DEVELOPMENT OF BIOSILICA PRODUCTION TECHNOLOGY FROM BAMBOO LEAVES WITH ENERGY EFFICENCY

• Main Author: Ramli, Yusrin
• Format: Theses
• Language: Indonesia
• Subjects: Teknik (Rekayasa, enjinering dan kegiatan berkaitan)
• Online Access: https://digilib.itb.ac.id/gdl/view/64877
• Institution: Institut Teknologi Bandung

Silica is one of the important chemicals whose use is very large in industry and in everyday life. Silica can be obtained from biomass such as bamboo leaves. Process required to obtain silica from biomass via extraction pathway. This extraction process involves biomass ash and alkaline solvent. There are several steps needed to produce silica from biomass (biosilica), namely the initial processing stage, the extraction stage, the gelation stage, and the smoothing stage. The initial processing stage is carried out to wash the biomass and ash, so that good quality biosilica can be obtained. After going through the initial processing stage, the biomass ash was extracted with NaOH. The extraction process that occurs is a reaction process between the silica in the ash and the solvent, so that at the end of the process the Na-silicate extract is obtained. The Na-silicate obtained was then gelled. This gelation process involves HCl so that a reaction occurs between Na-silicate and HCl. The product of the reaction that occurs is a biosilica gel. After the gel is obtained, the gel is continued to the smoothing stage. Smoothing is carried out in the form of drying and grinding processes. The process is carried out to obtain biosilica solids, while the grinding process is carried out to convert biosilica solids into biosilica powder. After obtaining the biosilica powder, the physical properties of the biosilica were analyzed by using XRD, XRF, SEM, BET-BJH and PSA. This study was conducted to investigate the effect of acid washing on bamboo leaves, the effect of extraction duration with NaOH and the effect of the ratio of NaOH on bamboo leaf ash on the purity and biosilica recovery using the Box-Behnken method. In addition, the manufacture of biosilica is targeted to achieve nanoparticles that can be utilized in various fields such as the health sector, nanomaterials, comectics, etc. From the results of this research, the smallest biosilica size is around 160 nm, with a surface area of 328.6 m2/g. The optimum conditions obtained were in a state without acid leaching, a solvent to feed ratio of 5, and an extraction time of 1.5 hours. In this study, an increase in the production scale from a 500 mL reactor to 5 L was also carried out. This upscaling method is conducted by maintaining the hydrodynamic properties of the fluid in the reactor such as the Reynolds number and Froude number which are dimensionless numbers. This dimensionless number is maintained by adjusting the stirrer speed in the reactor. In addition, the ratio of reactor height to reactor diameter is also maintained. Thus, the 5 L capacity reactor has a height of 26.3 cm and a diameter of 17.5 cm and a stirring speed of 44 rpm. The performance of the reactor that was built was able to provide a product gain of 29.8% and a purity of 74%. In addition, there are a simulation study in the form of energy utilization and extraction of biosilica from bamboo leaves using mass and energy balance software such as Aspen Plus®. The simulation was carried out on the basis of 2 tons of bamboo leaves/day. This simulation is divided into two main processes, namely the power generation process and the biosilica extraction process. The electricity generation process was studied using an organic Rankine cycle system with refrigerant R-134a as working fluid. This simulation uses bamboo leaf burning chimney gas which is then used to heat the media fluid in the form of vegetable oil. After that, vegetable oil is used to exchange heat to the refrigerant. The refrigerant that has been heated to high pressure conditions and is supersaturated is expanded in the turbine to obtain electrical energy. From the results of the study of the power generation system, the net electricity obtained can be used to meet the electricity needs of 24 houses in rural areas. In addition, the ash obtained in the power generation process is used as feed for the biosilica extraction process. From the results of this study of the extraction process, the biosilica that can be obtained is 3.3 kg/hour.