Rigorous design, techno-economic and environmental analysis of two catalytic transfer hydrogenation (CTH) processes to produce bio-based 2-methylfuran (2-MF)

Abstract

The catalytic transfer hydrogenation (CTH) reaction has emerged as a safer method for converting biomass derivatives into value-added chemicals. This study aims to comprehensively evaluate two processes for converting furfural into 2-methylfuran (2-MF) using either methanol (or MeOH, Scheme 1) or isopropyl alcohol (or IPA, Scheme 2) as hydrogen carriers. Both processes were rigorously simulated using Aspen Plus. The reaction performance was modeled using kinetic models developed from literature data. In addition, appropriate strategies are first established for separating the reactor effluents of both processes, which contain multiple azeotropes, based on the thermodynamic parameters estimated through COSMO-based calculations. From the techno-economic analysis, the minimum required selling price (MRSP) of 2-MF is 5.15 USD/kg when produced with Scheme 1, and 3.63 USD/kg when produced with Scheme 2. The MRSP in Scheme 1 becomes 4.50 USD/kg by considering the benefits of the side product, a formalin solution. Compared to various literature data, the MRSPs of these two process schemes are significantly lower than that obtained from direct hydrogenation (6.87 USD/kg). If the cost of the starting materials can be reduced by 25% or more, the MRSP becomes comparable to that obtained from an improved direct hydrogenation process (2.20–3.30 USD/kg). Furthermore, the CO2 emission analysis reveals that Scheme 2 has a lower rate of indirect CO2 emission rate (0.926 Ton-CO2/Ton-2-MF) compared to Scheme 1 (1.088 Ton-CO2/Ton-2-MF). With thorough assessment, we have concluded that the production of 2-MF through the CTH reaction in Scheme 2 is superior. This process shows promise in both economic and decarbonization aspects and could have industrial significance.