Utilization of Biomass Ash Waste For Geopolymer Production

• Main Author: Satriya Agung - Nim: 13014084, Dendi
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/26477
• Institution: Institut Teknologi Bandung

<p align="justify">Development is one of the vital points that are being intensively conducted to improve the quality of facilities and infrastructure in Indonesia . This is a problem because the cement industry contributes 5-7% of the CO2 emissions in the earth, and the cement industry is an industry with high energy consumption with the need for a system to generate clinker at a temperature of 1450°C. Therefore, it takes alternative building materials that are more environmentally friendly so that the use of cement as the main material of construction can be reduced. One alternative material is geopolymer. Geopolymer is an inorganic silica-alumina polymer activated by concentrated alkaline solution. Sources of silica-alumina for geopolymer raw materials can be obtained from various industrial wastes, such as ash and slag, then also from activated natural ingredients such as metakaolin. The objective of this study was to determine the effect of raw material composition on the compressive strength and characterize the resulting geopolymer morphology. <br /> <br /> <br /> The research is carried out with three main working procedures, there are ash preparation process, making geopolymer paste until the maturation stage and geopolymer characterization. The ash preparation stage consists of ash temperature analysis of the TGA method, followed by biomass burning and analysis of the resulting ash composition. Variations of ash compositions were performed using a simplex-centroid design mixture design. The geopolymer preparation was carried out by mixing the raw material according to the composition variation with sand and KOH 10 M solution, the mixture was molded and stored at curing temperatures (60ºC) and for each variation with a 14 day storage time. After the geopolymer is produced, a compressive strength test and SEM to geopolymer are applied. In addition, an FTIR test was also conducted to identify the geopolymer and XRD chemical bonds to identify the phase composition of the geopolymer. <br /> <br /> <br /> Based on the compressive strength test, all geopolymer variations meet the specified standard above 4,67 Mpa at 14 production days with a maximum compressive strength of the product is 10.46 MPa for the bagasse geopolymer and the minimum compressive strength is 7.25 MPa for the coco shell geopolymer . Whereas, according to the SEM test, microstructures of the geopolymer surfaces contain geopolymer gel, swelling, unreacted ash and voids. FTIR testing of geopolymer paste samples shows that there is an unsymmetrical Si-O-Al-O bond which indicates a geopolymerization reaction. From the XRD test results indicate that most of the geopolymer structure is amorphous.<p align="justify"> <br />