Sulfuryl Fluoride Absorption from Fumigation Exhaust Gas by Biobased Solvents: Thermodynamic and Quantum Chemical Analysis

Abstract

With the global phaseout of methyl bromide, much more sulfuryl fluoride (SO2F2) is pouring into the atmosphere after fumigation, intensifying the greenhouse effect. Therefore, the reduction of SO2F2 emission is urgently required. In this paper, biobased solvents are proposed to capture SO2F2. Solubilities of SO2F2 in eight biobased solvents at temperatures from 283.15 to 323.15 K and pressures up to 600 kPa are measured. On the basis of thermodynamic consideration, a parametric method is adopted to select potential physical solvents for SO2F2 absorption. Then, a preliminary quantum chemical analysis is conducted to reveal the mechanism of SO2F2 dissolution in biobased solvents. To verify the selective absorption of SO2F2 from fumigation exhaust gas, which is mainly air, the ideal selectivity of SO2F2/N2 and SO2F2/O2 is also probed. Additionally, the recyclability of biobased solvents is examined. Results show that these selected biobased solvents have significantly larger absorption capacities than water. Based on the analysis of solubility data, it is found that bis­(2-ethylhexyl) azelate with higher SO2F2 capacity also has smaller Hildebrand solubility parameter and larger SO2F2–solvent interaction energy. Moreover, the interactions between SO2F2 and biobased solvents are revealed to be dispersion interactions. The ideal selectivity of SO2F2/N2 and SO2F2/O2 ranging from 19.98 to 126.93 proves that the selective absorption of SO2F2 is feasible. In addition, the solubility of SO2F2 in bis­(2-ethylhexyl) azelate is almost unchanged after six absorption–desorption cycles.

The stable “F–SO2+” donor provides a mild and efficient approach to nitriles and amides

“… 22 However, the use of a greenhouse gas SO 2 F 2 is not safe as it may leak out in operation. 23 Although the organoselenium-catalyzed dehydration of aldoximes can produce nitriles under environment friendly conditions, it required for hours up to days. 24 To some extends, those disadvantages restrict its wide applications.…”

Solubility and Thermodynamic Properties of Sulfuryl Fluoride in Some Biobased Citrate Derivatives

“…SO 2 F 2 solubility was measured using the isochoric saturation method. − A detailed description of the apparatus shown in Figure is available in our previous studies. − It was mainly consisted of an equilibrium cell (EC) and a gas reservoir (GR), with the volumes of 1.5351 × 10 –4 and 3.6440 × 10 –4 m 3 , respectively. The temperatures of reservoirs were controlled by two water bathes and determined using PT100 resistance thermometers with a precision of ±0.05 K. Two pressure sensors were used to monitor and record the experimental pressures.…”

“…Up to date, based on the similar structure characteristics to acid gas (e.g., CO 2 , SO 2 , and H 2 S) that the central atom of the SO 2 F 2 molecule lacks electrons, some physical absorbents for SO 2 F 2 have been examined, such as propylene carbonate, N -methyl pyrrolidinone, tributyl phosphate, 2-butoxyethyl acetate, and 3-methoxybutyl acetate. , Biobased solvents with the ester group were proposed as effective SO 2 F 2 absorbents . These biobased solvents have significantly larger absorption capacities than water.…”

“…11,12 Biobased solvents with the ester group were proposed as effective SO 2 F 2 absorbents. 13 These biobased solvents have significantly larger absorption capacities than water. In addition, absorbents rich in the carboxyl or ester group usually a have large dissolution capacity for SO 2 F 2 .…”