Loss of Guide Wire as an Important Complication of Central Venous Catheterization; a Case Report

Many critically ill patients need aggressive procedures, such as central venous catheterization. The complication rate of central venous line placement is estimated to be 15%. Common complications include arterial puncture, hematoma, pneumothorax, hemothorax, arrhythmia, thoracic duct injury, infection, and thrombosis. Cardiac tamponade, pericardial effusions, pleural effusions, air or guidewire embolisms, and lost guide wires are rare but severe complications. Here we report a case of lost guide wire following central venous line insertion

Mixed matrix membranes for hydrocarbons separation and recovery: a critical review

The separation and purification of light hydrocarbons are significant challenges in the petrochemical and chemical industries. Because of the growing demand for light hydrocarbons and the environmental and economic issues of traditional separation technologies, much effort has been devoted to developing highly efficient separation techniques. Accordingly, polymeric membranes have gained increasing attention because of their low costs and energy requirements compared with other technologies; however, their industrial exploitation is often hampered because of the trade-off between selectivity and permeability. In this regard, high-performance mixed matrix membranes (MMMs) are prepared by embedding various organic and/or inorganic fillers into polymeric materials. MMMs exhibit the advantageous and disadvantageous properties of both polymer and filler materials. In this review, the influence of filler on polymer chain packing and membrane sieving properties are discussed. Furthermore, the influential parameters affecting MMMs affinity toward hydrocarbons separation are addressed. Selection criteria for a suitable combination of polymer and filler are discussed. Moreover, the challenges arising from polymer/filler interactions are analyzed to allow for the successful implementation of this promising class of membranes

Effect of operating conditions and effectiveness factor on hydrogenation of CO2 to hydrocarbons

The development of an efficient reactor for hydrocarbons (C2–C4) production through hydrogenation of CO2, requires a deep understanding of the operating conditions effects. Subsequently, a model is proposed to analyze the reaction rates and investigate the sensitivity of hydrocarbons yield and products distribution to the variations of temperature, pressure and space velocity (SV). Besides, Thiele modulus and effectiveness factor are calculated for all of the reactions considered in the model. Results reveal that simultaneous occurrence of both endothermic reverse water gas shift (RWGS) and exothermic Fischer-Tropsch (FT) reactions, may be the main reason of temperature and rate fluctuations at the fixed-bed reactor inlet. In addition, increasing temperature and pressure, and decreasing SV can shift the process to produce more light olefins. Finally, sensitivity analysis demonstrates that reactor behavior is independent of the changes in pressure and SV at high temperature, which is an indication of high temperature dependency of this process. These findings can be effectively employed to achieve a better insight about appropriate operating conditions of hydrocarbons production via hydrogenation of CO2

Modeling and optimization of hydrogenation of CO2: estimation of kinetic parameters via artificial bee colony (ABC) and differential evolution (DE) algorithms

Global warming, climate change, fossil fuel depletion and steep hikes in the price of environmentally friendly hydrocarbons motivate researchers to investigate CO2 hydrogenation for hydrocarbons production. However, due to the reaction complexities and varieties of produced species, the process mechanism and subsequently estimation of the kinetic parameters have been controversial yet. Therefore, estimating the kinetic parameters using Artificial Bee Colony (ABC) and Differential Evolution (DE) optimization algorithms based on Langmuir-Hinshelwood-Hougen-Watson (LHHW) mechanism is proposed as a possible remedy to fulfil the requirements. To this end, a one-dimensional heterogeneous model comprising detailed reaction rates of reverse water gas shift (RWGS), Fisher-Tropsch (FT) reactions and direct hydrogenation (DH) of CO2 is developed. It is observed that ABC exhibiting 6.3% error in predicting total hydrocarbons selectivity is superior to DE algorithm with 32.9% error. Therefore, the model employed the estimated kinetic parameters obtained via ABC algorithm, is exploited for products distribution analysis. Results reveal that maximum 73.21% hydrocarbons (C1–C4) selectivity can be achieved at 573 K and 1 MPa with 0.85% error compared to the experimental value of 72.59%. Accordingly, the proposed model can be exploited as a powerful tool for evaluating and predicting the performance of CO2 hydrogenation to hydrocarbons process

Effect of operating conditions and effectiveness factor on hydrogenation of CO\u3csub\u3e2\u3c/sub\u3e to hydrocarbons

\u3cp\u3eThe development of an efficient reactor for hydrocarbons (C\u3csub\u3e2\u3c/sub\u3e–C\u3csub\u3e4\u3c/sub\u3e) production through hydrogenation of CO\u3csub\u3e2\u3c/sub\u3e, requires a deep understanding of the operating conditions effects. Subsequently, a model is proposed to analyze the reaction rates and investigate the sensitivity of hydrocarbons yield and products distribution to the variations of temperature, pressure and space velocity (SV). Besides, Thiele modulus and effectiveness factor are calculated for all of the reactions considered in the model. Results reveal that simultaneous occurrence of both endothermic reverse water gas shift (RWGS) and exothermic Fischer-Tropsch (FT) reactions, may be the main reason of temperature and rate fluctuations at the fixed-bed reactor inlet. In addition, increasing temperature and pressure, and decreasing SV can shift the process to produce more light olefins. Finally, sensitivity analysis demonstrates that reactor behavior is independent of the changes in pressure and SV at high temperature, which is an indication of high temperature dependency of this process. These findings can be effectively employed to achieve a better insight about appropriate operating conditions of hydrocarbons production via hydrogenation of CO\u3csub\u3e2\u3c/sub\u3e.\u3c/p\u3

Evolution paths from gray to turquoise hydrogen via catalytic steam methane reforming: Current challenges and future developments

Fossil fuel depletion, global warming, climate change, and steep hikes in the price of fuel are driving scientists to investigate commercial and environmentally friendly energy carriers like hydrogen. Steam methane reforming (SMR), a current commercial route for H2 production, has been considered the best remedy to fulfill the re- quirements. Despite the remarkable quantity of H2 produced by the SMR, this technology still faces major challenges such as catalyst deactivation due to the sintering of metal nanoparticles, coking, and generation of a large quantity of CO2. Firstly, the effects of catalyst types, kinetic models, and operating conditions on high-yield H2 production, the evolution path from gray to blue, via the conventional SMR are comprehensively reviewed. Secondly, exploiting intensified techniques such as membrane technology, sorption, fluidization, and chemical looping for SMR to blue H2 are discussed in detail. Further, a novel and sustainable path for the SMR process, hybridizing the use of novel materials and emerging technologies to produce turquoise H2, is proposed. Finally, the critical points for steam reforming process technology that can help leverage environmental, social, and governance (ESG) profiling have been discussed

Oxidative dehydrogenation of ethane: Catalytic and mechanistic aspects and future trends

Ethene is a commodity chemical of great importance for manufacturing diverse consumer products, whose synthesis via crude oil steam cracking is one of the most energy-intensive processes in the petrochemical industry. Oxidative dehydrogenation (ODH) of ethane is an attractive, low energy, alternative route to ethene which could reduce the carbon footprint for its production, however, the commercial implementation of ODH requires catalysts with improved selectivity. This review critically assesses recent developments in catalytic technologies for ethane ODH, and discusses how insight into proposed mechanisms from computational studies, and CO2 assisted ethane dehydrogenation (CO2-DHE), provide opportunities for economically viable processes to meet growing demands for ethene while reducing carbon emissions. Future trends and emerging technologies for ethane ODH are also discussed. This journal isK. W. and A. F. L. thank the Australian Research Council for financial support through DP 200100204 and DP200100313. D. D. D acknowledges support from the University of Cincinnati through the Herman Schneider Professorship in the College of Engineering and Applied Sciences

Recent advances in CO2 hydrogenation to value-added products — Current challenges and future directions

Climate change, global warming, fossil fuel depletion and rising fuel prices have created great incentives to seek alternative fuel production technologies. CO transformation to value-added products using renewable H has proven to be an emerging solution to enable this goal. In this regard, three different promising processes, namely methane, methanol and hydrocarbon synthesis via CO hydrogenation are thoroughly discussed. In addition, the influential factors affecting process efficiencies such as catalyst design and mechanistic insight, operating conditions as well as reactor types are investigated, with key pathways that dictate catalyst activity and selectivity of the most promising materials described. Furthermore, a brief overview of the reactor configuration and its crucial role in the improving process viability is analyzed. Accordingly, fixed-bed, fluidized-bed, annular and spherical reactors along with HO/H perm-selective membrane reactors are disscussed for hydrocarbon production. In addition, different reactor configurations are compared to assess the best one that is adjustable depending on the reaction mechanism. Consequently, a corrugated-wall dual-type membrane reactor is proposed as an emerging alternative for CO hydrogenation to value-added products.This research has been supported by the NRDI Fund (TKP2020 NC, Grtant No. BME-NCS) based on the charter of bloster issued by the NRDI office under the auspices of the Ministry for Innovation and Technology. SLS acknowledges the support of the US Department of Energy, Office of Basic Energy Sciences, Division of Chemical, Biological and Geological Sciences under grant DE-FG02-86ER13622.A000