scholarly journals Methane Production from Carbondioxide in Polluted Areas Using Graphene Doped Ni/ NiO Nanocomposite via Photocatalysis

2021 ◽  
Keyword(s):  
Methane Production ◽  
High Efficiency ◽  
Co2 Reduction ◽  
Negative Influence ◽  
Electron Donors ◽  
Water Molecules ◽  
Co2 Gas ◽  
Ch4 Production ◽  
Quenching Factor ◽  
Ni Content

Background: Photocatalysis for the production of solar fuels and particularly to perform CO2 reduction with a sufficiently high efficiency depends to the presence of H2 and absence of H2 O using graphene doped Ni/ NiO nanocomposite. Objective: To examine the methane production from carbondioxide in polluted areas using graphene doped Ni/ NiO nanocomposite via photocatalysis with the use of dimethylaniline and xylene as electron donors. Methods: With 2 mg/l graphene doped Ni/ NiO nanocomposite with a Ni content of 19% wt from 786 μmol/h CO2 gas 563 μl CH4 /g Ni.h was obtained at 160oC temperature and the quantum yield was detected as 1.99%. It was found that H2 O has a negative influence on the photocatalytic activity. Under continuous flow operation, water molecules were easier desorbed from the graphene doped Ni/NiO photocatalyst Results: The maximum CH4 production rate was 650 μl/h for 2.4 mg of graphene doped Ni/ NiO nanocomposite after a detectione time of 17 min. Dimethylaniline and xylene were used as electron donors and 1.2 ml/l dimethylaniline and 0.9 ml/l xylene enhanced the CH4 productions by 8% and 12% as quenching factor. Conclusion: Photocatalysis methods was effected for methane production from carbondioxide in polluted areas using graphene doped Ni/ NiO nanocomposite with the use of dimethylaniline and xylene as electron donors.

Synergized Cu/Pb Core/Shell Electrocatalyst for High-Efficiency CO2 Reduction to C2+ Liquids

ACS Nano ◽  
2020 ◽  
Author(s):  
Pengtang Wang ◽  
Hao Yang ◽  
Yong Xu ◽  
Xiaoqing Huang ◽  
Juan Wang ◽  
...  
Keyword(s):  
High Efficiency ◽  
Co2 Reduction ◽  
Core Shell

scholarly journals Quasi-graphitic carbon shell-induced Cu confinement promotes electrocatalytic CO2 reduction toward C2+ products

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Ji-Yong Kim ◽  
Deokgi Hong ◽  
Jae-Chan Lee ◽  
Hyoung Gyun Kim ◽  
Sungwoo Lee ◽  
...  
Keyword(s):  
High Efficiency ◽  
Co2 Reduction ◽  
Value Added ◽  
Material Design ◽  
Catalyst System ◽  
Critical Issue ◽  
Reduction Reaction ◽  
Catalyst Design ◽  
Design Strategies ◽  
Faradaic Efficiency

AbstractFor steady electroconversion to value-added chemical products with high efficiency, electrocatalyst reconstruction during electrochemical reactions is a critical issue in catalyst design strategies. Here, we report a reconstruction-immunized catalyst system in which Cu nanoparticles are protected by a quasi-graphitic C shell. This C shell epitaxially grew on Cu with quasi-graphitic bonding via a gas–solid reaction governed by the CO (g) - CO2 (g) - C (s) equilibrium. The quasi-graphitic C shell-coated Cu was stable during the CO2 reduction reaction and provided a platform for rational material design. C2+ product selectivity could be additionally improved by doping p-block elements. These elements modulated the electronic structure of the Cu surface and its binding properties, which can affect the intermediate binding and CO dimerization barrier. B-modified Cu attained a 68.1% Faradaic efficiency for C2H4 at −0.55 V (vs RHE) and a C2H4 cathodic power conversion efficiency of 44.0%. In the case of N-modified Cu, an improved C2+ selectivity of 82.3% at a partial current density of 329.2 mA/cm2 was acquired. Quasi-graphitic C shells, which enable surface stabilization and inner element doping, can realize stable CO2-to-C2H4 conversion over 180 h and allow practical application of electrocatalysts for renewable energy conversion.

Photocatalytic CO2 reduction using water as an electron donor by a powdered Z-scheme system consisting of metal sulfide and an RGO–TiO2 composite

2017 ◽  
Vol 198 ◽  
pp. 397-407 ◽  
Author(s):  
Tomoaki Takayama ◽  
Ko Sato ◽  
Takehiro Fujimura ◽  
Yuki Kojima ◽  
Akihide Iwase ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Graphene Oxide ◽  
Visible Light ◽  
Water Splitting ◽  
Electron Donor ◽  
Visible Light Irradiation ◽  
Co2 Reduction ◽  
Metal Sulfide ◽  
Electron Donors ◽  
Reduced Graphene

CuGaS2, (AgInS2)x–(ZnS)2−2x, Ag2ZnGeS4, Ni- or Pb-doped ZnS, (ZnS)0.9–(CuCl)0.1, and ZnGa0.5In1.5S4 showed activities for CO2 reduction to form CO and/or HCOOH in an aqueous solution containing K2SO3 and Na2S as electron donors under visible light irradiation. Among them, CuGaS2 and Ni-doped ZnS photocatalysts showed relatively high activities for CO and HCOOH formation, respectively. CuGaS2 was applied in a powdered Z-scheme system combining with reduced graphene oxide (RGO)-incorporated TiO2 as an O2-evolving photocatalyst. The powdered Z-scheme system produced CO from CO2 in addition to H2 and O2 due to water splitting. Oxygen evolution with an almost stoichiometric amount indicates that water was consumed as an electron donor in the Z-schematic CO2 reduction. Thus, we successfully demonstrated CO2 reduction of artificial photosynthesis using a simple Z-scheme system in which two kinds of photocatalyst powders (CuGaS2 and an RGO–TiO2 composite) were only dispersed in water under 1 atm of CO2.

scholarly journals Pomegranate seed oil rich in conjugated linolenic acids reduces in vitro methane production

1970 ◽  
Vol 46 (3) ◽  
pp. 325-335
Author(s):  
E. Maleki ◽  
G.Y. Meng ◽  
M. Faseleh Jahromi ◽  
R. Jorfi ◽  
A. Khoddami ◽  
...  
Keyword(s):  
Methane Production ◽  
Volatile Fatty Acids ◽  
Seed Oil ◽  
Control Diet ◽  
Nutrient Utilization ◽  
Gas Production ◽  
Metabolizable Energy ◽  
Ruminal Fermentation ◽  
Ch4 Production

The objective of this study was to determine the effect of pomegranate (Punica granatum L.) seed oil (PSO) on gas and methane (CH4) production, ruminal fermentation and microbial populations under in vitro conditions. Three treatments consisting of a control diet containing 10 mg tallow (CON); the control diet with 5 mg PSO + 5 mg tallow (MPSO) and the control diet containing 10 mg PSO (HPSO) were compared. Ten mg of the experimental fat/oil samples were inserted into a gas-tight 100 mL plastic syringe containing 30 mL of an incubation inoculum and 250 mg of a basic substrate of a hay/concentrate (1/1, w/w) mixture. In vitro gas production was recorded over 0, 2, 4, 6, 8, 10, 12 and 24 h of incubation. After 24 hours, incubation was stopped, and methane production, pH, volatile fatty acids (VFAs) and microbial counts were measured in the inoculant. Gas production at 4, 6, 8, 10, 12 and 24 h incubation, metabolizable energy and in vitro organic matter disappearance increased linearly and quadratically as level of PSO increased. Furthermore, the 10 mg PSO (HPSO) decreased CH4 production by 21.0% compared with the control (CON) group. There were no significant differences in total and individual VFA concentrations between different levels of PSO, except for butyric acid. After 24 h of incubation, methanogenesis decreased in the HPSO compared with the MPSO and CON treatments. In addition, total bacteria and protozoa counts increased with rising PSO levels, while population methanogenesis declined significantly. These results suggested that PSO could reduce methane emissions, which might be beneficial to nutrient utilization and growth in ruminants.

The effects of essential oil and condensed tannin on fermentation and methane production under in vitro conditions

2016 ◽  
Vol 56 (10) ◽  
pp. 1707 ◽  
Author(s):  
Brittany Pinski ◽  
Mevlüt Günal ◽  
Amer A. AbuGhazaleh
Keyword(s):  
Fatty Acid ◽  
Methane Production ◽  
Volatile Fatty Acid ◽  
Condensed Tannin ◽  
Total Volatile ◽  
Tannin Extract ◽  
Ch4 Production ◽  
N Concentration ◽  
Total Volatile Fatty Acid

The potential of five different essential oils (EO) and quebracho condensed tannin extract (QCT) as antimethanogenic additives in ruminant feeds were investigated. The first experiment was conducted to screen the effects rosemary oil, sage oil, cinnamon oil (CNO), eucalyptus oil and myrrh oil at 500 mg/L of culture fluid on methane (CH4) production under in vitro conditions. Rumen contents were collected from a cannulated Holstein dairy cow and used for a 24-h batch-culture experiment. Treatments were a control (CON) or CON plus EO at 500 mg/L. Results showed that CNO decreased CH4 production and, therefore, was selected for Experiment 2. The second experiment was designed to test the effects of CNO at three different dose levels on CH4 production and fermentation in 24-h batch-culture experiments. Treatments were CON or CON plus CNO supplemented at 125, 250 and 500 mg/L. Relative to CON, CNO decreased total gas production at the 250 and 500 mg/L doses. All doses of CNO decreased CH4 production. Total volatile fatty acid production was lower in cultures incubated with CNO at the 500 mg/L. Ammonia-N concentration decreased in cultures incubated with CNO at the 500 mg/L. The third experiment was designed to test the effects of QCT on CH4 production and fermentation in 24-h batch cultures. Treatments were CON or CON plus QCT at 25, 50 and 75 g/kg of diet DM. Relative to CON, total volatile fatty acid concentration increased with the 50 g/kg QCT, but was similar to the 25 and 75 g/kg QCT. The proportions of acetate decreased, while the proportions of propionate increased with the 25 g/kg QCT compared with CON. Methane production was not affected in cultures incubated with QCT. Relative to CON, all doses of QCT decreased ammonia-N concentration. In conclusion, results from the present study showed that except for CNO, EO tested in the study had no effects on rumen CH4 production. Addition of CNO to rumen cultures at 125 and 250 mg/L reduced CH4 production without negative effects on rumen fermentation. Quebracho condensed tannin-extract supplementation had no effects on CH4 production and fermentation parameters except for ammonia-N concentration.

scholarly journals High-efficiency photocatalytic CO2 reduction in organic–aqueous system: a new insight into the role of water

RSC Advances ◽  
2018 ◽  
Vol 8 (7) ◽  
pp. 3798-3802 ◽  
Author(s):  
Jinliang Lin ◽  
Rongying Liao ◽  
Junli Xu
Keyword(s):  
High Efficiency ◽  
Co2 Reduction ◽  
Liquid System ◽  
Aqueous System ◽  
Binary Liquid System ◽  
Binary Liquid ◽  
System A ◽  
System P ◽  
Insight Into

A high efficiency photocatalytic conversion of CO2 into CO has been achieved by construction of a binary liquid system.

scholarly journals An electrode-assisted anaerobic digestion process for the production of high-quality biogas

2019 ◽  
Vol 79 (11) ◽  
pp. 2145-2155 ◽  
Author(s):  
K. Yanuka-Golub ◽  
K. Baransi-Karkaby ◽  
A. Szczupak ◽  
L. Reshef ◽  
J. Rishpon ◽  
...  
Keyword(s):  
Anaerobic Digestion ◽  
High Efficiency ◽  
Community Analysis ◽  
Microbial Community Analysis ◽  
High Rate ◽  
Production Yield ◽  
Organic Load ◽  
Electrolysis Cell ◽  
Biogas Upgrading ◽  
Ch4 Production

Abstract Biogas is a sustainable, renewable energy source generated from organic waste degradation during anaerobic digestion (AD). AD is applied for treating different types of wastewater, mostly containing high organic load. However, AD practice is still limited due to the low quality of the produced biogas. Upgrading biogas to natural gas quality (>90% CH4) is essential for broad applications. Here, an innovative bio-electrochemically assisted AD process was developed, combining wastewater treatment and biogas upgrading. This process was based on a microbial electrolysis cell (MEC) that produced hydrogen from wastewater at a relatively high efficiency, followed by high-rate anaerobic systems for completing biodegradation of organic matter and an in situ bio-methanation process. Results showed that CH4 production yield was substantially improved upon coupling of the MEC with the AD system. Interestingly, CH4 production yield increase was most notable once circulation between AD and MEC was applied, while current density was not markedly affected by the circulation rates. The microbial community analysis confirmed that the MEC enhanced hydrogen production, leading to the enrichment of hydrogenotrophic methanogens. Thus, directing soluble hydrogen from the MEC to AD is plausible, and has great potential for biogas upgrading, avoiding the need for direct hydrogen harvesting.

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