Recyclable Liquid Research Articles

Nitrogen oxides absorption into aqueous nitric acid solutions containing hydrogen peroxide tested using a cables-bundle contactor

This work aims to study the removal of dilute nitrogen oxides from gaseous effluents by absorption into aqueous nitric acid solutions containing or not hydrogen peroxide. NOx absorption tests (pNOx = 50 Pa with a varying composition) were performed in a cables-bundle contactor at ambient conditions. Tests runs were carried out with the recycling of the absorbent solution (0–8 mol/l for HNO 3 and 0–2 mol/l for H 2 O 2 ) allowing to observe the temporal evolution of the absorption efficiency. The effects of the different operating conditions on the NO, NO 2 and NOx absorption performances (A) were investigated. Results revealed in all the cases that A NOx increases when increasing the proportion of more oxidized species in NOx. Without H 2 O 2 A NOx decreases when the HNO 3 concentration of the solution is increased and also with the recycling of the scrubbing liquid, leading to NOx desorption phenomena. When hydrogen peroxide is added to the nitric acid solution the NOx absorption performances are much higher and increase with the initial H 2 O 2 concentration and the HNO 3 concentration. • A NOx increases when increasing the proportion of more oxidized species in NOx. • Without H 2 O 2 , A NOx decreases when the HNO 3 concentration of the solution is increased and also with the recycling of the scrubbing liquid, leading to NOx desorption phenomena. • When H 2 O 2 is added to HNO 3 solution, A NOx is much higher and increases with the initial concentration of H 2 O 2 and HNO 3 .

The synergetic particles collection in three different wet flue gas desulfurization towers: A pilot-scale experimental investigation

The synergetic removal of particulate matters (PM) in different wet flue gas desulfurization (WFGD) towers was investigated on a pilot-scale experimental setup with the gas flow up to 6372 m3/h. Three types of scrubbing tower, i.e. open scrubbing tower (OST), scrubbing tower with porous tray (TST), and scrubbing tower with a flow pattern control device (FST) were used in this study. The multiphase flow is a counter-current liquid-dispersed flow in OST, while it is an insufficient developed and fully developed bubble flow in TST and FST, respectively. The PM collection efficiency was significantly increased after adding internals (porous tray or flow pattern control device). The total collection efficiency for TST and FST was ~84.3% and ~87.2%, respectively, when using gypsum slurry as recycle liquid at a superficial gas velocity of 3 m/s and L/G = 10 L/m3. Comparing to that of OST, the improvement of the efficiency was ~9.2% and ~13% for TST and FST, respectively. Interestingly, even though the pressure drop of FST is lower than that of TST, the particle removal efficiency of FST is the highest among three scrubbing towers, which means FST is much more cost-effective. The performance index (PI) is introduced in this study to evaluate the particle removal effect of different internals. The PI for FST is approximately 4 times larger than that of TST at L/G = 10 L/m3, indicating a much better effect of FST for WFGD, especially for low-load operation in power plant.

Economic Synthesis of SSZ-13 Catalyst Using Waste Mother Liquid for the Methanol-to-Olefins Reaction

An economical and green way was attempted for the synthesis of SSZ-13 catalysts by recycling waste mother liquids without adding organic template in the initial gel. The synthesized samples were characterized by XRD, BET, SEM, and NH3-TPD. The results showed that the recycling of mother liquids did not change the crystal structure, textural properties and acidity of SSZ-13, all of the samples show similar crystallinity, surface areas (550–580 m2/g), micropore volumes (0.27–0.29 cm3/g), particle sizes (10–11 µm) and Bronsted acid sites. After three recycles of mother liquids, the synthesized SSZ-13 catalyst exhibited superior ethylene plus propylene selectivity (88.7%) and catalyst lifetime (490 min) as compared to the initial SSZ-13 catalyst.

Recyclable and reusable ionic liquid catalyzed synthesis of dihydropyridines

Recyclable and reusable ionic liquid catalyzed synthesis of dihydropyridines

Investigation of the liquid recycle in the reactor cascade of an industrial scale ebullated bed hydrocracking unit

Abstract One of the commercial means to convert heavy oil residue is hydrocracking in an ebullated bed. The ebullated bed reactor includes a complex gas–liquid–solid backmixed system which attracts the attention of many scientists and research groups. This work is aimed at the calculation of the internal recycle flow rate and understanding its effect on other parameters of the ebullated bed. Measured data were collected from an industrial scale residual hydrocracking unit consisting of a cascade of three ebullated bed reactors. A simplified block model of the ebullated bed reactors was created in Aspen Plus and fed with measured data. For reaction yield calculation, a lumped kinetic model was used. The model was verified by comparing experimental and calculated distillation curves as well as the calculated and measured reactor inlet temperature. Influence of the feed rate on the recycle ratio (recycle to feed flow rate) was estimated. A relation between the recycle flow rate, pump pressure difference and catalyst inventory has been identified. The recycle ratio also affects the temperature gradient along the reactor cascade. Influence of the recycle ratio on the temperature gradient decreased with the cascade member order.

Semi-preparative high-resolution recycling liquid chromatography

A semi-preparative high-resolution system based on twin column recycling liquid chromatography was built. The integrated system includes a binary pump mixer, a sample manager, a two-column oven compartment, two low-dispersion detection cells, and a fraction manager (analytical). It addresses challenges in drug/impurity purification, which involve several constraints simultaneously: (1) small selectivity factors (α < 1.2, poor resolution), (2) mismatch of elution strength between the sample diluent and the eluent causing severe band fronting or tailing, (3) diluent-to-eluent mismatch of viscosity causing viscous fingering and unpredictable band deformation, (4) low abundance of the impurity relative to the active pharmaceutical ingredient (API) (<1/100), and (5) yield and purity levels to be larger than 99% and 90%, respectively.The prototype system was tested for the preparation of a trace impurity present in a concentrated solution of an API, estradiol. The ultimate goal was to collect ∼1 mg of impurity (>90% purity) for unambiguous structure elucidation by liquid state nuclear magnetic resonance (NMR 600 MHz and above). First, the particle size (3.5 μm) used to pack the 4.6 mm × 150 mm long twin columns is selected so that the speed-resolution of the recycling process is maximized at 4000 psi pressure drop. Next, the production rate of the process is also maximized by determining the optimum number (7) of cycles and the corresponding largest sample volume (160 μL) to be injected. Finally, the process is fully automated by programming the time events related to (1) sample cleaning, (2) transfer of the targeted impurity from one to the second twin column, and (3) impurity collection. The process was tested without interruption during one week for the collection of a trace impurity (α = 1.166, strong acetonitrile-methanol sample diluent, concentration ∼2 mg/L) from a concentrated (10 g/L) stock solution (60 mL total) of estradiol. The process enriches the impurity content relative to the API by about a factor ∼5000. For the lack of a sufficient collected amount (∼120 μg only) of the pure impurity (purity 50% only), NMR experiments could not provide reliable results. Instead, the combination of LC–MS (single ion monitoring) and UV absorption spectra (λmax shift) revealed that the targeted impurity was likely the low-abundant enol tautomeric form of the ketone estrone, a possible intermediate or by-product of the synthesis reaction of estradiol.

Influence of alkalinity and temperature on photosynthetic biogas upgrading efficiency in high rate algal ponds

Algal-bacterial photobioreactors have emerged as a cost-effective platform for biogas upgrading. The influence on biomethane quality of the inorganic carbon concentration (1500, 500 and 100 mg L−1) and temperature (12 and 35 °C) of the cultivation broth was evaluated in a 180 L high rate algal pond (HRAP) interconnected to a 2.5 L absorption column via settled broth recirculation. The highest CO2 and H2S removal efficiencies (REs) from biogas were recorded at the highest alkalinity (CO2-REs of 99.3 ± 0.1 and 97.8 ± 0.8% and H2S-REs of 96.4 ± 2.9 and 100 ± 0% at 12 and 35 °C, respectively), which resulted in CH4 concentrations of 98.9 ± 0.2 and 98.2 ± 1.0% at 12 and 35 °C, respectively, in the upgraded biogas. At the lowest alkalinity, the best upgrading performance was observed at 12 °C (CO2 and H2S-REs of 41.5 ± 2.0 and 80.3 ± 3.9%, respectively). The low recycling liquid to biogas ratio applied (0.5) resulted in a negligible O2 stripping regardless of the alkalinity and temperature, which entailed a biomethane O2 content ranging from 0 to 0.2 ± 0.3%.

Design, synthesis, and application of 1H-imidazol-3-ium trinitromethanide {[HIMI]C(NO2)3} as a recyclable nanostructured ionic liquid (NIL) catalyst for the synthesis of imidazo[1,2-a]pyrimidine-3-carbonitriles

In this study, 1H-imidazol-3-ium trinitromethanide (1) {[HIMI]C(NO2)3} as a green and recyclable catalyst based on nanostructure ionic liquid (NIL) was designed, synthesized, fully characterized by various analysis techniques, and applied as catalyst for the synthesis of 4-amino-1,2-dihydrobenzo[4,5]imidazo[1,2-a]pyrimidine-3-carbonitrile derivatives via one-pot three-component condensation reaction. The reaction tolerates a wide range of electron-donating and electron-withdrawing substituents on aldehydes with malononitrile and 2-aminobenzimidazole at 50 °C under neat conditions. The described reaction is compatible with the green chemistry disciplines and their main advantages are short reaction time, high yields, simplicity of product isolation, and clean reaction profile. Additionally, the NIL catalyst (1) {[HIMI]C(NO2)3} can be readily recovered in the reaction vessel using a mixture of EtOAc/H2O (1:1) and reused for four consecutive runs without a significant loss in catalytic activity. The present study can open up a new and promising insight in the course of rational design, synthesis and applications of nanostructured task-specific ionic liquids (NTSILs) for numerous green purposes.

Effect of Ion Cluster on Concentration of Long-Alkyl-Chain Ionic Liquids Aqueous Solution by Nanofiltration

As a kind of green solvent and new material, recycling of ionic liquids (ILs) especially from aqueous solution is becoming a key barrier for industrial application. In this study, concentration pro...

Ultrasound and Ionic Liquid: An Ideal Combination for Organic Transformations

AbstractCombination of ultrasound and suitable ionic liquid is a powerful tool to carry out diverse organic transformations. In many occasions, this fruitful combination helps to get the desire products without using any further catalysts even at room temperature. Recyclability of ionic liquid makes a protocol cost effective also. The present review deals with the ultrasound‐assisted organic synthesis in various ionic liquids either as catalyst or reaction media.

The efficiency and comparison of novel techniques for cell wall disruption in astaxanthin extraction from Haematococcus pluvialis

SummaryThe efficiency of various techniques pulsed electric field (PEF), ultrasound (US), high‐pressure microfluidisation (HPMF), hydrochloric acid (HCl) and ionic liquids (ILs) for cell wall disruption in astaxanthin extraction from Haematococcus pluvialis was compared. The results indicated that ILs, HCl and HPMF treatment were shown the most efficient for cell disruption with more than 80% astaxanthin recovery. While the cell wall integrity of H. pluvialis cyst cell was less affected by US and PEF treatment. It was found that imidazolium‐based ILs showed the greater potential for cell disruption than pyridinium‐based and ammonium‐based ILs. Among all the ILs examined, 1‐butyl‐3‐methylimidazolium chloride ([Bmim] Cl) exhibited efficient cell disruption and capability of astaxanthin recovery at mild condition (pretreatment with 40% IL aqueous solution at 40 °C, followed by extraction with methanol at 50 °C) without extensive energy consumption and special facility requirement. In addition, recyclability of ILs was excellent.

Selective conversion of chitosan to levulinic acid catalysed by acidic ionic liquid: Intriguing NH2 effect in comparison with cellulose

A highly selective route to produce levulinic acid (LA), one of the top twelve platform chemicals, from chitosan has been provided by catalysis of acidic ionic liquids (ILs). The effect of NH2 group on the conversion efficiency, IL recyclability and catalytic mechanism has been elucidated thoroughly in comparison with cellulose. Dilution effect was displayed significantly at lower chitosan intake, whereby the yield of LA was dramatically improved up to 64%. The relationship between IL structure and LA yield was established, disclosing that acidity of IL dictates the conversion efficiency of chitosan to LA predominantly. Moreover, methyl isobutyl ketone (MIBK) proved to be efficient extractant for the separation of LA product, and IL can be recycled without loss of activity by supplementing sulfuric acid. In addition, the chemical structures and morphologies of the solid residues were investigated by SEM and IR, indicating two-stage mechanism that chitosan first quaternizes and depolymerizes to glucosammonium salt, followed by transformation into LA through NH3 elimination.

Separation and characterization of cellulose I material from corn straw by low-cost polyhydric protic ionic liquids

Separation of cellulose Ι material from biomass with high efficiency by using ionic liquid (IL) is still challenging. In this work, three low-cost polyhydric protic ammonium-salt ILs (about $1000/t) based on sulphonethane anion were synthesized via one-step protonation reaction and firstly applied in the pretreatment of corn straw. After study on the influence of selected process parameters, such as extraction time, extraction temperature and the IL recycling, 2-hydroxy-N-(2-hydroxyethyl)-N-methylethanaminium methanesulfonate ([BHEM]mesy) exhibits the highest efficiency with the content of cellulose up to 90 wt% in the cellulose material obtained at 140 °C for 6 h. Characterization analysis of the cellulose products certified that the cellulose materials maintain the same crystal structure of cellulose I as native corn straw. Gas chromatography–mass spectrometry and mass spectrometry methods were conducted to explore the possible separation mechanism. [BHEM]mesy shows the prospect of industrialization for cellulose I material separation from biomass owing to its low-cost and high-efficiency characteristics.

Hexamethylenetetramine grafted layered double hydroxides as a novel and green heterogeneous ionic liquid catalyst for the synthesis of pyrido[2,3-d]pyrimidine derivatives

In this research layered double hydroxides functionalized with (3r,5r,7r)-1-(3-(triethoxysilyl)propyl)-1,3,5,7-tetraazaadamantan-1-ium chloride (LDHs–TPTAACl) as a novel, green, efficient and recyclable heterogeneous ionic liquid were synthesized and characterized by various methods, such as FT-IR, TGA, SEM, EDX, TEM and XRD. The mentioned catalyst was applied as a new ionic liquid catalyst for the one-pot three-component synthesis of a new class of pyrido[2,3-d]pyrimidine derivatives through combination of aromatic aldehydes, 2,4-thiazolidinedione and N,N-dimethyl-6-amino uracil using water as solvent in high to excellent yield and short reaction times. The LDHs–TPTAACl catalyst could be simply recycled and reused up to five continuous runs with no substantial structural change and loss of activity.

A urine-fuelled soil-based bioregenerative life support system for long-term and long-distance manned space missions

A soil-based cropping unit fuelled with human urine for long-term manned space missions was investigated with the aim to analyze whether a closed-loop nutrient cycle from human liquid wastes was achievable. Its ecohydrology and biogeochemistry were analysed in microgravity with the use of an advanced computational tool. Urine from the crew was used to supply primary (N, P, and K) and secondary (S, Ca and Mg) nutrients to wheat and soybean plants in the controlled cropping unit. Breakdown of urine compounds into primary and secondary nutrients as well as byproduct gases, adsorbed, and uptake fractions were tracked over a period of 20 years. Results suggested that human urine could satisfy the demand of at least 3 to 4 out of 6 nutrients with an offset in pH and salinity tolerable by plants. It was therefore inferred that a urine-fuelled life support system can introduce a number of advantages including: (1) recycling of liquids wastes and production of food; (2) forgiveness of neglect as compared to engineered electro-mechanical systems that may fail under unexpected or unplanned conditions; and (3) reduction of supply and waste loads during space missions.

Understanding Lignin Fractionation and Characterization from Engineered Switchgrass Treated by an Aqueous Ionic Liquid

Aqueous ionic liquids (ILs) have received increasing interest because of their high efficacy in fractionating and pretreating lignocellulosic biomass while at the same time mitigating several challenges associated with IL pretreatment such as IL viscosity, gel formation during pretreatment, and the energy consumption and costs associated with IL recycling. This study investigated the fate of lignin, its structural and compositional changes, and the impact of lignin modification on the deconstruction of cell wall compounds during aqueous IL (10% w/w cholinium lysinate) pretreatment of wild-type and engineered switchgrass. The 4CL genotype resulting from silencing of 4-coumarate:coenzyme A ligase gene (Pv4CL1) had a lower lignin content, relatively higher amount of hydroxycinnamates, and higher S/G ratio and appeared to be less recalcitrant to IL pretreatment likely due to the lower degree of lignin branching and more readily lignin solubilization. The results further demonstrated over 80% of lignin dissolu...

Desulfurization of liquid fuels by extraction and sulfoxidation using H2O2 and [CpMo(CO)3R] as catalysts

Efficient and recyclable liquid–liquid extraction and catalytic oxidative desulfurization (ECODS) systems for the removal of refractory sulfur compounds from liquid fuels are reported that use the cyclopentadienyl molybdenum tricarbonyl complexes [CpMo(CO)3Me] (1), [CpMo(CO)3(CH2-pC6H4-CO2Me] (2) and [CpMo(CO)3CH2COOH] (3) as catalyst precursors. An ionic liquid, 1-butyl-3-methylimidazolium hexafluorophosphate, was used as both extractant and reaction medium, entrapping the active homogeneous MoVI catalysts that are formed in situ under the operating catalytic conditions (aqueous H2O2 as oxidant, 50 °C). The high sulfoxidation activity of the catalyst formed from 1 was largely responsible for enabling >99% desulfurization within 1 h of a model oil containing 1-benzothiophene, dibenzothiophene, 4-methyldibenzothiophene and 4,6-dimethyldibenzothiophene (2000 ppm S). The IL/catalyst phase could be repeatedly recycled with no loss of desulfurization efficiency. By sequentially performing extractive desulfurization and ECODS steps, 83–84% sulfur removal was achieved for untreated real diesel and jet fuel samples with initial sulfur contents of ca. 2300 and 1100 ppm, respectively.

THE ECO-EFFICIENCY OF THE DAIRY CHEESE CHAIN: AN ITALIAN CASE STUDY

The eco-efficiency of mozzarella cheese production was investigated in two dairy chains that differ in liquid whey recycling, with whey recycling (B) and without whey recycling (A), in cow diets. The total eco-efficiency (total GVA/total GWP) for 1 kg of mozzarella cheese ranged from € 0.19 (B) to € 0.16 per kg CO2-eq (A). The cheese-making phase of each diet accounted for about 3% of GWP total emissions. The mozzarella cheese making phase had the highest eco-efficiency ratio, while the milk production phase showed the lowest economic value and the highest impact. Findings suggest improvements in reducing the environmental burden of the primary phase while increasing its economic value.

Membrane fouling in vacuum membrane distillation for ionic liquid recycling: Interaction energy analysis with the XDLVO approach

Membrane fouling, essentially originated from the interactions between foulant and membrane surface, is a big obstacle to use membrane distillation (MD) for ionic liquid recycling from its aqueous solution. By applying the extended Derjaguin-Landau-Verwey-Overbeek (XDLVO) approach and surface element integration method, this study mainly investigated the fouling behavior of three kinds of hydrophobic membranes during the vacuum MD (VMD) separation of 1-butyl-3-methylimidazolium chloride ([Bmim]Cl) solutions. Effects of membrane surface chemical properties (e.g. elemental composition and zeta potential), membrane surface morphology (e.g. roughness), and [Bmim]Cl concentration on the interaction energy between [Bmim]Cl and membrane surface were studied. The results showed that the Lifshitz-van der Waals (LW) and electrostatic interaction (EL) components were positive (repulsion), while the acid-base (AB) interaction component was negative (attraction). Roughening membrane surface significantly decreased the interaction energy barrier, indicating a greater risk of being fouled. Even so, membrane surface chemical properties had more important impact on membrane fouling than surface morphology. Energy barrier would be also reduced when [Bmim]Cl concentration increased, signifying a severer membrane fouling potential in a concentration process. These results were expected to help to understand ILs-fouling mechanism in VMD process and guide the selection and fabrication of promising membrane for ILs recovery.

Synthesis and characterization of 4-methyl-1-(3-sulfopropyl)pyridinium hydrogen sulfate as a new ionic liquid immobilized on silica nanoparticles: A recyclable nanocomposite ionic liquid for the production of various substituted phthalazine-ones

4-Methyl-1-(3-sulfopropyl)pyridinium hydrogen sulfate ([MSPP][HSO4]) as a new acidic ionic liquid was prepared in a quick and easy process, and characterized by some techniques such as 1H NMR, 13C NMR and FT-IR analysis. Then, [MSPP][HSO4] was immobilized on silica nanoparticles by impregnation method to afforded heterogeneous acidic ionic liquid ([MSPP]HSO4@nSiO2) and characterized by elemental analysis (CHNS), FT-IR, and SEM. The worthiness of [MSPP]HSO4@nSiO2 has been investigated for the synthesis of various substituted phthalazine-ones as well as selective synthesis of mono- and bis-phthalazine-ones as imperative biologically active compounds. The reaction has been carried out under solvent-free conditions, simple work-up procedure and the products were obtained in excellent to good yields. Moreover, the catalyst was reused five times without decay in catalytic activity performance.