Ash Catalyzed Synthesis of Long-Chain Dialkyl Carbonates Through Carbonyl Exchange Reaction

Present work is focused on development of methodology involving utilization of cost effective, highly effective heterogeneous catalyst prepared from wood ash for carbonyl exchange reaction between long chain alcohols and diethyl carbonate to produce long-chain dialkyl carbonates. Whereas long-chain dialkyl carbonates are being explored as value added compounds as they are environmentally safe and non-corrosive in nature and useful in diesel as cetane improvers, lubricants and used in cosmetics. Thermal treatment (calcination) of wood ash was carried out at 500 and 800 °C temperatures and studied the activity of resulted catalyst towards the synthesis of long-chain dialkyl carbonates through carbonyl exchange reaction. The prepared catalyst was characterized by analytical techniques for surface morphology, crystalline phases and textural characteristics. In the present study, maximum yield of long-chain dialkyl carbonates (81%) was achieved using heterogeneous wood ash catalyst at 10 wt% of reactants and at temperature of 120 °C. The synthesized products were characterized by analytical techniques like infrared (IR), nuclear magnetic resonance (NMR), gas chromatography and mass spectroscopy respectively. Applications of prepared long-chain dialkyl carbonates in ultra low sulphur diesel (ULSD) have been explored as lubricity improvers and cetane number improvers. Graphic Abstract