International Journal of Greenhouse Gas Control
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2017
·
IF 3.741
Yan Zhou,Yiheng Rao,Tielin Wang,Klaus-J. Jens
Piperazine (PZ) based amine blends are promising solvents for post-combustion CO 2 capture, but PZ can form potential carcinogenic nitrosamines from nitrite. In this work, the kinetics of the reaction between nitrite and PZ to form N-nitrosopiperazine (MNPZ) was determined in 0.1–0.5 mol L −1 PZ in the presence of 17–170 mmol L −1 formaldehyde at 60–135 °C. The nitrosation of PZ can be catalyzed by formaldehyde, a primary degradation product of PZ. And the reaction involving nitrite and PZ is first order in nitrite, formaldehyde, and hydronium ion. A kinetic model was established, and the activation energy is 33.6 ± 1.8 kJ mol −1 with a rate constant of 2.3 × 10 3 ± 0.4 × 10 3 L 2 mol −2 s −1 at 100 °C. The kinetics will be helpful to develop strategies to reduce nitrosamine formation and accumulation in PZ based CO 2 capture systems.
研究领域:
环境科学
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化学工程
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产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2016
·
IF 2.567
Miaopeng Sheng,Chenguang Liu,Chunyuan Ge,Moses Arowo,Yang Xiang,Baochang Sun,Guangwen Chu,Haikui Zou
This study investigated the absorption performance of CO2 into a diethylenetriamine (DETA)-based solution containing piperazine (PZ) or 1-(2-aminoethyl)piperazine (AEPZ) as an activator in a packed column with Dixon rings. The effects of various operation conditions such as the activator concentration, gas flow rate, liquid flow rate, CO2 partial pressure, and solution temperature on overall gas-phase volumetric mass-transfer coefficient (KGav) were explored. Results indicate that the presence of PZ in DETA solution yields a better enhancement effect on KGav than AEPZ, and, thus, a combination of 5%PZ+25%DETA solution is expected to be a promising absorbent for CO2 absorption. The results further show that KGav increases with an increase in the liquid flow rate and a decrease in CO2 partial pressure and first increases and then decreases with an increase in solution temperature. On the other hand, the gas flow rate has an insignificant effect on KGav. A simplified empirical correlation for KGav as a function of the operation parameters has been proposed, and most of the calculated values are in agreement with the experimental data with a deviation within ±15%.
研究领域:
化学工程
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环境工程
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气体分离
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传质过程
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碳捕集
✓ 已验证
DOI
高影响因子
POLYMER
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2021
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IF 4.43
Wenjuan Li,Xingjiang Liu,Ailing Sun,Liuhe Wei,Rui Li,Hangyu He,Shaoli Yang,Shizhuo Wang,Yanfen Niu,Yuhan Li
Herein, we report a weather-proof, robust and self-healable poly(urethane urea) elastomer via exploring piperazine (PPA) as chain extender. The amidated PPA moiety enables it to maintain high-level transparency and mechanical properties upon heat and xenon aging for 16 days. Deliberate design of short and long hard segment is implemented by using isophorone diisocyanate (IPDI) and PPA as chain extenders. The long hard segments containing strong urea hydrogen bonds play a crucial role in generating strain-induced crystallization (SIC), resulting in outstanding robustness. The reversibility of hydrogen bonds embodies in room-temperature dissociation-reformation of urethane motifs, and transformation of free and regularly hydrogen-bonded urea motifs into irregular bonding above 35 °C. This elastomer exhibits exceptional comprehensive performances in tensile strength (38.5 ± 1.3 MPa), toughness (134.6 ± 7.0 MJ/m 3 ), puncture resistance (697.9 mJ), elasticity, self-healability and adhesion, which demonstrates outstanding ambient repair of scratches, anti-puncture and self-sealing performance.
研究领域:
材料科学
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化学工程
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产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
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2024
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IF 2
Jing Xia,Zhigao Sun
Carbon dioxide hydrate has a broad application such as the separation and capture of carbon dioxide and cold storage in hydrates. However, its industrial application is limited by the problems of hydrate formation conditions of lower temperature or higher pressure, long induction time, and slow growth rate. Thermodynamic promoters can effectively improve the hydrate formation conditions. Piperazine is selected as a new promoter to investigate the influence on carbon dioxide hydrate dissociation equilibrium conditions in this paper. Compared with pure carbon dioxide forming structure I hydrate, the addition of piperazine forms structure II hydrate, and hydrate dissociation conditions significantly move to lower pressures or higher temperatures. The higher the concentration of piperazine, the better the promoting effect.
研究领域:
化学工程
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环境科学
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产品关联
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2019
·Vol. 136
·期 25
·47593
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IF 2.188
Rong Yang,Binbin Ma,Xin Zhang,Jinchun Li
A macromolecular intumescent flame retardant (FR) named PPPAP was designed and synthesized with phosphorus chloride (the acid source), 2,6,7-trioxa- l -phosphabicyclo[2.2.2]-octane-4-methanol (the charring agent), and anhydrous piperazine (the blowing agent). Then, it was used to prepare an intumescent flame-retardant polypropylene (FR-PP). The thermal stability, flame retardancy, and fire performance of the FR-PPs were investigated. The results show that the initial decomposition temperature and char residue at 700 °C of PPPAP were 260.8 °C and 31.8%, respectively. The limiting oxygen index (LOI) value of polypropylene (PP) was enhanced with increasing PPPAP content. With the addition of 40 wt % PPPAP, the LOI value of FR-PP was 29%, and it passed the vertical burning UL-94 V-0 rating. The cone calorimetry results indicate that not only the peak heat-release rate but also the total smoke production of PP significantly decreased to 65.7 and 79.5%, respectively, with the incorporation of only 20 wt % PPPAP. The FR mechanism suggested that PPPAP played a part in both the gas and condensed phases, and the formation of the intumescent char layer during combustion was the dominant FR mechanism. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136 , 47593.
研究领域:
材料科学
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高分子化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
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2012
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IF 3.85
Meihong Liu,Guohua Yao,Qibo Cheng,Miao Ma,Sanchuan Yu,Congjie Gao
Acid stable thin-film composite membrane for nanofiltration was fabricated by interfacial polymerization of naphthalene-1,3,6-trisulfonylchloride (NTSC) and piperazine (PIP) on porous polysulfone support membrane. The performance of the membrane was optimized by studying the preparation parameters including monomer content, reaction temperature and additive in organic phase. The separation performance of the resultant membrane was evaluated through permeation experiments, the membrane property was characterized by ATR-FTIR, XPS AFM , SEM and streaming potential measurements, and the acid stability was investigated through both static acid soaking tests and long-term permeation tests under acidic condition. After exposure to 20%(w/v) H 2 SO 4 for 2 months or running with 4.9%(w/v) H 2 SO 4 for 60 day, the PIP-NTSC composite membrane showed minor change in separation performance and no evident chemical change in the active skin layer, indicating that the developed membrane possessed good acid stability. The desired membrane exhibited a pure water permeability of about 5.8 l/m 2 h bar, a MWCO of as high as 5000 Da, and an attractive solute rejection of higher than 86.5% for a feed containing 500 mg/l Na 2 SO 4 at 0.5 MPa. Furthermore, the PIP-NTSC composite membrane could be used to treat acidic effluents from metal industries with good perm-selectivity and long-term stability.
研究领域:
材料科学
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环境工程
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产品关联
DOI
高影响因子
FUEL
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2017
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IF 4.601
Yannan Li,Jun Cheng,Leiqing Hu,Jianzhong Liu,Junhu Zhou,Kefa Cen
In order to reduce energy consumption of absorbent regeneration, an amine absorbent piperazine (PZ) was dissolved in an organic solvent N , N -dimethylformamide (DMF) to prepare a phase-changing PZ/DMF solution for CO 2 absorption with solid precipitate of PZ-carbamate. The CO 2 absorption capacity and peak rate of PZ/DMF solution were 22.9% and 29% higher than those of PZ/water solution, respectively. Based on differential scanning calorimetry/thermogravimetry experiments, biscarbamate PZ(CO 2 ) 2 2− and protonation PZ(H) 2 2+ compositions (34.5 wt%) in the PZ-carbamate precipitate mainly decomposed at peak temperature of 91.9 °C due to their instability, and then PZ(CO 2 ) composition (65.5 wt%) in the PZ-carbamate precipitate decomposed at peak temperature of 125.7 °C. The electrochemical corrosion tests and scanning electron microscopy revealed that PZ/DMF solution had much lower corrosivity than PZ/water solution.
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
CHIRALITY
·
2013
·Vol. 25
·期 10
·656-662
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IF 1.894
Yangmin Ma,Hao Wu,Jin Zhang,Yanchao Li
A series of single isomers tetrahydro- β -carboline diketopiperazines were stereoselectively synthesized starting from l -tryptophan methyl ester hydrochloride and six aldehydes through a four-step reaction including Pictet-Spengler reaction, crystallization-induced asymmetric transformations (CIAT), Schotten-Baumann reaction, and intramolecular ester amidation. The chemical structures were characterized by nuclear magnetic resonance (NMR) and elemental analysis, among which two compounds were determined by x-ray single crystal diffraction. Moreover, antimicrobial activities of all the compounds were also tested. Chirality 25:656–662, 2013 . © 2013 Wiley Periodicals, Inc.
研究领域:
有机化学
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药物化学
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微生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MEMBRANE SCIENCE
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2022
·
IF 10.53
Xiuzhen Wei,Xufeng Xu,Jiahao Huang,Ze Wang,Huan Li,Fangyuan Shao,Zhongquan Guo,Qinghua Zhou,Jinyuan Chen,Bingjun Pan
High-performance hollow fiber NF membranes with network structure were successfully prepared by introducing macromolecular polyvinyl alcohol (PVA) into aqueous phase to change the diffusion coefficient of amine monomer (piperazine, PIP) in organic phase. Based on Wilke-Change equation, a theoretical model (DAO) dealing with viscosity of aqueous phase, molecular weight of PVA, and diffusion coefficient of amine monomer in organic phase was proposed. The applicability of the DAO model was verified by ultraviolet spectrophotometry (UV) monitoring and one-dimensional diffusion model. Subsequently, the structure of NF membranes was analyzed by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The results suggested that the diffusion coefficient of amine monomer was negatively correlated with aqueous phase's viscosity and polymer's molecular weight. With PVA205 (Molecular weight is 205000 Da) used to change the viscosity of aqueous phase, the diffusion coefficient of PIP (in n-hexane) was close to 2.70 × 10 −6 cm 2 /s, and the resultant NF membrane (NF-PVA205-1) showed excellent performance; specifically, NF-PVA205-1 achieved a flux as 107 L/m 2 ·h (4 bar), which is 3.5-times higher than that of pure polyamide NF membrane, and the rejection rate for sodium sulfate can reach 97.9%. Such a facile fabrication method proposed in this study can balance the "trade-off" effect of traditional NF membrane.
研究领域:
材料科学
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化学工程
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产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2024
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IF 8.1
Libo Ba,Chen Chen,Rui Meng,Yuliang Chen,Yuliang Wu,Yijiang Liu,Weiwei Huang,Fei Yang,Jun Cheng,Xuesong Yi
High-efficiency polyamide nanofiltration membranes were recognized as crucial for alleviating freshwater scarcity. However, the rapid reaction rate between piperazine (PIP) and trimesoyl chloride (TMC) resulted in low membrane flux and suboptimal separation efficiency, which limited the application and development of membrane technology. Herein, a novel MOF-303@GO nanomaterials were prepared by in-situ growth method, which were anchored in the framework of the substrate membrane through a phase separation method to regulate the speed of interfacial polymerization reaction to improve the performance of composite nanofiltration membranes. The MOF-303@GO was found to exhibit an adsorption effect on PIP monomers for the accumulation of the PIP molecules around the MOF-303@GO in the membrane pore, which effectively slowed transfer rate of PIP. This process resulted in a thin PA layer and rough surface, which alleviated the resistance to water molecule transport during the membrane separation process. The adsorption mechanism between MOF-303@GO and PIP was profoundly demonstrated by density-functional theory calculations. Besides, the fabricated membrane demonstrated a good water permeability of 14.53 L·m −2 ·h −1 ·bar −1 , along as well as a high Na 2 SO 4 rejection of 96.56 %. This research provided a novel material to regulate the diffusion state of PIP molecules and introduced a key strategy for uniformly blending to modify the substrate membrane, offering a potential solution to the issue of excessively rapid IP reaction rates.
研究领域:
材料科学
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环境工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2024
·
IF 8.4
Ruijun Zhang,Qianzhi Sun,Jiayu Tian,Bart Van der Bruggen,Junyong Zhu
Sharpening the pore size distribution is challenging but highly efficacious to boost the performance of polyamide (PA) membranes in nanofiltration (NF). Herein, a facile and applicable strategy for narrowing the pore size distribution of a piperazine (PIP)-based NF membrane is proposed by introducing 1,3-diamino-2-propanol (DAP) into the aqueous phase. The results show that the selective layer can be effectively remodeled via the incorporation of DAP. A thicker, rougher and more hydrophilic selective layer with a narrowed pore size distribution can be attained by adding 0.03 w/v% DAP to the 0.1 w/v% PIP solution, which exhibited a pure water permeance (PWP) of 20.7 L m −2 h −1 ·bar −1 and a MgSO 4 rejection up to 97.4 %. This transformation can be attributed to the stronger polarity and higher reactivity of DAP compared to PIP. During the IP process modified by DAP, the strong polarity of DAP could result in a slower and more homogeneous diffusion of PIP into the organic phase through hydrogen interaction to facilitate a uniform interfacial polymerization reaction. Meanwhile, the higher reactivity of DAP could remedy the probably produced defects. This work provides a straightforward route for the regulation of NF membrane structure and performance.
研究领域:
材料科学
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膜技术
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Mengxiang Fang,Ying Xie,Yan Shao,Xiaoming Xu,Yang Xia,Man Mou,Ximing Hu,Tao Wang,Zihao Liu
The steel industry generates 7–9 % of the world’s anthropogenic carbon emissions. Carbon capture, utilization, and storage (CCUS) technologies for low carbon emissions from the steel industry have attracted research attention. Chemical absorption is the most mature and widely used carbon capture method, and reducing the energy consumption of this technology is currently a research hotspot. This work focused on the development of amine blends suitable for carbon capture in a top gas recycling-oxygen blast furnace (TGR-OBF) for low-carbon steelmaking and further reduction of carbon emissions. The effects of piperazine (PZ) and its derivatives on methyldiethanolamine (MDEA) activation were explored. PZ and 2-(piperazin-1-yl)ethanamine (AEP) most significantly activated MDEA. The best absorption and regeneration performance was achieved with aqueous amine solutions at the MDEA:PZ and MDEA:AEP ratios of 5:3 and 1:1, respectively. Blast furnace gas is rich in CO, and we verified that CO does not significantly affect the overall performance of the aqueous amine solution. The maximum absorption rate of the developed MAA absorbent was similar to that of 30 wt% monoethanolamine (MEA), and at 20 % and 35 % CO 2 , the cyclic capacities were 1.57 and 1.47 times greater than that of 30 wt% MEA, while the maximum regeneration rates were 2.13 and 1.92 times greater than those of 30 wt% MEA, respectively. A bench-scale CO 2 capture experiment performed at a flow rate of 4 Nm 3 /h verified the scale-up application potential of the absorbent. The regeneration energy of MAA under the optimal operating conditions was 2.86 GJ/ton CO 2 , which was 28.5 % lower than that of 30 wt% MEA. Moreover, MAA displayed a lower latent heat and lower reaction heat. The developed MAA absorbent has great adaptability and low regeneration energy and is expected to be applied in the steel industry to effectively reduce blast furnace carbon emissions.
研究领域:
环境科学
·
化学工程
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）