Comprehensive elucidation of the apparent kinetics and mass transfer resistances for biodiesel production via in-house developed carbonaceous catalyst

2021 ◽  
Vol 165 ◽  
pp. 192-206 ◽  
Author(s):  
Sumit H. Dhawane ◽  
E.G. Al-Sakkari ◽  
Tarkeshwar Kumar ◽  
Gopinath Halder
Keyword(s):  
Mass Transfer ◽  
Biodiesel Production ◽  
Carbonaceous Catalyst

Hollow Fiber Membrane (HFM) Facilitated CO2 Delivery to a Cyanobacteria Layer for Biofuel Production

2013 ◽  
Author(s):  
Michael Kalontarov ◽  
Erica E. Jung ◽  
Aadhar Jain ◽  
Syed Saad Ahsan ◽  
David Erickson
Keyword(s):  
Mass Transfer ◽  
Hollow Fiber ◽  
Photosynthetic Bacteria ◽  
Co2 Fixation ◽  
Hollow Fiber Membrane ◽  
Biodiesel Production ◽  
Biofuel Production ◽  
Bacteria Growth ◽  
Post Process ◽  
Fiber Spacing

Photosynthetic bacteria have been shown to be advantageous organisms for biofuel production due to high CO2 fixation efficiencies, fast growth rates, and lower water requirements. Recently, cyanobacteria been metabolically engineered to efficiently secrete their products into a surrounding solution. This has the advantage of potentially eliminating the requirement to harvest and post-process the organisms in order to extract a biofuel, which is one of the most energy and water expensive processes in most biodiesel production strategies. Lagging behind the development of these organisms however has been the development of new photobioreactor (PBR) strategies that can efficiently delivery light and inorganic carbon to the bacteria while extracting the secreted product and O2 from the solution phase. Hollow fiber membranes (HFMs) are a method for bubble-less gas exchange that has been shown to be effective at enhancing mass transfer in applications such as wastewater and landfill treatment. HFM technology could be used to overcome the mass transport challenges associated with photobioreactors. HFM modules have been used to increase mass transfer of CO2 to the bulk media in bench scale PBRs; however, the use of HFM fibers as both a mean to exchange and deliver a gas phase throughout a PBR has not been explored. We have characterized the passive transport along a single fiber in a miniature reactor in previous work. Here we extend our work to arrays of HFM fibers. We performed a range of experiments to characterize bacteria growth rate and distribution as a function fiber spacing and active transport through the fibers, and report optimized values for these variables.

Mathematical Modeling of Biodiesel Production under Intense Agitation

2016 ◽  
Vol 14 (1) ◽  
pp. 445-451
Author(s):  
Aliakbar Roosta ◽  
Jafar Javanmardi ◽  
Elham Sadat Behineh
Keyword(s):  
Mass Transfer ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Rapeseed Oil ◽  
Catalyst Concentration ◽  
Biodiesel Production ◽  
Transfer Coefficients ◽  
Increasing Temperature ◽  
Intense Agitation

AbstractIn this study, a new approach is proposed to investigate the kinetics of sunflower oil and rapeseed oil transesterification in the presence of potassium hydroxide. Transesterification is a heterogeneous process which affected by a number of parameters, that are not readily available in the literature, such as mass transfer coefficients, partition coefficients, and specific surface area of the dispersed phase. However, under intense agitation condition, mass transfer restrictions may be neglected, and the two phases are supposed to remain in thermodynamic equilibrium, during the process. Therefore, a model was developed independent of the mass transfer coefficient and specific surface area, which is reliable for the intense agitation condition. According to the results, the model is valid at least for mixing rates over 500 rpm. The results of the model were used to study the effects of temperature, methanol-to-oil ratio, and catalyst concentration on the biodiesel conversion. Biodiesel production rate increases with increasing temperature, although rapeseed oil transesterification is more temperature dependent. The results show that the maximum amount of catalyst concentration is less than 1% (by weight); however, the optimum value depends on the operating temperature. The optimum value of the methanol-to-oil-ratio decreases with increasing temperature. Thus, at higher temperatures, less amount of methanol and catalyst are required, which leads to easier purification of biodiesel.

scholarly journals Jet cutter as tool to immobilize lipase for biodiesel production

2019 ◽  
Author(s):  
Marcelo D'Elia Feliciano ◽  
Ana Silvia Prata Soares ◽  
Marcus Bruno Soares Forte ◽  
Beatriz Travalia
Keyword(s):  
Mass Transfer ◽  
Environmental Impacts ◽  
Enzyme Immobilization ◽  
Contact Area ◽  
Industrial Applications ◽  
Biodiesel Production ◽  
Immobilize Lipase ◽  
Technical Aspects ◽  
Size Of Particles ◽  
Low Rate

The use of lipases as a biocatalyst for industrial applications is an interesting route due to technical aspects but also to reduce environmental impacts caused by the use of chemical catalysts. Gel immobilization of the enzyme allows its reuse and avoids contamination of the product with residual portions of free enzyme. However, a typical technique available for enzyme immobilization is based on dripping driven by gravity which produces big particles and low rate of production. The reduction of size can improve the mass transfer by increasing the contact area. Thus, aiming to increase the rate of particles production and reduce the size of particles, the objective of this work was to encapsulate lipase, using a tool designed to cut the jet produced by pumping, called as Jet Cutter.

Functional Nanomaterials-Catalyzed Production of Biodiesel

2020 ◽  
Vol 16 (3) ◽  
pp. 376-391
Author(s):  
Hu Pan ◽  
Hu Li ◽  
Heng Zhang ◽  
Anping Wang ◽  
Song Yang
Keyword(s):  
Fatty Acids ◽  
Mass Transfer ◽  
Free Fatty Acids ◽  
Active Site ◽  
Edible Oils ◽  
High Surface ◽  
Transesterification Reaction ◽  
Biodiesel Production ◽  
Synthesis Methods ◽  
Transfer Resistance

Background: Biodiesel, as a green and renewable biofuel, has great potential to replace fossil diesel. The development of efficient and stable heterogeneous catalysts is vital to produce biodiesel in an efficient and green way. Nanocatalysts provide a high surface-to-volume ratio as well as high active site loading and can improve mass transfer, which is beneficial to enhance their catalytic activity. Objective: The review focuses on the latest advances in the production of biodiesel using nanostructured catalysts. Methods: Biodiesel is mainly produced through esterification and transesterification reaction using acids, bases or lipases as catalysts. We mainly review the synthesis methods and physicochemical properties of various basic, acidic and lipase nanocatalysts. Meanwhile, their catalytic activities in biodiesel production are also discussed. Results: Alkali nanocatalysts are mainly suitable for transformation of oils with low acid values to biodiesel via transesterification reaction. In contrast, acidic nanocatalysts are not sensitive to water as well as free fatty acids and can avoid saponification associated with basic nanocatalysts while promote simultaneous esterification and transesterification reaction. However, acid-catalyzed transesterification usually requires harsh reaction conditions. In addition, the lipase-catalyzed process is also suitable for non-edible oils containing high contents of free fatty acids, which possess environmental and economic advantages. Conclusion: Nanocatalysts have many advantages such as good accessibility with nanostructure, high active site loading and reduction of mass transfer resistance. However, most of those materials undergo deactivation after several cycles. Therefore, the development of more efficient, stable, and low-cost nanocatalysts is desirable for producing biodiesel.

Numerical Investigation of Biodiesel Production in Capillary Microreactor

2011 ◽  
Author(s):  
Wei Han ◽  
Rachaneewan Charoenwat ◽  
Brian H. Dennis
Keyword(s):  
Mass Transfer ◽  
Volume Flow Rate ◽  
Flow Behavior ◽  
Chemical Species ◽  
Reaction Rates ◽  
Immiscible Fluids ◽  
Biodiesel Production ◽  
Reacting Flow ◽  
Two Phase ◽  
Capillary Microreactor

Synthesis of biodiesel through transesterification of vegetable oil with methanol has been experimentally studied in different types of microreactors though detailed numerical simulation has not yet been presented. The capillary microreactor has the potential to greatly intensify mass transfer between immiscible fluids that would result in higher chemical reaction rates. A segmented flow pattern of oil and methanol forms within the reactor. It has been shown experimentally that the two phase flow has dramatic benefits on the intensification of mass transfer and heat transfer. Such reactors have been proposed for the synthesis of biodiesel and detailed understanding of flow dynamics and chemical kinetics would be useful for process optimization. This paper presents a mathematical model and numerical solution for the synthesis of biodiesel in a capillary reactor. The model represents the unsteady incompressible viscous non-equilibrium chemically reacting flow. The equations are discretized with the finite element method (FEM) and solved to demonstrate the flow behavior and concentration distribution of each chemical species within two phases; different residence time will be obtained with different volume flow rate as well. Information about efficient computational treatment of the model will also be presented.

scholarly journals New High-Throughput Reactor for Biomass Valorization

2020 ◽  
Vol 2 (1) ◽  
pp. 31
Author(s):  
Irene Malpartida ◽  
Pedro Maireles-Torres ◽  
Valentin Lair ◽  
Samy Halloumi ◽  
Julien Thiel ◽  
...  
Keyword(s):  
Mass Transfer ◽  
High Throughput ◽  
Mechanical Energy ◽  
Scale Up ◽  
Reaction Times ◽  
Heating System ◽  
Biodiesel Production ◽  
Solid Catalyst ◽  
Materials Synthesis ◽  
Wide Range

The development of an innovative and sustainable high-throughput reaction platform allows optimizing a wide range of chemical processes (materials synthesis and catalysis, among others) to tackle the Green Deal. This tool unifies, for the first time, the benefits of mechanical energy, thermal and pressure activation in continuous flow with an induction in situ heating system, facilitating the incorporation of inputs (liquids, solids and gases) with controlled pressure. As a result of the synergistic effect of this simultaneous activation, this technology will: (i) shorten reaction times; (ii) decrease temperature; (iii) improve reactions kinetics as mass transfer limitations are reduced; (iv) minimize the use of solvents; (v) decrease the reaction steps; (vi) increase the volume treated, enabling a real scale-up; and (vii) enhance the yields and/or selectivity. This new high-throughput reactor is used for the synthesis of calcium diglyceroxide (CaDG), minimizing the reaction steps and cost, to obtain a pure CaDG. This heterogeneous catalyst is used for biodiesel production and valorization of the glycerol generated as a by-product. An efficient synthesis protocol of CaDG has been developed, requiring shorter time, without heating, and no need for a solvent. This new process facilitates oil–methanol mixing in the transesterification process, thus minimizing the mass transfer limitations associated with the immiscibility of reactants. In addition, this process has been optimized by using CaDG as a solid catalyst.

Sign in / Sign up

Export Citation Format

Share Document