scholarly journals Solar Fuels by Heterogeneous Photocatalysis: From Understanding Chemical Bases to Process Development

2018 ◽  
Vol 2 (3) ◽  
pp. 42 ◽  
Author(s):  
Alberto Olivo ◽  
Danny Zanardo ◽  
Elena Ghedini ◽  
Federica Menegazzo ◽  
Michela Signoretto
Keyword(s):  
Carbon Dioxide ◽  
Process Development ◽  
High Energy ◽  
Heterogeneous Photocatalysis ◽  
Catalyst Design ◽  
Solar Fuels ◽  
Reaction Pathways ◽  
Mechanistic Insight ◽  
Carbon Dioxide Photoreduction ◽  
Photocatalytic Reactions

The development of sustainable yet efficient technologies to store solar light into high energy molecules, such as hydrocarbons and hydrogen, is a pivotal challenge in 21st century society. In the field of photocatalysis, a wide variety of chemical routes can be pursued to obtain solar fuels but the two most promising are carbon dioxide photoreduction and photoreforming of biomass-derived substrates. Despite their great potentialities, these technologies still need to be improved to represent a reliable alternative to traditional fuels, in terms of both catalyst design and photoreactor engineering. This review highlights the chemical fundamentals of different photocatalytic reactions for solar fuels production and provides a mechanistic insight on proposed reaction pathways. Also, possible cutting-edge strategies to obtain solar fuels are reported, focusing on how the chemical bases of the investigated reaction affect experimental choices.

scholarly journals From sugars to FDCA: a techno-economic assessment using a design concept based on solvent selection and carbon dioxide emissions

2021 ◽  
Author(s):  
Amir Al Ghatta ◽  
James D. E. T. Wilton-Ely ◽  
Jason P. Hallett
Keyword(s):  
Carbon Dioxide ◽  
Carbon Dioxide Emissions ◽  
Process Development ◽  
Economic Assessment ◽  
Design Concept ◽  
Selling Price ◽  
Solvent Selection ◽  
Current Process ◽  
Process Simulations ◽  
Solvent Systems

Process simulations allow the evaluation of the emissions and selling price for the production of the key monomer FDCA based on different feedstocks and solvent systems, alongside considerations of safety and current process development.

Light-driven reduction of carbon dioxide: Altering the reaction pathways and designing photocatalysts toward value-added and renewable fuels

2021 ◽  
Vol 237 ◽  
pp. 116547
Author(s):  
Quyet Van Le ◽  
Van-Huy Nguyen ◽  
Trinh Duy Nguyen ◽  
Ajit Sharma ◽  
Gul Rahman ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Value Added ◽  
Reaction Pathways ◽  
Renewable Fuels

scholarly journals Turning Carbon Dioxide and Ethane into Ethanol by Solar-Driven Heterogeneous Photocatalysis over RuO2- and NiO-co-Doped SrTiO3

Catalysts ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 461
Author(s):  
Larissa O. Paulista ◽  
Josep Albero ◽  
Ramiro J. E. Martins ◽  
Rui A. R. Boaventura ◽  
Vítor J. P. Vilar ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Maximum Yield ◽  
Ruthenium Oxide ◽  
Photogenerated Electron ◽  
Band Gap Energy ◽  
Heterogeneous Photocatalysis ◽  
Solar Irradiation ◽  
Batch Mode ◽  
Molar Ratios ◽  
Co Doped

The current work focused on the sunlight-driven thermo-photocatalytic reduction of carbon dioxide (CO2), the primary greenhouse gas, by ethane (C2H6), the second most abundant element in shale gas, aiming at the generation of ethanol (EtOH), a renewable fuel. To promote this process, a hybrid catalyst was prepared and properly characterized, comprising of strontium titanate (SrTiO3) co-doped with ruthenium oxide (RuO2) and nickel oxide (NiO). The photocatalytic activity towards EtOH production was assessed in batch-mode and at gas-phase, under the influence of different conditions: (i) dopant loading; (ii) temperature; (iii) optical radiation wavelength; (vi) consecutive uses; and (v) electron scavenger addition. From the results here obtained, it was found that: (i) the functionalization of the SrTiO3 with RuO2 and NiO allows the visible light harvest and narrows the band gap energy (ca. 14–20%); (ii) the selectivity towards EtOH depends on the presence of Ni and irradiation; (iii) the catalyst photoresponse is mainly due to the visible photons; (iv) the photocatalyst loses > 50% efficiency right after the 2nd use; (v) the reaction mechanism is based on the photogenerated electron-hole pair charge separation; and (vi) a maximum yield of 64 μmol EtOH gcat−1 was obtained after 45-min (85 μmol EtOH gcat−1 h−1) of simulated solar irradiation (1000 W m−2) at 200 °C, using 0.4 g L−1 of SrTiO3:RuO2:NiO (0.8 wt.% Ru) with [CO2]:[C2H6] and [Ru]:[Ni] molar ratios of 1:3 and 1:1, respectively. Notwithstanding, despite its exploratory nature, this study offers an alternative route to solar fuels’ synthesis from the underutilized C2H6 and CO2.

scholarly journals Shedding light on the nature of the catalytically active species in photocatalytic reactions using Bi2O3 semiconductor

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Paola Riente ◽  
Mauro Fianchini ◽  
Patricia Llanes ◽  
Miquel A. Pericàs ◽  
Timothy Noël
Keyword(s):  
Experimental Studies ◽  
Heterogeneous Photocatalysis ◽  
Active Species ◽  
Organic Transformations ◽  
Alkyl Bromides ◽  
Catalytically Active ◽  
Visible Light Driven ◽  
Photocatalytic Reactions ◽  
Insight Into ◽  
Photocatalytic Processes

AbstractThe importance of discovering the true catalytically active species involved in photocatalytic systems allows for a better and more general understanding of photocatalytic processes, which eventually may help to improve their efficiency. Bi2O3 has been used as a heterogeneous photocatalyst and is able to catalyze several synthetically important visible-light-driven organic transformations. However, insight into the operative catalyst involved in the photocatalytic process is hitherto missing. Herein, we show through a combination of theoretical and experimental studies that the perceived heterogeneous photocatalysis with Bi2O3 in the presence of alkyl bromides involves a homogeneous BinBrm species, which is the true photocatalyst operative in the reaction. Hence, Bi2O3 can be regarded as a precatalyst which is slowly converted in an active homogeneous photocatalyst. This work can also be of importance to mechanistic studies involving other semiconductor-based photocatalytic processes.

scholarly journals Recent advances in metalloporphyrin-based catalyst design towards carbon dioxide reduction: from bio-inspired second coordination sphere modifications to hierarchical architectures

2020 ◽  
Vol 49 (8) ◽  
pp. 2381-2396 ◽  
Author(s):  
Philipp Gotico ◽  
Zakaria Halime ◽  
Ally Aukauloo
Keyword(s):  
Carbon Dioxide ◽  
Coordination Sphere ◽  
Three Dimensional ◽  
Carbon Dioxide Reduction ◽  
Catalyst Design ◽  
Recent Advances ◽  
Hierarchical Architectures ◽  
Second Coordination Sphere

The progress in CO2 reduction catalyst design was examined starting from simple metalloporphyrin structures and progressing to three-dimensional active architectures.

scholarly journals The Assessment of Carbon Dioxide Dissociation Using a Single-Mode Microwave Plasma Generator

Molecules ◽  
2020 ◽  
Vol 25 (7) ◽  
pp. 1558 ◽  
Author(s):  
George Mogildea ◽  
Marian Mogildea ◽  
Cristina Popa ◽  
Gabriel Chiritoi
Keyword(s):  
Carbon Dioxide ◽  
Microwave Plasma ◽  
Focal Point ◽  
Single Mode ◽  
Plasma Generator ◽  
High Energy ◽  
High Electron ◽  
Space Applications ◽  
Plasma Characterization ◽  
Co2 Atmosphere

This paper focuses on the dissociation of carbon dioxide (CO2) following the absorption processes of microwave radiation by noncontact metal wire (tungsten). Using a microwave plasma generator (MPG) with a single-mode cavity, we conducted an interaction of microwaves with a noncontact electrode in a CO2 atmosphere. High energy levels of electromagnetic radiation are generated in the focal point of the MPG’s cylindrical cavity. The metal wires are vaporized and ionized from this area, subsequently affecting the dissociation of CO2. The CO2 dissociation is highlighted through plasma characterization and carbon monoxide (CO) quantity determination. For plasma characterization, we used an optical emission spectroscopy method (OES), and for CO quantity determination, we used a gas analyzer instrument. Using an MPG in the CO2 atmosphere, we obtained a high electron temperature of the plasma and a strong dissociation of CO2. After 20 s of the interaction between microwaves and noncontact electrodes, the quantity of CO increased from 3 ppm to 1377 ppm (0.13% CO). This method can be used in space applications to dissociate CO2 and refresh the atmosphere of closed spaces.

Laser Ignition of Surgical Drape Materials in Air, 50% Oxygen, and 95% Oxygen

2004 ◽  
Vol 100 (5) ◽  
pp. 1167-1171 ◽  
Author(s):  
Gerald L. Wolf ◽  
George W. Sidebotham ◽  
Jackson L. P. Lazard ◽  
Jean G. Charchaflieh
Keyword(s):  
Carbon Dioxide ◽  
Operating Room ◽  
Oxygen Concentration ◽  
High Energy ◽  
Ignition Source ◽  
Laser Ignition ◽  
Surgical Tools ◽  
Time To Ignition ◽  
Room Fires ◽  
Surgical Laser

Background Operating room fires fueled by surgical drapes and ignited by high-energy surgical tools in air and oxygen-enriched atmospheres continue to occur. Methods The authors examined the time to ignition of huck towels and three commonly used surgical drape materials in air, 50% oxygen, and 95% oxygen using a carbon dioxide surgical laser as an ignition source. In addition, a phenol-polymer fabric was tested. Results In air, polypropylene and phenol polymer do not ignite. For polypropylene, the laser instantly vaporized a hole, and therefore, interaction between the laser and material ceased. When tested in combination with another material, the polypropylene time to ignition assumed the behavior of the material with which it was combined. For phenol polymer, the laser did not penetrate the material. Huck towels, cotton-polyester, and non-woven cellulose-polyester ignited in air with decreasing times to ignition. All tested materials ignited in 50% and 95% oxygen. Conclusion The results of this study reveal that with increasing oxygen concentration, the time to ignition becomes shorter, and the consequences become more severe. The possibility exists for manufacturers to develop drape materials that are safer than existing materials.

Analyzing the impact of fossil fuel import reliance on electricity prices: The case of the Iberian Electricity Market

2017 ◽  
Vol 28 (7) ◽  
pp. 687-705 ◽  
Author(s):  
Blanca Moreno ◽  
María T García-Álvarez
Keyword(s):  
Carbon Dioxide ◽  
Electricity Market ◽  
Fossil Fuel ◽  
Carbon Dioxide Emission ◽  
High Energy ◽  
Electricity Production ◽  
The European Union ◽  
Electricity Prices ◽  
The Impact ◽  
The Eu

Spain and Portugal are highly dependent on energy from abroad, importing more than 70% of all the energy they consume. This high energy dependence could involve important effects on the level and stability of their electricity prices as a half the gross electricity generated in both countries came from power stations using imported combustible fuels (such as natural gas, coal and oil). In general, changes in the prices of these fossil fuels can directly affect household electricity prices, since generation costs are likely to be transmitted through to the wholesale electricity market. Moreover, in the framework of the European Union Emission Trading System, electricity production technologies tend to incorporate their costs of carbon dioxide emission allowances in sale offers with the consequent increase of the electricity prices. The objective of this paper is to analyze the influence of fossil fuel costs and prices of carbon dioxide emission allowances in the EU on the Spanish and Portuguese electricity prices. With this aim, a maximum entropy econometric approach is used. The obtained results indicate that not only the price of imported gas are very important in explaining Spanish and Portuguese electricity prices but also the price of carbon dioxide emission allowances in the EU.

scholarly journals Separating Hydrogen From Coal Gasification Gases With Alumina Membranes

1991 ◽  
Author(s):  
B. Z. Egan ◽  
D. E. Fain ◽  
G. E. Roettger ◽  
D. E. White
Keyword(s):  
Carbon Dioxide ◽  
Coal Gasification ◽  
Process Development ◽  
Porous Alumina ◽  
Mean Value ◽  
Knudsen Flow ◽  
Gasification Process ◽  
Alumina Membranes ◽  
Separation Factors ◽  
Membrane Permeabilities

Synthesis gas produced in coal gasification processes contains hydrogen, along with carbon monoxide, carbon dioxide, hydrogen sulfide, water, nitrogen, and other gases, depending on the particular gasification process. Development of membrane technology to separate the hydrogen from the raw gas at the high operating temperatures and pressures near exit gas conditions would improve the efficiency of the process. Tubular porous alumina membranes with mean pore radii ranging from about 9 to 22 A have been fabricated and characterized. Based on the results of hydrostatic tests, the burst strength of the membranes ranged from 800 to 1600 psig, with a mean value of about 1300 psig. These membranes were evaluated for separating hydrogen and other gases. Tests of membrane permeabilities were made with helium, nitrogen, and carbon dioxide. Measurements were made at room temperature in the pressure range of 15 to 589 psi. In general, the relative gas permeabilities correlated qualitatively with a Knudsen flow mechanism; however, other gas transport mechanisms such as surface adsorption may also be involved. Efforts are under way to fabricate membranes having still smaller pores. At smaller pore sizes, higher separation factors are expected from molecular sieving effects.

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