Specialty Chemical Manufacturing Research Articles

Ring-Closing Metathesis as Methodology for the Synthesis of 2- and 3-Arylbenzo[b]furans

AbstractOlefin metathesis, which is well established in the petrochemical industry, is also emerging as a green technology in the manufacture of pharmaceutical and specialty chemicals. Arylbenzofurans are of interest for potential medicinal applications. In this paper we report on the synthesis of various 2-aryl- and 3-arylbenzo[b]furans with natural substitution patterns from readily available starting materials in a strategy that applies ring-closing metathesis with the Grubbs second generation catalyst as key step.

Mortality and cancer incidence in perfluorooctanesulfonyl fluoride production workers.

Exposure to per- and polyfluoroalkyl substances (PFAS) has been associated with several health outcomes, though few occupationally-exposed populations have been studied. We evaluated mortality and cancer incidence in a cohort of perfluorooctanesulfonyl fluoride-based specialty chemical manufacturing workers. The cohort included any employee who ever worked at the facility from 1961 to 2010 (N = 4045), with a primary interest in those who had 365 cumulative days of employment (N = 2659). Vital status and mortality records were obtained through 2014 and the cohort was linked to state cancer registries to obtain incident cancer cases from 1995 to 2014. Cumulative exposure was derived from a comprehensive exposure reconstruction that estimated job-specific perfluorooctanesulfonate (PFOS)-equivalents (mg/m3 ) exposure. Overall and exposure-specific standardized mortality ratios (SMR) were estimated in reference to the US population. Hazard ratios (HRs) and 95% confidence interval (CI) for cumulative PFOS-equivalent exposure (log2 transformed) were estimated within the cohort for specific causes of death and incident cancers using a time-dependent Cox model. Death rates were lower than expected except for cerebrovascular disease (SMR = 2.42, 95% CI = 1.25-4.22) and bladder cancer (SMR = 3.91, 95% CI = 1.07-10.02) in the highest exposure quartile. Within the cohort, the incidence of bladder, colorectal, and pancreatic cancer were positively associated with exposure, however except for lung cancer (HR = 1.05, 95% CI = 1.00-1.11) the CIs did not exclude an HR of 1. This study provides some evidence that occupational exposure to PFOS is associated with bladder and lung cancers and with cerebrovascular disease.

Analisis Beban Kerja Fore-Log Plant B PT XYZ Menggunakan Metode Workload Indicator Of Staffing Needs

PT XYZ is a specialty chemical manufacturing company with various products for Paper, Water Treatment, Oil Mining, Mining, Plastic, Masterbatch, Agriculture, Home Care, and other industries. PT XYZ in planning its Human Resources must be careful to get optimal workers and high work productivity, so a Workload Analysis is needed to optimize the existing workforce at PT XYZ. In the research process, researchers found the phenomenon of multiple positions in the organizational structure of the Logistics Department of PT XYZ, namely by fore log plant B. This research was conducted with a qualitative method with interviews, observations, and data processing of the daily report of the Foreman Logistic Plant B of PT XYZ. The workload analysis method used in this research is the Workload Indicator of Staffing Needs (WISN) method. With the WISN method, the standard workload can be determined to determine the appropriate number of workers. From the results of research conducted in August 2023, it shows that the standard workload fore log plant B is included in the fit or in accordance with the workload standards set by the company, namely 1.3 so that duplicate positions are allowed.

Only the best is good enough: Managing the risks of glass in hazardous service

AbstractWhen the consequences of failure are catastrophic, only the best is good enough. Sight glasses, flow glasses, and level glasses are used throughout the process industry to provide operator visibility into process equipment and operating conditions. They have great benefits for many operations, including observing reaction progress, phase separations, level, and more. However, the installation and utilization of glass also results in several Process Safety challenges. While the inherently safer solution is to eliminate glass components, this may not always be practical, particularly in Specialty Chemical manufacturing. If not properly specified, installed, and maintained, glass components can be the weak link in the process equipment or piping system, with failure of the glass resulting in loss of containment of hazardous materials, fire, explosion, chemical exposure, or personnel injuries. Numerous events throughout the chemical process industries have demonstrated the consequences of failure of glass components, with many serious injuries and fatalities. Clearly, there is a strong need for proper management of glass in hazardous chemical services. This paper will present the best practical engineering controls and mitigative protection layers, supported by robust management systems, which have been shown to be effective at operating facilities in managing the risks of glass in hazardous services.

Biotech in China 2021, at the beginning of the 14th five-year period ("145").

As China assumes a more and more dominant role in global science, this mini-review attempts to provide a bird’s eye view on how the bio-digital revolution impacts China’s biosciences and bioindustry. Triggered by top-down political programs and the buildup of an impressive infrastructure in science, information technology, and education, China’s biomedical and MedTech industries prosper. Plant and animal breeding programs transform agriculture and food supply as much as the Internet of things, and synthetic biology offers new opportunities for the manufacturing of specialty chemicals within the Chinese version of a “bioeconomy.” It is already becoming apparent that the new five-year period “145” (2021–2025) will further emphasize emission control, bioenvironmental protection, and more supply of biomass-derived energy. This review identifies key drivers in China’s government, industry, and academia behind these developments and details many access points for deeper studies.Key points Biotechnology in ChinaBiomedical technologyNew five-year period

William H. Pirkle: Stereochemistry pioneer.

Professor William H. Pirkle (1934-2018) made a profound impact on modern chemistry by inventing and popularizing widely used techniques for the analysis and purification of enantiomers, contributions that paved the way for the subsequent advances in the discovery, development, and manufacture of enantiopure pharmaceuticals, agrochemicals, and specialty chemicals. Pirkle's pioneering 1966 demonstration of the use of chiral solvating agents for the nuclear magnetic resonance determination of enantiopurity led to a lifelong interest in understanding the supramolecular interactions responsible for enantiodifferentiation. Ongoing research into the chromatographic resolution of stereoisomers throughout the 1970s led in 1981 to the very first commercialization of a chiral stationary phase for the high-performance liquid chromatography (HPLC) separation of enantiomers. The availability of this and subsequent "Pirkle columns" had a deep and lasting impact, becoming widely embraced by the chemical sciences research community worldwide and spearheading the wholesale changeover to HPLC as the preferred technique for measuring enantiopurity. Doc Pirkle was a highly creative, independent, and fun-loving collaborator whose circle of friends extends around the globe. His research group at the University of Illinois, often referred to as The Pirkle Zoo, became a refuge for an interesting assembly of characters who flourished under his mentorship and guidance.

Radical-based photoinactivation of fatty acid photodecarboxylases

Fatty acid photodecarboxylases (FAP) are a recently discovered family of FAD-containing, light-activated enzymes, which convert fatty acids to n-alkanes/alkenes with potential applications in the manufacture of fine and speciality chemicals and fuels. Poor catalytic stability of FAPs is however a major limitation. Here, we describe a methodology to purify catalytically stable and homogeneous samples of recombinant Chlorella variabilis NC64A FAP (CvFAP) from Escherichia coli. We demonstrate however that blue light-exposure, which is required for photodecarboxylase activity, also leads to irreversible inactivation of the enzyme, especially in the absence of palmitate substrate. Photoinactivation is attributed to formation of protein based organic radicals, which were observed by EPR spectroscopy. To suppress photoinactivation, we prepared stable and catalytically active FAP in the dark. The steady-state kinetic parameters of CvFAP (kcat: 0.31 ± 0.06 s−1 and KM: 98.8 ± 53.3 μM) for conversion of palmitic acid to pentadecane were determined using gas chromatography. Methods described here should now enable studies of the catalytic mechanism and exploitation of FAPs in biotechnology.

Passive Mixer cum Reactor Using Threaded Inserts: Investigations of Flow, Mixing, and Heat Transfer Characteristics

Significant efforts have been and are being spent on developing intensified tubular reactors for continuous manufacturing of fine and specialty chemicals. In this work, we have proposed a new desig...

William H. Pirkle

William H. Pirkle, 83, died on April 6 in Champaign, Ill. “William H. Pirkle made a profound impact on modern chemistry by inventing and popularizing widely used methodologies for the analysis and purification of enantiomers, contributions that enabled the subsequent revolution into the discovery, development, and manufacture of enantiopure pharmaceuticals, agrochemicals, and specialty chemicals. Pirkle’s pioneering 1966 demonstration of the use of chiral solvating agents for the NMR determination of enantiopurity led to a lifelong interest in understanding the supramolecular interactions responsible for enantiodifferentiation. An important line of research into the chromatographic resolution of stereoisomers throughout the 1970s led in 1981 to the commercialization of the very first chiral stationary phase for the HPLC separation of enantiomers. The availability of this and subsequent ‘Pirkle columns’ had a deep and lasting impact, becoming widely embraced by the chemical sciences research community worldwide and spearheading the wholesale changeover to chromatography as the

Scale − Up and economic evaluation of the atomized rapid injection solvent extraction process

The Atomized Rapid Injection Solvent Extraction (ARISE) process is a new technique for the production of micron-size particles using a supercritical antisolvent. Scale-up of the process can be achieved simply by maintaining the antisolvent/solvent ratios and pressure differentials while increasing batch volumes. In this work, two model compounds, para-coumaric acid (PCA) and hydroxypropyl-β-cyclodextrin (HPβCD), were processed using ARISE at different operating scales. The batch size for PCA varied between 0.2g/batch and 1.6g/batch, while the batch size of HPβCD varied from 0.8g/batch to 13.9g/batch.The economic evaluation of the process was based on production rates between 2 and 10t/a, which are typical for high-specialty grade chemicals. Capital investment and production costs were estimated using the scaling–exponential method. Investment costs were estimated between 190 and 950US$/kg of product while production costs were calculated between 52 and 255US$/kg of product (year 2015). The figures indicate that ARISE can be economically viable for the manufacturing of specialty chemicals as pharmaceuticals.

Modeling G-L-L-S Reactor: A Case of Hydrogenation of Nitrobenzene

Gas–liquid–liquid–solid (GLLS) reaction systems are often encountered in manufacturing of fine and specialty chemicals. More often than not, such reaction systems involve multiple reactions, and selectivity toward the desired component always poses challenges. An adequate understanding of various parameters affecting GLLS reactor performance is essential to develop strategies for realizing desired selectivity. In this work, a comprehensive reaction engineering model for simulating four phase hydrogenation reactions has been developed. A generalized mixing cell based framework for a reaction system with four interacting phases (gas [G], aqueous [L], organic [L], and solid catalyst [S]) was developed. The model is written in a general way so as to specify one of the liquid phases as a continuous phase, and the other three phases are dispersed into it. In each cell, vapor space is included. The model includes the possibility of evaporation of solvent and internal condensation (in vapor space). The model can ...

Catalyst design for biorefining.

The quest for sustainable resources to meet the demands of a rapidly rising global population while mitigating the risks of rising CO2 emissions and associated climate change, represents a grand challenge for humanity. Biomass offers the most readily implemented and low-cost solution for sustainable transportation fuels, and the only non-petroleum route to organic molecules for the manufacture of bulk, fine and speciality chemicals and polymers. To be considered truly sustainable, biomass must be derived from resources which do not compete with agricultural land use for food production, or compromise the environment (e.g. via deforestation). Potential feedstocks include waste lignocellulosic or oil-based materials derived from plant or aquatic sources, with the so-called biorefinery concept offering the co-production of biofuels, platform chemicals and energy; analogous to today's petroleum refineries which deliver both high-volume/low-value (e.g. fuels and commodity chemicals) and low-volume/high-value (e.g. fine/speciality chemicals) products, thereby maximizing biomass valorization. This article addresses the challenges to catalytic biomass processing and highlights recent successes in the rational design of heterogeneous catalysts facilitated by advances in nanotechnology and the synthesis of templated porous materials, as well as the use of tailored catalyst surfaces to generate bifunctional solid acid/base materials or tune hydrophobicity.

Mechanical, thermal and fire properties of sustainable rigid polyurethane foam derived from cashew nut shell liquid

Global efforts to find renewable feed stocks for the chemical industry are aimed at replacing fossil reserves and a reduction in global warming by employing environmently friendly technologies (green chemistry approaches) for specialty chemical manufacturing. Cardanol obtained from “Cashew Nut Shell Liquid” (CNSL) is a renewable resource of immense potential. Present work describes the synthesis of bio-based polyol for rigid polyurethane foam via step wise oxazolidine route. Synthesized polyol was characterized by spectral analysis. The foaming characteristics were studied, and the polyol were successfully used in making rigid Polyurethane foams with good mechanical, thermal and fire properties.

Model Building Methodology for Complex Reaction Systems

Most often reactor designs are scaled-up using experimental measurements, especially for the manufacture of fine and specialty chemicals. Yet without an appropriate model of the reaction system major opportunities can be missed in the design and optimization of the reactor. In this paper a model building methodology for complex reaction systems combined with experimental evaluation is developed. Preliminary experiments provide information for construction of a reaction network containing all feasible reactions. A strategy is employed for generating rival alternative simple models using different subsets (mechanisms or pathways) extracted from the reaction network. On the basis of model predictions further experiments can be carried out either at the optimal reactor performance conditions or at conditions that allow discrimination among rival models. These additional experiments can be used to refit and improve the rival models and to test and validate the predicted optimal reactor design. An example invol...

Treatment of High Strength Wastewater from Specialty Chemical Manufacturing Plants Using Activated Sludge

Treatment of High Strength Wastewater from Specialty Chemical Manufacturing Plants Using Activated Sludge

Production of xylose from Meranti wood sawdust by dilute acid hydrolysis.

Xylitol production by bioconversion of xylose can be economically interesting if the raw material can be recovered from a cheap lignocellulosic biomass (LCB). Meranti wood sawdust (MWS) is a renewable and low-cost LCB that can be used as a promising and economic source of xylose, a starting raw material for the manufacture of several specialty chemicals, especially xylitol. This study aimed to optimize the hydrolysis process of MWS and to determine the influence of temperature, H2SO4 concentration, and residence time on xylose release and on by-product formation (glucose, arabinose, acetic acid, furfural, hydroxymethylfurfural (HMF), and lignin degradation products (LDPs)). Batch hydrolysis was conducted under various operating conditions, and response surface methodology was adopted to achieve the highest xylose yield. Xylose production was highly affected by temperature, acid concentration, and residence time. The optimum temperature, acid concentration, and time were determined to be 124 °C, 3.26 %, and 80 min, respectively. Under these optimum conditions, xylose yield and selectivity were attained at 90.6 % and 4.05 g/g, respectively.

Catalysing sustainable fuel and chemical synthesis.

Concerns over the economics of proven fossil fuel reserves, in concert with government and public acceptance of the anthropogenic origin of rising CO2 emissions and associated climate change from such combustible carbon, are driving academic and commercial research into new sustainable routes to fuel and chemicals. The quest for such sustainable resources to meet the demands of a rapidly rising global population represents one of this century’s grand challenges. Here, we discuss catalytic solutions to the clean synthesis of biodiesel, the most readily implemented and low cost, alternative source of transportation fuels, and oxygenated organic molecules for the manufacture of fine and speciality chemicals to meet future societal demands.

Rapid Determination of Optimal Conditions in a Continuous Flow Reactor Using Process Analytical Technology

Continuous flow reactors (CFRs) are an emerging technology that offer several advantages over traditional batch synthesis methods, including more efficient mixing schemes, rapid heat transfer, and increased user safety. Of particular interest to the specialty chemical and pharmaceutical manufacturing industries is the significantly improved reliability and product reproducibility over time. CFR reproducibility can be attributed to the reactors achieving and maintaining a steady state once all physical and chemical conditions have stabilized. This work describes the implementation of a smart CFR with univariate physical and multivariate chemical monitoring that allows for rapid determination of steady state, requiring less than one minute. Additionally, the use of process analytical technology further enabled a significant reduction in the time and cost associated with offline validation methods. The technology implemented for this study is chemistry and hardware agnostic, making this approach a viable means of optimizing the conditions of any CFR.

Stress Responses of the Industrial Workhorse Bacillus licheniformis to Osmotic Challenges

The Gram-positive endospore-forming bacterium Bacillus licheniformis can be found widely in nature and it is exploited in industrial processes for the manufacturing of antibiotics, specialty chemicals, and enzymes. Both in its varied natural habitats and in industrial settings, B. licheniformis cells will be exposed to increases in the external osmolarity, conditions that trigger water efflux, impair turgor, cause the cessation of growth, and negatively affect the productivity of cell factories in biotechnological processes. We have taken here both systems-wide and targeted physiological approaches to unravel the core of the osmostress responses of B. licheniformis. Cells were suddenly subjected to an osmotic upshift of considerable magnitude (with 1 M NaCl), and their transcriptional profile was then recorded in a time-resolved fashion on a genome-wide scale. A bioinformatics cluster analysis was used to group the osmotically up-regulated genes into categories that are functionally associated with the synthesis and import of osmostress-relieving compounds (compatible solutes), the SigB-controlled general stress response, and genes whose functional annotation suggests that salt stress triggers secondary oxidative stress responses in B. licheniformis. The data set focusing on the transcriptional profile of B. licheniformis was enriched by proteomics aimed at identifying those proteins that were accumulated by the cells through increased biosynthesis in response to osmotic stress. Furthermore, these global approaches were augmented by a set of experiments that addressed the synthesis of the compatible solutes proline and glycine betaine and assessed the growth-enhancing effects of various osmoprotectants. Combined, our data provide a blueprint of the cellular adjustment processes of B. licheniformis to both sudden and sustained osmotic stress.

Rigid Polyurethane Foams from Cardanol: Synthesis, Structural Characterization, and Evaluation of Polyol and Foam Properties

Global efforts to find renewable feedstocks for the chemical industry are aimed at replacing fossil reserves and a reduction in global warming by employing environmently friendly technologies (green chemistry approaches) for specialty chemical manufacturing. Cardanol, obtained as a byproduct of the cashew processing industry, is an important renewable resource and a unique phenolic compound carrying a 15-carbon side chain in meta position with varying degrees of unsaturation. In this work, the synthesis of new biobased polyols for rigid polyurethane (PU) foams through oxidation of side chain unsaturation is reported using the environmentally benign reagent hydrogen peroxide. Polyols with hydroxyl values in the range of 350–400 mg KOH/g were prepared through epoxidation followed by hydrolysis and characterized for structure using IR,1H-NMR, 13C NMR, and mass spectroscopic techniques. The foaming characteristics were studied, and the polyols were successfully used in making rigid polyurethane foams with good physical and mechanical properties. The foams were characterized for density, compressive strength, morphology, and viscoelastic properties. The properties are compared with that of foams prepared using standard petroleum-based polyols.