Ni on FeCrAlloy Partially Oxides Methane at Short Contact Time and High Pressure

RÉSUMÉ: Le méthane est en train de devenir le principal vecteur d’énergie et élément de construction chimique non seulement en raison de sa disponibilité mais aussi parce que sa transformation en énergie et en produits chimiques implique une production d’émissions de gaz à effet de serre plus faible que celle du charbon et du pétrole. Même si le méthane est une ressource naturelle dont la disponibilité est limitée, c’est aussi un produit chimique vert produit par des digestions anaérobies de la biomasse. Pour remplacer les procédés chimiques actuels, de nouveaux procédés chimiques plus efficaces doivent challenger les procédés actuels. L’introduction des nouvelles technologies dans les activités industrielles dépend davantage de l’économie des procédés que des effets antropogènes sur l’environnement. Des exemples clairs de l’importance de l’économie des procédés sont le torchage des gaz et la production d’hydrogène. Actuellement dans le monde, la même quantité de méthane utilisée en un an par l’Allemagne et la France correspond à la quantité de gaz échoué. Cela correspond également à 1% de l’émission totale de CO2. La disponibilité d’hydrocarbures de faible poids moléculaire, associés à l’extraction du pétrole, dans des endroits éloignés où le flux de gaz est inférieur à 1000Nm3 h−1 est actuellement considérée comme un problème plus qu’une ressource. Le transport par gazoduc et la transformation en énergie électrique ou en liquides facilement transportables ne sont pas rentables économiquement et ce flux est donc brûlé à la torche. De cette façon, la combustion du gaz naturel non seulement diminue la qualité de l’air mais produit également de la chaleur et de la lumière qui modifient l’écosystème local traditionnel. L’évacuation du gaz naturel aurait cependant une influence plus forte sur les niveaux d’ozone troposphérique, car l’effet de serre du CH4 est beaucoup plus important que celui du CO2. Le reformage du méthane à la vapeur (SMR) est la principale réaction pour la production de gaz de synthèse et d’hydrogène dans l’industrie chimique. Même si le reformage du méthane à la vapeur est actuellement l’un des procédés chimiques qui émettent le plus de CO2, avec une contribution de 3%, les nouveaux procédés de production tels que l’oxydation partielle catalytique (CPOX) ne l’ont pas remplacé, car l’économie globale du procédé de reformage du méthane à la vapeur est inférieure à celle du CPOX, compte tenu de la technologie disponible.----------ABSTRACT: Methane is becoming the main energy vector and chemical building block not only because of its availability but also because its transformation into energy and chemicals involve a lower production of greenhouse emissions compared to coal and petroleum. Even if methane is a natural resource with limited availability, it is also a green chemical produced via biomass anaerobic digestions. To replace the current chemical processes, new and more efficient chemical routs must challenge the current ones. The penetration in the industrial activities of new technologies depends on process economy more than antropogenic impacts on the environment. Clear examples of the importance of the process economy are stranded gas flaring and hydrogen production. Currently in the world the same amount of methane used in one year by Germany and French corresponds to the amount of stranded gas. This also corresponds to 1% of the total CO2 emission. The availability of low molecular weight hydrocarbons, associated with the oil extraction, in remote locations where gas stream are below 1000Nm3 h−1 is currently seen as a problem rather than a resource. Transportation via gas pipeline and transformation into electrical energy or easily transportable liquids are not economic and therefore this stream is flared. In this way, burning natural gas not only decreases air quality but also produces heat and light that modify the traditional local ecosystem. Natural gas venting would however have stronger influences on the ozone levels, as the greenhouse effect of CH4 is much higher then CO2

Flexible ethylene production: Electrified ethane cracking coupled with oxidative dehydrogenation

This work reports the design of a flexible combined process in which electrified cracking and oxidative dehydrogenation (ODH) processes are coupled. An economic viable alternative to the conventional fuel-fired cracking for the production of ethylene is identified. This solution reduces energy consumptions and carbon dioxide emissions. Replacing the radiative heating (fuel-fired cracking) with electrical heating (electrified cracking) or partially combustion of the feed (ODH process) provides the necessary heat to compensate the endothermicity of the reaction. Electrified cracking and ODH have higher thermal efficiency compared to fuel-fired cracking (97.1% and 98.1% vs 89.9%). Both electrified cracking and ODH process reduce the carbon dioxide emissions by 55.4 and 49.5 % compared to fuel-fired cracking. Moreover, coupling the 2 processes pushes the reduction of carbon dioxide emissions to 57.7 %. From an economic perspective, this innovative and flexible process has operating costs comparable to the ones of traditional fuel-fired ethane cracking: 0.84 € Nm−3 C2H4 and 0.94 € Nm−3 C2H4. Finally, this combined process is not only the most profitable but also the one with the low carbon footprint

Techno economic analysis of a micro Gas-to-Liquid unit for associated natural gas conversion

none5siFlared and vented natural gas in remote regions of the world contribute ¿1% of the total CO2 emissions. High investment costs to build facilities to treat this gas and labor costs to operate the infrastructure are deterrents to addressing this environmental burden. Here we report a techno-economic analysis of a commercial mobile manufacturing plant that processes 2400 m3 d-1 of methane via a tandem short contact time catalytic partial oxidation (CPOX) and a single-pass Fischer–Tropsch fluidized bed to produce 7 bbl d-1. Starting from methane and air, a thermodynamic analysis identified the optimized operating conditions considering both carbon yield, CO/H2 ratio and adiabatic conditions. We studied the flammability limits of the mixture at operating pressures and temperatures. The economic analysis itemizes costs for all equipment rather than applying scale-up power law or factors. The greatest contributors to direct costs are the compressors and the CPOX reactor. Operating CPOX at 2.0 MPa reduces reactor volumes but to achieve 90% conversion and selectivity requires operating this unit above 900 °C. Avoiding syngas compression and upstream syngas conditioning reduces capital costs. The capital cost (CAPEX) reaches 570 000 USD when the whole process operates at 2.0 MPa. Considering numbering-up, the price of the 100th unit approaches 360 000 USD thus the MRU increases profitability. We demonstrate how thermodynamics constrains methane conversion and syngas selectivity. A large part of achieving low CAPEX is operating a single pass process, building multiple units, and replacing the methane to heat the treater at the oil tank battery with the incondensable gas leaving the three phases separator downstream the Fischer–Tropsch reactor.nonePauletto G.; Galli F.; Gaillardet A.; Mocellin P.; Patience G.S.Pauletto, G.; Galli, F.; Gaillardet, A.; Mocellin, P.; Patience, G. S

Short contact time CH4 partial oxidation over Ni based catalyst at 1.5MPa

Gas-to-liquid technologies to produce Fischer\u2013Tropsch fuels are economically sustainable at very large scales\u2014 30\u2008000bbld 121. To achieve a viable process at a scale less than 100bbld 121 requires a compact design, like a short contact time reactor and mass manufacturing to reduce capital cost. We tested the activity of 2.25%Ni/0.1%Ru/CeO2 supported on FeCrAl gauze (Ni2510) to partially oxide methane at a contact time less than 0.050s. Besides, the very short contact time, an additional feature of this work is that the catalyst activated on-stream without a hydrogen pretreatment step. The reactor operated at 1.5MPa, 800\ub0C\ua0to\ua0950\ub0C, and a CH4/O2 ratio varying from 1.6 to 1.8 v/v. Methane partially oxidized carbon monoxide (direct mechanism) rather than combusting to CO2 followed by steam reforming to CO (indirect mechanism). The following phenomena support the direct mechanism hypothesis: (i) the selectivity improved when reducing residence time, (ii) the mass spectrometer detected both O2 and CO at the effluent (simultaneously), (iii) metallic Ni clusters on the Ni2510 were absent under reaction conditions based on in situ X-ray absorption spectroscopy. Loading Ni/Al2O3 powder downstream of the Ni2510 increased syngas yield, as this catalyst promoted steam and dry reforming. Soot forms upstream of the Ni2510 catalyst via a retro-propagation mechanism in which methyl radicals produced on the catalyst surface react with the incoming feed gas

Clones of Interstitial Cells From Bovine Aortic Valve Exhibit Different Calcifying Potential When Exposed to Endotoxin and Phosphate

OBJECTIVE: Our purpose was to study in vitro whether phenotypically-distinct interstitial cell clones from bovine aortic valve (BVIC) possess different calcifying potential in response to endotoxin (lipopolysaccharide [LPS]) and phosphate (Pi). METHODS AND RESULTS: Among various clones of BVIC obtained by limited dilution technique we selected 4 clones displaying different growth patterns and immunophenotypes. Uncloned and cloned cells were treated with combinations of LPS (100 ng/mL) and Pi (2.4 mmol/L). Uncloned BVIC showed increased alkaline phosphatase activity (ALP) after treatment with LPS, which resulted in calcification after addition of Pi. Among BVIC clones, only Clone 1 (fibroblast-like phenotype) showed a relevant increase in ALP after LPS treatment in parallel with prevention of smooth muscle (SM) alpha-actin accumulation. No effect was observed in clonal cells harboring a more stable SM cell-like profile (Clone 4). None of the isolated clones calcified but mineralization was induced in the presence of LPS plus Pi when Clone 1 was cocultured with Clone 4 or after seeding on type I collagen sponges. CONCLUSIONS: Endotoxin and phosphate can act as valve calcification promoters by targeting specific fibroblast-like interstitial valve cells that possess a unique procalcific potential