Extraction of polycyclic aromatic hydrocarbons from fluid catalytic cracking diesel with ionic liquids

Abstract

Ionic liquids (ILs) as promising green solvents were first proposed to extract polycyclic aromatic hydrocarbons (PAHs) from fluid catalytic cracking (FCC) diesel. The COSMO-RS model was used for preliminary screening of IL extractants. The liquid-liquid equilibrium (LLE) experiments were performed to show that the IL [BMIM][BF 4 ] has a high selectivity for the model oil system. Further, the LLE experimental results show that the solubility of 1-methylnaphthalene in [BMIM][BF 4 ] is relatively low, while the IL exhibits a high selectivity of n-hexadecane to 1-methylnaphthalene. This means that the use of [BMIM][BF 4 ] can obtain the high-purity products when considering the almost nonvolatility of IL. Compared to the benchmark process, the multistage countercurrent-reflux extraction process can improve the PAHs purity by about 2% at the expense of 5.06% total annual cost and 6.42% energy consumption, rendering the use of IL to extract PAHs from FCC diesel more feasible in industry.

Molecular Refining: A Simulation Comparison between Real Fuel Oil and Model Oil

“…In addition, highly selective solvents tend to have low solvent capacity. Weighing the technical (i.e., solvent capacity and selectivity) and economic feasibility, IL [BMIM]­[BF 4 ] was considered to be the most suitable extractant because of its high decomposition temperature (603.15 K) and low viscosity (51.10 mPa·s at 373.15 K; see SI for IL screening strategies and descriptions in detail) …”

“…Res. XXXX, XXX, XXX−XXX be the most suitable extractant because of its high decomposition temperature (603.15 K) and low viscosity (51.10 mPa•s at 373.15 K; see SI for IL screening strategies and descriptions in detail) 17.…”

“…Figure Flowsheet and optimal operating conditions of the five-stage countercurrent-reflux extraction process for FCC diesel using [BMIM][BF 4 ] as the extractant (the solvent ratio is 5:1, streams in mass fraction).be the most suitable extractant because of its high decomposition temperature (603.15 K) and low viscosity (51.10 mPa•s at 373.15 K; see SI for IL screening strategies and descriptions in detail) 17. …”

Investigation of Ionic Liquids as Extraction Solvents for Separating Bicyclic Aromatic S/N-Compounds from FCC Diesel

“…Ionic liquids are molten salts that consist of organic cations and inorganic anions. As a promising neoteric solvent, ILs have been widely used in separation fields such as gas absorption, − extractive distillation, and liquid–liquid extraction. − ,, Compared to organic solvents, which easily volatilize and cause environmental pollution, the major advantages of ILs are their nonvolatility, broad liquid temperature range, good thermal stability, and high solvent capacity. Their attractive thermodynamic and physical properties make them sustainable solvents in diverse separation areas, especially in liquid–liquid extraction.…”

“…There is no doubt that the solvent capacity and selectivity of extractants are the most important thermodynamic properties to be considered in the screening of suitable extractants. According to this principle, many studies have been conducted in this field. ,− However, from an industrial perspective, it is insufficient to select the best solvent considering only the thermodynamic properties of a solvent. Some physical properties, including viscosity and thermal stability, also have a significant impact on the mass transfer, energy consumption, and IL regeneration of the extraction process.…”