scholarly journals Ex-situ biological CO2 methanation using trickle bed reactor: review and recent advances

2021 ◽  
Author(s):  
Michal Sposob ◽  
Radziah Wahid ◽  
Keno Fischer
Keyword(s):  
Large Scale ◽  
Ex Situ ◽  
Current Status ◽  
Comprehensive Overview ◽  
Co2 Methanation ◽  
Trickle Bed Reactor ◽  
Operational Conditions ◽  
Promising Solution ◽  
Biomethane Production ◽  
Trickle Bed

AbstractPower-to-methane technology is a promising solution to facilitate the use of excess variable renewable energy for biomethane production. In this approach, hydrogen produced via electrolysis is used to upgrade raw biogas, which can be subsequently used as fuel or stored in the gas grid. Ex-situ biomethanation is an emerging technology that could potentially replace conventional energy-intensive biogas upgrading methods and allow CO2 utilization for biomethane production. This work provides a comprehensive overview on the current status of ex-situ biomethanation with particular attention to trickle bed reactor. The review includes description of ex-situ biomethanation and summarizes previous works on this topic. The key elements related to operational conditions, efficiency, and microbiology of ex-situ biomethanation using trickle bed reactor are described here. Additionally, the review highlights the technical and economic issues that have to be addressed for future development and large-scale implementation of ex-situ biomethanation.

scholarly journals Population dynamics and conservation management of Himalayan mahseer (Tor species) in riverine aquatic ecosystem in Garhwal region of Uttarakhand (India)

2011 ◽  
Vol 3 (1) ◽  
pp. 97-101 ◽  
Author(s):  
Davendra Singh Malik
Keyword(s):  
Aquatic Ecosystem ◽  
Large Scale ◽  
Mature Female ◽  
Ex Situ ◽  
Current Status ◽  
Anthropogenic Factors ◽  
Total Species Richness ◽  
Viable Population ◽  
River Yamuna ◽  
Catch Composition

The mahseer, an Indian carp (Tor species) known as ‘Sport fish’ continues to be decimated by the large scale natural and anthropogenic factors and categorized as threatened fishes in India. The present research data revealed that total species richness of 33 and 24 number of fish species were identified in river Ganga and Yamuna respectively. The size group of mahseer (400-460mm) recorded as a dominant size of catch composition and contributed about 36.8% and 42.6% based on different sampling sites in river Yamuna and Ganga respectively. The populations of Tor tor, T. putitora have shown a decreasing trend at very alarming rate and influenced the sex ratio, maturity size and natural breeding condition. Only 12.5 to 14.8% mahseer female brooders have shown maturity phase or emenable to release ova during particular breeding seasons. The fecundity of mature female fish brooders ranged from 2500-4500 no. of eggs during July-August. The current status of mahseer fishery may be attributed to the over exploitative nature in riverine system. ‘In situ and Ex-situ” breeding techniques should be practiced for enhancement of viable population size of mahseer species to restore the genetic loss under mahseer conservation programme in aquatic ecosystem of Himalayan region.

Mathematical Modeling of Gas Oil HDS and Optimization of Operational Conditions in Trickle Bed Reactor by Genetic Algorithm

2009 ◽  
Vol 7 (1) ◽  
Author(s):  
Reza Abbasi ◽  
Shohreh Fatemi
Keyword(s):  
Genetic Algorithm ◽  
Film Theory ◽  
Gas Oil ◽  
Trickle Bed Reactor ◽  
Operational Conditions ◽  
Three Phase ◽  
Multivariable Process ◽  
Trickle Bed ◽  
Rigorous Model ◽  
Liquid And Solid Phases

The present work aims to employ genetic algorithm (GA) to optimize a HDS process, which is difficult to optimize by conventional methods. The considered chemical process is the three phase catalytic trickle-bed reactor in which hydrodesulphurization reaction occurs. Non-linear kinetics coupled with the transitional mathematical model of the gas, liquid and solid phases are used to describe the dynamic behavior of the multivariable process. The model, based on a two-film theory, was tested with regards to hydrodesulphurization of vacuum gas oil in a high-pressure pilot plant operated under isothermal conditions. Due to the high dimensionality and non-linearity of the model, a rigorous one, the solution of the optimization problem through conventional algorithms does not always lead to the convergence. This fact justifies the use of an evolutionary method, based on the GAs, to deal with this process. In this way, in order to optimize the process, the GA code is coupled with the rigorous model of the reactor. The aim of the optimization through GAs was to search for the optimal conditions that minimize the gas make and sulfur content of the outlet oil. Many simulations are conducted in order to find the maximization of the objective function without violating the constraints. The results show that the GA is used successfully in the process optimization.

CFD Study of an Evaporative Trickle Bed Reactor

2009 ◽  
Author(s):  
Wayne Strasser ◽  
Kurt Svihla
Keyword(s):  
Steady State ◽  
Distribution System ◽  
Large Scale ◽  
Phase Distribution ◽  
Numerical Study ◽  
Reaction Products ◽  
Substantial Impact ◽  
Minimal Impact ◽  
Trickle Bed Reactor ◽  
Trickle Bed

A numerical study was carried out to investigate steady-state and transient phase distribution, evaporation, and thermal runaway in a large-scale high-pressure trickle bed reactor operating in the low interaction regime. The thermal inertia of the catalyst particles proved to be a significant contribution to the overall energy balance. A cooling recycle stream, containing reaction products and a fresh feed, was included via a closed loop calculation. It was found that, as expected, phase distribution in the catalyst bed had a substantial impact production rate; a faulty feed distribution system can cost approximately 20% in overall steady-state product conversion. Grid resolution effects were quantified and were found to have minimal impact on macroscopic measures. Also, most results were insensitive to the extent of the modeled domain and the commercial solver version. In the event that the cooling recycle stream is lost, the external reactor shell temperature can exceed its design intent. It was found that reducing the quantity of fresh reactant feed in this situation can dramatically reduce the potential for vessel damage.

Optimized biological CO2-methanation with a pure culture of thermophilic methanogenic archaea in a trickle-bed reactor

2021 ◽  
pp. 125135
Author(s):  
Martin Thema ◽  
Tobias Weidlich ◽  
Anja Kaul ◽  
Andrea Böllmann ◽  
Harald Huber ◽  
...  
Keyword(s):  
Pure Culture ◽  
Methanogenic Archaea ◽  
Co2 Methanation ◽  
Trickle Bed Reactor ◽  
Trickle Bed

scholarly journals Petawatt class lasers worldwide

2015 ◽  
Vol 3 ◽  
Author(s):  
Colin Danson ◽  
David Hillier ◽  
Nicholas Hopps ◽  
David Neely
Keyword(s):  
Generation X ◽  
Inertial Confinement Fusion ◽  
Large Scale ◽  
Current Status ◽  
Secondary Source ◽  
Inertial Confinement ◽  
X Rays ◽  
Comprehensive Overview ◽  
Research Activities ◽  
Confinement Fusion

The use of ultra-high intensity laser beams to achieve extreme material states in the laboratory has become almost routine with the development of the petawatt laser. Petawatt class lasers have been constructed for specific research activities, including particle acceleration, inertial confinement fusion and radiation therapy, and for secondary source generation (x-rays, electrons, protons, neutrons and ions). They are also now routinely coupled, and synchronized, to other large scale facilities including megajoule scale lasers, ion and electron accelerators, x-ray sources and z-pinches. The authors of this paper have tried to compile a comprehensive overview of the current status of petawatt class lasers worldwide. The definition of ‘petawatt class’ in this context is a laser that delivers ${>}200~\text{TW}$ .

Comparison of jet loop and trickle-bed reactor performance in large-scale exploitation of glucose reductive aminolysis

2020 ◽  
Author(s):  
Jeroen Poissonnier ◽  
Annelies Callewaert ◽  
Kristof Moonen ◽  
Guy B. Marin ◽  
Joris W. Thybaut
Keyword(s):  
Large Scale ◽  
Reactor Performance ◽  
Trickle Bed Reactor ◽  
Trickle Bed

Electron-deficient boron-based catalysts for C–H bond functionalisation

2021 ◽  
Author(s):  
Yuanhong Ma ◽  
Shao-Jie Lou ◽  
Zhaomin Hou
Keyword(s):  
Review Article ◽  
Current Status ◽  
Comprehensive Overview

This review article provides a comprehensive overview to recognise the current status of electron-deficient boron-based catalysis in C–H functionalisations.

Dehydroepiandrosterone (DHEA) and its Sulphate (DHEAS) in Alzheimer’s Disease

2020 ◽  
Vol 17 (2) ◽  
pp. 141-157 ◽  
Author(s):  
Dubravka S. Strac ◽  
Marcela Konjevod ◽  
Matea N. Perkovic ◽  
Lucija Tudor ◽  
Gordana N. Erjavec ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Large Scale ◽  
Therapeutic Potential ◽  
Relevant Literature ◽  
Comprehensive Overview ◽  
Brain Functions ◽  
Specific Effects ◽  
And Behavior

Background: Neurosteroids Dehydroepiandrosterone (DHEA) and Dehydroepiandrosterone Sulphate (DHEAS) are involved in many important brain functions, including neuronal plasticity and survival, cognition and behavior, demonstrating preventive and therapeutic potential in different neuropsychiatric and neurodegenerative disorders, including Alzheimer’s disease. Objective: The aim of the article was to provide a comprehensive overview of the literature on the involvement of DHEA and DHEAS in Alzheimer’s disease. Method: PubMed and MEDLINE databases were searched for relevant literature. The articles were selected considering their titles and abstracts. In the selected full texts, lists of references were searched manually for additional articles. Results: We performed a systematic review of the studies investigating the role of DHEA and DHEAS in various in vitro and animal models, as well as in patients with Alzheimer’s disease, and provided a comprehensive discussion on their potential preventive and therapeutic applications. Conclusion: Despite mixed results, the findings of various preclinical studies are generally supportive of the involvement of DHEA and DHEAS in the pathophysiology of Alzheimer’s disease, showing some promise for potential benefits of these neurosteroids in the prevention and treatment. However, so far small clinical trials brought little evidence to support their therapy in AD. Therefore, large-scale human studies are needed to elucidate the specific effects of DHEA and DHEAS and their mechanisms of action, prior to their applications in clinical practice.

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