scholarly journals A Microwave-Based Chemical Factory in the Lab: From Milligram to Multigram Preparations

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Laura Rinaldi ◽  
Diego Carnaroglio ◽  
Laura Rotolo ◽  
Giancarlo Cravotto
Keyword(s):  
Process Intensification ◽  
Pilot Scale ◽  
Production Costs ◽  
Microwave Chemistry ◽  
Reaction Conditions ◽  
Flow Reactors ◽  
Advantages And Disadvantages ◽  
Microwave Reactors ◽  
Flow Through ◽  
Parallel Tests

Microwave technology is changing the way we design and optimize synthetic protocols and their scaling up to multigram production levels. The latest generation of dedicated microwave reactors enables operators to quickly screen reaction conditions by means of parallel tests and select the best catalyst, solvent, and conditions. Pilot scale synthetic procedures require flow-through conditions in microwave flow reactors which can be obtained by adapting classic batch protocols. Microwave-assisted chemical processes play a pivotal role in the design of sustainable multigram preparations which address the double requirement of process intensification and competitive production costs. Although most researchers are likely to be acquainted with the great potential of dielectric heating, the advantages and disadvantages of a particular device or the conditions needed to maximize efficiency and functionality are often overlooked. The double aims of the present review are to provide a panoramic snapshot of commercially available lab microwave reactors and their features as well as highlighting a few selected applications of microwave chemistry of particular relevance.

scholarly journals Towards a Novel Computer-Aided Optimization of Microreactors: Techno-Economic Evaluation of an Immobilized Enzyme System

Symmetry ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 524
Author(s):  
Philip Pietrek ◽  
Manfred Kraut ◽  
Roland Dittmeyer
Keyword(s):  
Magnetic Beads ◽  
Glucose Dehydrogenase ◽  
Packed Bed ◽  
Detailed Knowledge ◽  
Reaction Conditions ◽  
Flow Reactors ◽  
Continuous Flow Reactors ◽  
Enzyme Cascades ◽  
And Control ◽  
Physical And Chemical

Immobilized multi-enzyme cascades are increasingly used in microfluidic devices. In particular, their application in continuous flow reactors shows great potential, utilizing the benefits of reusability and control of the reaction conditions. However, capitalizing on this potential is challenging and requires detailed knowledge of the investigated system. Here, we show the application of computational methods for optimization with multi-level reactor design (MLRD) methodology based on the underlying physical and chemical processes. We optimize a stereoselective reduction of a diketone catalyzed by ketoreductase (Gre2) and Nicotinamidadenindinukleotidphosphat (NADPH) cofactor regeneration with glucose dehydrogenase (GDH). Both enzymes are separately immobilized on magnetic beads forming a packed bed within the microreactor. We derive optimal reactor feed concentrations and enzyme ratios for enhanced performance and a basic economic model in order to maximize the techno-economic performance (TEP) for the first reduction of 5-nitrononane-2,8-dione.

Process intensification for enzyme assisted turmeric starch hydrolysis in hydrotropic and supercritical conditions

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Yogita P. Labrath ◽  
Prafulla V. Belge ◽  
Uma G. Kulkarni ◽  
Vilas G. Gaikar
Keyword(s):  
Residence Time ◽  
Filtration Rate ◽  
Room Temperature ◽  
Curcuma Longa ◽  
Process Intensification ◽  
Enzyme Treatment ◽  
Starch Hydrolysis ◽  
Reaction Conditions ◽  
Natural Form ◽  
Hydrolysis Of

Abstract The turmeric rhizome (Curcuma longa) contains curcuminoids embedded in the starch matrix. It is thus important to target starch hydrolysis to enhance extraction of curcuminoids. In the case of starch hydrolysis, α-amylase is more efficient when the starch is in a gelatinised form than when it is in its natural form. The present work includes hydrolysis of turmeric starch in its natural and gelatinised forms using α-amylase in hydrotrope solution (HS) and scCO2. The optimum rate of starch hydrolysis was obtained using 200 IU cm−3 of α-amylase, at reaction conditions of 6.5 pH at 328 K when 10% w/w of turmeric powder was stirred at 900 rpm in HSs. The hydrolysis in 15 MPa scCO2 at room temperature required a phase modifier and 40 min of residence time (RT). The enzyme treatment of turmeric powder in HSs increased the filtration rate for curcuminoid extraction (gelatinised and native) compared to untreated turmeric powder.

scholarly journals EFFICIENCY OF REINFORCEMENT OF TECHNOLOGICAL SOIL BY MINERAL MODIFIERS

2019 ◽  
Vol 4 (7) ◽  
pp. 14-23
Author(s):  
Т. Дмитриева ◽  
T. Dmitrieva ◽  
Н. Куцына ◽  
N. Kucyna ◽  
А. Безродных ◽  
...  
Keyword(s):  
Raw Materials ◽  
Road Construction ◽  
Soil Reinforcement ◽  
Production Costs ◽  
Concrete Mixture ◽  
The Road ◽  
Physicomechanical Characteristics ◽  
Advantages And Disadvantages ◽  
Complex Binder ◽  
Technogenic Raw Materials

The paper discusses the main aspects of soil reinforcement in road construction by adding a binder component to them. The use of this technology allows to solve the problem of high-quality raw materials shortage while improving the physicomechanical characteristics or keeping them at the same level, as well as to increase labor productivity and reduce production costs. The technogenic raw materials for the production of soil concrete were studied, the main physicomechanical characteristics and requirements that must be taken into account when selecting the composition of the soil concrete mixture were analyzed. The paper compares the physicomechanical characteristics of the road composite, reveals the advantages and disadvantages of introducing binder components of various types: cement, cement with modifier and a complex binder. It has been established that the introduction of a complex binder or cement with modifier contributes to the improvement of the physicomechanical characteristics while reducing the consumption of cement in the composition of the soil-concrete mixture compared to traditional soil-concrete with cement.

scholarly journals Designs of new operating copper processing plants: process types, equipment selection, industry trends

2021 ◽  
pp. 44-52
Author(s):  
V. F. Baranov
Keyword(s):  
Large Scale ◽  
High Capacity ◽  
Process Intensification ◽  
Processing Plant ◽  
Advantages And Disadvantages ◽  
Sulphide Ores ◽  
Flotation Cells ◽  
Ore Preparation ◽  
Processing Plants ◽  
Technical Solutions

The article describes the largest operating processing plants for lowgrade copper sulphide ores of our time: 10 plants using the semi-autogenous grinding (SAG) technology and 10 plants using high-pressure grinding rolls (HPGR), with the output of 18 to 100 Mtpa. The unfavorable natural and economic factors are balanced by improved ore preparation and concentration technologies and high-capacity equipment units, combined with cost-saving layout solutions. The ore preparation sector is currently divided between the competing technologies of semi-autogenous grinding and HPGR. The article contains an overview of their advantages and disadvantages. The world’s largest monosection with the capacity of 55.5 Mtpa, that uses the SAG technology, is described. The role of the Drop Weght Test JKSimMet (A×b) parameter in the selection of the ore preparation method and the trend for using HPGR in the processing of strong ores are shown. Examples are provided for the consequences of an inadequate assessment of the feed strength in SAG-based plant designs. Examples of ore preparation process intensification through the use of HPGR in semi-autogenous grinding circuits are also given. The volume of impeller flotation cells installed has reached 600 m3. An overview of the two largest processing plants of our time with the output of 88 and 100 Mtpa of ore is presented. The innovative technical solutions of a newest low-capacity copper plant are highlighted. Based on the results of the overview, a future processing plant is predicted to use ∅12.8–13 m SAG mills, HPGRs with the roll diameter of 3 m, vertical VTM-7000 mills in ore grinding cycles, large fine screens, large-scale impeller flotation cells, and staged SFR and DFR flotation reactors.

Intensification of the Production of 2-Ethyl-Hexyl Acrylate: Batch Kinetics and Reactive Distillation

2018 ◽  
Vol 16 (7) ◽  
Author(s):  
Vivek D. Talnikar ◽  
Onkar A. Deorukhkar ◽  
Amit Katariya ◽  
Yogesh S. Mahajan
Keyword(s):  
Kinetic Model ◽  
Acrylic Acid ◽  
Process Development ◽  
Reactive Distillation ◽  
Batch Reactor ◽  
Process Intensification ◽  
Complete Conversion ◽  
Reaction Conditions ◽  
Batch Mode ◽  
Batch Kinetics

Abstract The reaction of acrylic acid and 2-ethyl-1 hexanol was explored in this work with the intent of process intensification. In order to assess the effect of important parameters on the course of reaction, this work initially conducted batch reactor experiments. Reaction conditions in the batch reactor for a specific conversion (~ 30 %) were obtained. A kinetic model was then obtained through regression to arrive at a rate expression that is later used in process development. Experiments were performed in the reactive distillation (RD) environment in batch mode, which showed substantial increase in conversion (~ 80 %) indicating the applicability of RD. Further, this work performed simulation in the RD environment to assess process intensification. Simulations show that it is possible to obtain complete conversion of the acid.

Flow-through Respirometry: The Basics

2018 ◽  
pp. 71-93
Author(s):  
John R. B. Lighton
Keyword(s):  
Carbon Dioxide ◽  
Signal Amplitude ◽  
Data Acquisition System ◽  
Metabolic Rates ◽  
Flow Rates ◽  
Advantages And Disadvantages ◽  
Carbon Dioxide Analysis ◽  
Response Correction ◽  
Flow Through ◽  
Mathematical Techniques

This chapter describes the basic theory behind the most widely used method for measuring metabolic rates: flow-through or open-system respirometry. The advantages and disadvantages of the technique are summarized and the two major types of flow-through respirometry systems are described. Recommendations are given on choosing an appropriate flow rate to compromise between speed of response and signal amplitude; on the nature and importance of the cage time-constant; on using mathematical techniques for response correction by compensating for first-order wash-out kinetics and avoiding mixing errors; the essential differences between oxygen and carbon dioxide analysis; choosing a data acquisition system; generating and measuring flow rates; removing or mathematically compensating for water vapor; important tools; and checklists for deciding on system configuration for a given investigation.

A critical evaluation of a pilot scale subsurface flow wetland: 10 years after commissioning

1997 ◽  
Vol 35 (5) ◽  
pp. 337-343 ◽  
Author(s):  
Allan Batchelor ◽  
Pierre Loots
Keyword(s):  
Critical Evaluation ◽  
Subsurface Flow ◽  
Plug Flow ◽  
Pilot Scale ◽  
Preliminary Evidence ◽  
Surface Flow ◽  
Organic Load ◽  
Hydraulic Load ◽  
Flow Through ◽  
Back Mixing

A pilot scale subsurface flow wetland, commissioned in 1986, has been continuously operated since 1990 at a hydraulic load of 330 mm/day and a corresponding organic load of 1200 kg/ha·day. At these loading rates preliminary evidence suggests that the microbial biomass in the wetland was dominated by anaerobes. Attempts to increase the hydraulic load resulted in surface flooding which was attributed to suspended solids clogging the surface. Despite short circuiting, revealed by tracer studies, COD removal exceeded 70%. The hydraulic flow through the wetland was modelled and was described as modified plug flow with a degree of back mixing. A comparative costing exercise revealed that the unit treatment cost of a combination of a subsurface flow wetland/nitrification column, surface flow wetland was lower than that of an activated sludge system treating the same volume of effluent.

scholarly journals Enzymatic Bioreactors: An Electrochemical Perspective

Catalysts ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1232
Author(s):  
Simin Arshi ◽  
Mehran Nozari-Asbemarz ◽  
Edmond Magner
Keyword(s):  
Direct Electron Transfer ◽  
High Surface ◽  
High Surface Area ◽  
Enzyme Engineering ◽  
Future Perspective ◽  
Enzymatic System ◽  
Reaction Conditions ◽  
Flow Reactors ◽  
Recent Developments ◽  
Enzyme Cascades

Biocatalysts provide a number of advantages such as high selectivity, the ability to operate under mild reaction conditions and availability from renewable resources that are of interest in the development of bioreactors for applications in the pharmaceutical and other sectors. The use of oxidoreductases in biocatalytic reactors is primarily focused on the use of NAD(P)-dependent enzymes, with the recycling of the cofactor occurring via an additional enzymatic system. The use of electrochemically based systems has been limited. This review focuses on the development of electrochemically based biocatalytic reactors. The mechanisms of mediated and direct electron transfer together with methods of immobilising enzymes are briefly reviewed. The use of electrochemically based batch and flow reactors is reviewed in detail with a focus on recent developments in the use of high surface area electrodes, enzyme engineering and enzyme cascades. A future perspective on electrochemically based bioreactors is presented.

scholarly journals Progress in electrochemical flow reactors for laboratory and pilot scale processing

2018 ◽  
Vol 280 ◽  
pp. 121-148 ◽  
Author(s):  
Frank C. Walsh ◽  
Carlos Ponce de León
Keyword(s):  
Pilot Scale ◽  
Flow Reactors
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