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The construction industry represents the largest energy-consuming sector globally, primarily due to its substantial operational processes power demand. To address this, there has been an increased emphasis on using materials capable of absorbing and storing heat as alternative energy storage in buildings. Phase Change Materials (PCMs) demonstrate this capability, harnessing the latent heat principle to absorb surplus heat energy and subsequently release it in times of deficiency. This study examines the mechanical and thermal properties of wall cladding materials integrated with PCMs, specifically beef tallow and rice husk charcoal. These composites were produced via direct incorporation, with rice husk charcoal weight fractions of 8, 10, and 12 %. This approach resulted in weight fractions of 28, 30, and 32 % in the plaster layer material. Fourier Transform Infrared Spectroscopy (FTIR) tests confirmed the PCM composite's chemical compatibility across all its components, with the composite morphology appearing as microcapsules. In terms of thermal conductivity, the addition of rice husk charcoal to beef tallow enhanced the PCM composite's performance. This enhancement indicated that approximately 10 % of rice husk charcoal weight fraction could be successfully incorporated into the plaster layer material without leakage. At an ambient temperature of 45 ℃, a plaster composite with 30 wt. % PCM met the standard compressive strength for plaster coating. Furthermore, it was found that this composite could reduce the temperature by 2.4 ǃ. The results concluded that beef-tallow PCM exhibits promising potential as a heat storage system for buildings, contributing to energy conservation in the construction industry. [ABSTRACT FROM AUTHOR]

In the esterification-transesterification method, a catalyst increases the reaction rate to produce biofuel (biodiesel). This study investigated the use of a solid catalyst consisting of green nano-CaO as a support modified by KOH solution and sulfated TiO2 for converting waste frying oil (WFO) into biodiesel in a single-step esterification-transesterification reaction. With nano-CaO prepared from eggshell, a green nanocomposite of CaO/K-sulfated TiO2 was synthesized by physical mixing and the hydrothermal method. Crystallite size, surface basicity-acidity, functional groups, and surface morphology were used to characterize the solid catalyst, which was then tested for its ability to convert WFO into biodiesel. The results showed that green-CaO had nanoparticles (93.13 nm) and that its size decreased after being modified with KOH (46.43 nm) and sulfated TiO2 (62.10 nm), with CaO/K-sulfated TiO2 being the optimum surface acidity-basicity. The optimum conditions for conversion were found to be 5% catalyst concentration to oil, a molar ratio of methanol/oil of 9:1, and a reaction time of 60 minutes, which resulted in a biodiesel mass yield of 94.17% higher than CaO/K (67.88%). WFO was successfully converted into fatty acid methyl esters, according to the GC-MS analysis of the biodiesel. The synthesized solid catalyst has the potential to be used in single-step esterification-transesterification reactions to produce biodiesel. [ABSTRACT FROM AUTHOR]