Synthesis of Silica Powder from Sugar Cane Bagasse Ash and Its Application as Adsorbent in Adsorptive-distillation of Ethanol-water Solution

In this study, sugarcane bagasse ash (SCBA) as waste from sugarcane factory was extracted into silica powder. This powder was then used as adsorbent for ethanol purification. Prior to used, the SCBA was washed using HCl solution. The silica extraction was conducted using various NaOH concentrations (0.5; 1; 1.5 and 2 mol/L) as well as extraction times (30, 60 and 90 minutes). After that the mixture was precipitated using HCl solution. The solution was filtrated through a paper filter and its solid particle was dried until its weight was constant. The particle was grounded and sieved using 18 mesh sieves. The silica powder obtained was analysed using FTIR and its result showed that the powder has silica functional groups. The silica yield increases with increasing of concentration of NaOH solution as well as extraction time. The highest silica yield (45.5% w/w) was achieved at 2 mol/L NaOH solution at 90 min. The surface area, pore diameter, and pore volume of silica powder were measured to be 407 m2/g, 3.81Å, and 2.76 dm3/g, respectively. From application of silica powder as adsorbent in adsorptive-distillation, ethanol concentration can reach 99.3% w/w which indicates azeotropic point can be passed

Synthesis of Silica Powder from Sugar Cane Bagasse Ash and Its Application as Adsorbent in Adsorptive-distillation of Ethanol-water Solution

In this study, sugarcane bagasse ash (SCBA) as waste from sugarcane factory was extracted into silica powder. This powder was then used as adsorbent for ethanol purification. Prior to used, the SCBA was washed using HCl solution. The silica extraction was conducted using various NaOH concentrations (0.5; 1; 1.5 and 2 mol/L) as well as extraction times (30, 60 and 90 minutes). After that the mixture was precipitated using HCl solution. The solution was filtrated through a paper filter and its solid particle was dried until its weight was constant. The particle was grounded and sieved using 18 mesh sieves. The silica powder obtained was analysed using FTIR and its result showed that the powder has silica functional groups. The silica yield increases with increasing of concentration of NaOH solution as well as extraction time. The highest silica yield (45.5% w/w) was achieved at 2 mol/L NaOH solution at 90 min. The surface area, pore diameter, and pore volume of silica powder were measured to be 407 m2/g, 3.81Å, and 2.76 dm3/g, respectively. From application of silica powder as adsorbent in adsorptive-distillation, ethanol concentration can reach 99.3% w/w which indicates azeotropic point can be passed

Comparative Study on the Various Hydrolysis and Fermentation Methods of Chlorella vulgaris Biomass for the Production of Bioethanol

One of the microalgae that can be potentially used to produce bioethanol is Chlorella vulgaris, as it is rich in carbohydrates. However, the carbohydrates in C. vulgaris cannot be converted directly into ethanol. This study aimed to investigate the chemical and enzymatic hydrolysis of C. vulgaris, which is subsequently followed by fermentation. The catalysts used in the chemical hydrolysis were hydrochloric acid, sodium hydroxide, and potassium hydroxide, while the enzymes used were the mixture of alpha-amylase + glucoamylase, alpha-amylase + cellulase, and alpha-amylase + glucoamylase + cellulase. The hydrolysate obtained from chemical hydrolysis was fermented through Separate Hydrolysis Fermentation (SHF), while the one from enzymatic hydrolysis was fermented through Simultaneous Saccharification and Fermentation (SSF), in which both processes used S. cerevisiae. After undergoing five hours of enzymatic hydrolysis (using alpha-amylase + glucoamylase), the maximum glucose concentration obtained was 9.24 ± 0.240 g/L or yield of 81.39%.  At the same time and conditions of the substrate on chemical hydrolysis, glucose concentration was obtained up to 9.23 + 0.218 g/L with a yield of 73.39% using 1 M hydrochloric acid. These results indicate that chemical hydrolysis is less effective compared to enzymatic hydrolysis. Furthermore, after 48 hours of fermentation, the ethanol produced from SHF and SSF fermentation methods were 4.42 and 4.67 g/L, respectively, implying that producing bioethanol using the SSF is more effective than the SHF method