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1.
Top Curr Chem (Cham) ; 378(1): 14, 2020 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-31933069

RESUMO

Classical molecular simulations can provide significant insights into the gas adsorption mechanisms and binding sites in various metal-organic frameworks (MOFs). These simulations involve assessing the interactions between the MOF and an adsorbate molecule by calculating the potential energy of the MOF-adsorbate system using a functional form that generally includes nonbonded interaction terms, such as the repulsion/dispersion and permanent electrostatic energies. Grand canonical Monte Carlo (GCMC) is the most widely used classical method that is carried out to simulate gas adsorption and separation in MOFs and identify the favorable adsorbate binding sites. In this review, we provide an overview of the GCMC methods that are normally utilized to perform these simulations. We also describe how a typical force field is developed for the MOF, which is required to compute the classical potential energy of the system. Furthermore, we highlight some of the common analysis techniques that have been used to determine the locations of the preferential binding sites in these materials. We also review some of the early classical molecular simulation studies that have contributed to our working understanding of the gas adsorption mechanisms in MOFs. Finally, we show that the implementation of classical polarization for simulations in MOFs can be necessary for the accurate modeling of an adsorbate in these materials, particularly those that contain open-metal sites. In general, molecular simulations can provide a great complement to experimental studies by helping to rationalize the favorable MOF-adsorbate interactions and the mechanism of gas adsorption.


Assuntos
Gases/isolamento & purificação , Estruturas Metalorgânicas/química , Adsorção , Dióxido de Carbono/isolamento & purificação , Simulação por Computador , Hidrogênio/isolamento & purificação , Modelos Químicos , Modelos Moleculares , Método de Monte Carlo , Eletricidade Estática , Termodinâmica
3.
Nature ; 575(7781): 87-97, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31695213

RESUMO

The capture and use of carbon dioxide to create valuable products might lower the net costs of reducing emissions or removing carbon dioxide from the atmosphere. Here we review ten pathways for the utilization of carbon dioxide. Pathways that involve chemicals, fuels and microalgae might reduce emissions of carbon dioxide but have limited potential for its removal, whereas pathways that involve construction materials can both utilize and remove carbon dioxide. Land-based pathways can increase agricultural output and remove carbon dioxide. Our assessment suggests that each pathway could scale to over 0.5 gigatonnes of carbon dioxide utilization annually. However, barriers to implementation remain substantial and resource constraints prevent the simultaneous deployment of all pathways.


Assuntos
Dióxido de Carbono/economia , Dióxido de Carbono/isolamento & purificação , Sequestro de Carbono , Tecnologia/economia , Tecnologia/tendências , Dióxido de Carbono/metabolismo , Carvão Vegetal/metabolismo , Florestas , Microalgas/metabolismo , Fotossíntese , Solo/química
4.
Sensors (Basel) ; 19(8)2019 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-31013815

RESUMO

This paper proposes an IoT-based intelligent hydroponic plant factory solution called PlantTalk. The novelty of our approach is that the PlantTalk intelligence can be built through an arbitrary smartphone. We show that PlantTalk can flexibly configure the connections of various plant sensors and actuators through a smartphone. One can also conveniently write Python programs for plant-care intelligence through the smart phone. The developed plant-care intelligence includes automatic LED lighting, water spray, water pump and so on. As an example, we show that the PlantTalk intelligence effectively lowers the CO2 concentration, and the reduction speed is 53% faster than a traditional plant system. PlantTalk has been extended for a plant factory called AgriTalk.


Assuntos
Jardinagem/tendências , Hidroponia/métodos , Plantas , Smartphone , Dióxido de Carbono/isolamento & purificação , Humanos , Internet , Água/análise
6.
Environ Sci Pollut Res Int ; 26(16): 16195-16209, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30972683

RESUMO

CO2, SO2, and NO are the main components of flue gas and can cause serious environmental issues. Utilization of these compounds in oleaginous microalgae cultivation not only could reduce air pollution but could also produce feedstock for biodiesel production. However, the continuous input of SO2 and NO inhibits microalgal growth. In this study, the toxicity of simulated flue gas (15% CO2, 0.03% SO2, and 0.03% NO, balanced with N2) was reduced through automatic pH feedback control. Integrated lipid production and CO2 fixation with the removal of SO2 and NO was achieved. Using this technique, a lipid content of 38.0% DW was achieved in Chlorella pyrenoidosa XQ-20044. The lipid composition and fatty acid profile indicated that lipid production by C. pyrenoidosa XQ-20044 cultured with flue gas is suitable as a biodiesel feedstock; 81.2% of the total lipids were neutral lipids and 99.5% of the total fatty acids were C16 and C18. The ratio of saturated fatty acids to monounsaturated fatty acids in the microalgal lipid content was 74.5%. In addition, CO2, SO2, and NO from the simulated flue gas were fixed and converted to biomass and lipids with a removal efficiency of 95.9%, 100%, and 84.2%, respectively. Furthermore, the utilization efficiencies of CO2, SO2, and NO were equal to or very close to their removal efficiencies. These results provide a novel strategy for combining biodiesel production with biofixation of flue gas.


Assuntos
Biotecnologia/métodos , Chlorella/efeitos dos fármacos , Chlorella/metabolismo , Lipídeos/biossíntese , Poluentes Atmosféricos/química , Poluentes Atmosféricos/isolamento & purificação , Poluentes Atmosféricos/toxicidade , Biocombustíveis , Biomassa , Biotecnologia/instrumentação , Dióxido de Carbono/isolamento & purificação , Dióxido de Carbono/toxicidade , Chlorella/crescimento & desenvolvimento , Ácidos Graxos/análise , Ácidos Graxos/metabolismo , Concentração de Íons de Hidrogênio , Microalgas/efeitos dos fármacos , Microalgas/crescimento & desenvolvimento , Microalgas/metabolismo , Óxido Nítrico/isolamento & purificação , Óxido Nítrico/toxicidade , Dióxido de Enxofre/isolamento & purificação , Dióxido de Enxofre/toxicidade
8.
Artif Organs ; 43(8): 719-727, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30706485

RESUMO

Low flow extracorporeal veno-venous CO2 removal (ECCO2 R) therapy is used to remove CO2 while reducing ventilation intensity. However, the use of this technique is limited because efficiency of CO2 removal and potential beneficial effects on pulmonary hemodynamics are not precisely established. Moreover, this technique requires anticoagulation that may induce severe complications in critically ill patients. Therefore, our study aimed at determining precise efficiency of CO2 extraction and its effects on right ventricular (RV) afterload, and comparing regional anticoagulation with citrate to systemic heparin anticoagulation during ECCO2 R. This study was performed in an experimental model of severe hypercapnic acidosis performed in two groups of three pigs. In the first group (heparin group), pigs were anticoagulated with a standard protocol of unfractionated heparin while citrate was used for ECCO2 R device anticoagulation in the second group (citrate group). After sedation, analgesia and endotracheal intubation, pigs were connected to a volume-cycled ventilator. Severe hypercapnic acidosis was obtained by reducing tidal volume by 60%. ECCO2 R was started in both groups when arterial pH was lower than 7.2. Pump Assisted Lung Protection (PALP, Maquet, Rastatt, Germany) system was used to remove CO2 . CO2 extraction, arterial pH, PaCO2 as well as systemic and pulmonary hemodynamic were continuously followed. Mean arterial pH was normalized to 7.37 ± 1.4 at an extracorporeal blood flow of 400 mL/min, coming from 7.11 ± 1.3. RV end-systolic pressure increased by over 30% during acute hypercapnic acidosis and was normalized in parallel with CO2 removal. CO2 extraction was not significantly increased in citrate group as compared to heparin group. Mean ionized calcium and MAP were significantly lower in the citrate group than in the heparin group during ECCO2 R (1.03 ± 0.20 vs. 1.33 ± 0.19 and 57 ± 14 vs. 68 ± 15 mm Hg, respectively). ECCO2 R was highly efficient to normalize pH and PaCO2 and to reduce RV afterload resulting from hypercapnic acidosis. Regional anticoagulation with citrate solution was as effective as standard heparin anticoagulation but did not improve CO2 removal and lead to more hypocalcemia and hypotension.


Assuntos
Acidose/terapia , Anticoagulantes/uso terapêutico , Dióxido de Carbono/isolamento & purificação , Citratos/uso terapêutico , Oxigenação por Membrana Extracorpórea/métodos , Hipercapnia/terapia , Acidose/etiologia , Animais , Feminino , Heparina/uso terapêutico , Hipercapnia/complicações , Masculino , Respiração Artificial/métodos , Suínos
9.
Chem Commun (Camb) ; 55(22): 3235-3238, 2019 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-30809609

RESUMO

In this work, we propose a pH-regulated and target-activated fluorescent nanoprobe for highly selective monitoring of lysosomal azoreductase under hypoxia in living cells. We expect it will offer a potentially rich opportunity to understand the physiological processes of lysosomes under hypoxic conditions.


Assuntos
Dióxido de Carbono/isolamento & purificação , Hipóxia Celular , Corantes Fluorescentes/química , Lisossomos/enzimologia , NADH NADPH Oxirredutases/metabolismo , Nanoestruturas , Gás Natural , Adsorção , Humanos , Concentração de Íons de Hidrogênio , Cinética , Células MCF-7 , Transição de Fase , Termodinâmica
10.
Chem Commun (Camb) ; 55(24): 3449-3452, 2019 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-30747173

RESUMO

Bio-renewables are emerging as potential materials for CO2 sorption. Epinephrine is employed as a green scrubbing agent for CO2 capturing through the formation of a metal carbamate as proved by 1H, 13C and 1H-15N NMR and ex situ ATR-FTIR spectroscopy, as well as supported by quantum-chemical calculations.


Assuntos
Carbamatos/química , Dióxido de Carbono/isolamento & purificação , Epinefrina/química , Química Verde/métodos , Agentes Molhantes/química , Dióxido de Carbono/química , Modelos Moleculares
11.
Artif Organs ; 43(6): 599-604, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30431163

RESUMO

Extracorporeal removal of carbon dioxide in patients experiencing severe hypercapnia due to lung protective mechanical ventilation was first described over four decades ago. There have been many devices developed and described in the interim, many of which require additional training, resources, and staff. This manuscript describes a readily available and relatively simple adjunct that can provide partial lung support in patients with acute respiratory distress syndrome complicated by severe hypercapnia and acute kidney injury requiring dialysis.


Assuntos
Lesão Renal Aguda/terapia , Dióxido de Carbono/isolamento & purificação , Hipercapnia/terapia , Síndrome do Desconforto Respiratório do Adulto/terapia , Lesão Renal Aguda/complicações , Adulto , Oxigenação por Membrana Extracorpórea/métodos , Feminino , Humanos , Hipercapnia/complicações , Masculino , Pessoa de Meia-Idade , Diálise Renal/métodos , Síndrome do Desconforto Respiratório do Adulto/complicações , Ventiladores Mecânicos/efeitos adversos
12.
Trends Biotechnol ; 37(5): 532-547, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30447878

RESUMO

Microbial CO2 sequestration not only provides a green and sustainable approach for ameliorating global warming but also simultaneously produces biofuels and chemicals. However, the efficiency of microbial CO2 fixation is still very low. In addition, concomitant microbial CO2 emission decreases the carbon yield of desired chemicals. To address these issues, strategies including engineering CO2-fixing pathways and energy-harvesting systems have been developed to improve the efficiency of CO2 fixation in autotrophic and heterotrophic microorganisms. Furthermore, metabolic pathways and energy metabolism can be rewired to reduce microbial CO2 emissions and increase the carbon yield of value-added products. This review highlights the potential of biotechnology to promote microbial CO2 sequestration and provides guidance for the broader use of microorganisms as attractive carbon sinks.


Assuntos
Bactérias , Dióxido de Carbono , Sequestro de Carbono , Engenharia Metabólica , Bactérias/genética , Bactérias/metabolismo , Dióxido de Carbono/isolamento & purificação , Dióxido de Carbono/metabolismo
13.
Bioresour Technol ; 273: 592-598, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30481658

RESUMO

The aim of this study was to develop nanofibers containing nanoparticles with potential for the biological fixation of CO2 together with the microalgae Chlorella fusca LEB 111. An electrospinning technique was used for the production of polymeric nanofibers with different concentrations of iron oxide nanoparticles: 0, 2, 4, 6, 8, and 10% (w v-1). Nanofibers with a nanoparticle concentration of 4% (w v-1) were selected for use in the microalgal cultivation due to their smaller diameter (434 nm), high specific surface area (13.8 m2 g-1) and higher CO2 adsorption capacity (164.2 mg g-1). The microalgae C. fusca LEB 111 presented a higher CO2 biofixation rate of 216.2 mg L-1 d-1 when cultivated with these nanofibers. The results demonstrated the potential of electrospun nanofibers as physical adsorbents of CO2 since they can increase the contact time between the gas and the microorganism and consequently increase the CO2 biofixation by the microalgae.


Assuntos
Dióxido de Carbono/metabolismo , Chlorella/metabolismo , Microalgas/metabolismo , Nanofibras , Biomassa , Dióxido de Carbono/isolamento & purificação
14.
Biochemistry ; 58(11): 1470-1477, 2019 03 19.
Artigo em Inglês | MEDLINE | ID: mdl-30395445

RESUMO

Alarming changes in environmental conditions have prompted significant research into producing renewable commodities from sources other than fossil fuels. One such alternative is CO2, a determinate greenhouse gas with historically high atmospheric levels. If sequestered, CO2 could be used as a highly renewable feedstock for industrially relevant products and fuels. The vast majority of atmospheric CO2 fixation is accomplished by photosynthetic organisms, which have unfortunately proven difficult to utilize as chassis for industrial production. Nonphotosynthetic CO2 fixing microorganisms and pathways have recently attracted scientific and commercial interest. This Perspective will review promising alternate CO2 fixation strategies and their potential to supply microbially produced fuels and commodity chemicals, such as higher alcohols. Acetogenic fermentation and microbial electrosynthesis are the primary focuses of this review.


Assuntos
Ciclo do Carbono/fisiologia , Dióxido de Carbono/isolamento & purificação , Dióxido de Carbono/metabolismo , Biocombustíveis/microbiologia , Crescimento Quimioautotrófico/fisiologia , Fermentação , Fotossíntese , Engenharia de Proteínas/métodos , Engenharia de Proteínas/tendências
15.
Environ Sci Pollut Res Int ; 26(29): 29532-29543, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29872979

RESUMO

Li2CuO2 and different iron-containing Li2CuO2 samples were synthesized by solid state reaction. On iron-containing samples, atomic sites of copper are substituted by iron ions in the lattice (XRD and Rietveld analyses). Iron addition induces copper release from Li2CuO2, which produce cationic vacancies and CuO, due to copper (Cu2+) and iron (Fe3+) valence differences. Two different physicochemical conditions were used for analyzing CO2 capture on these samples; (i) high temperature and (ii) low temperature in presence of water vapor. At high temperatures, iron addition increased CO2 chemisorption, due to structural and chemical variations on Li2CuO2. Kinetic analysis performed by first order reaction and Eyring models evidenced that iron addition on Li2CuO2 induced a faster CO2 chemisorption but a higher thermal dependence. Conversely, CO2 chemisorption at low temperature in water vapor presence practically did not vary by iron addition, although hydration and hydroxylation processes were enhanced. Moreover, under these physicochemical conditions the whole sorption process became slower on iron-containing samples, due to metal oxides presence.


Assuntos
Dióxido de Carbono/isolamento & purificação , Cobre/química , Dióxido de Carbono/química , Ferro/química , Cinética , Lítio/química , Temperatura Ambiente , Água/química , Difração de Raios X
17.
J Am Chem Soc ; 140(40): 12662-12666, 2018 10 10.
Artigo em Inglês | MEDLINE | ID: mdl-30256632

RESUMO

A Zn benzotriazolate metal-organic framework (MOF), [Zn(ZnO2CCH3)4(bibta)3] (1, bibta2- = 5,5'-bibenzotriazolate), has been subjected to a mild CH3CO2-/HCO3- ligand exchange procedure followed by thermal activation to generate nucleophilic Zn-OH groups that resemble the active site of α-carbonic anhydrase. The postsynthetically modified MOF, [Zn(ZnOH)4(bibta)3] (2*), exhibits excellent performance for trace CO2 capture and can be regenerated at mild temperatures. IR spectroscopic data and density functional theory (DFT) calculations reveal that intercluster hydrogen bonding interactions augment a Zn-OH/Zn-O2COH fixation mechanism.


Assuntos
Materiais Biomiméticos/química , Dióxido de Carbono/isolamento & purificação , Estruturas Metalorgânicas/química , Triazóis/química , Zinco/química , Materiais Biomiméticos/síntese química , Anidrases Carbônicas/química , Domínio Catalítico , Ligações de Hidrogênio , Estruturas Metalorgânicas/síntese química , Modelos Moleculares , Triazóis/síntese química
18.
J Colloid Interface Sci ; 532: 433-440, 2018 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-30099307

RESUMO

Advanced porous organic materials with high gas storage capacity and high selectivity have been rapidly developed for CO2 adsorbents in the recent decade, due to extremely high surface area and nanoscale pore size. Here, novel amino acids-incorporated solid adsorbents based on porous hypercrosslinked polymers were fabricated by a dispersion polymerization of an aromatic monomer and quaternary ammonium salt comonomer, subsequently a hypercrosslinked reaction and an ion-exchange step. The developed adsorbents presented mesopores structure with BET surface area up to 864 m2/g and an extremely high CO2 capturing capacity up to 60.7 wt% (13.8 mmol/g) at 273 K/1 bar. The results also showed the adsorbent had an excellent recycling ability over repetitive adsorption-desorption cycles. All the results suggest that the amino acids-modified porous sorbents are promising CO2 sorbents that can meet the challenges of the current CO2 capture and storage technology.


Assuntos
Aminoácidos/química , Dióxido de Carbono/isolamento & purificação , Microesferas , Nanoporos , Adsorção , Reagentes para Ligações Cruzadas/química , Tamanho da Partícula , Polimerização , Polímeros/química , Porosidade
19.
N Biotechnol ; 46: 31-37, 2018 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-29909071

RESUMO

In order to limit ammonia (NH3) emissions from pig farms, various air cleaning solutions are widely applied. However, the literature data report that these systems (chemical scrubbers, bioscrubbers and biofilters) can be both inefficient and promote nitrous oxide (N2O) production. As air cleaning technologies should not contribute to secondary trace gases that may have a stronger environmental impact than the raw gas compounds themselves, the objective of this study was to quantify the effect of NH3 treatment in pig farms on greenhouse gas (GHG) emissions. GHGs (carbon dioxide, methane and nitrous oxide) emitted at the outlet of three different cleaning systems ("chemical scrubber", "bioscrubber" and "bioscrubber + denitrification step") were assessed and compared with the emissions generated by the exhaust air with "no treatment". The calculations show that the chemical scrubber has no effect whereas biological treatments can increase GHG emissions. The use of bioscrubbers alone for NH3 removal can remain acceptable provided that less than 3% of the NH3 entering the apparatus is converted into N2O. In such cases, a maximum increase of 1.9% in GHG emissions could be obtained. Conversely, the addition of a denitrification step to a bioscrubber must be avoided. Increases in overall GHG emissions of up to 25.8% were calculated but more significant increases could occur. With regard to GHG emissions, it is concluded that the use of a chemical scrubber is more suitable than a bioscrubber to treat exhaust air from pig farms.


Assuntos
Amônia/isolamento & purificação , Dióxido de Carbono/isolamento & purificação , Monitoramento Ambiental , Fazendas , Gases de Efeito Estufa/isolamento & purificação , Metano/isolamento & purificação , Óxido Nitroso/isolamento & purificação , Sus scrofa/metabolismo , Animais , Gases de Efeito Estufa/química
20.
Int J Biol Macromol ; 117: 189-198, 2018 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-29803747

RESUMO

CO2 capture by immobilized carbonic anhydrase (CA) has become an alternative and environmental friendly approach in CO2 sequestration technology. However, the immobilized CA usually exhibits low CO2 sequestration efficiency due to no gas adsorption function for the conventional CA supports. Metal organic frameworks (MOFs) are an excellent material for gas adsorption and enzyme immobilization. Herein, a combined immobilization system of CA and ZIF-8 with cruciate flower-like morphology for CO2 adsorption was prepared for the first time by adsorbing CA onto ZIF-8. The immobilization efficiency was greater than 95%, and the maximum activity recovery reached 75%, indicating the highly efficient immobilization process. The resultant CA@ZIF-8 composites exhibited outstanding thermostability, the tolerance against denaturants, and reusability compared with free CA. Furthermore, we demonstrated for the first time that the shape of ZIF-8 could be controlled by adjusting concentrations of Zn2+ ions at the high concentration of 2-methylimidazole (1 M). More importantly, we also demonstrated the applicability of the CA@ZIF-8 composites to the sequestration of CO2 in carbonate minerals. The yields of the CaCO3 obtained by using CA@ZIF-8 composites were 22-folds compared to free CA. Thus, this CA@ZIF-8 composite can be successfully used as a robust biocatalyst for sequestration of CO2.


Assuntos
Dióxido de Carbono/química , Dióxido de Carbono/isolamento & purificação , Anidrases Carbônicas/química , Enzimas Imobilizadas/química , Estruturas Metalorgânicas/química , Adsorção , Biocatálise , Anidrases Carbônicas/metabolismo , Enzimas Imobilizadas/metabolismo , Imidazóis/química , Cinética , Nanopartículas/química , Porosidade
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