Mixed Solvent Extraction Research Articles

Mechanism analysis and energy-saving intensified exploration of green mixed solvents extractive distillation to separate ether-containing azeotropes

2-Methoxyethanol is an important solvent with wide application prospects. Recovering 2-Methoxyethanol from wastewater has significant environmental and economic benefits. In this work, quantum chemistry methods are used to calculate the surface electrostatic potential, mutual penetration analysis, and reduced density gradient-independent gradient model of solvents and azeotrope. From the perspective of the mechanism of action, suitable extractants are selected. With the minimum total annual cost as the goal, the splendid process parameters and the excellent ratio of mixed solvents (30 % 1-ethyl-3-methylimidazole acetate + 70 % N, N-dimethyl acetamide) are acquired. Moreover, two reinforcing processes for energy saving and consumption reduction are also researched. All processes are appraised from three aspects: economy, environment and exergy. The results show that the total annual cost and gas emission of mixed solvent extraction distillation are reduced by 26.79 % and 35.45 %, respectively, compared with the process with NMP as an entrainer. Compared with the process with [EMIM][AC] as an entrainer, the total annual cost and gas emissions are reduced by 44.99 % and 25.04 %, respectively. Relative to mixed solvent, the total annual cost and gas emissions of the heat pump combined with mixed solvent extractive distillation technology decreased by 6.77 % and 21.78 % respectively, while that of the heat integration process decreased via 9.93 % and 12.30 % respectively. From the point of view of environmental sustainability, the process effect combined with the heat pump is better, and from the point of view of economic benefits, the heat integration process has better performance. This study reveals the intrinsic relationship between the structure of mixed solvents and explores the intensification of the process, which provides a theoretical basis for the industrial separation of 2-Methoxyethanol/water azeotrope.

Ultrasound–assisted solvent extraction combined with magnetic ionic liquid based-dispersive liquid–liquid microextraction for the extraction of mycotoxins from tea samples

In this work, for the first time, a combination of ultrasound–assisted mixed solvent extraction method with magnetic ionic liquid-based effervescent tablet–assisted dispersive liquid–liquid microextraction has been employed as an efficient method for the extraction of aflatoxins B1, B2, G1, and G2 and ochratoxin A from tea samples. In the extraction process, first the analytes were effectively extracted into a mixture of the solvents optimized by simplex centroid design with the aid of sonication process. Then, the extracted phase was used in the microextraction step to preconcentrate the analytes for obtaining high enrichment factors and low detection limits. Effervescent tablet eliminated the use of disperser solvent. Also magnetic ionic liquids usage as the extraction solvent directed the method towards a green approach. Various parameters that can affect the efficiency of the introduced method were evaluated and under the best experimental situations, satisfactory data including acceptable extraction recoveries (76–88%) and enrichment factors (304−352), low limits of detection (0.15–0.28 ng g–1) and quantification (0.49–0.92 ng g–1), and good repeatability (relative standard deviations equal to or less than 3.1% and 3.5% for intra– and inter-day precisions, respectively) were obtained. Lastly, the proposed method was utilized for the determination of the studied mycotoxins in different tea samples sold in Tabriz city (Iran).

Separation of Citrus Essential Oil and Hesperidin from Citrus Peel Through Combined Mixed-Solvent and Multi-Phase Salting Out Extraction

Large amounts of citrus peel are discarded as solid waste owing to the lack of recycling methods. In this study, mixed solvent extraction combined with multi-phase salting-out extraction was performed to explore the extraction process of essential oil and hesperidin. Optimal conditions were used for mixed solvent extraction (citrus peel 6%; ratio of ethanol to n-hexane 1:5; duration, stirring speed, and temperature were 150 min, 120 r/min, and 45°C, respectively) and multi-phase salting-out extraction (citrus peel residue 10%; ratio of salt to ethanol 19:24; mass fraction of n-hexane 25%; extraction duration 120 min). Under two-step extraction conditions, 63.74±2.40% essential oil and 27.13±1.36% hesperidin were recovered, with total extraction efficiencies of 5.19±0.09 and 1.91±0.25%, respectively. The amplification effect was not significant, and the organic solvents could be reused three times while maintaining 80% recovery in both steps to balance the commercial cost and extraction efficiency.

Physical properties and hypoglycaemic activity of biscuits as affected by the addition of stigma maydis extract

SummaryThe study aimed to evaluate the potential ingredient of stigma maydis (S.M.) as a hypoglycaemic functional food. In the present study, waxy corn flour and corn‐resistant starch were used to make biscuits; the influence of S.M. extracts (aqueous extract, SMA; ethanol extract, SME; mixed solvent extract, SMM) on the physical features and in vitro digestibility of biscuit were surveyed. In the meantime, the α‐amylase and α‐glucosidase inhibition of different S.M. extracts were analysed. Compared with the control dough, 5% ethanol S.M. extract (SME2) dough was observed to have the lowest storage modulus (G'), loss modulus (G"), hardness, water absorption capacity (P < 0.05), while creep strain was the highest (P < 0.05). Adding S.M. extracts could significantly reduce the L*, b* value and increase the a* value of biscuits. Besides, the S.M. extracts could decrease the glycaemic index (G.I.) of biscuits and reduce postprandial blood glucose levels. The GI of SMA1, SMA2, SME1, SME2, SMM1 and SMM2 was decreased to 62.47, 55.17, 51.46, 44.89, 53.05 and 50.11 respectively. Further, the addition of S.M. extract could show a certain inhibitory rate of α‐amylase and α‐glucosidase when added to biscuits. The inhibition ratio of 5% extract (SMA2, SME2 and SMM2) biscuit was higher than that of 1% extract (SMA1, SME1 and SMM1) biscuit (P < 0.05). As a natural functional component, S.M. extract could be a potential food supplement for type II diabetic mellitus.

Ameliorative role of mixed hydro-methanolic (60:40) extract of Andrographis Paniculata on chromium (VI)-induced immunomodulation in male albino rats

The immune system controls the body’s homeostatic state and helps to defend against infections. Activation and expansion of many biomolecules are crucial for the homeostatic state. Chromium, a common heavy metal found in nature, is an active in its hexavalent state. The abundant use of chromium in paints, steel plants, intoxicated the workers and modulates their body homeostasis. In this article, we were intended to evaluate the role of Andrographis paniculata Nees extract on restoration of the body homeostatic state in terms of immune system. For the present investigation, a group of male albino rats (80–100 g) were induced by intraperitonial injection of vehicle (0.9% NaCl), Potassium dichromate (K2Cr2O7) (0.8 mg / 100 g body weight / day), K2Cr2O7 plus mixed hydro-methanol solvent extract in the ratio of 60:40 at a dose of 500 mg/kg body weight daily at an interval of six hours after injection of K2Cr2O7 for a period of 28 days. We found that Cr (VI) induces a hyper response of pro-inflammatory cytokines followed by apoptosis in liver and lung tissue. Excess production of reactive oxygen species (ROS) is controlling the whole phenomena. The A. paniculata Nees extract successively inhibit the ROS generation, as a result a significant quenching of pro-inflammatory cytokine production was noted. A. paniculata Nees extract prompted decrease amount of ROS and its associated inflammation provoke the cell survival and helps to maintain a homeostatic state of the body.

Recovery of lithium from salt lake brine using a mixed ternary solvent extraction system consisting of TBP, FeCl3 and P507

The consumption of lithium has been increasing rapidly due to its increasing application in lithium-ion batteries. The recovery of lithium from salt lake brines, which accounts for more than 70% of global lithium resources, has become increasingly studied; however, some challenges remain. In a previous study, a mixed ternary solvent extraction system consisting of TBP (tributyl phosphate), FeCl3 and P507 (2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester) was developed. This newly developed system demonstrated good selectivity of Li over Mg and efficient lithium stripping simply using water. In the current study, to demonstrate its practical effectiveness, the TBP/FeCl3/P507 system was tested with a real salt lake brine in both batch and multi-stage simulated counter-current modes. Detailed conditions for extraction, scrubbing and stripping were investigated. In the three-stage simulated counter-current extraction tests, the recovery of lithium reached 99.8%, and in the three-stage simulated counter-current stripping tests, the obtained loaded strip liquor contained (g·L−1): Li, 20.9; Mg, 2.2; and B, 1.6. During stripping, the Fe3+ remained fully in the organic phase, enabling the organic phase to be directly used in the next extraction without regeneration. The high lithium selectivity, lithium recovery and efficient lithium stripping with water of the above process promotes it as a cost-effective and sustainable method for recovering lithium from brines with high Mg/Li ratios.

A comparative production and characterisation of fast pyrolysis bio-oil from Populus and Spruce woods

This study focuses on the production and characterisation of fast pyrolysis bio-oil from hardwood (Populus) and softwood (Spruce) using a bench-scale pyrolysis reactor at two different temperatures. In this study, a mixed solvent extraction method with different polarities was developed to extract different components of bio-crude oil into three fractions. The obtained fractions were characterized by using gas chromatography and mass spectrometry (GC-MS). The effect of temperature on the production of bio-oil and on the chemical distribution in bio-oil was examined. The maximum bio-oil yield (71.20%) was obtained at 873 K for bio-oil produced from softwood (Spruce). In contrast, at a temperature of 773 K, the bio-oil yields were 62.50% and 65.40% for bio-oil obtained from hardwood (Populus) and softwood (Spruce) respectively. More phenolic compounds were extracted at a temperature of 773 K for bio-oil derived from softwood (Spruce) whereas the bio-oil obtained from hardwood (Populus) produced mostly furans, acids and sugar compounds at this temperature. For both types of bio-oil, a wide variety of chemical groups were identified at a temperature of 873 K in comparison to 773 K.

Mild mixed-solvent extraction for determination of total mineral oil hydrocarbon contaminants in milk powder products

A mild mixed-solvent of n-hexane/isopropanol is proposed for extracting total mineral oil hydrocarbons (MOH) from commercial milk powder products. Unlike acid-hydrolysis, the mixed-solvent extraction was performed at ambient temperature and the low-boiling-point hydrocarbons were retained to the greatest extent. After extraction, total MOH was determined by on-line liquid chromatography-gas chromatography with a flame ionization detector (LC-GC-FID). The validation of the proposed extraction method revealed a recovery efficacy of 83.0–107.5% and a limit of quantification of 0.5 mg/kg. Then, the total MOH in ten commercial milk powders was determined and mineral oil saturated hydrocarbons (MOSH)/polyolefin oligomeric saturated hydrocarbons (POSH) were found to be within the range of 0.61–5.46 mg/kg. The comparison of the total and surface MOSH/POSH indicated that a major part of the contamination was derived from sources before packaging. The present study provides a robust method for the extraction and determination of total MOH in milk powders.

Characterization of Fast Pyrolysis Bio-Oil from Hardwood and Softwood Lignin

The depletion of fossil fuel reserves and the increase of greenhouse gases (GHG) emission have led to moving towards alternative, renewable, and sustainable energy sources. Lignin is one of the significant, renewable and sustainable energy sources of biomass and pyrolysis is one of the most promising technologies that can convert lignocellulosic biomass to bio-oil. This study focuses on the production and characterization of bio-oil from hardwood and softwood lignin via pyrolysis process using a bench-scale batch reactor. In this study, a mixed solvent extraction method with different polarities was developed to fractionate different components of bio-crude oil into three fractions. The obtained fractions were characterized by using gas chromatography and mass spectrometry (GCMS). The calculated bio-oil yields from Sigma Kraft lignin and Chouka Kraft lignin were about 30.2% and 24.4%, respectively. The organic solvents, e.g., toluene, methanol, and water were evaluated for chemical extraction from bio-oil, and it was found that the efficiency of solvents is as follows: water > methanol > toluene. In both types of the bio-oil samples, phenolic compounds were found to be the most abundant chemical groups which include phenol, 2-methoxy, 2-methoxy-6-methylphenol and phenol, 4-ethyl-2-methoxy that is due to the structure and the originality of lignin, which is composed of phenyl propane units with one or two methoxy groups (O-CH3) on the aromatic ring.

The Potential of some Plant Extracts as Radical Scavengers and Dipeptidyl Peptidase-4 Inhibitors

Seeds, beans, leaves, fruit peel and seeds of five plants (Ferula assa-foetida, Coffea robusta, Olea europaea, Punica granatum and Vitis vinifera, respectively) were extracted with four solvents (distilled water, 80% methanol, 80% acetone and a mixed solvent that included methanol, ethanol, acetone and n-butanol at proportions 7:1:1:1). Such manipulation yielded 20 extracts, which were phytochemically analyzed for total polyphenols (TP) and flavonoids (TF). The DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity (RSA) and DPP-4 (dipeptidyl peptidase-4) relative inhibition activity (RIA) were also assessed for each extract. The results revealed that mixed solvent extract of V. vinifera seeds showed the highest content of TP (194.8 ± 2.5 mg Gallic acid equivalent/g dry mass), while methanol extract of V. vinifera seeds recorded the highest content of TF (75.9 ± 0.3 mg catechin equivalent/g dry mass). The C. robusta bean aqueous extract was remarkable in scoring the highest DPPH RSA (87.2 ± 1.2%), while O. europaea leaf methanol extract had the highest DPP-4 RIA (86.4 ± 0.8%). In conclusion, the importance of natural products as radical scavengers and DPP-4 inhibitors is encouraged, and such biological effects were dependent on the plant species and the solvent of extraction. C. robusta beans are suggested to have a prominent RSA, while O. europaea leaves are recommended to be a target for investigations involved in the development of anti-T2DM therapies.

The Potential of some Plant Extracts as Radical Scavengers and Dipeptidyl Peptidase-4 Inhibitors

Seeds, beans, leaves, fruit peel and seeds of five plants (Ferula assa-foetida, Coffea robusta, Olea europaea, Punica granatum and Vitis vinifera, respectively) were extracted with four solvents (distilled water, 80% methanol, 80% acetone and a mixed solvent that included methanol, ethanol, acetone and n-butanol at proportions 7:1:1:1). Such manipulation yielded 20 extracts, which were phytochemically analyzed for total polyphenols (TP) and flavonoids (TF). The DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity (RSA) and DPP-4 (dipeptidyl peptidase-4) relative inhibition activity (RIA) were also assessed for each extract. The results revealed that mixed solvent extract of V. vinifera seeds showed the highest content of TP (194.8 ± 2.5 mg Gallic acid equivalent/g dry mass), while methanol extract of V. vinifera seeds recorded the highest content of TF (75.9 ± 0.3 mg catechin equivalent/g dry mass). The C. robusta bean aqueous extract was remarkable in scoring the highest DPPH RSA (87.2 ± 1.2%), while O. europaea leaf methanol extract had the highest DPP-4 RIA (86.4 ± 0.8%). In conclusion, the importance of natural products as radical scavengers and DPP-4 inhibitors is encouraged, and such biological effects were dependent on the plant species and the solvent of extraction. C. robusta beans are suggested to have a prominent RSA, while O. europaea leaves are recommended to be a target for investigations involved in the development of anti-T2DM therapies.

Effect of solvent extraction pretreatments on the variation of macromolecular structure of low rank coals

In order to understand the effects of solvent pretreatment on the inherent macromolecular structure of low rank coal, Xilinguole lignite (XLL) and Shenfu sub-bituminous coal (SFC) were extracted by tetrahydrofuran (THF) Soxhlet extraction, carbon disulfide/N-methyl-2-pyrrolidone (CS2/NMP) mixed solvent extraction and thermal dissolution, respectively. The extracted coals were characterized by diffuse reflection FT-IR spectroscopy (DRIFT), thermogravimetric analysis (TGA), mercury intrusion method (MI) and swelling ratio determination. The results indicated that the extraction resulted in the arrangement and reassociation of coal inherent macromolecules. THF Soxhlet extraction and CS2/NMP mixed solvent extraction can relax the macromolecular structure of coal to varying degrees by changing the non-covalent bond cross-linking, especially the distribution of hydrogen bond interactions. However, thermal dissolutions at high temperature mainly increased the covalent cross linking of coal macromolecules, especially for XLL. Swelling of all extracted coals was limited by Fickian diffusion, and the extracted coal showed lower swelling activation energy than the corresponding raw coals.

Laboratory simulations of the mixed solvent extraction recovery of dominate polymers in electronic waste

The recovery of four dominant plastics from electronic waste (e-waste) using mixed solvent extraction was studied. The target plastics included polycarbonate (PC), polystyrene (PS), acrylonitrile butadiene styrene (ABS), and styrene acrylonitrile (SAN). The extraction procedure for multi-polymers at room temperature yielded PC, PS, ABS, and SAN in acceptable recovery rates (64%, 86%, 127%, and 143%, respectively, where recovery rate is defined as the mass ratio of the recovered plastic to the added standard polymer). Fourier transform infrared spectroscopy (FTIR) was used to verify the recovered plastics’ purity using a similarity analysis. The similarities ranged from 0.98 to 0.99. Another similar process, which was denoted as an alternative method for plastic recovery, was examined as well. Nonetheless, the FTIR results showed degradation may occur over time. Additionally, the recovery cost estimation model of our method was established. The recovery cost estimation indicated that a certain range of proportion of plastics in e-waste, especially with a higher proportion of PC and PS, can achieve a lower cost than virgin polymer product. It also reduced 99.6%, 30.7% and 75.8% of energy consumptions and CO2 emissions during the recovery of PC, PS and ABS, and reduced the amount of plastic waste disposal via landfill or incineration and associated environmental impacts.

N-methyl-2-pyrrolidone/CS2 extraction induced changes in surface and bulk structures of a lignite

Investigation on the changes in detailed surface and bulk structures during N-methyl-2-pyrrolidone/CS2 mixed solvent extraction is crucial to improve and develop the technology of clean and value-added utilization of coals. The surface and bulk structures of Longkou lignite (LL) were investigated before and after ultrasonic-assisted extraction with mixed solvent by multiple direct tools, including, Fourier transform infrared (FTIR) spectrometer, X-ray photoelectron spectrometer (XPS), scanning electron microscope (SEM), and solid-state 13C nuclear magnetic resonance (NMR). The results show that phenols, alcohols, and ethers are the main C–O bond containing species in LL, which is further confirmed by 13C NMR and XPS analyses. The average ring number in each aromatic cluster and substituents in each aromatic ring are 4 and 2–3, respectively. XPS analysis shows that pyrrolic nitrogen is the main nitrogen occurrence and sulfur is mainly present in sulfoxide and sulfone in LL. 13C NMR and FTIR analyses all reveal that aromaticity and aromatic cluster size for LL decreased, while the length and the number of substituents on aromatics increased after extraction. C–O and multi-substituted aliphatic carbons are not easy to dissolve and concentrate in extract residue. It is the basic pyridine-N rather than pyrrolic-N species that are easy to extract with mixed solvent. The content of thiophene-S increased significantly, while other organic sulfur species decreased after extraction, especially for thiophenol and sulfone. Furthermore, solvent extraction leads to the reduction of particle size and increase of surface roughness of LL.

Gas chromatography-mass spectrometry and Raman imaging measurement of squalene content and distribution in human hair.

A sensitive and specific gas chromatography-mass spectrometry (GC-MS) method was developed and validated for the measurement of the squalene content from root to tip, in both Chinese black virgin and bleached hair. Deuterated squalene was used as the internal standard. For quantification, selective ion monitoring (SIM) at m/z 410.0 and 347.0 were monitored for squalene and deuterated squalene, respectively. Different methods for the extraction of squalene from ex vivo human hair were compared including organic solvent extraction and acid/alkali hydrolysis. The best extraction efficiency was obtained by using a mixed solvent consisting of chloroform:methanol = 2:1 (v:v). The linear range of squalene ran from 1.0 to 50.0 μg mL(-1). The limit of detection (LOD) was 0.10 μg mL(-1) (corresponding to 0.005 mg g(-1) in human hair), which enabled quantification of squalene in human hair at very low level. The recovery of squalene was 96.4 ± 1.46% (n = 3). Using the above-mentioned mixed solvent extraction, squalene content in human hair was successfully quantified from root to tip. Meanwhile, a Raman imaging method was developed to visualize the squalene distribution in Chinese white virgin hair from cuticle to medulla.

Fractionation and characterization of bio-oil from microwave-assisted pyrolysis of corn stover

Bio-oil from thermochemical conversion of biomass is a complex mixture of polar and non-polar compounds, and cannot be used directly as a combustion engine fuel due to its low heating value, high viscosity, chemical instability, and incomplete volatility. Mixed-solvent extraction was developed to fractionate bio-oils from microwave-assisted pyrolysis of corn stover to produce light oil (a mixture of light and inflammable fuel oil components from bio-oil) with low viscosity and low combustion residue, and high value chemicals. Different fractions from bio-oil were characterized using GC/MS and TG, and a major chemical (hydroxy-butanedioic acid diethyl ester) was separated. Keywords: fractionation, characterization, pyrolysis, bio-oil, corn stover DOI: 10.3965/j.issn.1934-6344.2010.03.054-061 Citation: Changyan Yang, Bo Zhang, Johannes Moen , Kevin Hennessy, Liu Yuhuan, Lin Xiangyang, et al. Fractionation and characterization of bio-oil from microwave-assisted pyrolysis of corn stover. Int J Agric & Biol Eng, 2010; 3(3): 54 <span style=font-size: 9pt; line-height: 130%; font-family:

Identification of 19 phthalic acid esters in dairy products by gas chromatography with mass spectrometry.

A detection method for 19 kinds of phthalic acid ester compounds analyzed by n-hexane/ether/acetonitrile 1:7:8 v/v/v mixed solvent extraction, quick, easy, cheap, effective, rugged, and safe purification and internal standard method of quantitative gas chromatography with mass spectrometry was established. This method can effectively remove interfering materials, such as lipids, fatty acids, and pigments, from dairy products. The 19 kinds of phthalic acid ester compounds were within a 0.025-0.2 mg/kg range, the recovery rate was 65.2-125.7%, relative standard deviation was 7.9-15.4% (n = 6), and the limit of detection was 0.005-0.02 mg/kg. Concentrations of the 19 kinds of phthalic acid ester compounds ranged between 0.01 and 0.12 mg/kg in ten dairy materials and 20 dairy products. The established method is simple, rapid, accurate, and highly sensitive.

Partitioning of elements from coal by different solvents extraction

Mixed samples of the whole seam and coal ply sample #1, 3, 9, 10, 14, 19, and 23 of the No. 11 coal seam from the Antaibao mining district, Shanxi, China were conducted by the sequential chemical, carbon disulfide/N-methyl-2-pyrrolidone (CS2/NMP) mixed solvent, and fractional (methanol, benzene, acetone and tetrahydrofuran (THF)) extraction experiments. More than 30 major and trace elements in the coal samples and resultant extracts were determined by means of instrumental neutron activation analysis (INAA), inductively coupled plasma atomic emission spectroscopy (ICP-AES), inductively coupled plasma mass spectroscopy (ICP-MS) and atomic fluorescence spectrometry (AFS) in order to investigate their partitioning during the extraction. The results show that: (1) generally, an element with a higher content in coal is relatively enriched in organic solvent extracts of the coal, though its content in the extracts is significantly lower than that in the original coal. However, some elements occurring as organic phase like Br, Mo, Ni, Sb and Se are relatively enriched in the extracts; (2) the contents of most studied elements in different organic solvent extracts of coal are positively correlated with the polarity of solvent, i.e. most elements have the highest content in the methanol extract, higher in the acetone and THF extracts, and the lowest in the benzene extract in the order of the solvent polarity; (3) most studied elements have the highest extraction rate by sequential chemical extraction, higher by CS2/NMP mixed solvent extraction, and the lowest by fractional extraction. The difference in extraction rate could reflect the affinity of elements with small or large organic molecules in coal. In detail, elements Al, As, Co, Cr, Ni, and Zn more enriched in the fractional extracts have a higher affinity with small molecules, while the other studied elements are more related to larger molecules.

Evaluation of Coal Extraction with Supercritical Carbon Dioxide/1-Methyl-2-pyrrolidone Mixed Solvent

A novel coal extraction method using supercritical carbon dioxide (scCO2)/1-methyl-2-pyrrolidone (NMP) mixed solvent, which has the advantages of high efficiency, diffusibility, separability, and environmental friendliness, is proposed in this paper. The physical and chemical properties of the extracts and residues in scCO2/NMP mixed solvent extraction of coal were studied. The results showed that 8 bituminous coals had relatively higher extraction yields. The bituminous coal with 85.12% carbon content had the maximum observed extraction yield. The mixed solvent of scCO2 and NMP had a good extractability for hydroxyl-rich substances, oxygen, sulfur, and other heteroatom-containing compounds. The extracts of Bei Su (BS) and Qu Jin (QJ) coals with higher extraction yields contained more aromatic ring structures. Studies of coal structure revealed that BET surface area of residues were generally lower than that of raw coals, especially for low-rank coals. After extraction, BET and pore volume declined whereas the pore size increased with increasing pressure. It could also be concluded that stacking heights of four coals (QJ, BS, Nan Lu Tian, and Yang Chang Wan) decreased after the extraction procedure. The degree of decline of NLT lignite was larger than that of other coals according to the carbon minicrystal research. A microcrystalline structure similar to raw coal was formed in the process of the solvent evaporation, with a lower stacking height and a higher interplanar spacing. The gasification reactivities of the four coals have been improved by the extraction with scCO2/NMP mixed solvent, especially for QJ and BS coals, which have high extraction yields.

The Comprehensive Utilization of Waste Water Derived from the Glyphosate Production

The glyphosate solution, sodium chloride and phosphate solid are separated concurrently by using different mixed solvent extraction processing from glyphosate production wastewater. Among them, ethanol-acetone is the best solvent extraction agent. In glyphosate solution after treatment, glyphosate content is 6.14 %, meanwhile, the content of sodium chloride and phosphate is rather low. So, it can be used as glyphosate agent production. The content of sodium chloride is up to 98 % after recrystallization, which can be as the raw material of chlor-alkai production. When the mother liquor of recrystallization combined with the original wastewater, the glyphosate can be close to the maximum recovery.