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1.
Environ Sci Technol ; 58(16): 7020-7031, 2024 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-38608167

RESUMO

Adjusting the electronic state of noble metal catalysts on a nanoscale is crucial for optimizing the performance of nanocatalysts in many important environmental catalytic reactions, particularly in volatile organic compound (VOC) combustion. This study reports a novel strategy for optimizing Pt catalysts by modifying their electronic structure to enhance the electron density of Pt. The research illustrates the optimal 0.2Pt-0.3W/Fe2O3 heterostructure with atomic-thick WO3 layers as a bulking block to electronically modify supported Pt nanoparticles. Methods such as electron microscopy, X-ray photoelectron spectroscopy, and in situ Fourier transform infrared spectroscopy confirm Pt's electron-enriched state resulting from electron transfer from atomic-thick WO3. Testing for benzene oxidation revealed enhanced low-temperature activity with moderate tungsten incorporation. Kinetic and mechanistic analyses provide insights into how the enriched electron density benefits the activation of oxygen and the adsorption of benzene on Pt sites, thereby facilitating the oxidation reaction. This pioneering work on modifying the electronic structure of supported Pt nanocatalysts establishes an innovative catalyst design approach. The electronic structure-performance-dependent relationships presented in this study assist in the rational design of efficient VOC abatement catalysts, contributing to clean energy and environmental solutions.

2.
Environ Sci Technol ; 58(9): 4145-4154, 2024 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-38381076

RESUMO

The deactivation of selective catalytic reduction (SCR) catalysts caused by alkali metal poisoning remains an insurmountable challenge. In this study, we examined the impact of Na poisoning on the performance of Fe and Mo co-doped TiO2 (FeaMobTiOx) catalysts in the SCR reaction and revealed the related alkali resistance mechanism. On the obtained Fe1Mo2.6TiOx catalyst, the synergistic catalytic effect of uniformly dispersed FeOx and MoOx species leads to remarkable catalytic activity, with over 90% NO conversion achieved in a wide temperature range of 210-410 °C. During the Na poisoning process, Na ions predominantly adsorb on the MoOx species, which exhibit stronger alkali resistance, effectively safeguarding the FeOx species. This preferential adsorption minimizes the negative effect of Na poisoning on Fe1Mo2.6TiOx. Moreover, Na poisoning has little influence on the Eley-Rideal reaction pathway involving adsorbed NHx reacting with gaseous NOx. After Na poisoning, the Lewis acid sites were deteriorated, while the abundant Brønsted acid sites ensured sufficient NHx adsorption. As a benefit from the self-defense effects of active MoOx species for alkali capture, FeaMobTiOx exhibits exceptional alkali resistance in the SCR reaction. This research provides valuable insights for the design of highly efficient and alkali-resistant SCR catalysts.


Assuntos
Álcalis , Amônia , Catálise , Ácidos de Lewis , Metais
3.
J Environ Sci (China) ; 140: 146-156, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38331496

RESUMO

Non-aqueous absorbents (NAAs) have attracted increasing attention for CO2 capture because of their great energy-saving potential. Primary diamines which can provide high CO2 absorption loading are promising candidates for formulating NAAs but suffer disadvantages in regenerability. In this study, a promising strategy that using tertiary amines (TAs) as proton-transfer mediators was proposed to enhance the regenerability of an aminoethylethanolamine (AEEA, diamine)/dimethyl sulfoxide (DMSO) (A/D) NAA. Surprisingly, some employed TAs such as N,N-diethylaminoethanol (DEEA), N,N,N',N'',N''-pentamethyldiethylenetriamine (PMDETA), 3-dimethylamino-1-propanol (3DMA1P), and N,N-dimethylethanolamine (DMEA) enhanced not only the regenerability of the A/D NAA but also the CO2 absorption performance. Specifically, the CO2 absorption loading and cyclic loading were increased by about 12.7% and 15.5%-22.7%, respectively. The TA-enhanced CO2 capture mechanism was comprehensively explored via nuclear magnetic resonance technique and quantum chemical calculations. During CO2 absorption, the TA acted as an ultimate proton acceptor for AEEA-zwitterion and enabled more AEEA to form carbamate species (AEEACOO-) to store CO2, thus enhancing CO2 absorption. For CO2 desorption, the TA first provided protons directly to AEEACOO- as a proton donor; moreover, it functioned as a proton carrier and facilitated the low-energy step-wise proton transfer from protonated AEEA to AEEACOO-. Consequently, the presence of TA made it easier for AEEACOO- to obtain protons to decompose, resulting in enhanced CO2 desorption. In a word, introducing the TA as a proton-transfer mediator into the A/D NAA enhanced both the CO2 absorption performance and the regenerability, which was an efficient way to "kill two birds with one stone".


Assuntos
Dióxido de Carbono , Etanolaminas , Prótons , Aminas , Diaminas
4.
J Environ Sci (China) ; 140: 331-340, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38331512

RESUMO

Bi2O3 catalyst with Bi-O bond crystal structure has more active sites, which shows better CO2 catalytic performance than pure Bi catalysts in many catalytic reactions. How to strengthen the Bi-O bond in Bi2O3 to obtain higher selectivity and catalytic activity is a problem worthy of consideration. Here, we develop a N2 pre-reduced spherical Bi2O3/ATO catalyst that has a high formate Faradaic efficiency of 92.7%, which is superior to the existing tin oxide catalyst. Detailed electrocatalytic analysis shows that N2 pre-reduction and spherical structure are helpful for Sn to stabilize the oxidation state of Bi, thus retaining part of the Bi-O structure. The existence of the Bi-O structure can reduce the energy barrier of the CO2 production *OCHO reaction and promote the reaction rate of the CO2-*OCHO-HCOOH path, thus promoting the formation of formate.


Assuntos
Dióxido de Carbono , Formiatos , Catálise
5.
J Hazard Mater ; 467: 133705, 2024 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-38335618

RESUMO

Generation of sulfate radicals (SO4•-) from sulfite activation has emerged as a promising method for abatement of organic pollutants in the water and wastewater treatment. Co(II) has garnered attention due to its high catalytic activity in the sulfite activation, which is compromised by the slow Co(II)/Co(III) redox cycling. Regarding the regulation of Co(II) electronic structure via the complexation effect, monoethanolamine (MEA), a common chelator, is introduced into the Co(II)/sulfite system. MEA addition results in a significant improvement in iohexol abatement efficiency, increasing from 40% to 92%. The superior iohexol abatement relies on the involvement of SO4•-, hydroxyl radicals (HO•) and Co(IV). Hydrogen radical (•H) is unexpectedly detected, acting as a strong reducing agent, contributing to the reduction of Co(III). This enhancement of sulfite activation by MEA is due to the formation of the Co(II)-MEA complex, in which the complexation ratio of Co(II) and MEA is critical. Electrochemical characterization and theoretical calculations demonstrate that the complexation can facilitate the Co(II)/Co(III) redox cycling with the concomitant enhancement of sulfite activation. This work provides a new insight into the Co(II)/sulfite system in the presence of organic ligands.

6.
J Environ Manage ; 350: 119584, 2024 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-38035501

RESUMO

The growing demand for pesticide manufacturing and increasing public awareness of sustainable development, have let to urgent requirements for a refined environmental management framework. It is imperative to conduct process-based life cycle assessments (LCAs) to promote clean and environment-friendly technologies. Herein, the cradle-to-gate LCA of glyphosate production was executed as an example to investigate crucial production factors (materials or energy) and multiple environmental impacts during the production processes. Results showed that methanol caused the highest environmental damage in terms of toxicity, with a normalized value of 85.7 × 10-8, followed by coal-fired electricity in 6.00 × 10-8. Furthermore, optimized schemes were proposed, including energy improvement (electricity generated by switching from coal-fired power to solar power) and wastewater targeted conversion. Regarding the normalization results before and after optimization, the latter showed more significant results with the normalized value decreasing by 21.10 × 10-8, while that of the former only decreased by 6.50 × 10-8. This study provides an integrated LCA framework for organophosphorus pesticides (OPs) from upstream control and offers an important supplement to managing the key pollution factors and control links of the OP industry. Moreover, it reveals the positive influence of optimized schemes in facilitating cleaner production technologies, thus ultimately promoting new methodologies for resource recycling.


Assuntos
Praguicidas , Animais , Compostos Organofosforados , Carvão Mineral , Estágios do Ciclo de Vida
7.
Langmuir ; 39(43): 15343-15354, 2023 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-37857276

RESUMO

Volatile organic compounds such as benzene are hazardous air pollutants that require effective elimination. Noble metal-based catalysts exhibit high benzene combustion activity, but their prohibitive cost necessitates strategies to enhance utilization efficiency. This study investigates a Pt-Cu alloy catalyst for improved benzene combustion by preferentially exposing Pt active sites through Cu alloying. Aberration-corrected scanning transmission electron microscopy and X-ray spectroscopy characterize the nanoscale distribution and enrichment of Pt on the alloy surface. Kinetic measurements demonstrate substantially enhanced activity compared with Pt catalysts, attributed to increased Pt metallic site exposure rather than alteration of the reaction mechanism. In situ Fourier transform infrared (FTIR) spectroscopy reveals a higher abundance of terrace-like Pt sites in the alloy, beneficial for benzene adsorption. Partial pressure dependence analyses indicate competitive adsorption of benzene and O2, following Langmuir-Hinshelwood kinetics. These findings provide conceptual insights into tuning surface composition in bimetallic catalysts to optimize noble metal efficiency, with broad applicability for sustainable catalytic process advancement.

8.
Sci Total Environ ; 905: 166826, 2023 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-37673253

RESUMO

The fine chemical industry is currently facing challenges in energy saving, material conservation, and pollution reduction due to the dual policy pressure of precise system management and collaborative pollution and carbon reduction. However, the interweaving of materials and energy input-output was not well understood due to the incomplete coverage and the lack of a generic framework. Therefore, a methodology based on the energy-material-pollution (E-M-P) coupling nexus was proposed to quantitatively assess multi-level coupling. According to the selected generic 32 coupling units, two representative glyphosate (PMG) production processes were taken as case studies. Quantification results showed that the solvent element and the material system had a higher priority. Moreover, Process 2 owned a greater optimization potential as the coupling relationship pairs were 2.55 compared to 2.32 for Process 1, and the correlation proportions of material systems reached 69.26 % and 56.92 %, respectively. In addition, assessment results indicated that Process 2 was more environmentally friendly because of the lower ecological indexes (9.7 GPt vs. 15.8 GPt) and weaker carbon footprint (CF) (1.16E+08 vs. 2.32E+08). Combined coupling nexus and environmental assessment organically, methanol had the most optimization potential and was beneficial for the measures such as solvent substitution. This work offered theory and practice guidance with demonstrative value to support the sustainable development of precise system management.

9.
J Hazard Mater ; 454: 131434, 2023 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-37146337

RESUMO

Achieving high atomic utilization and low cost of desirable Pt/TiO2 catalysts is a major challenge for room temperature HCHO oxidation. Here, the strategy of anchoring stable Pt single atoms by abundant oxygen vacancies over TiO2-nanosheet-assembled hierarchical spheres (Pt1/TiO2-HS) was designed to eliminate HCHO. A superior HCHO oxidation activity and CO2 yield (∼100% CO2 yield) at relative humidity (RH) > 50% over Pt1/TiO2-HS is achieved for long-term run. We attribute the excellent HCHO oxidation performance to the stable isolated Pt single atoms anchored on the defective TiO2-HS surface. The Ptδ+ on the Pt1/TiO2-HS surface has a facile intense electron transfer with the support by forming Pt-O-Ti linkages, driving HCHO oxidation effectively. Further in situ HCHO-DRIFTS revealed that the dioxymethylene (DOM) and HCOOH/HCOO- intermediates were further degraded via active OH- and adsorbed oxygen on the Pt1/TiO2-HS surface, respectively. This work may pave the way for the next generation of advanced catalytic materials for high-efficiency catalytic HCHO oxidation at room temperature.

10.
Water Res ; 222: 118930, 2022 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-35944409

RESUMO

Recently, iron-based heterogenous catalysts have received much attention in the activation of peracetic acid (PAA) for generating reactive radicals to degrade organic pollutants, yet the PAA activation efficiency is compromised by the slow transformation from Fe(III) to Fe(II). Herein, considering the electron-donating ability of reducing sulfur species, a novel advanced oxidation process by combining pyrite and PAA (simplified as pyrite/PAA) for the abatement of tetracycline (TC) is proposed in this study. In the pyrite/PAA process, TC can be completely removed within 30 min under neutral conditions by the synergy of homogeneous and heterogenous Fe(II) species. CH3C(O)OO• is the main radical generated from the pyrite/PAA process responsible for TC abatement. The excellent activation properties of pyrite can be attributed to the superior electron-donating ability of reducing sulfur species to facilitate the reduction of Fe(III). Meanwhile, the complexation of leached Fe2+ with TC favors PAA activation and concomitant TC abatement. In addition, the degradation pathways of TC and the toxicity of the degradation intermediates are analyzed. The pyrite/PAA process shows an excellent TC abatement efficacy in the pH range of 4.0∼10.0. The coexistence of Cl-, HCO3-, and HPO42- exhibits negligible effect on TC abatement, while the HA slightly inhibits the abatement rate of TC. This study highlights the efficient activation of PAA by pyrite and the important role of sulfur in promoting the conversion of Fe(III) to Fe(II) in the pyrite/PAA process.


Assuntos
Ácido Peracético , Poluentes Químicos da Água , Compostos Férricos , Compostos Ferrosos , Peróxido de Hidrogênio/química , Ferro/química , Oxirredução , Sulfetos , Enxofre , Tetraciclina
11.
Ecotoxicol Environ Saf ; 234: 113411, 2022 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-35298971

RESUMO

Formaldehyde (CHOH), a common volatile organic compound, causes many adverse effects on human health. The highly exposed TiO2(001) facet possesses a high photodegradation efficiency of CHOH due to its excellent ability to trap photogenerated holes and high density of surface unsaturated Ti atoms (Ti5c) to bind CHOH. However, the rapid recombination of photoinduced electron-hole pairs of TiO2(001) limits the photodegradation efficiency. We adopted a strategy of decorating TiO2(001) with g-C3N4 quantum dots (QDs), exploiting the quantum effect of g-C3N4QDs and their combined staggered band structure. This decoration improves the photocatalytic activity of TiO2(001). Moreover, the chemical configuration of g-C3N4QDs/TiO2(001) and the combination mode between the g-C3N4QDs and TiO2(001) support were explored in detail using high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), and density functional theory (DFT) calculations. Following the physiochemical characteristic results, the transport mechanism of photoinduced carriers was further analyzed by ultraviolet photoelectron spectroscopy (UPS), electron paramagnetic resonance (EPR), and Heyd-Scuseria-Ernzerh (HSE) exchange-correlation functional calculations. Finally, the performance and reaction mechanism of the photodegradation of CHOH by TiO2(001) and g-C3N4QDs/TiO2(001) were thoroughly investigated. The results show that the g-C3N4QDs were composed of an N-defect tri-s-triazine supported by TiO2(001) via a strong C-O-Ti chemical bond, which accelerated the separation of photoinduced carriers through a Z-scheme route. The photodegradation and mineralization efficiencies of CHOH were significantly promoted by 30% and 60% for g-C3N4QDs/TiO2(001) compared with those of TiO2(001). The photodegradation mechanism proceeded as CHOH - dioxymethylene - formate - carbonate - CO2. This study provides a surface engineering means to design highly active modified TiO2 for CHOH photodegradation.

12.
J Hazard Mater ; 424(Pt D): 127653, 2022 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-34801301

RESUMO

Peracetic acid (PAA) is an excellent oxidant that can produce multiple carbon-centered radicals (R•C). A novel advanced oxidation process (AOP) that combines PAA and nanoscale zero-valent iron (i.e. nZVI/PAA) is constructed to evaluate its performance toward tetracycline (TC) abatement. The nZVI/PAA process shows excellent abatement efficacy for TC in the pH range of 3.5-7.5. The presence of humic acid, HPO42- and HCO3- exerts inhibitory effects on TC abatement, while the presence of Cl- displays negligible influence in the nZVI/PAA process. Nanoscale zero-valent iron (nZVI) exhibits excellent reusability with no apparent variation in crystallinity. CH3C(O)OO• is the predominant active radical that contributes to TC abatement, in which leakage of Fe(II) from the nZVI surface is crucial for a radical generation. Due to the strong complexation tendency of TC towards Fe(II), the Fe(II)-TC complexes are formed, which significantly accelerates the PAA decomposition and TC abatement compared to free Fe(II). In addition, the degradation intermediates of TC are identified, and a possible degradation pathway is proposed. These results will be useful for the application of PAA-based AOPs in the treatment of water containing organic micropollutants.


Assuntos
Ácido Peracético , Poluentes Químicos da Água , Compostos Ferrosos , Ferro , Tetraciclina , Poluentes Químicos da Água/análise
13.
Environ Sci Pollut Res Int ; 29(10): 13805-13821, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34599445

RESUMO

TiO2-based photocatalysts are a potential technology for removing indoor formaldehyde (CHOH) owing to their strong photooxidation ability. However, their photooxidation performance is generally weakened when suffering from the competitive adsorption of H2O. In a method inspired by the oxygen evolution reaction (OER) to generate intermediates with hydroxyl radicals on the anode electrode catalysts, an electric field was employed in this research and applied to the photooxidation of CHOH to prevent the competitive adsorption of H2O. Additionally, 0.5-5% Fe2O3 decorated TiO2 was employed to improve the photoelectrocatalytic activity. The influence of an electric field on hydroxyl-radical production was investigated by both density functional theory (DFT) with direct-imposed dipole momentum and photoelectrocatalytic experimental tests. The surface characterization of the photocatalysts, including transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and electron paramagnetic resonance (EPR), was conducted. DFT results show that a positive electric field with a strength of 0.05 Å/V was more favorable to produce hydroxyl on Fe2O3/TiO2(010) than was a negative electric field. Fe2O3 decoration can significantly boost hydroxyl formation, resulting from a decrease in the binding energy between the Fe of Fe2O3 and the oxygen and hydrogen atoms of H2O. The dissociated hydrogen atom of the H2O preferentially remained on the catalysts' surface rather than being released into the gas flow. The experimental results demonstrated that applying 150 V could not directly enhance the photooxidation of CHOH by either TiO2 or Fe2O3/TiO2 but that it could relieve the H2O inhibitory effect by more than 10% on the Fe2O3/TiO2.


Assuntos
Titânio , Água , Catálise , Formaldeído
14.
J Hazard Mater ; 418: 126289, 2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-34102355

RESUMO

Slow progress in discovering new catalysts to circumvent the problem of ammonium bisulfate (NH4HSO4, ABS) poisoning has hindered further development of selective catalytic reduction (SCR) technology of NOx with ammonia (from numerous industrial processes) in afterburning systems at temperatures below dew point of ABS (typically between 280 °C and 320 °C). Recently, we have explored the use of atomically dispersed Mo species on TiO2 particles (hereafter denoted as MoO3/TiO2) as highly efficient catalyst for NH3-SCR reaction. In the present study, it will be shown that this type of catalyst is highly resistant to ABS poisoning for NH3-SCR reaction, overcoming a major issue afflicting the application of commercial V2O5-WO3/TiO2 catalyst at temperatures below the dew point of ABS. Aberration-corrected scanning transmission electron microscopy (STEM) suggests that most of the Mo species are present in atomically dispersed form in the MoO3/TiO2 catalyst. SO2 oxidation measurements show that the MoO3/TiO2 catalyst exhibits a substantially lower SO2 oxidation rate compared to the commercial V2O5-WO3/TiO2, mitigating ABS formation. Furthermore, decomposition of ABS on MoO3/TiO2 surface is found to be extremely facile. Temperature-programmed surface reaction (TPSR) with NO shows that the decomposition temperature of ABS over MoO3/TiO2 is 70 °C lower than that found on the commercial V2O5-WO3/TiO2 catalyst. Our investigations provide valuable information for the development of NH3-SCR catalysts with exceptional resistance to ABS poisoning for NOx emission control.

15.
Chem Commun (Camb) ; 57(40): 4942-4945, 2021 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-33876164

RESUMO

Our work sheds light on using the O 2p-band center as a useful electronic descriptor for understanding the variations in catalytic reducibility of transition metal oxides (TMOs) and the promotional effect of MnO2 during catalytic benzene combustion. The "volcano"-type activity plot, in conjunction with the reduction characteristic of the TMOs, ultimately reflects the Sabatier principle, which states that a good catalyst (i.e., MnO2) balances the capability of oxygen abstraction and uptake in the case of benzene combustion.

16.
J Hazard Mater ; 406: 124535, 2021 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-33302186

RESUMO

This study aims to investigate the coeffects of predominantly exposed anatase TiO2{001} and {101} and CeO2 loading on the photo-oxidation of Hg0 to relieve the adverse effects caused by higher temperatures of 50-250 °C. The effect of loading CeO2 on the photocatalytic activity of morphology-controlled TiO2 was not only investigated using DFT with U correction but also experimentally analyzed by characterizing the electrochemical properties and the formation of free radicals. The theoretical calculation showed that CeO2 loading on TiO2{101} was more stable than that on TiO2{001}. Accordingly, a larger portion of CeO2 was observed to anchor to the (101) plane than to the (001) plane. CeO2 loading is more beneficial for increasing the distribution of photo-induced electrons and holes on the surface of 7%CeTi than on the surface of TiO2 and increases the energy difference between the conduction band edge of 7%CeTi and the standard redox potential of O2/·O2-. Correspondingly, the photocatalytic removal efficiencies (PREs) of Hg0 by 7%CeTi were significantly enhanced compared with those of pristine TiO2. The effect of CeO2 was highly morphologically dependent on the photocatalytic activity. This study provides valuable insight into surface engineering strategies for morphology-controlled photocatalysts for air pollution control technology.

17.
Environ Sci Technol ; 54(12): 7078-7087, 2020 06 16.
Artigo em Inglês | MEDLINE | ID: mdl-32407624

RESUMO

The commercially available V2O5/WO3-TiO2 is a well-known catalyst for selective catalytic reduction (SCR) of NO with NH3. When alkali ions are present in the exhaust (e.g., as impurities such as dust) of a reactor containing commercial V2O5/WO3-TiO2, alkali poisoning occurs, deactivating the catalyst. Consequently, there is substantial interest in the development of better-performing and more durable NH3-SCR catalysts with an improved resistance to alkali deactivation. For the present study, the protonated (H+) form of zeolite Y, HY, was used as a support and acted as buffer zone, leading to trapping (sticking) of foreign alkali poisons in the zeolite pore structure, preventing alkali poisoning of the Fe2O3/HY catalyst. Catalytic tests showed that the Fe2O3/HY retained 100% of its original catalytic reactivity for NH3-SCR reaction even after 1000 µmol Na+ g-1 poisoning. 1000 µmol Na+ g-1 treatment indicates a 26 000-h exposure under an alkaline dust-containing condition. In contrast, upon 1000 µmol Na+ g-1 treatment, severe alkali deactivation occurred for a commercial V2O5/WO3-TiO2. The catalyst activity of Fe2O3/HY remained unchanged because of the intercalation of Na+ in the internal HY zeolite pores that impedes the blocking of Na+ poison to the external active sites of Fe2O3. The findings in this work suggest that the zeolite HY may be revealed as an attractive building block for designing an alkali poisoning-resistant catalyst.


Assuntos
Zeolitas , Álcalis , Amônia , Catálise , Titânio , Emissões de Veículos
18.
Environ Sci Pollut Res Int ; 27(21): 26965-26973, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32385823

RESUMO

Amino-functionalized ionic liquid biphasic solvents present excellent absorption capacity, regeneration ability, and energy consumption savings, which make them a possible candidate for CO2 capture. The kinetics and regeneration heat duty of the [TETAH][Lys]-ethanol-water system capturing CO2 were investigated in this work. The mass transfer and kinetic parameters, including the overall reaction rate constant (kov), the reaction rate constant (k2), and the enhancement factor (E), were assessed at diverse concentrations and temperatures. At 303.15 K, the k2 of CO2 capture into the [TETAH][Lys]-ethanol-water solution was 58,907.30 m3 kmol-1 s-1. The Arrhenius equation was introduced to evaluate the relations between k2 and the reaction temperature, which can be presented as [Formula: see text] The regeneration heat duty of the novel biphasic solvent was 35.5 and 62.39% lower than those of [TETAH][Lys]-water and the benchmark monoethanolamine solution, respectively. An efficient absorption performance and lower energy requirement indicate the great potential for this application.


Assuntos
Dióxido de Carbono , Líquidos Iônicos , Temperatura Alta , Cinética , Solventes
19.
Environ Sci Technol ; 54(10): 6281-6288, 2020 05 19.
Artigo em Inglês | MEDLINE | ID: mdl-32320224

RESUMO

To address the problems of high viscosity and difficult regeneration of the rich phase solution, a dual-functionalized ionic liquid ([DETAH][Tz]) was dissolved into a 1-propanol-water solvent to form a novel biphasic solvent for CO2 capture. The rich phase kept 96% of the total CO2 loading (1.713 mol mol-1) but only 44% of the total volume, and its viscosity was only 2.57 mPa s. As a regeneration promoter, 1-propanol helped the rich phase to maintain 90% of its initial loading after fifth regeneration. The high number of amine functional groups into [DETAH]+ and the equimolar reaction of [Tz]- provided the high CO2 loading, while [Tz]-H and 1-propanol ensured the high regeneration efficiency of the rich solution by enhancing the hydrolysis of RNCOO- to form HCO3-/CO32- and propyl carbonate. Due to a stronger polar and an aggregation of the CO2 absorption products in water, the CO2 products were enriched into the lower water phase while most of the 1-propanol was in the upper phase. The heat duty of [DETAH][Tz]-1-propanol-water was approximately 29.93% lower than [DETAH][Tz]-water (2.84 GJ ton-1 CO2) and 47.63% lower than MEA (3.80 GJ ton-1 CO2), which would be a promising candidate for CO2 capture.


Assuntos
Dióxido de Carbono , Líquidos Iônicos , Aminas , Solventes , Água
20.
Environ Sci Pollut Res Int ; 27(20): 25197-25208, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32347496

RESUMO

Sustainable management of dyeing industry is of paramount importance in order to minimize resource consumption and reduce related environmental impacts. Herein, an environmental study is conducted wherein life cycle assessment (LCA) is applied to a two-scenario process for Disperse blue 60 production with short and long processing chains with different (a) material types, (b) consumptions, (c) processes, and (d) functional units with yields of 300 t/a. The most important influenced substances of the two scenarios were sodium cyanide and electricity next. Results proved that the largest damage of the dye production was attributed to resources and reached 46 and 62 kPt in the two scenarios. Compared with the conventional coal-fired power generation, damaged values of electricity from nature gas (NG) could reduce from 102 to 86 kPt in scenarios 1 and from 123 to 104 kPt in scenarios 2, respectively. When the electricity switched from NG to solar power, the values of the two scenarios could further decrease by 17 and 27 kPt, respectively. Therefore, the process of scenario 1 with the short process chain was more environmentally friendly for the production of Disperse blue 60 owing to the more efficient process and lower resource consumption. Graphic abstract.


Assuntos
Carvão Mineral , Meio Ambiente , Eletricidade , Gás Natural
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