FORMIC ACID PRODUCTION VIA GLYCEROL OXIDATION ROUTE

• Main Author: Fauzan Mahendraputra S., Naafi
• Format: Theses
• Language: Indonesia
• Subjects: Teknik kimia
• Online Access: https://digilib.itb.ac.id/gdl/view/63525
• Institution: Institut Teknologi Bandung

Formic acid (HCOOH) is a chemical compound known as a hydrogen carrier and source (a liquid that can be easily converted to hydrogen). The development of a renewable (bio-based) formic acid production process will support renewable hydrogen production technology. One of biomass, glycerol (C3H8O3), a byproduct of biodiesel production, is interesting to be studied as a raw material for the production of renewable formic acid, which can certainly improve the economic and environmental aspects of the biodiesel industries. In this research, an effort to develop formic acid production through the autoxidation route of glycerol was carried out using only manganese metal ions (Mn2+/Mn3+) as a catalyst. Mangano ion (Mn2+), with the presence of metal oxide surface, activates (reduces) oxygen in the air into hydrogen peroxide (H2O2, the desired selective oxidizing agent) without a Fenton-like reaction, so it does not produce hydroxyl radical (*OH) which decomposes formate products. As a result, glycerol conversion of 1.87% and selectivity of formic acid 15.77% can be produced with a reaction time of 8 hours, T = 100oC, concentration of metal oxide ZnMn2O4 = 0.5 g/L; Mn2P2O7 = 1%-b glycerol; P2O7 4- : Mn2P2O7 = 63 : 1; CH3COOH = 6.5 mM. The data of the substrates conversion as well as the selectivity of formic acid indicate the autoxidation process of the metal ion Mn2+ to Mn3+ (which promotes the formation of H2O2) is still very slow (not observed) even in the presence of metal oxides. The autoxidation of glycerol by Mn3+ is relatively slower than that of glucose. Another development conducted is an autoxidation reaction with the use of the methanol-water system as a solvent. The formic acid formed immediately reacts with methanol to form methyl formate (T boil = 32oC), so it can be separated from the solution immediately. As a result, a glycerol conversion of 7.46% with a total selectivity of formate products of 20.21% can be obtained using a pyrophosphate ligand system with a reaction time of 6 hours, T = ~65oC, pH 6, Mn/Fe = 6/4 (Mn+Fe = ~0.68%-mol substrate), ligand : (Mn+Fe) = 40 : 1, Cu/Fe = 1/10. The influence of factor variables on substrate conversion and formate products selectivity is also examined in this research.