameters were optimized using Response Surface Methodology (RSM) in conjunction with Central Composite Design (CCD). RBO extraction with α-amylase parameters such as the incubation temperature (A) 35, 50, and 65 ^oC and incubation time (B) 2, 3, and 4 hours to optimize the processing condition. RBO yield (%) and free fatty acid (FFA) were analyzed. A statistical model predicted that the highest conversion yield of RBO would be 1.533% at the following optimized reaction conditions: reaction temperature of 50 ^oC and time of 4.41 h. Experiments performed at the predicted optimum conditions yielded 1.663% better than the predicted value. A quadratic model was selected to estimate the RBO extraction with α-amylase based on the analysis of variance (ANOVA) of the findings from several models. The linear regression coefficient (R²) between experiments and different response values in the model was 0.97 for RBO yield and 0.8929 for FFA of RBO. The optimal conditions based on all process variables (incubation temperature of 51 ^oC and incubation time of 4 h) were determined by Derringer’s desired function methodology. Under the conditions mentioned, the yield and FFA of RBO were 1.6% and 7.3%, respectively. All the optimizing parameters and results were validated by regression analysis model fit data using p-value (<0.05), R² value (yield and FFA of RBO were 0.9749 and 0.8929), and desirability value (>0.05).

Effect of Some Mineralizers and Organic Acids on the Structural and Luminescence Properties of Zn2SiO4 : Mn Phosphor Synthesized at Low Temperature by Impregnation – Coprecipitation Method

Thi Thanh Nguyen, Xuan Thanh Le — Tue, 31 Dec 2024 13:16:13 +0700

Suitable mineralizers promote the formation of the desired phases upon sintering, and organic acids have reducing properties that make the Mn²⁺ ions more stable during synthesis. The purpose of this work is to study the effect of some mineralizers and organic acids as well as sintering temperature on the structural and luminescence properties of manganese-doped zinc orthosilicate phosphor, synthesized at low temperature by impregnation-coprecipitation method. Photoluminescence spectroscopy, XRD, SEM and EDS were used to investigate the samples. The results show that the most suitable mole ratio of the constituents in the precursor is: 1.97 Zn : 0.03 Mn : 1.0 SiO₂ : 0.03 H₃BO₃ : 0.03 CH₃COOH. During 45 minutes, the sample calcined at 700 ^oC is a bi-phase mixture of β-Zn₂SiO₄ and α-Zn₂SiO₄, emitting yellow light at 575 nm wavelength when excited by 254 nm UV radiation. Boric acid is the mineralizer for α-Zn₂SiO₄. At 800 ^oC, there is a phase transition from the orthorhombic β-Zn₂SiO₄ to the rhombo H. axes α-Zn₂SiO₄. The sample calcined at 900 ^oC is a single-phase zinc manganese borosilicate solid solution with rhombo H. axes structure of α-Zn₂SiO₄, consisting of fairly uniform spherical particles with size from 0.3-0.5 µm and emitting 525 nm green light with a luminescence intensity of 46% higher than that of the control sample. The resulting luminescent pigment has the potential for security applications.

Performance Recovery Following Upward and Downward Flushing of Up-flow Sand Filter

Farhana Abd Lahin, Abigail Bernardette Yong, Rosalam Sarbatly — Tue, 31 Dec 2024 13:17:12 +0700

The up-flow sand filter (USF) is an excellent alternative to conventional downward sand filters, reducing susceptibility to clogging. Two methods of cleaning the USF are upward flushing and downward flushing. The efficiency of both methods towards water quality was investigated by comparing the recovery of turbidity, total suspended solids (TSS), dissolved oxygen (DO), and pressure drop. The results obtained after upward flushing include turbidity levels of 22.64 NTU, TSS levels of 33.13 mg/L, DO levels of 4.78 mg/L (top layer), 5.20 mg/L (middle layer), and 4.20 mg/L (bottom layer), as well as a pressure loss recovery difference of 6.05 cm. Meanwhile, downward flushing obtained turbidity levels of 27.84 NTU, TSS levels of 34.5 mg/L, DO levels of 6.12 mg/L (top level), 6.38 mg/L (mid-level), and 5.48 mg/L (bottom level), as well as a pressure drop recovery difference of 12.87 cm. The ripening period of a filter refers to the stage where the sand filter matures and reaches its optimum filtration ability. In this research, the ripening period achieved after upward flushing was 11 hours, while after downward flushing was 8 hours. This was obtained by measuring the time it took for water parameters to stabilize after flushing. Overall results showed that upward flushing was more efficient due to higher turbulence during upward flushing, allowing contaminants to dislodge from gaps or surfaces of sand particles.

Utilization of Plastic Waste as an Alternative Fuel in Cement Industry for Improved Energy Sustainability

Ranoe Bramantiyo, Erna Lestianingrum, Rochim Bakti Cahyono — Tue, 31 Dec 2024 13:18:24 +0700

The cement industry primarily relies on fossil fuels, particularly coal, which carries a significant environmental impact and constitutes about 30 – 40% of the total production costs per ton of cement. Thus, prioritizing the reduction of both economic expenditure and environmental impact through diverse alternative energy sources becomes a crucial objective in the cement industry. With a target of incorporating 11% alternative fuels by 2025, PT Indocement Tunggal Prakarsa (ITP) Tbk unit Palimanan Cirebon has adopted plastic waste as an alternative fuel in its production process. This study aims to assess the energy contribution of plastic waste and its economic benefits. Based on 2022 data, the PT. ITP Palimanan unit utilized 796 tons/year of plastic waste as an alternative fuel, reflecting an annual increase of around 241%. The heating value of plastic waste was evaluated at 7234 kcal/kg to ensure the alternative fuel’s quality. Compared to low-grade coal like lignite coal, this plastic waste holds a higher heating value, resulting in additional advantages for the cement factory. Consequently, this program could substitute nearly 24,113 GJ/year of fossil energy. This utilization not only replaces fossil fuels but also combats marine pollution as the waste originates from the north coast of Java. Considering a coal price of approximately 82,767 IDR/GJ, this program can yield savings of almost 1.99 billion/year. Prioritizing process reliability and cement product quality can consistently encourage the development of more environmentally friendly cement products. Additionally, this program addresses society's waste problem by transforming it into a renewable energy source.

The Oxidation of Nanocellulose from Oil Palm Empty Fruit Bunch (OPEFB) by TEMPO/NaClO/NaBr

Annisa Amalia Ulfah, Muslikhin Hidayat, Rochim Bakti Cahyono, Teguh Ariyanto — Tue, 31 Dec 2024 13:20:14 +0700

One of the largest biomass wastes in Indonesia is oil palm empty fruit bunch (OPEFB), which produces thousands of tons of waste in a year. The value of biomass can be upgraded to nanocellulose-based adsorbents. Cellulose is extracted through three processes: delignification, bleaching, and hydrolysis. In this study, nanocellulose was oxidated with TEMPO (2,2,6- tetramethylpiperidine-1-oxyl radical)/NaClO/NaBr at pH 10 in a temperature room. The influence of oxidizer (NaClO 2, 4, 6, 8, and 10 mmol/gram) and catalysator (NaBr 25, 50, 100, 150, 200 mg/gram) in the formation of carboxylate groups and reaction time was studied. After the pretreatment process, cellulose content in the final product reached 61.8% with a crystallinity index of 58%. With lengths ranging from 127.4 nm to 512 nm and a diameter of less than 20 nm, nanocellulose is classified as cellulose nanofiber. Conductometry titration is used to find the carboxylate group formed on the nanocellulose surface. The highest carboxylate groups were found in 1,600 mmol/gram by adding 20 mmol/gram NaClO. As the addition of oxidants, degradation of nanocellulose occurred, which was indicated by a decrease in nanocellulose weight and shifting of function groups. All the reaction processes happened below 25 minutes, increasing the reaction rate by adding more than 50 mg/gram NaBr.

Effect of Operating Condition of Natural Dye Production from Red Spinach (Amaranthus Dubius ) using Solvent Extraction

Asdarina Yahya, Siti Nur Azeera Sulaiman, Maryudi Maryudi — Tue, 31 Dec 2024 13:21:16 +0700

Due to synthetic dyes’ health and environmental impacts, there is a growing demand for natural dyes as a sustainable alternative. This study investigates the production of natural dye from red spinach (Amaranthus dubius) using solvent extraction methods. The dominant pigment, betacyanin, was extracted and analyzed under various operating conditions. The effects of different solvents (water, ethanol, acetone, ethanol-water, and acetone-water), extraction temperatures (20°C, 40°C, 60°C, and 80°C), and extraction times (30, 60, 90, and 120 minutes) on dye yield were evaluated. The highest yield of 34% was achieved using acetone water (50:50) at 60°C for 60 minutes. The extracted dyes were analyzed using a chroma meter. These findings suggest optimal conditions for maximizing dye yield from presenting a viable alternative to synthetic dyes at 60℃ and 60 minutes can get ca. 34% of yield. FTIR analysis showed that the extracted natural dye contains antioxidants compared with synthetic dye.

Synthesis of Polyglycerol under Superbasic Conditions to Reduce the Severity of the Reaction Conditions

Malikul Mulki Anas Suyadi, Giovani Andre Halim, Jenny Rizkiana — Tue, 31 Dec 2024 13:22:13 +0700

The increasing biodiesel production in Indonesia will affect the supply of glycerol because it is a by-product of the transesterification reaction. Abundant glycerol can provide added value if further processed into higher-value products such as polyglycerol. Polyglycerol is made from the polymerization of glycerol with the help of an alkaline catalyst, such as KOH, but the temperature and reaction time used are very high and long. Therefore, this study aims to increase the conversion of glycerol by adding DMSO to the glycerol and KOH solution to increase the basicity of the mixture, increase the polymerization rate, and decrease the temperature and reaction time. The conversion of glycerol to polyglycerol with the addition of 10 mL DMSO to the KOH and glycerol mixture, giving a DMSO to KOH-glycerol volume ratio of 1:5, with a reaction time of 2 hours and a reaction temperature of 140-150°C was 77%, compared to without the addition of KOH which required a reaction time of 8 hours and a reaction temperature of 260-280 °C resulting in a glycerol conversion of 99%. Adding DMSO, with constant KOH-glycerol volume, affects the polymerization reaction because compared to adding 5 mL DMSO (volume ratio of 1:10), the resulting glycerol conversion is 16%. For the effect of reaction time on the results of glycerol polymerization, 5 mL DMSO shows that the longer the time, the more polyglycerol formed can depolymerize into short-chain oligomers or back into glycerol. The optimum reaction time for 5 mL DMSO is 6 hours because the glycerol conversion is 63%, producing diglycerol and triglycerol with 30% and 17% selectivities, respectively.

Sulphurization of Kapok (Ceiba Pentandra ) Seed Oil via H2S Bubbling Under UV Radiation and The Product’s Performance as Extreme Pressure Additives for Lubricant

Sukirno Sukirno, Cleo, Devan — Tue, 31 Dec 2024 13:23:04 +0700

In this research, extreme pressure additive (EP additive) for lubricants was manufactured from Ceiba pentandra seed oil (kapok oil) via sulfurization reaction at a low temperature (50°C) by using a photochemical reactor under UV-radiation (254 nm). The sulfurization process was conducted by recirculating bubbling H₂S gas through kapok oil filled in a glass chamber. The sulfurization reaction has been proven successful, as shown from the FTIR spectrum of the sulfurized kapok oil, where carbon-sulfur bond (C-S) vibration appears at a peak of 581 cm^-1. It was also found that within 20 hours, the recirculated-bubbling sulfurization produced sulfurized kapok oil with a sulfur content of 32,682 ppm, viscosity of 72.17 cSt, and density of 0.92 g/cm³. The product was then used as an EP additive by mixing it with mineral oil and testing it using a 4-ball wear tester. The mineral oil containing sulfurized kapok oil 10% v/v or equal to sulfur content 3,268 ppm reduced wear amount by 98%. Results of corrosion tests via copper strip corrosion ASTM D130 showed that the copper strip’s color only had level 1a, meaning that mineral oil containing 10% Kapok oil as EP additives is not corrosive.