The determination of activity coefficients at infinite dilution using g.l.c. for hydrocarbons in furfural at T=278.15 K and T=298.15 K (original) (raw)
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Journal of Chemical & Engineering Data, 2003
Liquid-liquid equilibrium results for mixtures of furfural + an aromatic hydrocarbon + an alkane at T) 298.15 K are reported, where an aromatic hydrocarbon is benzene or methylbenzene or 1,2dimethylbenzene or 1,3-dimethylbenzene or 1,4-dimethylbenzene and an alkane refers to n-hexane or n-dodecane or n-hexadecane. The data were measured using the titration method and show a large solubility gap for all mixtures studied. The selectivity values are large, indicating that furfural is capable of separating aromatic hydrocarbons from aliphatic hydrocarbons by solvent extraction. The data were correlated with the UNIQUAC equation, the NRTL equation, and three analytical equations.
Industrial & Engineering Chemistry Research, 2019
Furfural is a platform chemical that can be obtained from renewable resources. It can be produced by acid-catalyzed dehydration of xylose. Currently, the furfural yield is relatively low due to side reactions (degradation of furfural). The furfural yield can be improved by rapid and continuous removal of the furfural from the reaction mixture (in situ extraction), preventing further furfural degradation. In this work, the (in situ) extraction of furfural from the reaction mixture using different organic solvents and hydrophobic deep eutectic solvents is investigated. First, the distribution coefficients of furfural in various organic solvents were determined. It was found that extracting agents containing phenol groups showed the highest distribution ratios. Thereafter, the acid-catalyzed degradation of furfural in the presence of the different solvents was assessed. Addition of organic solvents or hydrophobic deep eutectic solvents resulted in a significant decrease in furfural degradation compared to the blank and the benchmark. Finally, in situ extraction with the different extracting agents was performed. The xylose conversion was not influenced by solvent addition, whereas the furfural yields were significantly higher compared to the blank experiment, even when low amounts of extracting agents were applied. This was explained by the limited co-extraction of the acid to the organic phase, preventing further contact/reaction between the furfural and the acid. Hence, organic solvents and hydrophobic deep eutectic solvents can be promising in situ extracting agents for the removal of furfural from biorefinery processes.
ACS Sustainable Chemistry & Engineering, 2021
Furfural comes from lignocellulosic biomass that, together with its derived products, has many useful applications in several industries. Furfural is usually obtained via pentose dehydration using a biphasic reactor to extract furfural in situ from its reaction medium. However, the conventional solvents used so far, mainly toluene and methyl isobutyl ketone (MIBK), are harmful to health and the environment. Therefore, hydrophobic natural solvents have been successfully tested in this work to improve the performance of the process from a sustainable point of view. First, 30 natural solvents were screened using the conductor-like screening model for real solvents (COSMO-RS) method to select solvents with high affinity to furfural. From the results obtained in the screening, 14 natural and 2 conventional solvents were selected for experimentation, including thymol, eugenol, toluene, MIBK, and several hydrophobic eutectic solvents formed by thymol. Then, the liquid−liquid extraction of furfural was carried out both in vials and in a reactor, simulating the usual temperature and pH conditions for obtaining furfural. Thymol and eugenol showed extraction yields of 95 and 91%, significantly higher than those of conventional solvents MIBK and toluene, which were 85 and 81%, respectively. Finally, the in situ reaction and extraction of furfural from xylose were performed using the natural solvents eugenol and thymol and the conventional solvent MIBK. Under operating conditions, namely, microwave heating to 443.2 K, 10 min of reaction, and a solvent-to-feed ratio of 1.00, xylose conversion of 96.7%, furfural selectivity of 75.3%, and a furfural production yield of 72.8% from xylose were obtained using eugenol as the organic solvent, with improved outcomes over MIBK and thymol cases, pointing an adequate approach to improve both the effectiveness and the sustainability of the process.
Energies
Furfural is only derived from lignocellulosic biomass and is an important chemical used in the plastics, agrochemical, and pharmaceutical industries. The existing industrial furfural production process, involving reaction and purification steps, suffers from a low yield and intensive energy use. Hence, major improvements are needed to sustainably upgrade the furfural production process. In this study, the conventional furfural process based on a continuous stirred tank reactor and distillation columns was designed and optimized from an actual aqueous xylose solution via a biomass pretreatment step. Subsequently, a reactive distillation (RD) and extraction/distillation (ED) configuration was proposed for the reaction and purification steps, respectively, to improve the process efficiency. RD can remove furfural instantly from the reactive liquid phase and can separate heavy components from the raw furfural stream, while the ED configuration with toluene and butyl chloride used as ext...
Background: Lignocellulosic biomass is one of the most promising alternatives for replacing mineral resources to overcome global warming, which has become the most important environmental issue in recent years. Furfural was listed by the National Renewable Energy Laboratory as one of the top 30 potential chemicals arising from biomass. However, the current production of furfural is energy intensive and uses inefficient technology. Thus, a hybrid purifica‑ tion process that combines extraction and distillation to produce furfural from lignocellulosic biomass was considered and investigated in detail to improve the process efficiency. This effective hybrid process depends on the extracting solvent, which was selected based on a comprehensive procedure that ranged from solvent screening to complete process design. Results: Various solvents were first evaluated in terms of their extraction ability. Then, the most promising solvents were selected to study the separation feasibility. Eventually, processes that used the three best solvents (toluene, benzene, and butyl chloride) were designed and optimized in detail using Aspen Plus. Sustainability analysis was performed to evaluate these processes in terms of their energy requirements, total annual costs (TAC), and carbon dioxide (CO 2) emissions. The results showed that butyl chloride was the most suitable solvent for the hybrid furfural process because it could save 44.7% of the TAC while reducing the CO 2 emissions by 45.5% compared to the toluene process. In comparison with the traditional purification process using distillation, this suggested hybrid extraction/ distillation process can save up to 19.2% of the TAC and reduce 58.3% total annual CO 2 emissions. Furthermore, a sensitivity analysis of the feed composition and its effect on the performance of the proposed hybrid system was conducted. Conclusions: Butyl chloride was found to be the most suitable solvent for the hybrid extraction/distillation process of furfural production. The proposed hybrid sequence was more favorable than the traditional distillation process when the methanol fraction of the feed stream was <3% and more benefit could be obtained when that fraction decreased.
Journal of the Brazilian Chemical Society
Acid catalyzed decomposition of C 5 and C 6 sugars has been considered an important source of biomass derived chemicals. An essential step in this process is the extraction of furfural, hydroxymethylfurfural and levulinic acid from aqueous phase. In this work, a computational screening of 178 organic solvents for simultaneous extraction of these chemicals from aqueous phase has been done with the continuum SMD (solvation model based on density) model. Our analysis has taken in account the partition coefficient, water miscibility, boiling point and toxicity of the organic solvents. The present theoretical results indicate that C 6 and C 7 ketones are the most adequate solvents, and 4-heptanone is predicted to be particularly useful.
Journal of Chemical & Engineering Data, 2018
2,5-Furandicarboxylic acid (FDCA) serves as a monomer in various polyesters and is often obtained through the oxidation of 5hydroxymethylfurfural. The solubility data of FDCA are of great value for the reaction process analysis and separation technology. The experimental solubility of FDCA in eight pure solvents (water, methanol, acetonitrile, acetic acid, ethyl acetate, methyl isobutyl ketone (MIBK), 1butanol, and isobutanol) and two binary solvent systems (water + acetonitrile and water + acetic acid) in the temperature range of 313.15− 363.15 K was determined. In pure solvents and binary mixtures, the solubility of FDCA increased with the increasing temperature. The order from largest to smallest solubility in pure solvents was as follows: methanol, 1-butanol, isobutanol, acetic acid, water, MIBK, ethyl acetate, and acetonitrile. The mole fraction of FDCA in binary mixtures increased first and then decreased with the increasing mole fraction of water. The solubility data were correlated with the UNIQUAC model, NRTL model, and WILSON model.
Liquid + liquid) equilibrium data of the solubility (binodal) curves and tie-line end compositions are presented for mixtures of [water (1) + tetrahydrofurfuryl alcohol (2) + cyclohexane or cyclohexanol or cyclohexyl acetate or chlorobenzene ] at T = 298.2 K and P = 101.3 kPa. Among the studied C6 ring containing organic solvents, cyclohexanol and cyclohexyl acetate show the best extraction efficiency for tetrahydrofurfuryl alcohol, giving the largest distribution coefficients. The tie lines have been estimated in terms of the UNIFAC-original model. The model matches the distribution data of the studied ternaries moderately accurately.
Detection and determination of furfural in crude palm oil
In the palm oil mill, fresh fruit bunch (FFB) undergoes various thermal and mechanical treatments to produce the crude palm oil (CPO). FFB consists of many fruits attached to the spikelets that are spirally arranged on the main bunch stalk. Each fruit is made up of a nut enveloped by the fleshy mesocarp, which is reinforced by strands of fibers running from the base towards the fruit tip. A ripe fruit mesocarp contains oil-rich cellulosic cells. These cells are bound together by hemicellulose. Whilst cellulose is very stable, the hemicellulose is easily hydrolyzed. This hydrolysis occurs during sterilization of the FFB when it is exposed to temperatures of 140-145°C and pressure of 40-45 pound per square inch (psi) or 275.8-310.3 kPa for 1-1½ hours. This condition aims at and ensures the detachment of fruits from the bunch. The in-depth chemical changes that occur in the FFB during sterilization are not fully understood and continuously being investigated. Xyloses form one of the products of hydrolysis, and furfural is another product that results from the dehydration of pentose formed also upon the hydrolysis of hemicellulose. Presence of furfural was tested in six extracted samples, namely CPO, mill-pressed crude, condensate oil, sludge oil, sterilized FFB oil and unsterilized FFB oil, using aniline acetate colorimetric method, thin-layer chromatography (TLC) and UV-visible spectrophotometry. The color formation was compared to that of standard furfural. Furfural was detected in CPO, crude, condensate oil, sludge oil and sterilized FFB oil, while it was undetected in the unsterilized FFB. The amount of furfural was quantified in CPO, condensate oil and sludge oil using high-performance liquid chromatography (HPLC).