CONVERSION OF Navicula salinicola STRAIN NLA SILICA INTO ALUMINOSILICATE FOR A CATALYTIC REACTION OF ETHYL TERT-BUTYL ETHER SYNTHESIS

• Main Author: SAPITRI (NIM:20516047), RISKA
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/30534
• Institution: Institut Teknologi Bandung

The cell wall of diatom Navicula salinicola contains nanopore silica with a unique <br /> <br /> morphology, high mechanical strength, and large surface area. The diatom cell wall <br /> <br /> as been applied for a gas sensor, microfilter, drug delivery agent, and battery <br /> <br /> electrode. However, the diatom cell wall use for a catalyst in ethyl tertiary butyl ether <br /> <br /> (ETBE) synthesis has not been studied yet. The objective of the research was to <br /> <br /> convert N. salinicola strain NLA silica into aluminosilicate, and to apply the <br /> <br /> aluminosilicate as catalyst for the synthesis of ETBE. The methods included <br /> <br /> cultivation of N. salinicola strain NLA, separation and purification of the diatom <br /> <br /> silica, conversion of the silica into aluminosilicate, physical characterization of the <br /> <br /> silica and the aluminosilicate, and determination of aluminosilicate catalytic activity. <br /> <br /> The results showed that the density of N. salinicola strain NLA with an initial density <br /> <br /> of 1 × 105 cell/mL for 7 d was 6.56 ± 0.38 g/L. The wet biomass contained 9.57% <br /> <br /> water, 26.66% organic compound, and 63.77% silica. The content of purified silica <br /> <br /> obtained from the wet biomass of N. salinicola strain NLA was 100%. The shape of <br /> <br /> the silica was boat like with a cell length of 15–30 &#956;m, cell width of 6–8 &#956;m, and pore <br /> <br /> size of 74–328 nm. The silica has been successfully converted into aluminosilicate <br /> <br /> that was identified by Si–O–Si vibration bands at wave numbers of 453, 802, and <br /> <br /> 1109 cm-1 and O–Al–O vibration bands at wave numbers of 553, and 1230 cm-1. The <br /> <br /> aluminosilcate was fine sphere crystals with a diameter range of 611–1590 nm. The <br /> <br /> aluminosilicate crystal had a similar structure with ZSM-5 crystal. The <br /> <br /> aluminosilicate showed a catalytic activity on the etherification reaction of ethanol <br /> <br /> and tert-butanol. The main product of ETBE was obtained from the reaction at 80 oC <br /> <br /> for 1 h. This results indicated that the N. salinicola strain NLA cell wall might use for <br /> <br /> raw material of aluminosilicate catalyst.