Dynamic evolution of PSD in continuous flow processes: A comparative study of fixed and moving grid numerical techniques

Part IV: Dynamic evolution of the particle size distribution in particulate processes. A comparative study between Monte Carlo and the generalized method of moments

Solution of the bivariate dynamic population balance equation in batch particulate systems: Combined aggregation and breakage

Solution of PBE by MOM in finite size domains

A controlled radical polymerization process using the Reversible Addition-Fragmentation Chain Transfer (RAFT) approach was scaled up by a factor of 100 from a small laboratory scale of 5 mL to a preparative scale of 500 mL, using batch and continuous flow processing. The batch polymerizations were carried out in a series of different glass vessels, using either magnetic or overhead stirring, and different modes of heating: Microwave irradiation or conductive heating in an oil bath. The continuous process was conducted in a prototype tubular flow reactor, consisting of 6 mm ID stainless steel tubing, fitted with static mixers. Both reactor types were tested for polymerizations of the acid functional monomers acrylic acid and 2-acrylamido-2-methylpropane-1-sulfonic acid in water at 80 °C with reaction times of 30 to 40 min. By monitoring the temperature during the exothermic polymerization process, it was observed that the type and size of reactor had a significant influence on the temperature profile of the reaction.

Mathematical modeling of the bivariate molecular weight—Long chain branching distribution of highly branched polymers.: A population balance approach

A first‐order finite‐element scheme is proposed for solving the 1‐D dynamic population balance equation. The model includes the kinetic processes of nucleation, growth, aggregation, and breakage in a spatially uniform system with or without flow. The numerical scheme features improved stability by taking into account the convective nature of the growth term, and enhanced conservation of moments at nonuniform grids by identifying and mitigating the sources of conservation error in the evaluation of the aggregation source term. Exhaustive benchmarking is carried out against analytical solutions for size‐dependent growth and nucleation, size‐dependent aggregation with a variety of kernels, binary and multiple breakage with uniform and parabolic daughter particle distributions, and combinations of these, respectively. In all cases tested the method proves capable of producing accurate results at a reasonable CPU time, while being relatively simple and easy to implement.

ABSTRACTCopper(0)‐mediated controlled radical polymerization (CRP), or single‐electron transfer‐living radical polymerization (SET‐LRP) is a robust and dynamic technique that has attracted considerable academic and industrial interest as a synthetic tool for novel value‐added materials. Although SET‐LRP possesses many advantages over other forms of CRP, this novel chemistry still requires concurrent engineering solutions for successful commercial application. In this highlight, the evolution of atom‐transfer radical polymerization chemistry and development in continuous processes is presented, leading to recent research on the use of SET‐LRP in continuous flow tubular reactors. The proofs of concept are reviewed, and remaining challenges and unexplored potential on the use of continuous flow processes with SET‐LRP as a powerful platform for the synthesis of novel polymeric materials are discussed. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 3081–3096

Visible light-driven complete photocatalytic oxidation of organic dye by plasmonic Au-TiO2 nanocatalyst under batch and continuous flow condition

Upgrading from batch to continuous flow process for the pyrolysis of sugarcane bagasse: Structural characterization of the biochars produced

Synthesis of layered double hydroxides through continuous flow processes: A review

An automated continuous flow system capable of producing protected deoxy‐sugar donors from commercial material is described. Four 2,6‐dideoxy and two 3‐amino‐2,3,6‐trideoxy sugars with orthogonal protecting groups were synthesized in 11–32 % overall yields in 74–131.5 minutes of total reaction time. Several of the reactions were able to be concatenated into a continuous process, avoiding the need for chromatographic purification of intermediates. The modular nature of the experimental setup allowed for reaction streams to be split into different lines for the parallel synthesis of multiple donors. Further, the continuous flow processes were fully automated and described through the design of an open‐source Python‐controlled automation platform.

Modelling of Continuous Synthesis Process of TiO 2 Particles Using Slug Flow Tubular Reactor

Abstract. New particle formation (NPF) and growth are a major source of atmospheric fine particles. In polluted urban environments, NPF events are frequently observed with characteristics distinct from those in clean environments. Here we simulate NPF events in urban Beijing with a discrete-sectional model that couples cluster dynamics and multicomponent particle growth. In the model, new particles are formed by sulfuric acid–dimethylamine nucleation, while particle growth is driven by particle coagulation and the condensation of sulfuric acid, its clusters, and oxygenated organic molecules (OOMs). A variable simulation domain in the particle size space is applied to isolate newly formed particles from preexisting ones, which allows us to focus on new particle formation and growth rather than the evolution of particles of non-NPF origin. The simulation yields a rich set of information including the time-dependent NPF rates, the cluster concentrations, the particle size distributions, and the time- and size-specific particle chemical compositions. These can be compared with the field observations to comprehensively assess the simulation–observation agreement. Sensitivity analysis with the model further quantifies how metrics of NPF events (e.g., particle survival probability) respond to model input variations and serves as a diagnostic tool to pinpoint the key parameter that leads to simulation–observation discrepancies. Seven typical NPF events in urban Beijing were analyzed. We found that with the observed gaseous precursor concentrations and coagulation sink as model inputs, the simulations roughly captured the evolution of the observed particle size distributions; however, the simulated particle growth rate was insufficient to yield the observed particle number concentrations, survival probability, and mode diameter. With the aid of sensitivity analysis, we identified under-detected OOMs as a likely cause for the discrepancy, and the agreement between the simulation and the observation was improved after we modulated particle growth rates in the simulation by adjusting the abundance of OOMs.

Review for "Selective reduction of oxalic acid to glycolic acid at low temperature in a continuous flow process"

Review for "Selective reduction of oxalic acid to glycolic acid at low temperature in a continuous flow process"