Molecular Dynamics Simulations of Furfural and 5-Hydroxymethylfurfural at Ambient and Hydrothermal Conditions

Abstract

In this work, we present results from molecular dynamics simulations of aqueous solutions of furfural and 5-hydroxymethylfurfural, which are important intermediates in the hydrothermal carbonization processes of biomass conversion. The computations were performed both at ambient and hydrothermal conditions using a two-level factorial design varying concentration, temperature, and pressure. A number of equilibrium and dynamic properties have been computed including enthalpies and free energies of vaporization, free energies of solvation, diffusion coefficients, and rotational/reorientational correlation times. Structural properties of solutions were analyzed using radial and spatial distribution functions. It was shown that the formation of hydrogen bonds among 5-hydroxymethylfurfural molecules is preferred compared to hydrogen bonding between 5-hydroxymethylfurfural and water. In addition, our results suggest that the oxygen atoms in the furan rings of furfural and 5-hydroxymethylfurfural do not participate in hydrogen bonding to the same extent as the oxygen atoms in the hydroxyl and carbonyl groups. It is also observed that furfural molecules aggregate under certain conditions, and we show how this is affected by changes in temperature, pressure, and concentration in agreement with experimental solubility data. The analysis of the computational results provides useful insight into the structure and dynamics of the considered molecules at conditions of hydrothermal carbonization, as well as at ambient conditions.

Insight into the Interaction of Furfural with Metallic Surfaces in the Electrochemical Hydrogenation Process

“…This was also reported in Ref. [70] for the solution of FF in water. In all three RDF curves in Figure 14, there was no correlation found between the changing applied voltages and the intensity of RDF peaks.…”

“…Due to the molecular structural of FF, it involves in a hydrogen bond as an acceptor of proton. [70,71] Therefore, RDFs were calculated between oxygen atoms in FF molecules and hydronium ions and water molecules to analyse the tendency for HB in the simulated systems. Among these pairs, we identified the interaction of water (Hw atom) and the hydronium ions (Hh atoms) with the oxygen in the aldehyde group (O1) of FF molecules as most relevant (SI, Figure S7-S11).…”

Role of Anions in 5‐Hydroxymethylfurfural Solvation in Ionic Liquids from Molecular Dynamics Simulations

“…To address this issue, the coordination environment of HMF within bulk liquids must be treated via molecular dynamics (MD) techniques. There exist classical MD studies of HMF in water, [18,19] and DMSO-water mixtures, [18,20] as well as ab initio MD studies of HMF in water. [21] To the best of our knowledge, only one computational report considers HMF in [BMIM][Cl] (1-butyl-3-methyl-imidazolium chloride), but structural information is barely discussed.…”