Journal of Cleaner Production
·
2022
·
IF 11.072
Yuanlin Chen,Guangsheng Huo,Xueyi Guo,Qinmeng Wang
Acid digestion of tungsten concentrates has attracted more and more attention in recent years, sustainable extraction of tungsten from acid digestion product of tungsten concentrates to obtain (NH 4 ) 2 WO 4 solution with low impurity content is the key for ammonium paratungstate production. In this work, a process of extracting tungsten from acid digestion product by leaching-solvent extraction together with raffinate circulation was introduced. The acid digestion product was firstly leached by Na 2 CO 3 , and the leaching efficiency was 99.47% with circulation of Na 2 CO 3 solution converted from the raffinate of solvent extraction . The tungsten in pure Na 2 WO 4 solution with 121.26 g/L WO 3 could be almost completely extracted by solvents containing 15% N235 or 15% Alamine 308 in one stage. The extraction mechanism of N235 and Alamine 308 was the same, while Alamine 308 showed better performance and higher saturated loading capacities for tungsten extraction. The loaded tungsten was stripped from organic phases using NH 3 ·H 2 O with stripping efficiency of 99.98%, obtaining (NH 4 ) 2 WO 4 solutions with WO 3 concentration above 260 g/L and low impurity content. The raffinate containing high Na 2 SO 4 concentration was converted to Na 2 CO 3 solution by adding BaCO 3 and recycled for the leaching of digestion product, which could significantly reduce the discharge of sodium salt wastewater. The presented work provides a cleaner production route for preparing pure (NH 4 ) 2 WO 4 solution from acid digestion product of tungsten concentrates.
研究领域:
冶金工程
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2020
·
IF 10.652
Yu Xie,Guoming Huang,Yujun Wang,Zhengren Yan,Xin Wang,Juan Huang,Mingtang Gao,Weiyang Fei,Guangsheng Luo
The synthesis of piperacillin is very sensitive to the mixing effect and the pH of the system. Because of poor micro-mixing and imprecise pH control in the ampicillin chloride method using the traditional reactor, the impurity content of piperacillin does not meet the production standard. Therefore, a novel three-feed membrane dispersion microreactor was proposed and used to synthesize piperacillin, in which ampicillin was first mixed with 4-ethyl-2,3-dioxo-1-piperazine carbonyl chloride (EDPC) and then mixed with ammonia water under rapid and intense mixing conditions. The process of ampicillin circulation and slow addition of the EDPC also contributed to stabilizing the pH value. The effects of the distance between the ammonia feed and the EDPC feed, pH, reaction temperature, EDPC ratio, and circulation flow rate on the content of piperacillin and impurities were investigated. The piperacillin content of the condensation solution reached ~94.90% within 10 min under the optimal conditions in the microreactor, but the content only reached 91.06% in 60 min in the traditional tank; more importantly, the content of the key impurities D and E decreased from 0.340% to 0.080%, and 0.176% to 0.035%, respectively. Subsequent processes were carried out to obtain the final piperacillin product, where the average yield was around 93.99%; the purity was generally above 99.7%; the content of impurity D was generally less than 0.1%, and the content of impurity E was less than 0.05%, meeting the guidelines of the pharmacopoeia and antibiotic impurity.
研究领域:
制药工程
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2018
·Vol. 8
·期 72
·41603-41611
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IF 2.936
Benxue Liu,Min Gao,Xiaochan Liu,Yongshuai Xie,Xibin Yi,Luyi Zhu,Xinqiang Wang,Xiaodong Shen
Zirconia (ZrO2) aerogels are potential candidates for use at temperatures higher than those attainable with silica aerogels. However, fabricating a robust ZrO2 aerogel with a high thermal stability is still a challenge. The extreme electronegativity of Zr makes the hydrolysis and polycondensation of zirconium precursors difficult to control, leading to poor structural integrity and unsatisfactory physical properties. In the present research, we prepared a ZrO2 aerogel by using a synthetic zirconium precursor, namely polyacetylacetonatozirconium (PAZ), and ammonia hydroxide as the gel initiator. The ammonia hydroxide catalyzes the cross-linking of PAZ via promotion of the dehydration between hydroxyls in PAZ and the acetylacetonate group in PAZ binds the zirconium ion firmly upon the addition of ammonia hydroxide to avoid a gel precipitate. A monolithic ZrO2 aerogel with a large diameter size of 4.4 cm and high optical transmittance was achieved after drying. The surface area and pore volume of the as-dried ZrO2 aerogel were as high as 630.72 m2 g−1 and 5.12 cm3 g−1, respectively. They decreased to 188.62 m2 g−1 and 0.93 cm3 g−1 after being heat-treated at 1000 °C for 2 h. The best mechanical performances of the ZrO2 aerogels showed a compressive strength of 0.21 ± 0.05 MPa and a modulus of 1.9 ± 0.3 MPa with a density of 0.161 ± 0.008 g cm−3. Both pore structures and mechanical performances varied according to the ammonia hydroxide gel initiator used. The thermal insulating properties of the ZrO2 aerogel performed better than a silica aerogel blanket with a thermal conductivity of 0.020 W (m−1 K−1).
研究领域:
材料科学
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化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
TALANTA
·
2018
·
IF 4.244
Dongqin Tan,Jing Jin,Longxing Wang,Xueqin Zhao,Cuicui Guo,Xiaoli Sun,Dhanjai,Xianbo Lu,Jiping Chen
As one of the most important analytical techniques for accurate quantification of bisphenol compounds, liquid chromatography coupled to online electrospray ionization (ESI) tandem mass spectrometry exhibits relative weak ESI response in negative mode, which greatly reduces their sensitivity and limits their detection at trace levels, especially in complex samples such as blood. Based on the facilitated deprotonation of bisphenol molecule under alkaline condition, post-column injection of ammonium hydroxide (NH 3 ·H 2 O) to mass spectrometer was explored to enhance the ionization efficiency of BPA and its eight analogs and improve their analytical sensitivity. Parameters effecting response intensity and stability were investigated, including mass concentration and flow rate of NH 3 ·H 2 O. Under the optimal conditions with the addition of 2% (w/w) of NH 3 ·H 2 O at 4 μL min −1 , the instrument detection limits for bisphenol compounds were greatly lowered to 0.001–0.04 ng mL −1 , which were 2–28.6 times lower than the result obtained without injecting NH 3 ·H 2 O, except TBBPA (0.03 ng mL −1 in either case). The relative standard deviations (RSDs) for instrument repeatability of BPA and its analogs at three different concentration levels were in a range of 1.2–20%. Furthermore, a decreased matrix effects (90–111%) for bisphenols (except TBBPA) analysis in serum extracts were found compared with the result obtained without NH 3 ·H 2 O injection (43–111%). The results demonstrated that the improved instrumental method coupled with suitable pretreatment techniques is more feasible to analyze bisphenol compounds in complex bio-samples.
研究领域:
分析化学
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环境科学
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毒理学
✓ 已验证
DOI
PubMed
高影响因子
Canadian Journal of Chemistry
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2011
·Vol. 89
·期 6
·
IF 1.374
ZhuYefeng,WeiYunyang
The copper(I) iodide/1,4-bis(2-hydroxy-3,5-di-tert-butylbenzyl)piperazine (CuI–L2) system catalyzed the cross-coupling reactions between aryl halides and aqueous ammonia in water to produce primary aromatic amines in good yields. The protocol was simple and efficient, avoiding the need for inert atmosphere, additional base, or other additives.
研究领域:
有机化学
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催化化学
✓ 已验证
DOI
高影响因子
CHEMICAL PHYSICS LETTERS
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2019
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IF 1.901
Shenghan Zhang,Yang Jiao
Aqueous ammonia is a potential absorbent for post-combustion carbon capture. Desorption of carbon dioxide (CO 2 ) from ammonium bicarbonate (NH 4 HCO 3 ) solution is one of key reactions of regeneration of the absorbent. Experimental studies on decomposition of NH 4 HCO 3 solution with and without nano-TiO 2 at different temperatures were conducted. Additions of nano-TiO 2 into ammonium bicarbonate solutions decrease the apparent activation energy of overall decomposition reaction and accelerate the decomposition of ammonium bicarbonate solutions. Moreover, compared to hydrophilic nano-TiO 2 , hydrophilic lipophilic nano-TiO 2 exerts more significant promoting effects on the decomposition reaction.
研究领域:
化学工程
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
HYDROMETALLURGY
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2016
·
IF 2.29
Yue Yang,Boyi Xie,Ruixiang Wang,Shengming Xu,Jianlong Wang,Zhenghe Xu
The utilization of high-phosphorus tungsten ores has attracted extensive attention with the mining and utilization of rich tungsten ores. To extract and separate tungsten from acidic high-phosphorus solution effectively, a novel process was developed. Firstly, tungsten was extracted directly in acid medium by solvent extraction . 99.8% tungsten in acidic high-phosphorus solution was extracted with Aliquat 336 in kerosene by one extraction stage under the conditions of O:A = 1, pH = 2, 25 °C, t = 10 min, 5% v/v 2-Octanol and 10% v/v Aliquat 336. And then, tungsten and phosphorus were preliminary separated through stripping process. Over 95% tungsten were recovered after five stripping stages under the optimum stripping conditions of 2.5 M ammonium bicarbonate , 8 min stripping time, O:A = 1:1, pH = 9, and 60 °C, but only about 1.2% phosphorus was recovered from feed liquor. Finally, a small amount of phosphorus left in strip liquor was deeply removed by magnesium salt precipitation method on the optimum conditions of pH = 10.0, 25 °C, reaction time 1 h and Mg/P molar ratio of 1:2 and the ammonium tungstate solution meeting the requirements of producing high-quality ATP can be obtained successfully. Compared to traditional phosphorus removal route, the process in this paper can help extract tungsten directly in acidic medium and decrease the quantity of phosphorus through extraction-stripping process, significantly reducing the consumption of alkali and magnesium salt and improving the separation efficiency of tungsten from acidic high-phosphorus solution.
研究领域:
冶金化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
ACS Sustainable Chemistry & Engineering
·
2025
·
IF 7.3
Yichun Lou,Haoyu Chen,Linrui Wang,Shengpeng Chen,Yameng Song,Yifei Ding,Zixiang Hao,Chengli He,Dong Qiu,Hui Li,Junjian Wang,Duanyang Liu,Xiaoli Cui
The production of urea predominantly relies on the energy-intensive Bosch–Meiser process, which operates at temperatures ranging from 150 to 200 °C and pressures of approximately 150 to 250 bar. More sustainable approaches to urea synthesis under milder conditions remain a significant challenge. Herein, we demonstrate that urea can be synthesized via a mechanochemical method using ammonia–water and CO2 under an ambient environment. Without extra catalysts, the ZrO2 texture of the jar and grinding balls has a crucial mechanocatalytic effect on direct urea synthesis. Experimental data coupled with theoretical calculation results indicate that the mechano-induced oxygen vacancies (OV) within the (101) crystal plane of ZrO2 play a pivotal role in urea formation. These vacancies notably reduce the energy barrier for the generation of *NH2 and the subsequent decomposition of NH2COOH, thereby facilitating a more energy-efficient urea synthesis process. This work presents a novel method for synthesizing urea under mild conditions, offering potential cost-effective alternatives to urea production.
研究领域:
化学工程
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2018
·Vol. 8
·期 35
·19486-19493
·
IF 2.936
Gang-Tian Zhu,Fei Liu,Sheng He,Xiao-Mei He,Shu-Kui Zhu,Yu-Qi Feng
Magnetic aqueous ammonia (MAA) was prepared as a magnetic extractant for dispersive microextraction of petroleum acids (PAs). The amount of extractant in MAA was custom-made by a simple approach. In the MAA composed of an aqueous ammonia coating and Fe3O4@SiO2 core, the coating is a base extractant that can selectively extract acids, while the magnetic core serves as a support to achieve dispersion as well as rapid magnetic retrieval of the extractant during the extraction processes. This is the first use of reusable, stable and modifiable Fe3O4@SiO2 as a support instead of bare Fe3O4 in a magnetic particle assisted dispersive liquid–liquid microextraction technique. The parameters that affect extraction efficiency were investigated. The sampling step as well as the desorption step can be completed in 2 min. The linear ranges are 5–5000 ng g−1, while the limits of quantification range from 2.5 to 6.2 ng g−1. The recoveries in spiked crude oil samples are in the range of 79.1% to 112.1% with relative standard deviations less than 11.3% (intra-day) and 13.4% (inter-day). Finally, the proposed method was applied to the analysis of PAs in diluted crude oils with different maturities. In comparison to the existing methods for extraction of PAs, the proposed method provides superior performances including high throughput (12-well plate), high degree of sample clean-up, and low consumption of separation material, solvent and time.
研究领域:
分析化学
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环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
GLYCOCONJUGATE JOURNAL
·
2018
·Vol. 35
·期 4
·411-420
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IF 2.548
Wang Chengjian,Yang Meifang,Gao Xi,Li Cheng,Zou Zihua,Han Jianli,Huang Linjuan,Wang Zhongfu
Despite the great significance of release and analysis of glycans from glycoproteins, the existing N -glycan release methods are undermined by some limitations and deficiencies. The traditional enzymatic protocols feature high N -glycan release specificity but are generally costly and inefficient for some types of N -glycans. The existing chemical methods require harsh reaction conditions or are accompanied by the remarkable formation of by-products. Herein, we describe a versatile chemical method for the release and analysis of N -glycans from glycoproteins. This method differs from the existing methods as only aqueous ammonia is used to catalyze the N -glycan release reactions. Optimization of reaction conditions was performed using RNase B as a model glycoprotein and the obtained results indicated a highest N -glycan yield in ammonia at 60 °C for 16 h. Comparison of this method with traditional enzymatic protocols and recently reported NaClO methods confirmed the good reliability and efficiency of the novel approach. We also successfully applied this method to some complex biological samples, such as Ginkgo seed protein, fetal bovine serum (FBS) and hen egg white, and demonstrated its great compatibility with various neutral N -glycans, core α-1,3-fucosylated N -glycans and sialylated N -glycans. This method is very simple and cost-effective, enabling convenient analysis and large-scale preparation of released reducing N- glycans from various biological samples for structural and functional glycomics studies.
研究领域:
生物化学
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分子生物学
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分析化学
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF POWER SOURCES
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2014
·
IF 5.211
Song-Il O,Jun-Min Yan,Hong-Li Wang,Zhi-Li Wang,Qing Jiang
Ni/La 2 O 3 nanocatalyst with Pt and Rh content as low as 5 mol%, respectively, is successfully synthesized by a facile co-reduction method in the presence of hexadecyl trimethyl ammonium chloride aqueous solution under ambient atmosphere. Interestingly, the resulted Ni/La 2 O 3 catalyst with low cost exhibits excellent catalytic activity to dehydrogenation of hydrous hydrazine (N 2 H 4 ·H 2 O), producing hydrogen with 100% selectivity at room temperature (298 K), which represents a promising step toward the practical application for N 2 H 4 ·H 2 O system on fuel cells.
研究领域:
催化化学
·
能源材料科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Cleaner Production
·
2018
·
IF 5.651
Leiting Shen,Xiaobin Li,Qiusheng Zhou,Zhihong Peng,Guihua Liu,Tiangui Qi,Pekka Taskinen
To directly obtain solution of (NH 4 ) 2 WO 4 instead of Na 2 WO 4 is the key for developing a cleaner technology of ammonium paratungstate production. In this paper, ammoniacal ammonium carbonate solution was adopted for leaching tungsten from the converted product, a mixture of H 2 WO 4 and CaSO 4 obtained by treating scheelite with sulfuric acid . The research indicates that tungsten can be efficiently extracted in form of ammonium tungstate solution with WO 3 leaching yield of >99.5% under moderate leaching conditions. The WO 3 leaching yield is influenced by the transformation of calcium sulfate to calcium carbonate due to forming CaWO 4 through the secondary reaction between CaSO 4 and (NH 4 ) 2 WO 4 , whereas an excess (NH 4 ) 2 CO 3 (≥0.64 mol/L) can suppress the secondary reaction by facilitating the transformation. Additionally, the consumed ammonium carbonate can be recovered by treating the leaching residue with ammonium sulfate solution at above 70 °C. This work presents a cleaner and sustainable technique for producing ammonium paratungstate, with circulating the leaching reagents and bypassing the conversion of Na 2 WO 4 to (NH 4 ) 2 WO 4 .
研究领域:
化学工程
·
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）