Scale-up Conditions Research Articles

Bioconversion of industrial wastes to hydrogen: A review on waste-to-wealth technologies.

Energy plays a significant role in attaining the sustainable growth of the industrial sector of any nation. The resources for getting energy are limited and cannot fulfill the huge demand for energy supply in the near future. Generating fuels from various waste materials and biomass is widely viewed as a sustainable energy source and a viable option for the future. Currently, researchers are particularly interested in synthesizing hydrogen (H2) without emitting CO2 and other greenhouse gases (GHGs). Hydrogen is recognized as a pristine and environmentally friendly energy source, presenting an optimal substitute for fossil fuels due to its high energy content of 122 kJg-1. The traditional methods for the production of H2 are cost-intensive and heavy input requirements are needed. Thus, the synthesis of H2 through biological approaches is cost-effective and eco-friendly alternating with easy operational requirements with ambient reaction conditions. The most common drawback of the biological production of H2 is the low yield and production rates of gas during scale-up conditions. This review is focused on different processes used to convert the wastes into H2 energy along with their pattern of utilization and the effect on the environment.

Synthesis of High-Molecular-Weight Biobased Aliphatic Polyesters by Acyclic Diene Metathesis Polymerization in Ionic Liquids.

Acyclic diene metathesis (ADMET) polymerization of an α,ω-diene monomer of bis(undec-10-enoate) with isosorbide (M1) using a RuCl2(IMesH2)(CH-2-O i Pr-C6H4) (HG2, IMesH2 = 1,3-bis(2,4,6-trimethylphenyl)imidazolin-2-ylidene) catalyst and conducted at 50 °C (in vacuo) in ionic liquids (ILs) afforded higher-molecular-weight polymers (P1, M n = 32 200-39 200) than those reported previously (M n = 5600-14700). 1-n-Butyl-3-methyl imidazolium hexafluorophosphate ([Bmim]PF6) and 1-n-hexyl-3-methyl imidazolium bis(trifluoromethanesulfonyl)imide ([Hmim]TFSI) were suitable as effective solvents among a series of imidazolium salts and the pyridinium salts. The polymerization of α,ω-diene monomers of bis(undec-10-enoate) with isomannide (M2), 1,4-cyclohexanedimethanol (M3), and 1,4-butanediol (M4) in [Bmim]PF6 and [Hmim]TFSI also afforded the higher-molecular-weight polymers. The M n values in the resultant polymers did not decrease even under the scale-up conditions (300 mg to 1.0 g scale, M1, M2, and M4) in the polymerizations in [Hmim]TFSI; the subsequent reaction of P1 with ethylene (0.8 MPa, 50 °C, and 5 h) gave oligomers (proceeded via depolymerization). Tandem hydrogenation of the resultant unsaturated polymers (P1) in a [Bmim]PF6-toluene biphasic system upon the addition of Al2O3 (1.0 MPa H2 at 50 °C) gave the corresponding saturated polymers (HP1), which waswere isolated by a phase separation in the toluene layer. The [Bmim]PF6 layer containing the ruthenium catalyst could be recycled without a decrease in the activity/selectivity of the olefin hydrogenation at least eight times.

Tales, tips & teachable moments from applications support veterans

Charlotte Barker, Editor, BioInsights speaks to three Field Application Scientist Managers at Corning Life Sciences: Chris Suarez, Catherine Siler & Austin Mogen Dr Chris Suarez is the Manager of the Field Application Scientist team at Corning Life Sciences. He received his PhD in Medicinal Chemistry and Molecular Pharmacology from Purdue University working on viral production, cell line engineering, and cancer biology. Dr Suarez has held positions in academia focusing on translational research to overcome mechanisms of therapeutic resistance in breast and prostate cancer using 3D tumor organoid models. Dr Suarez works extensively with process development groups, optimizing production capabilities and cellular scale-up conditions from viral production to cellular therapeutics. In addition, he focuses on collaborations utilizing 3D technology like the Corning spheroid and Elplasia® microplates, Transwell® inserts and extracellular matrices to provide more predictive models for therapeutic response.Dr Catherine Siler is an accomplished Field Application Scientist for Corning Life Sciences, with a PhD in Biology from Johns Hopkins University. Dr Siler enables scientists and researchers in the life science industry to overcome challenges with cell culture and scale-up for clinical manufacturing of advanced therapies. She also utilizes her research and teaching experience to drive the adoption of an industry-leading global product portfolio of innovative single-use consumables for research, process development and bioprocessing applications.Dr Austin Mogen is a Field Application Scientist Manager for Western United States and Latin America at Corning Life Sciences. He received his doctorate from the University of Florida and gained industry experience as a Senior Scientist of upstream process development and manufacturing supervisor for viral vector manufacturing. In this position he focused on bioprocess development, closed system solutions for cell culture scale-up, and viral vector production. Since joining Corning Dr Mogen works extensively with academic researchers and process development groups, optimizing cell culture assays and cellular scale-up conditions for viral production, cellular therapeutics, and biologics.

Strengthening effectiveness evaluations to improve programs for women, children and adolescents

ABSTRACT A full understanding of the pathways from efficacious interventions to population impact requires rigorous effectiveness evaluations conducted under realistic scale-up conditions at country level. In this paper, we introduce a deductive framework that underpins effectiveness evaluations. This framework forms the theoretical and conceptual basis for the ‘Real Accountability: Data Analysis for Results’ (RADAR) project, intended to address gaps in guidance and tools for the evaluation of projects being implemented at scale to reduce mortality among women and children. These gaps include needs for a framework to guide decisions about evaluations and practical measurement tools, as well as increased capacity in evaluation practice among donors and program planners at global, national and project levels. RADAR aimed to improve the evidence base for program and policy decisions in reproductive, maternal, newborn and child health and nutrition (RMNCH&N). We focus on five linked methodological steps – presented as core evaluation questions – for designing and implementing effectiveness evaluation of large-scale programs that support both the needs of program managers to improve their programs and the needs of donors to meet their accountability responsibilities. RADAR has operationalized each step with a tool to facilitate its application. We also describe cross-cutting methodological issues and broader contextual factors that affect the planning and implementation of such evaluations. We conclude with proposals for how the global RMNCH&N community can support rigorous program evaluations and make better use of the resulting evidence.

Performance prediction of pneumatic conveying of powders using artificial neural network method

This paper studies the ability of the ANN to predict the pneumatic conveying performance of powders. At high air velocity, the flow is dilute. But at low air velocities it is fluidized dense. Fluidized dense flow involves several complex interactions among gas, particle and wall. But in dilute flow, the particle-particle interaction is less. Implementation of these interactions in a model is difficult. Experimental data available for pneumatic conveying were used to train the network and then predict the pressure drop. Three different training methods Levenberg Marquardt, Bayesian Regularization and Scaled Conjugate Gradient are used. The BR method takes more time for analysis, but it gives better results than others when sample size is small and noisy. For larger sample size the LM method gives better results than the other two methods. The model is also predicts the pressure drop within ±10% error margin under length scale-up conditions.

Environmentally Friendly Cross-Linked Antifouling Coatings Based on Dual Antimicrobial Action.

The synthesis of environmentally friendly antimicrobial polymeric coatings, especially in the case of aquaculture, that inhibit the growth of bio-deposits is a very important issue that will contribute to the cost reduction of nets’ cleaning process as well as the protection of the submarine wealth from the biostatic substances used so far. In the present work, the antimicrobial polymers P(SSAmC16-co-VBCHAMx) and the terpolymer P(SSAmC16w-co-VBCHAMx-co-GMAy) were synthesized, bearing quaternary ammonium compounds, electrostatically bound and covalently attached at the same polymer chain. The combination of the two types is of particular importance, as it can provide effective antimicrobial polymeric materials with self-polishing capabilities as a result of the released nature of the antimicrobial, in combination with the permanent local action of the immobilized species. The cross-linking reaction of the terpolymer P(SSAmC16w-co-VBCHAMx-co-GMAy) with the homopolymer polyacrylic acid (PAA) was tested at 120 °C in terms of the equivalent ratio between epoxy and carboxyl groups. The synthesized polymers were further used for the coating of aquaculture nets and tested in terms of antifouling efficiency in lab and scale-up conditions. Uncoated nets were also used in all applications for comparison reasons. The coated nets performed efficiently for 35 days in lab-scale and 66 days in scale-up conditions, showing a high antifouling activity in both fields compared to the uncoated nets.

A droplet microfluidic platform for high-throughput photochemical reaction discovery

The implementation of continuous flow technology is critical towards enhancing the application of photochemical reactions for industrial process development. However, there are significant time and resource constraints associated with translating discovery scale vial-based batch reactions to continuous flow scale-up conditions. Herein we report the development of a droplet microfluidic platform, which enables high-throughput reaction discovery in flow to generate pharmaceutically relevant compound libraries. This platform allows for enhanced material efficiency, as reactions can be performed on picomole scale. Furthermore, high-throughput data collection via on-line ESI mass spectrometry facilitates the rapid analysis of individual, nanoliter-sized reaction droplets at acquisition rates of 0.3 samples/s. We envision this high-throughput screening platform to expand upon the robust capabilities and impact of photochemical reactions in drug discovery and development.

Review and analysis of solids friction factor correlations in fluidized dense phase conveying

ABSTRACT Few researchers have presented solids friction factor correlations for the fluidized dense phase conveying of fine particles or powders. Pressure drop for conveying can be predicted using these correlations. These correlations predict the pressure drop with minimum error margin for a definite pipeline configuration or for some specific types of conveying materials. Few researchers have applied their correlations for different pipeline configurations (of different pipeline lengths or diameters) or different conveying materials to predict the pressure drop. In this paper, different solids friction factor correlations for the fluidized dense phase conveying have been considered which are available in the literature and the behaviour of these correlations have been studied under length scale-up or diameter scale-up conditions. It has been observed that only few correlations exhibit natural pressure drop variation with change in pipeline length or pipeline diameter.

Limitations and Prospects for Wastewater Treatment by UV and Visible-Light-Active Heterogeneous Photocatalysis: A Critical Review.

Heterogeneous photocatalysis (HPC) has been widely investigated in recent decades for the removal of a number of contaminants from aqueous matrices, but its application in real wastewater treatment at full scale is still scarce. Indeed, process and technological limitations have made HPC uncompetitive with respect to consolidated processes/technologies so far. In this manuscript, these issues are critically discussed and reviewed with the aim of providing the reader with a realistic picture of the prospective application of HPC in wastewater treatment. Accordingly, consolidated and new photocatalysts (among which the visible active ones are attracting increasing interest among the scientific community), along with preparation methods, are reviewed to understand whether, with increased process efficiency, these methods can be realistically and competitively developed at industrial scale. Precipitation is considered as an attractive method for photocatalyst preparation at the industrial scale; sol-gel and ultrasound may be feasible only if no expensive metal precursor is used, while hydrothermal and solution combustion synthesis are expected to be difficult (expensive) to scale up. The application of HPC in urban and industrial wastewater treatment and possible energy recovery by hydrogen production are discussed in terms of current limitations and future prospects. Despite the fact that HPC has been studied for the removal of pollutants in aqueous matrices for two decades, its use in wastewater treatment is still at a "technological research" stage. In order to accelerate the adoption of HPC at full scale, it is advisable to focus on investigations under real conditions and on developing/improving pilot-scale reactors to better investigate scale-up conditions and the potential to successfully address specific challenges in wastewater treatment through HPC. In realistic terms, the prospective use of HPC is more likely as a tertiary treatment of wastewater, particularly if more stringent regulations come into force, than as pretreatment for industrial wastewater to improve biodegradability.

Modelling solids friction for fluidized dense-phase pneumatic conveying

Fluidized dense-phase pneumatic conveying of powders has a number of benefits in various industries such as coal-fired thermal power plants, chemical, cement, pharmaceutical, petrochemical plants, etc. However, reliable designing of fluidized dense phase pneumatic conveying system is significantly difficult due to the complex and turbulent nature of the flow. In the present work, power station fly ash was conveyed through different pipeline configurations. Governing equations were developed for the fluidized dense-phase flow in the pneumatic conveying system and were solved using Runge-Kutta-Fehlberg method (RKF45). The results revealed that the particle velocity and actual gas velocity and the ratio of the two velocities increase along the direction of flow, while an opposite trend was observed for the solids volumetric concentration. A particle velocity model has been developed using solid loading ratio and dimensionless velocity terms. This particle velocity model, when employed in the existing two-layer model format for solids friction factor, has provided improved scale-up predictions (under diameter and length scale-up conditions) compared to the original two-layer model.

From Experiments and Models to Business Decisions: A Scale-up Study on the Reactive Crystallization of a Crop Protection Agent

Industrial R&D organizations often operate under a paradigm in which the scope of process research is narrowed significantly to the extent needed to solve the problem that is hindering the business from moving forward. In this work we discuss an R&D effort carried out in such a constrained environment toward assessing the feasibility of commercial manufacturing for a crop protection agent. The work, which started as a “brute-force” search for optimal process scale-up conditions, quickly led us to the realization that the process under consideration is far more complex than it appeared at a first glance. The synthesis of the compound of interest involved a reactive crystallization, and the product exhibited rich and intriguing phase separation phenomena that result in drusy crystals of undesirable particle size distribution. Recognizing the crystal “agglomerates” to originate from liquid−liquid phase separation (LLPS), we adopted a simplified process development approach in which we combined a few key expe...

Effect of temperature in the conversion of methanol to olefins (MTO) using an extruded SAPO-34 catalyst

The methanol-to-olefin (MTO) reaction was investigated in a bench-scale, fixed-bed reactor using an extruded catalyst composed of a commercial SAPO-34 (65 weight percentage, wt-%) embedded in an amorphous SiO2 matrix (35 wt-%). The texture properties, acidity and crystal structure of the pure SAPO-34 and its extruded form (E-SAPO-34) were analyzed and the results indicated that the extrusion step did not affect the properties of the catalyst. Subsequently, E-SAPO-34 was tested in a temperature range between 300 and 500 °C, using an aqueous methanol mixture (80 wt-% water content) fed at a weight hour space velocity (WHSV) of 1.21 h‒1. At 300 °C, a low conversion was observed combined with the catalyst deactivation, which was ascribed to oligomerization and condensation reactions. The coke analysis showed the presence of diamandoid hydrocarbons, which are known to be inactive molecules in the MTO process. At higher temperatures, a quasi-steady state was reached during a 6 h reaction where the optimal temperature was identified at 450 °C, which incidentally led to the lowest coke deposition combined with the highest H/C ratio. Above 450 °C, surges of ethylene and methane were associated to a combination of H-transfer and protolytic cracking reactions. Finally, the present work underscored the convenience of the extrusion technique for testing catalysts at simulated scale-up conditions.

Stable and efficient generation of poly(β-amino ester)s for RNAi delivery

Cationic polymers are promising delivery systems for RNAi due to their ease of manipulation, scale-up conditions and transfection efficiency.

Dual-Drug Chiral Resolution: Enantiospecific Cocrystallization of (S)-Ibuprofen Using Levetiracetam

In this work we show the feasibility of resolving a racemic drug substance with a second chiral drug. Via enantiospecific cocrystallization a dual-drug cocrystal is obtained. Such a method can be useful not only for chiral resolution but also for the parallel creation of dual-drug formulations. Here, racemic ibuprofen is resolved using levetiracetam through the formation of an enantiospecific cocrystal. Cocrystallization is utilized as a resolution tool for (in this case) (S)-ibuprofen, the active enantiomer. To find the right conditions to resolve the system, the appropriate ternary and quaternary phase diagrams were constructed. Since these diagrams are governed by thermodynamics, where the kinetic forms are prevented via seeding, the system is robust under scale-up conditions and is an interesting alternative to chiral chromatography or enantioselective synthesis for the pharmaceutical industry.

Scale-up cultivation enhanced arachidonic acid accumulation by red microalgae Porphyridium purpureum.

The present study attempts to cultivate Porphyridium purpureum under different scale-up conditions for further development and commercialization of microalgae-derived PUFAs such as ARA and EPA. Different temperatures (25, 30, and 35°C) and light intensities (70, 165, and 280μmol/m2s) were applied to the 50 L pilot-scale cultivation of P. purpureum in ASW. The cultivation under the light intensity of 280μmol/m2s at 35°C obtained biomass concentration up to 9.52g/L, total fatty acid content to 56.82mg/g, and ARA content to 22.29mg/g. While the maximum EPA content of 7.00mg/g was achieved under the light intensity of 280μmol/m2s at 25°C and the highest ratio of UFAs to TFAs of 74.66% was also obtained in this trial. Both biomass concentration and TFAs content were improved by increasing light intensity and temperature. Moreover, the ratio of ARA to EPA was enhanced by increasing cultivation temperature under the light intensity of 280μmol/m2s. In contrast with flask culture, the conversionof linoleic acid (C18:2) to ARA was enhanced in scale-up culture, leading to more ARA content. Phosphate limitation enhanced the synthesis of lipid and LPUFAs. Moreover, the biomass concentration and biosynthesis of palmitic acid were preferred by sufficient C (NaHCO3).

Spirulina platensis biomass composition is influenced by the light availability and harvest phase in raceway ponds

ABSTRACTThe behavior of cyanobacteria and its potential use for biofuel production in scale-up conditions is a topic of growing importance. The aim of our work is to study the effects of illumination, stirring, and different growth phases on the cultivation of the cyanobacteria Spirulina platensis in 10 L raceways. The cultivations were carried out in a greenhouse under measured, but not controlled, illumination and in agitated raceways with stirring speeds varying from 0.1 to 0.4 m s−1, using culture media with nutrient depletion. At the end of the stationary phase (SP) and decline of culture, the biomass was harvested and used to determine the chemical composition. The stirring rate and the growing phase influenced the carbohydrate concentration. In both phases of cultivation, compared to high-speed stirring, stirring at lower speeds produced fewer carbohydrates in the culture. Biomass grown until the end of the SP with a stirring speed of 0.35 m s−1 had a carbohydrate content of 72%, which is very high compared to that reported in the literature.

Production of putative enhanced oral cholera vaccine strains that express toxin-coregulated pilus.

The use of whole cell killed (WCK) oral cholera vaccines is an important strategy for cholera prevention in endemic areas. To overcome current vaccine limitations, we engineered strains of V. cholerae to be non-toxigenic and to express the protective protein colonization factor, toxin-coregulated pilus (TCP), under scale-up conditions potentially amenable to vaccine production. Two V. cholerae clinical strains were selected and their cholera toxin genes deleted. The tcp operon was placed under control of a rhamnose-inducible promoter. Production and stability of TCP were assessed under various conditions. The strains lack detectable cholera toxin production. The addition of 0.1% rhamnose to the growth medium induced robust production of TCP and TcpA antigen. The strains produced intact TCP in larger growth volumes (1 L), and pili appeared stable during heat-killing or acid treatment of the bacterial cultures. To date, no WCK cholera vaccines have included TCP. We have constructed putative strains of V. cholerae for use in a vaccine that produce high levels of stable TCP antigen, which has not previously been achieved.

An experimental investigation into modeling solids friction for fluidized dense-phase pneumatic transport of powders

Results are presented of an ongoing investigation into modeling friction in fluidized dense-phase pneumatic transport of bulk solids. Many popular modeling methods of the solids friction use the dimensionless solids loading ratio and Froude number. When evaluated under proper scale-up conditions of pipe diameter and length, many of these models have resulted in significant inaccuracy. A technique for modeling solids friction has been developed using a new combination of dimensionless numbers, volumetric loading ratio and the ratio of particle free settling velocity to superficial conveying air velocity, to replace the solids loading ratio and Froude number. The models developed using the new formalism were evaluated for accuracy and stability under significant scale-up conditions for four different products conveyed through four different test rigs (subject to diameter and length scale-up conditions). The new model considerably improves predictions compared with those obtained using the existing model, especially in the dense-phase region. Whereas the latter yields absolute average relative errors varying between 10% and 86%, the former yielded results with errors from 4% to 20% for a wide range of scale-up conditions. This represents a more reliable and narrower range of prediction that is suitable for industrial scale-up requirements.

Modeling minimum transport boundary for fluidized dense-phase pneumatic conveying systems

For the reliable design of fluidized dense-phase pneumatic conveying systems, it is of paramount importance to accurately estimate blockage conditions or the minimum transport boundary. Existing empirical models for the fluidized dense-phase conveying of fine powders are either based on a limited number of products and pipelines or have not been tested for their accuracy and stability over a wide range of scale-up conditions. In this paper, based on the test results of 22 different powders conveyed through 38 pipelines, a unified model for the minimum transport boundary has been developed that represents gas Froude number as a function of solid loading ratio and particle Froude number. The model has been validated by predicting the minimum transport boundary for 3 different products, conveyed through 5 different pipelines. Various other existing models have also been validated for the same products and pipelines. Comparisons between experimental blockage boundary and predicted results have shown that the new particle Froude number and solid loading ratio based model provides more accurate and stable predictions compared to the other existing models, which can unexpectedly provide significant inaccuracies. The model incorporates both pipe diameter effect and some important physical properties of the particles. The model is believed to be useful in predicting minimum conveying velocities to avoid pipe blockage and to ensure optimum operating point for industrial pneumatic conveying systems.

An Investigation into Pressure Fluctuations and Improved Modeling of Solids Friction for Dense-Phase Pneumatic Conveying of Powders

The aim of this paper is to investigate into flow mechanism with the help of pressure signal fluctuations analysis and modeling solids friction in case of solids–gas flows for fluidized-dense-phase pneumatic conveying of fine powders. Materials conveyed include fly ash (median particle diameter 30 µm; particle density 2300 kg m−3; loose-poured bulk density 700 kg m−3) and white powder (median particle diameter 55 µm; particle density 1600 kg m−3; loose-poured bulk density 620 kg m−3). These were conveyed in different flow regimes varying from fluidized-dense-to-dilute phase. To obtain information on the nature of flow inside pipeline, static pressure signals were studied using technique of Shannon entropy. Increase in the values of Shannon entropy along the flow direction through the straight-pipe sections were found for both the powders. However, drop occurred in the Shannon entropy values after the flow through bend(s). Change in slope of straight-pipe pneumatic conveying characteristics along the flow direction is another factor which provided indication regarding change in flow mechanisms along the flow. A new technique for modeling solids friction factor has been developed using a solids volumetric concentration and ratio of particle terminal settling velocity to superficial air velocity by replacing the conventional use of solids loading ratio and Froude number, respectively. The new model format has shown promise for predictions under diameter scale-up conditions.