Chemical Process Research Research Articles

APPLICATION OF YATES METHOD FOR MISSING DATA ESTIMATION IN YOUDEN SQUARE DESIGN AND ANALYSIS

The Youden square design is widely used in experimental research to control two sources of variability, but missing data can compromise the results. Addressing missing data is critical to maintaining the integrity and reliability of such experiments. This paper proposes to adapt the Yates method to handle missing data specifically in Youden square designs. We begin by outlining the structure of the Youden square design and the challenges posed by missing data. The Yates method, known for its robustness in estimating missing data, is adapted to fit this design. We demonstrate its effectiveness through simulations and real-world case studies. The simulation involved generating experimental data with one missing value, and the case study analyzed chemical process research with critical missing data points. The results show that the Yates method maintains statistical validity and improves data completeness compared to traditional methods. Its advantage lies in utilizing Youden's quadratic structure for more accurate estimation. This study highlights the Yates method as a solution to handle missing data, improving the quality and reliability of experimental research.

Thermodynamic solubility modeling of 2, 2ʹ, 4, 4ʹ, 6, 6ʹ - hexanitrostilbene (HNS)

Accurate thermodynamic modeling is essential for chemical process research and development. In this work, four thermodynamic models: UNIFAC, COSMO-SAC, Hansen Solubility Parameter (HSP) and Nonrandom Two-liquids Segment Activity Coefficient (NRTL-SAC) are examined for their utility to estimate the solubility of 2, 2ʹ, 4, 4ʹ, 6, 6ʹ - hexanitrostilbene (HNS) [CAS# 20062-22-0] in pure and mixed solvents. UNIFAC yields qualitatively correct HNS solubility predictions for a few solvents while COSMO-SAC fails to provide reliable predictions. In comparison to the two group contribution-based predictive models, the hybrid correlative and predictive model HSP gives qualitatively correct results for pure solvents while the other hybrid model NRTL-SAC provides qualitative to semi-quantitative predictions for HNS solubility in both pure and mixed solvents. NRTL-SAC is then used to predict the solubilities of HNS and 2, 2ʹ, 4, 4ʹ, 6, 6ʹ - hexanitrobibenzyl (HNBB) [CAS# 5180-53-0], an important byproduct of HNS synthesis, in Shipp reaction media for HNS synthesis. Moreover, n-octanol-water partition coefficients of HNS and HNBB are predicted with NRTL-SAC.

Research of physical and chemical processes associated with corrosion of cements (“Caking”) in dampy wet air

Objective. The paper is aimed at clarifying the mechanism and kinetics of the processes leading to cement caking. Methods. To determine phase composition, the following modern physical and chemical methods were used: XRF, derivatography and electron microscopy. Results. The data obtained show that the “aging” of cements during their forced storage in humid air through the adsorption of water vapor, and then CO2, is associated with the processes of hydrolysis, hydration in surface layers of particles, is primarily relevant for the most reactive minerals of Portland cement clinker. The deepening of these processes also depends on the state of the corroded surface of minerals. Conclusion. The work carried out makes it is possible to preliminarily outline storage conditions for freshly ground Portland cements (according to the kinetics of sorption – the storage duration, according to isotherms – the permissible relative humidity), at which the LOI value of commercial cement remains stable for the required minimum time.

Использование элементов искусственного интеллекта при исследовании физико-химических процессов производства конвертерной стали

Использование элементов искусственного интеллекта при исследовании физико-химических процессов производства конвертерной стали

Simulation Study of Citronellol-geraniol Rectification Tower Based on Aspen Plus Software

Aspen Plus is a large-scale chemical simulation software based on steady-state chemical simulation, optimization, sensitivity analysis and economic evaluation. It can analyze the planning, research, development and technical reliability of chemical processes. High-purity citronellol and geraniol, the main high-value components of citronella oil, make the rectification and purification process difficult due to their boiling point and heat sensitivity, with high separation cost and poor effect, resulting in low economic benefits. This paper uses Aspen Plus software to estimate the physical properties of citronellol and geraniol system through known structural formula and room temperature boiling point; uses citronellol-geraniol vapor-liquid equilibrium experimental data to select physical properties analytical methods of Aspen Plus software; conducts process design and simulation of the high vacuum separation of citronellol and geraniol by using DSTWU simple simulation tower and RadFrac strict simulation tower respectively, gets the process parameters of citronellol and geraniol distillation tower, checks the separation process, and optimizes the separation conditions, which provide support for using industrial production in the high-purity separation of citronella oil system.

Vitamins and Nutraceuticals from the Perspective of Process Research.

The development of efficient, sustainable low-cost processes is the basis for providing high-quality products for daily life applications in human and animal nutrition. In this account, the importance of chemical process research towards ecologically benign and competitively advantageous processes for the large-scale preparation of various vitamins, nutraceuticals and fine chemicals is highlighted. Selected and representative examples are given, including contributions from collaborations with external partners. General trends include the shift from stoichiometric to catalytic protocols and from batch to continuous processes. In addition, the use of renewable (bio-based) raw materials as an alternative to access key building blocks for the production of vitamins is addressed.

Resveratrol, phenolic antioxidants, and saccharides in South American red wines

Resveratrol, phenolic antioxidants, and saccharides in South American red wines Daniel E Osorio-Macías,1,2 Pamela Vásquez,3 Cristhian Carrasco,3 Bjorn Bergenstahl,1 J Mauricio Peñarrieta2 1Department of Food Technology, Faculty of Engineering LTH, Lund University, Lund, Sweden; 2School of Chemistry, Faculty of Pure and Natural Sciences, 3Institute of Research and Development of Chemical Processes, Department of Chemical Engineering, Faculty of Engineering, Universidad Mayor de San Andrés (UMSA), La Paz, Bolivia Abstract: Wine is an important beverage with a long tradition, and its moderate consumption may be considered beneficial for human health. Although there are many studies regarding phenolic compounds in wines, there is a lack of information about antioxidants and phenolic content in South American wines. In this study, 35 South American red wines from four different countries, vintages 2004–2013, purchased at retail stores in La Paz, Bolivia, were studied. Resveratrol content, total antioxidant capacity (TAC) by the 2,2′-azino-bis(3-ethylbenzotiazoline-6-sulfonic acid) (ABTS) and ferric-reducing antioxidant power (FRAP) methods, total phenolic content (TPH), total flavonoids (TF), and main saccharides were assessed using the well-established spectrophotometric and high-performance liquid chromatography methods. The results ranged from 4 to 24 mmol/L for TAC determined by ABTS method and 14 to 43 mmol/L for TAC determined by FRAP method, 1600 to 3500 mg gallic acid equivalents/L for TPH, and 2 to 6 mmol catechin equivalents /L for TF. The resveratrol content ranged from 0.1 to 8 mg/L. Saccharides, glucose, and fructose content ranged from 0.4 to 10 g/L, 1.4 to 8.6 g/L, and 0.2 to 12 g/L, respectively. There was a high correlation among the different methods. The results showed that some wines growing at high altitude (>1500 meters above the sea level) have higher amounts of TAC and phenolic content, including resveratrol, while non-varietal wines showed the lowest values. It was also observed that the saccharose content in some wines was surprisingly high, suggesting saccharose dosing after fermentation. Keywords: ABTS, FRAP, high altitude, HPLC, PCA, Bolivia

Liquid–liquid centrifugal separation — New equipment for optical (photographic) evaluation at laboratory scale

Since liquid–liquid separation techniques are applied in chemical process industry, research and development received a strong level of attention. Thus, liquid–liquid separation behavior in gravity equipment – e.g., in settling tanks – especially sedimentation and coalescence are investigated in detail. However, for liquid–liquid separation in centrifugal equipment – e.g., tube centrifuges – only superficial knowledge and less detailed investigations are given in open literature. This work focuses on the development of a new laboratory equipment for optical (photographic) evaluation of the centrifugal liquid–liquid separation processes. A new stirred centrifugal batch settling cell (SCBSC) utilizing a rotor–rotor/stator concept, experimental setup and method as well as analytical procedures are presented and discussed. Furthermore, results of mixing and separation process within the SCBSC are shown. The centrifugal force field thereby affects the required differential rotation speed for the dispersion process. The evaluation of the separation process is presented and discussed considering sedimentation and coalescence curves exemplary for two liquid–liquid systems. In the course of this, a comparison between gravitational and centrifugal separation was successful. Finally, the separation behavior is described by a dimensionless dispersion number.

Apigenin-7-O-glucoside oxidation catalyzed by P450-bioinspired systems

Apigenin-7-O-glucoside (A7G) is the main flavonoid of Bidens gardneri Bak., a Brazilian plant with wide application in folk medicine. Despite the popular use of this plant, its biological effects are not completely known. This work tested the 5,10,15,20-tetrakis(pentafluorophenyl)porphyrin iron(III) and manganese(III) chloride (Fe(TFPP)Cl and Mn(TFPP)Cl), and Jacobsen's catalyst as P450-bioinspired catalysts for A7G oxidation by different oxidants (PhIO, H2O2, m-CPBA, and t-BuOOH). Up to nine different products were detected by HPLC analysis; Reactions with metalloporphyrin/PhIO systems afforded high catalytic conversions (58–89%). In spite of providing smaller product yields, the metalloporphyrin/H2O2 systems led to superior product distribution. Fe(TFPP)Cl yielded the highest A7G conversion rates (79–93%) with the four different oxidants tested herein. In the presence of PhIO, the oxidative profile of the manganese catalysts was very close to the oxidative profile of Fe(TFPP)Cl. However, in medium containing peroxide, the reactivity of the manganese catalysts was lower as compared to the reactivity of Fe(TFPP)Cl. Reactions with Fe(TFPP)Cl/oxidant systems were analyzed by UPLC-MS; up to thirteen compounds were detected. A7G oxidation catalyzed by Fe(TFPP)Cl yielded seven compounds. Three other compounds had m/z profile compatible with the profile of the A7G metabolites. The A7G oxidation assays performed in the presence of P450-bioinspired catalysts demonstrated their great catalytic potential toward A7G. The present results may be useful to many areas of knowledge and to the research and development of numerous chemical and phamarcological processes, especially in terms of drug design, biological assays, and applications in medicinal chemistry.

Transient Cataluminescence on Flowerlike MgO for Discrimination and Detection of Volatile Organic Compounds

Methodologies for simple and rapid identification of gas compounds are needed in the fields of environmental and security. Here, a new and simple method for the discrimination of gas compounds was designed through an interesting transient cataluminescence (TRCTL) phenomenon on the highly efficient MgO materials. The flowerlike MgO with high CTL activity was controllably synthesized via a facile and time-saving aqueous precipitation route and characterized by scanning electron microscopy, powder X-ray diffractometry, high-resolution transmission electron microscopy, and N2 adsorption measurements, etc. With flowerlike MgO working as the sensing material, the newly developed CTL gas sensor exhibited highly active, ultrafast, and characteristic responses toward many analytes; the TRCTL curves thus were obtained and 10 VOCs have been successfully identified. Parallel experimental results show that the controllable synthesis of flowerlike MgO can greatly enhance the discrimination capacities for VOCs. Further, the TRCTL of CHCl3 and C2H5OC2H5 were taken as typical examples to illustrate the possible sensing mechanism, which could contribute to explaining processes of catalytic oxidations. We expect this novel TRCTL concept will be of practical importance for applications including gas detection, gas discrimination, and research of chemical kinetics processes.

Исследование физико-химических процессов протекающих при взаимодействии нержавеющей стали с элементами внешней среды используемой для импрегнирования абразивного инструмента

Исследование физико-химических процессов протекающих при взаимодействии нержавеющей стали с элементами внешней среды используемой для импрегнирования абразивного инструмента

Numerical Research of Physical and Chemical Processes at Polymeric Material Ignition by Several “Hot” Particles

The mathematical model of heat and mass transfer processes at polymeric material ignition by several metal particles heated to high temperatures was developed. Numerical research of integrated characteristic at the accounting of diffusive and convective heat and mass transfer in the oxidizer during the induction period was executed. Common effect of several local sources with limited power consumption on the main integrated characteristic of process – ignition delay time was established.

Spatial and temporal variations of six criteria air pollutants in 31 provincial capital cities in China during 2013–2014

Long-term air pollution data with high temporal and spatial resolutions are needed to support the research of physical and chemical processes that affect the air quality, and the corresponding health risks. However, such datasets were not available in China until recently. For the first time, this study examines the spatial and temporal variations of PM2.5, PM10, CO, SO2, NO2, and 8h O3 in 31 capital cities in China between March 2013 and February 2014 using hourly data released by the Ministry of Environmental Protection (MEP) of China. The annual mean concentrations of PM2.5 and PM10 exceeded the Chinese Ambient Air Quality Standards (CAAQS), Grade I standards (15 and 40μg/m3 for PM2.5 and PM10, respectively) for all cities, and only Haikou, Fuzhou and Lasa met the CAAQS Grade II standards (35 and 70μg/m3 for PM2.5 and PM10, respectively). Observed PM2.5, PM10, CO and SO2 concentrations were higher in cities located in the North region than those in the West and the South-East regions. The number of non-attainment days was highest in the winter, but high pollution days were also frequently observed in the South-East region during the fall and in the West region during the spring. PM2.5 was the largest contributor to the air pollution in China based on the number of non-attainment days, followed by PM10, and O3. Strong correlation was found between different pollutants except for O3. These results suggest great impacts of coal combustion and biomass burning in the winter, long range transport of windblown dust in the spring, and secondary aerosol formation throughout the year. Current air pollution in China is caused by multiple pollutants, with great variations among different regions and different seasons. Future studies should focus on improving the understanding of the associations between air quality and meteorological conditions, variations of emissions in different regions, and transport and transformation of pollutants in both intra- and inter-regional contexts.

Advances in research of microstructured chemical process

The research of microstructured chemical process is one of the high promising directions in chemical engineering field, because the new process may lead chemical industry to be more safety, friendly and efficient. In recent years, the key points in microstructured chemical process research mainly include multi-phase microflow, flow pattern control, micromixing, multi-phase reaction at micrometer scale, and so on. This paper reviews the latest progress and development of the research. The characterizations and advantages of microstructured chemical process are summarized and the future development directions are suggested.

Computer-aided assessment of occupationally healthier processes during research and development stage

Each year more people die from occupational related diseases than are killed in industrial accidents. Therefore it is critical to start considering health aspect early when developing a new chemical process. In this paper, a computer-aided tool for assessing inherent occupational health is proposed for chemical process research and development stage. The method was developed based on the reaction chemistry data, which is the only data available at this stage. Three types of approaches were formulated to calculate the route index value using additive type, average type and worst case type calculations. The tool can be used to rank the alternative chemical synthesis routes by their health properties as well as characterize the hazard level of single process. Finally the tool was applied to six process routes for methyl methacrylate production for demonstration. The case study revealed hazards of the processes from different perspectives, e.g. the results from the additive-type calculation were mainly affected by the total number of steps in the route, which indicates the impact of process complexity on the level of hazard. The introduction of such tool provides a swift yet reliable means that will encourage health criteria to be considered earlier in process development besides economic, safety and environment.

ChemInform Abstract: Chemical Process Research and Development in the 21st Century: Challenges, Strategies, and Solutions from a Pharmaceutical Industry Perspective

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Chemical Process Research and Development in the 21st Century: Challenges, Strategies, and Solutions from a Pharmaceutical Industry Perspective

In process research and development (PR&D), the generation and manipulation of small-molecule drugs ranges from bench-scale (laboratory) chemistry to pilot plant manufacture to commercial production. A broad range of disciplines, including process chemistry (organic synthesis), analytical chemistry, process engineering (mass and heat transfer, unit operations), process safety (chemical risk assessment), regulatory compliance, and plant operation, must be effectively applied. In the critical handover between medicinal chemistry and PR&D, compound production is typically scaled up from a few hundred grams to several kilograms. Can the methodologies applied to the former also satisfy the technical, safety, and scalability aspects that come into play in the latter? Occasionally, the transition might occur smoothly, but more often the situation is the opposite: much work and resources must be invested to design a process that is feasible for manufacturing on pilot scale and, eventually, for commercial production. Authentic examples provide enlightening illustrations of dos and don'ts for developing syntheses designed for round-flask operation into production-scale processes. Factors that are easily underestimated or even neglected in the laboratory, such as method robustness, chemical hazards, safety concerns, environmental impact, availability of starting materials and building blocks in bulk quantities, intellectual property (IP) issues, and the final cost of the product, will come into play and need to be addressed appropriately. The decision on which route will be the best for further development is a crucial event and should come into focus early on the R&D timeline. In addition to scientific and technical concerns, the parameter of speed has come to the forefront in the pharmaceutical arena. Although historically the drug industry has tolerated a total time investment of far more than 10 years from idea to market, the current worldwide paradigm requires a reduction to under 10 years for the specific segment covering preclinical development through launch. This change puts enormous pressure on the entire organization, and the implication for PR&D is that the time allowed for conducting route design and scale-up has shrunk accordingly. Furthermore, molecular complexity has become extremely challenging in many instances, and demand steadily grows for process understanding and knowledge generation about low-level byproduct, which often must be controlled even at trace concentrations to meet regulatory specifications (especially in the case of potentially genotoxic impurities). In this Account, we paint a broad picture of the technical challenges the PR&D community is grappling with today, focusing on what measures have been taken over the years to create more efficiency and effectiveness.

The Synthetic-Technical Development of Oseltamivir Phosphate Tamiflu™: A Race against Time

The clinical development of the first orally available neuraminidase inhibitor prodrug oseltamivir phosphate (Tamiflu™) proceeded very fast. In order to support this program an unprecedented team effort in chemical process research, development, piloting, production and analytics took place, which allowed the successful launch of Tamiflu™ in 1999, only two and a half years after it was licensed from Gilead Sciences. This article describes selected aspects of the commercially used synthesis route and a brief summary of alternative syntheses devised by Roche chemists.

Expeditious Process Improvement for the Synthesis of RWJ-333966

ADVERTISEMENT RETURN TO ISSUEPREVTechnical NoteNEXTExpeditious Process Improvement for the Synthesis of RWJ-333966Michel GuillaumeView Author Information Chemical Process Research, Johnson & Johnson Pharmaceutical Research and Development, Turnhoutseweg, 30, 2340 Beerse, Belgium Cite this: Org. Process Res. Dev. 2006, 10, 6, 1227–1230Publication Date (Web):October 21, 2006Publication History Received1 August 2006Published online21 October 2006Published inissue 1 November 2006https://doi.org/10.1021/op0601565Copyright © 2006 American Chemical SocietyRIGHTS & PERMISSIONSArticle Views461Altmetric-Citations8LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit Read OnlinePDF (62 KB) Get e-AlertsSUBJECTS:Amides,Aromatic compounds,Chromatography,Hydrocarbons,Solvents Get e-Alerts

Statistical Simplex Method for Experimental Design in Process Optimization

Experimental optimization with scarce and noisy process data is a key issue in laboratory automation for faster chemical process research and development, real-time process optimization, and the ability to embed a learning capability into the design of self-calibrating instruments and extremum-seeking controllers. To deal successfully with noise and uncontrollable factors in experimental design for process optimization, a statistical characterization of an optimum using process data is proposed. The Kendall's tau statistic is used for identifying a minimum (maximum) in a data set as a cluster center of positively (negatively) correlated points. A new simplex search algorithm with a logic that resorts to correlation-based ranking of simplex vertices for reflection, expansion, contraction, and shrinking steps is proposed. The advantage of resorting to a data set that cumulatively provides a global perspective of the output landscape through Kendall's tau calculations is a novel feature of the statistical simplex method. Encouraging results obtained for Rastringin's multimodal function and in the optimization of the operating policy for a semibatch reactor are presented.