Synthesis of Fine Chemicals Using Catalytic Nanomaterials: Structure Sensitivity

2013 ◽  
pp. 279-294
Keyword(s):  
Structure Sensitivity ◽  
Fine Chemicals

Formic Acid: A Promising Bio-Renewable Feedstock for Fine Chemicals

2012 ◽  
Vol 354 (17) ◽  
pp. 3180-3186 ◽  
Author(s):  
Manuel G. Mura ◽  
Lidia De Luca ◽  
Giampaolo Giacomelli ◽  
Andrea Porcheddu
Keyword(s):  
Formic Acid ◽  
Fine Chemicals ◽  
Renewable Feedstock

Structure Sensitivity Analysis and Dynamic Performance Optimization of Marine Gearbox

2017 ◽  
Author(s):  
Tengjiao Lin ◽  
Daokun Xie ◽  
Ziran Tan ◽  
Bo Liu
Keyword(s):  
Sensitivity Analysis ◽  
Performance Optimization ◽  
Optimization Design ◽  
Dynamic Performance ◽  
Structure Sensitivity ◽  
Superposition Method ◽  
Structure Parameters ◽  
Analysis Model ◽  
Vibration Acceleration ◽  
Response Optimization

The aim of this paper is to investigate the influence of structure parameters on the vibration characteristics and improve the dynamic performance of marine gearbox. A finite element model was established to solve the dynamic response by using modal superposition method. Based on the theory of multi-objective optimization design, the structure sensitivity analysis model of marine gearbox was established, which takes the structure parameters of the housing as design variables. The modal and response sensitivity was obtained by using the optimal gradient method. According to the results of sensitivity analysis, a modal and response optimization model of marine gearbox was established. The objective was to avoid natural frequencies from the excitation frequencies and minimize the root mean square of vibration acceleration of the evaluating points on the surface of housing. Then the modal optimization and response optimization of gearbox were carried out by using zero-order and first-order optimization method. The results indicate that the dynamic optimization of the gearbox can be achieved. After optimization, the amplitude of vibration acceleration of the evaluating points on the housing surface has been reduced and the resonance of marine gearbox can be avoided.

scholarly journals Nitrile Synthesis with Aldoxime Dehydratases: A Biocatalytic Platform with Applications in Asymmetric Synthesis, Bulk Chemicals, and Biorefineries

Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4466
Author(s):  
Pablo Domínguez de María
Keyword(s):  
Asymmetric Synthesis ◽  
Organic Solvents ◽  
Raw Materials ◽  
Aqueous Media ◽  
Industrial Processes ◽  
Polymer Chemistry ◽  
Fine Chemicals ◽  
Mild Conditions ◽  
Bulk Chemicals ◽  
Recent Developments

Nitriles comprise a broad group of chemicals that are currently being industrially produced and used in fine chemicals and pharmaceuticals, as well as in bulk applications, polymer chemistry, solvents, etc. Aldoxime dehydratases catalyze the cyanide-free synthesis of nitriles starting from aldoximes under mild conditions, holding potential to become sustainable alternatives for industrial processes. Different aldoxime dehydratases accept a broad range of aldoximes with impressive high substrate loadings of up to >1 Kg L−1 and can efficiently catalyze the reaction in aqueous media as well as in non-aqueous systems, such as organic solvents and solvent-free (neat substrates). This paper provides an overview of the recent developments in this field with emphasis on strategies that may be of relevance for industry and sustainability. When possible, potential links to biorefineries and to the use of biogenic raw materials are discussed.

scholarly journals Biocatalysis with Laccases: An Updated Overview

Catalysts ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 26
Author(s):  
Ivan Bassanini ◽  
Erica Elisa Ferrandi ◽  
Sergio Riva ◽  
Daniela Monti
Keyword(s):  
Organic Synthesis ◽  
Alcohol Oxidation ◽  
Industrial Processes ◽  
Organic Substrates ◽  
Fine Chemicals ◽  
Multicopper Oxidases ◽  
Carbohydrate Chemistry ◽  
Nucleophilic Substitutions ◽  
Mediator System ◽  
Integrated Processes

Laccases are multicopper oxidases, which have been widely investigated in recent decades thanks to their ability to oxidize organic substrates to the corresponding radicals while producing water at the expense of molecular oxygen. Besides their successful (bio)technological applications, for example, in textile, petrochemical, and detoxifications/bioremediations industrial processes, their synthetic potentialities for the mild and green preparation or selective modification of fine chemicals are of outstanding value in biocatalyzed organic synthesis. Accordingly, this review is focused on reporting and rationalizing some of the most recent and interesting synthetic exploitations of laccases. Applications of the so-called laccase-mediator system (LMS) for alcohol oxidation are discussed with a focus on carbohydrate chemistry and natural products modification as well as on bio- and chemo-integrated processes. The laccase-catalyzed Csp2-H bonds activation via monoelectronic oxidation is also discussed by reporting examples of enzymatic C-C and C-O radical homo- and hetero-couplings, as well as of aromatic nucleophilic substitutions of hydroquinones or quinoids. Finally, the laccase-initiated domino/cascade synthesis of valuable aromatic (hetero)cycles, elegant strategies widely documented in the literature across more than three decades, is also presented.

scholarly journals Biosynthesis of pinene in purple non-sulfur photosynthetic bacteria

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Xiaomin Wu ◽  
Guang Ma ◽  
Chuanyang Liu ◽  
Xin-yuan Qiu ◽  
Lu Min ◽  
...  
Keyword(s):  
Fusion Protein ◽  
Heterologous Expression ◽  
Rhodobacter Sphaeroides ◽  
Photosynthetic Bacteria ◽  
Fine Chemicals ◽  
Isopentenyl Diphosphate ◽  
Isopentenyl Diphosphate Isomerase ◽  
Geranyl Diphosphate ◽  
Ribosome Binding ◽  
Geranyl Diphosphate Synthase

Abstract Background Pinene is a monoterpene, that is used in the manufacture of fragrances, insecticide, fine chemicals, and renewable fuels. Production of pinene by metabolic-engineered microorganisms is a sustainable method. Purple non-sulfur photosynthetic bacteria belong to photosynthetic chassis that are widely used to synthesize natural chemicals. To date, researches on the synthesis of pinene by purple non-sulfur photosynthetic bacteria has not been reported, leaving the potential of purple non-sulfur photosynthetic bacteria synthesizing pinene unexplored. Results Rhodobacter sphaeroides strain was applied as a model and engineered to express the fusion protein of heterologous geranyl diphosphate synthase (GPPS) and pinene synthase (PS), hence achieving pinene production. The reaction condition of pinene production was optimized and 97.51 μg/L of pinene was yielded. Then, genes of 1-deoxy-d-xylulose 5-phosphate synthase, 1-deoxy-d-xylulose 5-phosphate reductoisomerase and isopentenyl diphosphate isomerase were overexpressed, and the ribosome binding site of GPPS-PS mRNA was optimized, improving pinene titer to 539.84 μg/L. Conclusions In this paper, through heterologous expression of GPPS-PS, pinene was successfully produced in R. sphaeroides, and pinene production was greatly improved by optimizing the expression of key enzymes. This is the first report on pinene produce by purple non-sulfur photosynthetic bacteria, which expands the availability of photosynthetic chassis for pinene production.

Rationalizing an Unexpected Structure Sensitivity in Heterogeneous Catalysis—CO Hydrogenation over Rh as a Case Study

ACS Catalysis ◽  
2021 ◽  
pp. 5189-5201
Author(s):  
Max Schumann ◽  
Monia R. Nielsen ◽  
Thomas E. L. Smitshuysen ◽  
Thomas W. Hansen ◽  
Christian D. Damsgaard ◽  
...  
Keyword(s):  
Heterogeneous Catalysis ◽  
Co Hydrogenation ◽  
Structure Sensitivity
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