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A Leak Free Phase Change Materials with Enhanced Thermal Buffering Properties by TiO2/Biochar Ariyanti, Dessy; Huda, Khoirul; Bayu Samudra, Muhammad; Lesdantina, Dina; Adi Saputra, Erwan; Hamzah, Fazlena
Reaktor Volume 23 No.3 December 2023
Publisher : Department of Chemical Engineering, Faculty of Engineering, Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/reaktor.23.3.116-126

Abstract

A leak free organic phase change material of palmitic acid with enhanced thermal buffering properties was synthesized by simple chemical TiO2/biochar encapsulation process. By utilizing the optimum amount of TiO2 as an encapsulation agent the minimalization of leakage phenomena during the phase change process can be achieved with the value 20-25% of weight loss. Furthermore, the additional sugar cane bagasse-based biochar that was introduced to the encapsulation system acts as a support matrix that enhances further the leakage properties into free leak category with the percentage of weight lost 1.1-1.4 %. Moreover, the introduction of sugar cane bagasse-based biochar in the encapsulation system of the palmitic acid PCM can improve the thermal buffering properties by keeping a package box temperature in the range of 2-80C for more than 20 h by means small increment of temperature 0.72oC/h.  Keywords: PCM, encapsulation, palmitic acid, thermal buffering, leakage
Characteristics of all organic redox flow battery (AORFB) active species TEMPO-methyl viologen at different electrolyte solution Ariyanti, Dessy; Purbasari, Aprilina; Hapsari, Farida Diyah; Saputra, Erwan Adi; Hamzah, Fazlena
International Journal of Renewable Energy Development Vol 13, No 5 (2024): September 2024
Publisher : Center of Biomass & Renewable Energy (CBIORE)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.61435/ijred.2024.60155

Abstract

The practice of using wind and solar energy to generate electricity represents a solution that would be beneficial for the environment and ought to be explored. However, in order to ensure users' stability and continuous access to electricity, the increasing usage of renewable energy needs to align with the advancement of energy storage technologies. Redox flow batteries, which use an organic solution as the electrolyte and a proton exchange membrane as an ion exchange layer, are currently the subject of extensive research as one of the alternative renewable energy storage systems with the benefit of a techno economy. This study investigated the solubility of organic solution, namely 2,2,6,6-Tetramethylpiperidinyloxy or 2,2,6,6-Tetramethylpiperidine 1-oxyl (TEMPO) and methyl viologen (MV) in various essential electrolyte solutions such as NaCl, KCl, KOH, and H2SO4 that can be used as electrolytes of all organic redox flow battery (AORFB) system to produce high energy density and charging and discharging capacity. The result shows the optimum condition for effective charge transfer in AORFB is TEMPO catholyte and MV anolytes in the 0.08 M H2SO4electrolyte solution. Additionally, a correlation between the acquisition of electrolyte solutions on TEMPO catalyst and MV anolytes was discovered by the data. Electrolyte solution can improve electrical conductivity in TEMPO solution, which in turn can improve the efficiency of AORFB charging and discharging. Contrarily, MV anolytes exhibit a different pattern where the addition of electrolyte solutions reduces their electrical conductivity. RFBs systems with the aforementioned catholyte and anolyte can be used to store solar energy with a maximum current of 0.6 A for 35 minutes. Storage effectiveness is characterized by a change in colour in the catholyte and anolyte. The findings firming the possibility of using AORFB as one of the alternative energy storage systems that can accommodate the intermittence of the renewable energy input resource. 
Enzymatic Transesterification Using Different Immobilized Lipases and its Biodiesel Effect on Gas Emission Mohamad Nor, Nur Fatin Syafiqah; Veny, Harumi; Hamzah, Fazlena; Muhd Rodhi, Miradatul Najwa; Kusumaningtyas, Ratna Dewi; Prasetiawan, Haniif; Hartanto, Dhoni; Sulaiman, Sarina; Sazali, Rozana Azrina
Bulletin of Chemical Reaction Engineering & Catalysis 2024: BCREC Volume 19 Issue 2 Year 2024 (August 2024)
Publisher : Masyarakat Katalis Indonesia - Indonesian Catalyst Society (MKICS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.9767/bcrec.20143

Abstract

Biodiesel, a third-generation bio-fuels, offering several advantages over regular diesel fuel. Waste cooking oil (WCO) emerges as an ideal feedstock due to its availability and easy accessibility. In this work, biodiesel is utilized from two different types of immobilized lipases: Rhizomucor miehei lipase (RMIM) and Candida antarctica lipase B (CALB). The impact of the molar ratio of oil to methyl acetate (1:3-1:12) was evaluated for both lipases, and the resultant biodiesel was tested in diesel engine. The enzymatic transesterification was carried out in ultrasonic assistance and the results showed that the greatest yield of 81.20% at 45℃, using CALB as a biocatalyst, 1.8% (w/v) lipase and oil to methyl acetate molar ratio of 1:12 within 3 hours. Triacetin, by-product was determined their concentration for each molar ratio and analyzed using FTIR range of 500cm-1 to 4000cm-1, revealing a significant absorption peak at 1238.90cm-1. Biodiesel was blended with commercial diesel fuel in varying quantities of 7, 10, and 20% by volume (B20). The results were compared to Industrial Diesel Fuel 7% (B7) and Commercial Diesel Fuel 10% (B10). NOx and CO2 emission drops as the percentage of diesel/biodiesel blends increases, supporting WCO as a cost-effective biodiesel feedstock with low petrol pollution.