Scale-up Effects Research Articles

Gas Hydrate Growth Kinetics: A Parametric Study

Gas hydrate growth kinetics was studied at a pressure of 90 bars to investigate the effect of temperature, initial water content, stirring rate, and reactor size in stirred semi-batch autoclave reactors. The mixing energy during hydrate growth was estimated by logging the power consumed. The theoretical model by Garcia-Ochoa and Gomez for estimation of the mass transfer parameters in stirred tanks has been used to evaluate the dispersion parameters of the system. The mean bubble size, impeller power input per unit volume, and impeller Reynold’s number/tip velocity were used for analyzing observed trends from the gas hydrate growth data. The growth behavior was analyzed based on the gas consumption and the growth rate per unit initial water content. The results showed that the growth rate strongly depended on the flow pattern in the cell, the gas-liquid mass transfer characteristics, and the mixing efficiency from stirring. Scale-up effects indicate that maintaining the growth rate per unit volume of reactants upon scale-up with geometric similarity does not depend only on gas dispersion in the liquid phase but may rather be a function of the specific thermal conductance, and heat and mass transfer limitations created by the limit to the degree of the liquid phase dispersion is batched and semi-batched stirred tank reactors.

Scale-Up Effects of CO2 Capture by Methyldiethanolamine (MDEA) Solutions in Terms of Loading Capacity

In the present study, results from three different CO2 capture experimental scales (laboratory, pilot unit, and a larger pilot unit), using aqueous amine solutions of methyldiethanolamine (MDEA) 20 wt %, are compared in terms of loading capacity. All three tested scales produced results regarding CO2 absorption using MDEA aqueous solutions, which were largely in accordance with the theoretical loading capacity of the used amine. Nevertheless, the observed differences between the theoretical and actual absorption behaviors of MDEA solutions for the different scales can be justified with the relative weight that process variables exhibit when the process is scaled up. Therefore, in order to achieve a correct scale-up of the process, simulations should be performed in order to define the best set of operational parameters in order to achieve high production yields and therefore more process profitability.

Experimental and numerical investigations of scale-up effects on the hydrodynamics of slurry bubble columns

Experiments and simulations were conducted for bubble columns with diameter of 0.2m (180mm i.d.), 0.5m (476mm i.d.) and 0.8m (760mm i.d.) at high superficial gas velocities (0.12–0.62m·s−1) and high solid concentrations (0–30vol%). Radial profiles of time-averaged gas holdup, axial liquid velocity, and turbulent kinetic energy were measured by using in-house developed conductivity probes and Pavlov tubes. Effects of column diameter, superficial gas velocity, and solid concentration were investigated in a wide range of operating conditions. Experimental results indicated that the average gas holdup remarkably increases with superficial gas velocity, and the radial profiles of investigated flow properties become steeper at high superficial gas velocities. The axial liquid velocities significantly increase with the growth of the column size, whereas the gas holdup was slightly affected. The presence of solid in bubble columns would inhibit the breakage of bubbles, which results in an increase in bubble rise velocity and a decrease in gas holdup, but time-averaged axial liquid velocities remain almost the same as that of the hollow column. Furthermore, a 2-D axisymmetric k–ε model was used to simulate heterogeneous bubbly flow using commercial code FLUENT 6.2. The lateral lift force and the turbulent diffusion force were introduced for the determination of gas holdup profiles and the effects of solid concentration were considered as the variation of average bubble diameter in the model. Results predicted by the CFD simulation showed good agreement with experimental data.

Mini-hydrocyclones applied to the removal of solids from non-Newtonian fluids and analysis of the scale-up effect

In the solids control system, the removal of fine solids from drilling fluid is performed by decanter centrifuges. The use of these centrifuges is limited not only by the costs involved but also by the available space on the oil rig, so they cannot process the entire volume of fluid circulating in the drilling system. This paper proposes the use of hydrocyclones to support decanter centrifuges, aiming to increase the removal rate of fine material from the fluid to be reinjected into the well. To this end, a highly efficient with low flow ratio hydrocyclone geometry was tested, using non-Newtonian fluids with a particulate matter size distribution similar to the conditions encountered in the field. Empirical expressions were obtained to predict the total separation efficiency, flow ratio, capacity and cut diameter of the equipment as a function of the operating conditions. The hydrocyclone scale-up results indicated that the larger device maintains practically the same separation performance as the original device, but provides an evident improvement in processing capacity.

Synthesis and Characterisation of In Situ Doped Silicon Nanoparticles

In situ boron, or phosphorous doped silicon nanoparticles were synthesised by pyrolysis of monosilane-diborane and monosilane-phosphane mixtures in free-space reactors. The studies were performed under atmospheric pressure in a laboratory reactor and a pilot plant for examination of scale-up effects. In the laboratory scale experiments, 1 vol % monosilane diluted in helium was used. The synthesis temperature varied between 600 and 800 ∘C. Pilot plant tests were run at 600 ∘C with 13.3 vol % silane diluted in hydrogen. The dopant content of the synthesised silicon powders was characterised by ETV-ICP-OES. Further investigations were carried out by using SEM, XRD, particle size analysis and FT-IR. An inhibition of the boron incorporation into the growing silicon lattice was found during the decomposition of the silane-diborane mixtures. This effect is a result of the low thermal stability of diborane. Silicon powders with higher boron contents and a wider particle size distribution leading to bigger particles, which showed no affinity to electrostatic charging, were obtained on the pilot plant scale. In phosphorus doping, reactor temperature was found crucial for the doping process.

Photocatalytic activity and scale-up effect in liquid–solid mini-fluidized bed reactor

Photocatalytic degradation of methylene blue was studied in three mini-fluidized bed reactors, with Fe3+/TiO2 photocatalyst coated on the inner wall of fluidized bed (Fe3+/TiO2/quartz tube), on the surface of fluidized particles (Fe3+/TiO2/glass beads) or on both. In the reactor of Fe3+/TiO2/quartz tube with glass beads (d=3mm, initial bed height H0=15mm), due to addition and fluidization of glass beads, mass transfer coefficient increased 11–13 times and apparent reaction rate constant increased 4.9 times compared to the empty tube. In the reactor of quartz tube with Fe3+/TiO2/glass beads (d=3mm, H0=15mm), experimental results were fitted well with a simplified kinetic model. Degradation rate per unit reaction volume reached highest value at voidage of 0.75 for all inner diameter (ID) beds. In the reactor of Fe3+/TiO2/quartz tube with Fe3+/TiO2/glass beads which combined the advantages of above two forms of catalyst, the degradation ratios were 5–35% higher than that in the other two reactors. With the increase of tube ID, scale-up effect was found. Degradation rate per unit reaction volume in Fe3+/TiO2/quartz tube with glass beads (Rav,I) and that in quartz tube with Fe3+/TiO2/glass beads (Rav,II) were introduced to quantitatively describe the processing ability and scale-up effect. The values of Rav,I of 1mm ID bed were between 4.5 and 1.8 times to 3mm ID bed when glass beads increased from empty tube to H0=15mm. The values of Rav,II of 1mm ID bed were about 1.4–1.9 times to 3mm ID bed at all H0. Scale-up effect was caused by the variation of radiation flux density, specific surface area, mass transfer distance and light penetration distance.

Decomposition analysis of green chemical technology inventions from 1971 to 2010 in Japan

Green chemistry plays an important role in achieving sustainable development through pollution prevention in manufacturing sectors. This study examines the determining factors leading to green chemical patent applications in Japan from 1971 to 2010. The novel contribution of the present research is to clarify companies' research and development strategies using log mean Divisia index with a focus on two factors: corporate priority given to green chemical patent inventions and the scale effect of research and development activities. I focus on five green chemical technologies: (1) aqueous solvents, (2) selected white biotechnology, (3) totally chlorine-free bleaching, (4) biodegradable packaging, and (5) biochemical fuel cells. The first three technologies are mainly applied in production processes in manufacturing sectors. I describe two main findings. First, green chemical technologies applied in production processes have increased due to both the scale-up effect and increased research prioritization. This result implies that policies that encourage overall research activity promote the invention of green chemical technologies that can be utilized in production. Second, biodegradable packaging and biochemical fuel cells related to product design and renewable energy increased mainly as a result of increased research prioritization. Therefore, a specific research policy is more important than a policy intended to stimulate overall research activities in encouraging the invention of biodegradable packaging and biochemical fuel cell technologies.

Pilot-scale cross-flow microfiltration of Chlorella minutissima: A theoretical assessment of the operational parameters on energy consumption

Microalgae biomass is seen as a sustainable and socially more responsible feedstock for the production of biofuels and other fine chemical products. Dewatering algae using membrane filtration is a leading technology, however the associated costs are typically not determined. This work investigates the filtration of Chlorella minutissima using a pilot-scale cross-flow microfiltration unit. A filtration model was developed and validated based on permeate flux as a function of biomass concentration (0.6–19.0 dry cell weight/L) and transmembrane pressure (ΔP, 1.80–2.10bar). Processing times for harvesting C. minutissima were determined by iteration of the model and costs were related to energy consumption. For the experimental conditions of 1.95bar, 1.0gDCW/L initial biomass concentration, 0.70kWh, 25°C and 3.8m2 membrane area, harvesting costs were determined as 2.86kWh/kg biomass. Subsequent investigation of the influence of the operating parameters and scale-up effects demonstrated that significant cost reduction to 1.27kWh/kg biomass was possible at 1.95bar, 2.0gDCW/L initial biomass concentration, 0.46kWh, 20°C and 7.6m2 membrane area. Further, biomass concentration was demonstrated to be one of the major drivers to reduce the cost of harvesting microalgae. Membrane filtration was demonstrated to be a feasible harvesting process allowing biomass concentrations up to 150gDCW/L without using chemicals which complicate the downstream processing stages.

CFD prediction of scale-up effect on the hydrodynamic behaviors of a pilot-plant fluidized bed reactor and preliminary exploration of its application for non-pelletizing polyethylene process

This work aims to explore the scale-up effect on the hydrodynamic natures in a pilot-plant gas phase ethylene polymerization fluidized bed reactor (FBR) based on two-dimensional (2D) transient Eulerian model integrating the kinetic theory of granular flow (KTGF). Unlike lab scale FBR, significant differences in the core–annulus structures caused by the scale-up effect are revealed. The core region in pilot-plant scale FBR is much broader, and the distribution is nearly flat for two phases. The annulus structure is thin, and exhibits a very small particle velocity fluctuation. The bed expanding section could reduce the solid velocity and improve the flow patterns of gas and polymer particles. Simulations are also performed to assess the effects of polymer particle size and gas velocity on the hydrodynamics for the non-pelletizing polyethylene process. With the increase of polymer particle diameter (446μm to 1338μm), the superficial gas velocity should be increased from 0.60m/s to 0.90m/s to achieve better steady fluidized state. The results are helpful for understanding how the local mean two phases' velocities and volume fractions vary in pilot-plant reactor for PE production caused by scale-up effect.

Kinetic and Scale-up Investigations of a Michael Addition in Microreactors

Microreactors are an efficient tool for process development and intensification. However, the scale-up from lab studies to small-scale commercial production is challenging, since a change in the channel dimensions requires good knowledge of heat and mass transfer phenomena. In this work, complete process development for an exothermic Michael addition is presented. In a systematic scale-up approach, kinetic studies and experimental characterization of the employed reactors provide key parameters for detailed reactor modelling. The residence time distribution, reactant mixing, and removal of reaction heat are taken into account. It is exemplarily shown how preliminary experiments can be the basis for the prediction of scale-up effects and the development of a continuous production process. Plug flow behavior and short mixing times could be confirmed for all investigated flow reactors. Furthermore, interactions of reaction kinetics and the formation of hot spots in the reactor channel were investigated. For ...

Combined modification of ultra-stable Y zeolites via citric acid and phosphoric acid

The modification of commercial ultra-stable Y zeolites using citric acid and phosphoric acid was investigated systematically via a L18(38) orthogonal experiment. The pore structure, acid property and crystal structural of modified USY zeolites were characterized by a variety of means such as N2 adsorption–desorption, Fourier transform infrared spectroscopy, NH3-temperature programmed desorption and X-ray diffraction. The optimal modification condition is found to be that the volume ratio of citric acid (0.3 mol/L) and phosphoric acid (0.3 mol/L) is 1.0, and the operation is performed at 100 °C for 6 h. The as-synthesized sample presents an increased secondary pore volume up to 0.207 cm3/g which accounts for 42.9 % of the total pore volume, and appropriate acidity distribution as well as good crystallinity. In addition, the USY obtained by 1.0 L scale-up modification possesses a secondary pore volume of 0.210 cm3/g which accounts for 42.4 % of the total pore volume, showing no obvious scale-up effects. Furthermore, the hydrothermal stability of the modified samples meets the requirements of commercial catalysts for hydrocracking. Performance evaluation was carried out on a 200 mL fixed-bed single stage hydrogenation unit using Daqing VGO as feedstock. The 140–370 °C middle distillate yield is 66.09 %, and middle distillate selectivity can reach up to 80.45 %. Compared with commercial catalyst, the yield and selectivity are increased by 5.67 and 4.07 %, respectively.

Efficient purification of antiproliferative polysaccharides from Hypsizigus marmoreus with radial flow chromatography.

The increasing commercial significance of natural polysaccharides for use in medicinal products is stimulating the development of efficient and easy scale-up techniques for polysaccharide purification. In this research, the crude polysaccharides from submerged cultivation broth of Hypsizigus marmoreus were purified using radial flow chromatography (RFC), and the antiproliferative activity of the purified fractions was evaluated in vitro. DEAE Sepharose CL-6B was selected to be packed in the RFC column based on its good resolution, physical stability, and low cost. Compared with axial flow chromatography (AFC), an efficient chromatographic process with significantly less time and buffer consumption but yielding higher polysaccharide recovery and resolution was established in RFC, which could clearly purify the crude polysaccharides into different fractions. An acceptable linear scale-up effect of RFC from 100 to 500 mL was successfully achieved without loss of resolution and enhancement of time consumption. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays in cell cultures indicated that the purified polysaccharide fractions possess moderate antiproliferative activities in three different human cancer cell lines, but have significantly lower cytotoxicity in normal human cell lines in vitro. Among the polysaccharide fractions, the main purified acidic fraction W-I could be considered as a novel potential antitumor agent candidate for several tumors, especially for human alveolar epithelial tumors. This research confirmed for the first time that RFC would be a new fast and efficient tool for purification of polysaccharides into different fractions, both at laboratory and commercial scales.

Experimental Study and Modeling on Effects of a New Multilayer Baffle in a Turbulent Fluid Catalytic Cracking Regenerator

A new multilayer baffle for intensifying the catalyst regeneration process of a dense bed fluid catalytic cracking (FCC) regenerator was proposed and its effects on hydrodynamics and gas/solids mixing in fluidized beds of FCC particles were investigated experimentally in a large cold fluidized bed model. Experimental results show that, due to scale-up effects and serious gas bypassing, the new baffle was more effective in improving gas–solids contact as indicated by the weaker pressure fluctuations, increased bed expansion, and reduced freeboard particle carryover measured in the baffled fluidized bed (BFB) of this study. Compared with baffle-free fluidized bed (FFB), the new baffle can reduce internal gas circulation flux by 89–96%, indicating stronger suppression on gas/solids backmixing. An established baffled FCC regenerator model shows that, in a regenerator with this new baffle, cleaner regenerated catalysts can be obtained with less air consumption and catalyst inventory. Moreover, the modeled resu...

Minimizing the Energy Requirement of Dewatering Scenedesmus sp. by Microfiltration: Performance, Costs, and Feasibility

The harvesting of the microalgae Scenedesmus species using a 200 L pilot-scale microfiltration system was investigated and critically assessed. The energy requirement was determined and correlated to the different operating parameters, such as transmembrane pressure (ΔP), membrane area, temperature, and initial biomass concentration. A filtration model was developed and showed a strong correlation with experimental data up to 20.0 g of dry cell weight (DCW)/L. The non-optimized filtration system had an energy requirement of 2.23 kWh/m(3) with an associated cost of $0.282/kg of microalgae. The investigation into the influence of the operating parameters and scale-up effects showed that the energy requirement could be substantially reduced to 0.90 kWh/m(3) and $0.058/kg of microalgae harvested. Maintenance costs associated with cleaning were estimated to be 0.23 kWh or $0.029/batch of microalgae processed. Dependent upon the operating conditions, harvesting may represent 6-45% of the energy embedded in the microalgae with a carbon footprint of 0.74-1.67 kg of CO2/kg of microalgae. Microfiltration was demonstrated to be a feasible microalgae harvesting technology allowing for more than 99% volume reduction. The energy requirement and associated carbon footprint of microalgae harvesting reported here do not forfeit the need for an industrial-scale study; however, the information provided presents a more realistic approximation than the literature reported to date.

Effects of scale-up on a hybrid moving bed biofilm reactor – membrane bioreactor for treating urban wastewater

A hybrid moving bed biofilm reactor–membrane bioreactor (hybrid MBBR–MBR) system has been tested in this study at two scales to analyse the scale-up effect. Two municipal wastewater treatment plants were used, one at laboratory scale (hybrid MBBR–MBRL) with a reactor working volume of 24 l and one at pilot scale (hybrid MBBR–MBRP) with a reactor working volume of 358 l. Hybrid MBBR–MBRL and hybrid MBBR–MBRP showed that the hybrid MBBR–MBR systems used in this research were reliable for organic matter removal with COD removal percentages of 90.97±2.55% and 95.56±2.01% for hybrid MBBR–MBRL and hybrid MBBR–MBRP, respectively. In hybrid MBBR–MBRL, the sludge retention time was higher but the biofilm density was lower due to the wall effect, so the two effects cancelled one another out and the COD removal efficiencies were found to be similar. The study identified the most influential variables and their effects on the process. Hybrid MBBR–MBRL and hybrid MBBR–MBRP were influenced by the attached and suspended biomass and temperature, while the influent loading rate only affected hybrid MBBR–MBRP. On the whole, hybrid MBBR–MBRP showed a better performance from the point of view of the kinetics of the heterotrophic biomass, with values of YH=0.6130mgVSSmgCOD−1, μm,H=0.0146h−1, KS=9.8852mgO2L−1, and bH=0.0031h−1.

Scale-up effects on flow patterns in the high shear mixing of cohesive powders

Processing of granular material often requires mixing steps in order to blend cohesive powders, distribute viscous liquids into powder beds or create agglomerates from a wet powder mass. For this reason, using bladed, high-speed mixers is frequently considered a good solution by many types of industry. However, despite the importance of such mixers in powder processing, the granular flow behavior inside the mixer bowl is generally not totally understood. In this work extensive experimentation was performed comparing the behavior of a lab-scale mixer (1.9l vessel volume) to that of a pilot-scale mixer (65l vessel volume) with a mixture of some pharmaceutical excipients (e.g. lactose, cellulose). The aim was to propose a new and more detailed method for describing the complex powder rheology inside an high shear mixer using impeller torque, current consumption and particle image velocimetry (PIV) analysis. Particularly, a new dimensionless torque number is proposed for the torque profile analysis in order to isolate the contributions of mass fill and blade clearance at the vessel base. Impeller torque and motor current consumption were integrated with PIV to obtain more detailed information about the surface velocity and flow pattern changes in the pilot-scale mixer. Mass fill resulted to be one of the most critical variables, as predicted by the torque model, strongly affecting the powder flow patterns. An additional mixing regimes was furthermore defined according to the observation of the surface velocity of the powder bed.

Process cost and facility considerations in the selection of primary cell culture clarification technology

The bioreactor volume delineating the selection of primary clarification technology is not always easily defined. Development of a commercial scale process for the manufacture of therapeutic proteins requires scale-up from a few liters to thousands of liters. While the separation techniques used for protein purification are largely conserved across scales, the separation techniques for primary cell culture clarification vary with scale. Process models were developed to compare monoclonal antibody production costs using two cell culture clarification technologies. One process model was created for cell culture clarification by disc stack centrifugation with depth filtration. A second process model was created for clarification by multi-stage depth filtration. Analyses were performed to examine the influence of bioreactor volume, product titer, depth filter capacity, and facility utilization on overall operating costs. At bioreactor volumes <1,000 L, clarification using multi-stage depth filtration offers cost savings compared to clarification using centrifugation. For bioreactor volumes >5,000 L, clarification using centrifugation followed by depth filtration offers significant cost savings. For bioreactor volumes of ∼ 2,000 L, clarification costs are similar between depth filtration and centrifugation. At this scale, factors including facility utilization, available capital, ease of process development, implementation timelines, and process performance characterization play an important role in clarification technology selection. In the case study presented, a multi-product facility selected multi-stage depth filtration for cell culture clarification at the 500 and 2,000 L scales of operation. Facility implementation timelines, process development activities, equipment commissioning and validation, scale-up effects, and process robustness are examined.

Production of Ethanol from Sweet Sorghum Juice Using VHG Technology: A Simulation Case Study

The aims of this study were to develop the kinetic model and determine kinetic parameters describing ethanol production from sweet sorghum juice using very high gravity technology in the batch fermentation of Saccharomyces cerevisiae NP01. The obtained experimental data were tested with four different types of model, based on the experimental data, accounting for the substrate limitation, substrate inhibition, product inhibition, and the combination of those three effects, respectively. The optimization technique to find kinetic parameters was non-linear regression using Marquardt method performed through numerical procedure. The chosen model with its kinetic parameters obtained in the batch mode was validated and tested against the other independent experimental data in the small batch-scale and large-scale fermenter, in order to investigate the applicability and scale-up effect of the model, respectively. Then, the obtained model with its parameters was applied in the simulations of the continuous and fed-batch operations to examine the concentration profiles of fermentation components with the variations in operating parameters such as the dilution rate, feed-flow rate, start-up time, and feed concentration. The results indicated that the kinetic model (the substrate limitation with substrate and product inhibition effects) was suitable to describe ethanol fermentation. In the continuous mode, using the dilution rate of 0.01h(-1), the maximum ethanol concentration obtained was, approximately, 90g/l whereas the simulated results from the fed-batch operation revealed that the maximum ethanol concentration at quasi-steady state condition was, approximately, 96g/l. The start-up time of 21h was the fastest time to reach the steady-state and quasi-steady state for both the continuous and fed-batch modes, respectively.

Maximum Drag Reduction Asymptote for Surfactant-Based Fluids in Circular Coiled Tubing

Surfactants are superior to polymers in reducing drag and their advantages are very well established. As drag reducers, several factors, such as concentration, temperature, salinity, shear rate, etc., can affect their behavior. Other unique factors relevant to surfactants may include tubing diameter (scale-up effect), head group structure, counterion, charge, etc. Although, drag reduction envelope is customarily employed to investigate drag reduction phenomena, it is defined only for polymeric fluids in both straight and coiled tubing and for surfactant-based (SB) fluids in straight tubing. No such envelope is available for SB fluids in coiled tubing. The present research aims at experimentally investigating the drag reduction characteristics of the most widely used Aromox APA-T surfactant-based fluids. It is a highly active surfactant used as gelling agent in aqueous and brine base fluids. Flow data are gathered using small and large scale flow loops. Straight and coiled tubing with various sizes (1.27 cm to 7.30 cm o.d.) and curvature ratios (0.01 to 0.031) covering the field application range are utilized. The results show that SB fluids exhibit superior drag reduction characteristics. Their behavior is significantly affected by surfactant concentration, shear, tubing size, and geometry. Higher drag reduction is seen in straight tubing than in coiled tubing and increasing curvature ratio yields higher friction pressure losses. In coiled tubing, SB fluids exhibit better drag reduction characteristics than Shah and Zhou maximum drag reduction (MDR) asymptote for polymeric fluids. Therefore, a new maximum drag reduction asymptote is developed using data gathered in 1.27 cm o.d. tubing. The proposed correlation agrees with Zakin MDR asymptote for SB fluids in straight tubing where the curvature ratio is set to be zero. Employing the proposed correlation, a modified drag reduction envelope can be used to evaluate drag reduction characteristics of SB fluids.

Chemo-enzymatic asymmetric synthesis of S-citalopram by lipase-catalyzed cyclic resolution and stereoinversion of quaternary stereogenic center

A chemo-enzymatic synthesis method of S-citalopram was developed to overcome the disadvantage of relatively low selectivity of enzyme towards tertiary alcohols. The combination of kinetic resolution, cyclic resolution and stereoinversion synthesis was successfully applied in the asymmetric synthesis of the S-citalopram. Using the kinetic model to predict the cyclic resolution, R-diol with high ee value was obtained by controlling the conversion rate. Subsequently, the unwanted R-diol was inverted to S-citalopram by stereoinversion of chiral quaternary center with 98.0% yield and ee value of 91.0%. Based on dynamic simulation and experiments, the kinetic resolution was scaled up from 10 mL to 1 L and 14 L, gradually. There was no significant scale-up effect and the dynamic simulation result fitted the experimental data well, with an error of 12.5 and 14.0%, respectively. This chemo-enzymatic synthesis route is a promising model system for the production of pharmaceuticals with the chiral tertiary alcohols intermediate.