chemical production
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Significance Recovery in the corporate sector is unevenly divided between large and smaller companies. More robust global demand and rising commodity prices boosted the profitability of large exporters, whereas the recovery of small and medium-sized enterprises (SMEs) was delayed by pandemic restrictions and falling real disposable incomes. Impacts High metals prices will constrain investment in infrastructure. Rising interest rates will limit capital market borrowing by medium-sized companies. Government price controls threaten to undermine private investment in agriculture, metallurgy and chemical production. A deterioration in banks' corporate portfolio will be adequately offset by high earnings and previous provisioning.


2022 ◽  
Vol 934 ◽  
Author(s):  
E. Guilbert ◽  
B. Metzger ◽  
E. Villermaux

The interplay between chemical reaction and substrate deformation is discussed by adapting Ranz's formulation for scalar mixing to the case of a reactive mixture between segregated reactants, initially separated by an interface whose thickness may not be vanishingly small. Experiments in a simple shear flow demonstrate the existence of three regimes depending on the Damköhler number $Da=t_s/t_c$ where $t_s$ is the mixing time of the interface width and $t_c$ is the chemical time. Instead of treating explicitly the chemical cross-term, we rationalize these different regimes by globalizing it as a production term involving a flux which depends on the rate at which the reaction zone is fed by the reactants, a formulation valid for $Da>1$ . For $Da<1$ , the reactants interpenetrate before they react, giving rise to a ‘diffusio-chemical’ regime where chemical production occurs within a substrate whose width is controlled by molecular diffusion.


2022 ◽  
Vol 11 (4) ◽  
pp. 511-517
Author(s):  
P Sean Morris*

While the debate on intellectual property and international investment law is relatively young, the role of historical cases will be important in offering some interpretative analysis. Due to the niche nature of both areas of law, where, often times, the legal luminaries found in both areas often speak past each other, in an earlier issue of this journal I offered an interpretative history of Chorzów Factory as an example of early case law by an international court illustrating the origins of the ISDS involving intellectual property. As with any interpretation, there are bound to be opposing views or explicit endorsement, but whatever the merits, that interpretative history has initiated a debate in the pages of this journal. That debate is in part, a response to my original analysis, to which I offer a response. This response is to endorse the fact that additional information has come forward that will enrich the debate on Chorzów Factory and its connection to intellectual property. Moreover, this response argues that the reply misses the point regarding the formal connection of international law to intellectual property in ISDS, a connection that I attempted to demonstrate through the example of the Chorzów Factory case – where a legal fight in the 1920s over nitrate, other chemical production and ownership still continue to be of relevance to international law.


Author(s):  
Andrew C. Dyer ◽  
Mohamad A. Nahil ◽  
Paul T. Williams

AbstractBiomass and waste polystyrene plastic (ratio 1:1) were co-pyrolysed followed by catalysis in a two-stage fixed bed reactor system to produce upgraded bio-oils for production of liquid fuel and aromatic chemicals. The catalysts investigated were ZSM-5 impregnated with different metals, Ga, Co, Cu, Fe and Ni to determine their influence on bio-oil upgrading. The results showed that the different added metals had a different impact on the yield and composition of the product oils and gases. Deoxygenation of the bio-oils was mainly via formation of CO2 and CO via decarboxylation and decarbonylation with the Ni–ZSM-5 and Co–ZSM-5 catalysts whereas higher water yield and lower CO2 and CO was obtained with the ZSM-5, Ga–ZSM-5, Cu–ZSM-5 and Fe–ZSM-5 catalysts suggesting hydrodeoxygenation was dominant. Compared to the unmodified ZSM-5, the yield of single-ring aromatic compounds in the product oil was increased for the Co–ZSM-5, Cu–ZSM-5, Fe–ZSM-5 and Ni–ZSM-5 catalysts. However, for the Ga–ZSM-5 catalyst, single-ring aromatic compounds were reduced, but the highest yield of polycyclic aromatic hydrocarbons was produced. A higher biomass to polystyrene ratio (4:1) resulted in a markedly lower oil yield with a consequent increased yield of gas.


2021 ◽  
Author(s):  
Kelsey Stewart ◽  
Dylan Wythe Domaille

Biocatalysis provides facile access to selective chemical transformations and helps satisfy sustainable chemical production criteria. However, the reaction scope of biocatalysts is significantly narrower compared to synthetic chemical transformations. Hybrid biocatalytic-chemocatalytic cascades expand the scope of products while maintaining many of the benefits associated with biocatalysis. Here, we report that single-pot systems with whole cell K. pastoris (ATCC® 28485™) or isolated enzyme alcohol oxidase (E 1.1.3.13) as oxidative biocatalysts with a lysine organocatalyst yields the commercial target, 2-ethyl-2-hexenal (2-EH) from n-butanol in a two-step hybrid cascade. Peak yields for both biocatalysts were achieved with 100 mM n-butanol at pH 8 and 30°C. The isolated enzyme slightly outperformed whole cell K. pastoris, reaching 73% conversion (4.7 g/L titers) compared to 61% (3.9 g/L titers) in whole cells systems. Titers could be improved for both biocatalysts (5.7 – 6.7 g/L) at increased butanol loading; however, this came at the expense of decreased yields. Compared to our initial results with a Gluconobactor oxidans whole cell biocatalyst, the reported system improves upon 2-EH titers by 2.8-3.3-fold at maximal yields.


2021 ◽  
Vol 21 (24) ◽  
pp. 18319-18331
Author(s):  
Jin Liao ◽  
Glenn M. Wolfe ◽  
Reem A. Hannun ◽  
Jason M. St. Clair ◽  
Thomas F. Hanisco ◽  
...  

Abstract. Formaldehyde (HCHO) is one of the most abundant non-methane volatile organic compounds (VOCs) emitted by fires. HCHO also undergoes chemical production and loss as a fire plume ages, and it can be an important oxidant precursor. In this study, we disentangle the processes controlling HCHO by examining its evolution in wildfire plumes sampled by the NASA DC-8 during the Fire Influence on Regional to Global Environments and Air Quality experiment (FIREX-AQ) field campaign. In 9 of the 12 analyzed plumes, dilution-normalized HCHO increases with physical age (range 1–6 h). The balance of HCHO loss (mainly via photolysis) and production (via OH-initiated VOC oxidation) seems to control the sign and magnitude of this trend. Plume-average OH concentrations, calculated from VOC decays, range from −0.5 (± 0.5) × 106 to 5.3 (± 0.7) × 106 cm−3. The production and loss rates of dilution-normalized HCHO seem to decrease with plume age. Plume-to-plume variability in dilution-normalized secondary HCHO production correlates with OH abundance rather than normalized OH reactivity, suggesting that OH is the main driver of fire-to-fire variability in HCHO secondary production. Analysis suggests an effective HCHO yield of 0.33 (± 0.05) per VOC molecule oxidized for the 12 wildfire plumes. This finding can help connect space-based HCHO observations to the oxidizing capacity of the atmosphere and to VOC emissions.


2021 ◽  
Author(s):  
Song Zhenlong ◽  
Jianguo Liu ◽  
Qi Zhang

The oxidation of aromatic alcohols to produce carbonyl compounds is of great significance in fine chemical production. The traditional oxidation produces waste gas and pollutes the environment during the reaction. As a new field, photocatalysis has attracted people's attention because of its environmental friendliness. At present, there have been much research on TiO2, or noble metal modified TiO2 to catalyze alcohol oxidation, but the high cost is not conducive to large-scale production. Herein, a [email protected]/TiO2 catalyst was prepared by in-situ hydrothermal synthesis. This catalyst has a better oxidation effect on benzyl alcohol than [email protected] supported on TiO2 on the market and has a good catalytic effect on aromatic alcohols with different substituents. It is more interesting that the selectivity of the product can be adjusted by choosing different reaction solvents. The highly active catalyst with low cost and wide applicability has certain significance for the large-scale use of photocatalytic alcohol oxidation.


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