PURITY AND YIELD IMPROVEMENTS OF LACTIC ACID FROM CHEMICAL CONVERSION OF EMPTY FRUIT BUNCH (EFB)

• Main Author: Natanael
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/48276
• Institution: Institut Teknologi Bandung

Lactic acid is categorized as a platform chemical which can be used to produce biodegradable plastic, namely poly lactic acid (PLA). PLA is one of the solutions to the reduction of fossil fuel plastic. Due to the high demand of PLA, production of lactic acid through catalytic conversion of empty fruit bunches (EFB) can be an alternative way to produce high quality PLA. On the other hand, catalytic conversion route is still facing a problem such as low purity. Besides, the polymerization processes need high purity lactic acid to obtain high quality PLA. The process starts with the pre-treatment of EFB which consists of size reduction up to 60-80 mesh, soaking with 4%-wt NaOH, bleaching with 5%-wt NaOCl, and steam explosion. Catalytic reaction of TKS is carried out on 2 L reactor at 20 bar and 220oC with PbCl2 as catalyst. The products obtained from the reactor is purified through esterification and hydrolysis with the help of Amberlyst-15 as catalyst, butanol, and water. These two steps are not sufficient in purifying the lactic acid solution from 5-HMF which may disrupt the polymerization of lactic acid. Thus, steam distillation as an additional purification step is added. Additionally, models of vacuum steam distillation and lactic acid polymerization are perform through using Aspen Plus V.10 to compare and verify the data acquired from the experiment The results shows that bleaching as pretreatment can improve lactic acid yield up to 91.5% compared with the previous research, 84.80%. An addition of a vigreux column in the steam distillation step increased the yield and purity of lactic acid up to 62.25% and 96.40% respectively. These values showed a significant improvement considering previous research results at 13.5% yield. Vacuum steam distillation simulation results show that a higher solution temperature and lower operating pressure can increase lactic acid yield up to 75%. Furthermore, based on polymerization simulation results, lactic acid obtained from vacuum steam distillation method can produce high quality PLA with a molecular weight of 81667 gr/mol compared with the previous research, 76489 gr/mol.