scholarly journals Is the Fischer-Tropsch Conversion of Biogas-Derived Syngas to Liquid Fuels Feasible at Atmospheric Pressure?

Energies ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 1031 ◽  
Author(s):  
Rawan Hakawati ◽  
Beatrice Smyth ◽  
Helen Daly ◽  
Geoffrey McCullough ◽  
David Rooney
Keyword(s):  
Atmospheric Pressure ◽  
Active Sites ◽  
Liquid Fuel ◽  
Biogas Production ◽  
Liquid Fuels ◽  
Feed Ratio ◽  
Small Scale ◽  
Fischer Tropsch ◽  
Technical Problems ◽  
The Eu

Biogas resulting from anaerobic digestion can be utilized for the production of liquid fuels via reforming to syngas followed by the Fischer-Tropsch reaction. Renewable liquid fuels are highly desirable due to their potential for use in existing infrastructure, but current Fischer-Tropsch processes, which require operating pressures of 2–4 MPa (20–40 bar), are unsuitable for the relatively small scale of typical biogas production facilities in the EU, which are agriculture-based. This paper investigates the feasibility of producing liquid fuels from biogas-derived syngas at atmospheric pressure, with a focus on the system’s response to various interruption factors, such as total loss of feed gas, variations to feed ratio, and technical problems in the furnace. Results of laboratory testing showed that the liquid fuel selectivity could reach 60% under the studied conditions of 488 K (215 °C), H2/CO = 2 and 0.1 MPa (1 bar) over a commercial Fischer–Tropsch catalyst. Analysis indicated that the catalyst had two active sites for propagation, one site for the generation of methane and another for the production of liquid fuels and wax products. However, although the production of liquid fuels was verified at atmospheric pressure with high liquid fuel selectivity, the control of such a system to maintain activity is crucial. From an economic perspective, the system would require subsidies to achieve financial viability.

scholarly journals International overview on waste to biofuel options with a focsu on waste potentials in Germany and funding incentives in the EC

2013 ◽  
Vol 14 (2) ◽  
pp. 183-191
Keyword(s):  
Anaerobic Fermentation ◽  
Biogas Production ◽  
Raw Materials ◽  
Ghg Emissions ◽  
Small Scale ◽  
Double Counting ◽  
Industrialized Countries ◽  
Fischer Tropsch ◽  
The Past ◽  
Ghg Reduction

Biofuels represent a possibility to reduce greenhouse gas (GHG) emissions within the transport sector. In this context the sustainability of biofuels, especially so called 1st generation biofuels led to controversial discussions in the past. Biofuels from waste and residues represent a well suited but quantitative limited alternative due to their sustainability. At an international level, different approaches for converting waste and residues into biofuels can be found. Developing countries in general use classic transesterification of waste fats to produce biodiesel. Technically advanced options such as pyrolysis, gasification, Fischer-Tropsch-Diesel, anaerobic fermentation and distillation, as well as biogas production coupled with biomethane upgrading, are mostly found in industrialized countries. Within this study, different waste to biofuel options are reviewed ranging from small scale to industrial scale and take into account used raw materials, technological application and (potential) GHG-reduction. Further the potential of several wastes and residues for gasification processes and synthesis of biofuels in Germany is described. Biofuel from waste offers promising funding incentives because of the “double counting” according to 2009/28/EC and the switch in mandatory blending from an amount based quota to a GHG-based blending quota in 2015.

scholarly journals Design, Fabrication and Performance Study of Co-Pyrolysis System for Production of Liquid Fuel from Jatropha Cake with Polystyrene Waste

2021 ◽  
Vol 25 (3) ◽  
pp. 407-414
Author(s):  
S.A. Babajo ◽  
J.S. Enaburekhan ◽  
I.A. Rufa’i
Keyword(s):  
Reaction Time ◽  
Liquid Fuel ◽  
Fixed Bed ◽  
Chemical Properties ◽  
Calorific Value ◽  
Liquid Fuels ◽  
Feed Ratio ◽  
Performance Study ◽  
Polystyrene Waste ◽  
Jatropha Cake

The increasing quantities of plastics and their disposal has been a major public concern. This paper therefore describes a fixed bed co-pyrolysis system designed and fabricated to obtain liquid fuel from a combination of Jatropha seed cake and polystyrene (plastic) waste using appropriate standard technique. The characterization of the feedstock materials (Jatropha cake and polystyrene) were carried out based on proximate and ultimate analysis. The products of the experiment were: liquid fuel, char and gas, while char and gas were considered as by-product. The parameters that were found to influence the product yields significantly includes: feed ratio, temperature and reaction time. The optimum liquid yield obtained from the co-pyrolysis of Jatropha cake with plastic (polystyrene)  waste was 65.0 wt% (that is at the optimum parameters of feed ratio 1:1, temperature 500 oC and reaction time of 45 minutes). The  liquid fuel obtained at these optimum conditions were analyzed based on physical and chemical properties, and compared to that of conventional diesel. The results of the liquid fuel obtained and conventional diesel in terms of viscosity, density and pH were 3.8 cP, 3.5 cP, and 830 kg/m3 , 853 kg/m3 , and 1.0, and neutral respectively. Elemental analyses of the liquid fuels from Jatropha cake with polystyrene waste showed that there is high contents of carbon and hydrogen, 87.2 and 8.3 respectively, which indicates that the liquid fuels may support combustion. The calorific value of liquid fuel from copyrolysis of Jatropha cake with polystyrene waste was 42.3 MJ/Kg, and closer to that of conventional diesel 45.5 MJ/Kg. Considering the results obtained from the study, the liquid fuel from Jatropha cake and polystyrene waste can be used as an alternative fuel Keywords: Co-pyrolysis, Jatropha cake, Polystyrene waste, calorific value

Thermodynamic Analysis of Evaporation Characteristics of Moving Two-Component Liquid Fuel Droplets in Pre-Vaporizer Systems

2012 ◽  
Author(s):  
S. Raghuram ◽  
Vasudevan Raghavan
Keyword(s):  
Atmospheric Pressure ◽  
Liquid Fuel ◽  
Droplet Diameter ◽  
Liquid Fuels ◽  
Liquid Equilibrium ◽  
Fuel Component ◽  
Fuel Droplets ◽  
Nusselt Numbers ◽  
Two Component ◽  
Methyl Butyrate

In the current study, a thermodynamic model is presented for predicting the vaporization characteristics of moving two-component fuel droplets, at an ambient temperature of 350 K, atmospheric pressure and with an initial droplet diameter of 100 microns, as typically observed in a gas turbine pre-vaporizing system. Liquid fuels considered are iso-octane (surrogate of gasoline) and decane (surrogate of diesel), blended with ethanol and methyl-butyrate (surrogate of biodiesel), respectively. The model evaluates the vapor-liquid equilibrium based on activity coefficients calculated using UNIFAC group contribution method. The gas-phase properties are calculated as functions of temperature and mixture molecular weight. The temporally varying parameters such as equilibrium surface temperature, concentration of the higher volatile fuel component, evaporation constant and droplet Reynolds and Nusselt numbers have been studied. Variation of integrated parameters such as time-average evaporation constant, droplet lifetime, average velocity and the final droplet penetration distance are also discussed.

Kinetics of the catalytic hydrodesulphurization reaction system; hydrogenolysis of thiophene

1980 ◽  
Vol 45 (10) ◽  
pp. 2728-2741 ◽  
Author(s):  
Pavel Fott ◽  
Petr Schneider
Keyword(s):  
Atmospheric Pressure ◽  
Active Sites ◽  
Flow Reactor ◽  
Kinetic Equations ◽  
Reaction System ◽  
Reaction Products ◽  
Molybdenum Catalyst ◽  
Cobalt Molybdenum Catalyst ◽  
Kinetics Of ◽  
Reaction Schemes

Kinetics have been studied of the reaction system taking place during the reaction of thiophene on the cobalt-molybdenum catalyst in a gradientless circulation flow reactor at 360 °C and atmospheric pressure. Butane has been found present in a small amount in the reaction products even at very low conversion. In view of this, consecutive and parallel-consecutive (triangular) reaction schemes have been proposed. In the former scheme the appearance of butane is accounted for by rate of desorption of butene being comparable with the rate of its hydrogenation. According to the latter scheme part of the butane originates from thiophene via a different route than through hydrogenation of butene. Analysis of the kinetic data has revealed that the reaction of thiophene should be considered to take place on other active sites than that of butene. Kinetic equations derived on this assumption for the consecutive and the triangular reaction schemes correlate experimental data with acceptable accuracy.

Constructing efficient hcp-Co active sites for Fischer-Tropsch reaction on an activated carbon supported cobalt catalyst via multistep activation processes

Fuel ◽  
2021 ◽  
Vol 292 ◽  
pp. 120244
Author(s):  
Hong Du ◽  
Miao Jiang ◽  
Hejun Zhu ◽  
Chuande Huang ◽  
Ziang Zhao ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Active Sites ◽  
Cobalt Catalyst ◽  
Fischer Tropsch

scholarly journals Small-Scale Coastal Fisheries in the Midst of Adaptation and Diversification: Insights from Southern Italy

2021 ◽  
Vol 13 (13) ◽  
pp. 7393
Author(s):  
Agata Nicolosi ◽  
Donatella Di Gregorio ◽  
Giuseppe Arena ◽  
Valentina Rosa Laganà ◽  
Donatella Privitera
Keyword(s):  
Southern Italy ◽  
Multiple Correspondence Analysis ◽  
Marketing Strategies ◽  
Small Scale ◽  
Artisanal Fishing ◽  
Economic Activities ◽  
Coastal Fisheries ◽  
Cluster Identification ◽  
The Eu

The study looks at the problems facing coastal fishing communities. It highlights the impacts that, in the complex framework of the EU reforms, have manifested themselves on economic activities and on society. The aim of the paper is twofold: to examine small-scale artisanal fishing in an area of Southern Italy in order to develop resilience and diversification and at the same time to outline the profiles of local bluefish buyers to highlight development strategies for the sector. The research carried out through a direct survey by administering a questionnaire to fishermen operating in areas of Southern Italy and the data cross-referenced with the opinions of local consumers. A conjoint experiment, followed by a multiple correspondence analysis and cluster identification, was used to outline the profiles of local bluefish buyers. The results of the analysis reveal that the fish market and the restaurant sector are the main distribution channels preferred by fishermen. Furthermore, fishermen are very sensitive to environmental issues and are willing to collaborate and actively participate in the environmental protection of the sea. Consumers recognise the quality of local bluefish, and they implicitly perceive the sustainability of the method of capture. The results show the need to undertake synergistic actions for the fishing industry, capable of activating marketing strategies adequately to support, promote and develop the sector. The results of the study provide helpful information for food companies in order to better segment their market and target their consumers, as well as to effectively promote their product using brands, certifications and traceability.

Numerical Approaches for Modeling Gas–Solid Fluidized Bed Reactors: Comparison of Models and Application to Different Technical Problems

2019 ◽  
Vol 141 (7) ◽  
Author(s):  
Peter Ostermeier ◽  
Annelies Vandersickel ◽  
Stephan Gleis ◽  
Hartmut Spliethoff
Keyword(s):  
Calcium Carbonate ◽  
Size Distribution ◽  
Fluidized Bed ◽  
Fluid Model ◽  
Industrial Applications ◽  
Small Scale ◽  
Fluidized Bed Reactors ◽  
Discrete Phase Model ◽  
Technical Problems ◽  
Numerical Approaches

Gas–solid fluidized bed reactors play an important role in many industrial applications. Nevertheless, there is a lack of knowledge of the processes occurring inside the bed, which impedes proper design and upscaling. In this work, numerical approaches in the Eulerian and the Lagrangian framework are compared and applied in order to investigate internal fluidized bed phenomena. The considered system uses steam/air/nitrogen as fluidization gas, entering the three-dimensional geometry through a Tuyere nozzle distributor, and calcium oxide/corundum/calcium carbonate as solid bed material. In the two-fluid model (TFM) and the multifluid model (MFM), both gas and powder are modeled as Eulerian phases. The size distribution of the particles is approximated by one or more granular phases with corresponding mean diameters and a sphericity factor accounting for their nonspherical shape. The solid–solid and fluid–solid interactions are considered by incorporating the kinetic theory of granular flow (KTGF) and a drag model, which is modified by the aforementioned sphericity factor. The dense discrete phase model (DDPM) can be interpreted as a hybrid model, where the interactions are also modeled using the KTGF; however, the particles are clustered to parcels and tracked in a Lagrangian way, resulting in a more accurate and computational affordable resolution of the size distribution. In the computational fluid dynamics–discrete element method (CFD–DEM) approach, particle collisions are calculated using the DEM. Thereby, more detailed interparticulate phenomena (e.g., cohesion) can be assessed. The three approaches (TFM, DDPM, CFD–DEM) are evaluated in terms of grid- and time-independency as well as computational demand. The TFM and CFD–DEM models show qualitative accordance and are therefore applied for further investigations. The MFM (as a variation of the TFM) is applied in order to simulate hydrodynamics and heat transfer to immersed objects in a small-scale experimental test rig because the MFM can handle the required small computational cells. Corundum is used as a nearly monodisperse powder, being more suitable for Eulerian models, and air is used as fluidization gas. Simulation results are compared to experimental data in order to validate the approach. The CFD–DEM model is applied in order to predict mixing behavior and cohesion effects of a polydisperse calcium carbonate powder in a larger scale energy storage reactor.

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