Liquid-liquid extraction, COSMO-SAC predictions and process flow sheeting of 1-butanol enhancement using mesitylene and oleyl alcohol

Techno-Economic Analysis of Macroalgae Biorefineries: A Comparison between Ethanol and Butanol Facilities

Ulva rigida seaweed is constituted by ulvan, which is a sulfated polysaccharide with uses in a wide variety of applications. After the ulvan-oriented extraction process, a crystalline and recalcitrant residue, the so-called pulp, appears. In this work, this residue was valorized through a multiple-stage process. The total processing of the algae consists of hot water extraction, acid hydrolysis, ABE fermentation, and distillation in order to obtain not only ulvan but also butanol and bioethanol to be used as biofuels by simulating two third-generation algae-based biorefineries in Aspen Plus v10 software. Third-generation plants do not compete with food and algae biomass, and they do not require delignification nor pretreatment steps, which are usually the bottleneck of second-generation plants. A plant producing butanol as biofuel together with diluted ulvan, acetone, and ethanol as byproducts was modelled in Aspen Plus software. Regarding the profitability of the investment, the plants producing bioethanol and butanol were economically feasible. The economic parameters for the bioethanol and butanol plants were as follows: NPV equal to 27.66 M$ and 16.67 M$, and IRR equal to 46% and 37%, respectively. The discounted return period was acceptable for these types of plants, which were 4.11 and 3.16 years for the ABE biorefinery and the bioethanol biorefinery, respectively.

Nanofibrous membranes comprising intrinsically microporous polyimides with embedded metal-organic frameworks for capturing volatile organic compounds

Here, we report the fabrication of nanofibrous air-filtration membranes of intrinsically microporous polyimide with metal-organic frameworks (MOFs). The membranes successfully captured VOCs from air. Two polyimides with surface areas up to 500 m² g^-1 were synthesized, and the impact of the porosity on the sorption kinetics and capacity of the nanofibers were investigated. Two Zr-based MOFs, namely pristine UiO-66 (1071 m² g^-1) and defective UiO-66 (1582 m² g^-1), were embedded into the nanofibers to produce nanocomposite materials. The nanofibers could remove polar formaldehyde and non-polar toluene, xylene, and mesitylene from air. The highest sorption capacity with 214 mg g^-1 was observed for xylene, followed by mesitylene (201 mg g^-1), toluene (142 mg g^-1), and formaldehyde (124 mg g^-1). The incorporation of MOFs drastically improved the sorption performance of the fibers produced from low-surface-area polyimide. Time-dependent sorption tests revealed the rapid sequestration of air pollutants owing to the intrinsic porosity of the polyimides and the MOF fillers. The porosity allowed the rapid diffusion of pollutants into the inner fiber matrix. The molecular level interactions between VOCs and polymer/MOFs were clarified by molecular modeling studies. The practicality of material fabrication and the applicability of the material were assessed through the modification of industrial N95 dust masks. To the best of our knowledge, this is the first successful demonstration of the synergistic combination of intrinsically microporous polyimides and MOFs in the form of electrospun nanofibrous membranes and their application for VOC removal.

Palmitic-Acid-Based Hydrophobic Deep Eutectic Solvents for the Extraction of Lower Alcohols from Aqueous Media: Liquid-Liquid Equilibria Measurements, Validation and Process Economics

A new, natural, hydrophobic deep eutectic solvent (NADES) based on DL-menthol and palmitic acid is adopted for the extraction of alcohols from aqueous phase. DL-menthol is used as a hydrogen bond acceptor and palmitic acid, being a natural organic acid, as a hydrogen bond donor. The synthesis is carried out by the addition of DL-menthol and palmitic acid in a defined molar ratio. Physical properties of NADES along with water stability are then measured. Liquid-liquid equilibria (LLE) of lower alcohols, namely, DES (1) + lower alcohols (ethanol/1-propanol/1-butanol) (2) + water (3) are carried out at p = 1 atm and T = 298.15 K. LLE results show type-I phase behavior, where alcohol is preferentially attracted toward DES. The tie lines are then regressed via nonrandom two liquid and universal quasichemical models, which give root mean square deviation (RMSD) in the range of 0.29-0.35% and 0.39-0.75%, respectively. Finally, the quantum-chemical-based conductor-like screening model-segment activity coefficient is used to predict the tie lines, which gives an RMSD of 2.1-5.2%. A hybrid extractive distillation flowsheet is then used for scale up, process economics, and solvent recovery aspects in ASPEN using DES as a "pseudocomponent."