Development Of Chemical Processes Research Articles

A Career in Catalysis: Maurice Brookhart

On the occasion of Professor Maurice Brookhart’s retirement and recent acceptance of the Gabor A. Somorjai Award for Creative Research in Catalysis, we honor his numerous contributions to the fields of organometallic chemistry and catalysis. His truly interdisciplinary research has resulted in seminal contributions to polymer, synthetic, and mechanistic organometallic and organic chemistry. Detailed mechanistic investigations that have provided unparalleled understanding of these reactions have been supplemented by the development of new chemical methodology and polymerization processes. In this Account, we present some of his notable contributions toward understanding the chemistry of electrophilic transition-metal carbene complexes and agostic interactions, metal-catalyzed olefin polymerization and copolymerization reactions, and metal-mediated C–H bond activation and functionalization processes.

Practical comparison of traditional and definitive screening designs in chemical process development

Practical comparison of traditional and definitive screening designs in chemical process development

Practical comparison of traditional and definitive screening designs in chemical process development

Traditional Screening Designs, such as resolution III 2k-p fractional factorials are used routinely in the initial stages of process development. These designs are used to determine which process variables have the largest effect on process outcomes. Once a screening design is complete and the data are analysed, follow-up experiments are normally required in order to develop useful prediction equations involving the important variables and to identify the optimal process operating conditions. Recently developed definitive screening designs allow researchers to identify important variables and optimum process conditions after one set of experiments, eliminating the need for follow-up experiments. This leads to the question: What is now the role of traditional and definitive screening designs in process optimisation? We share our insights gained from using both of these designs in developing a process to produce catalyst support material to shed light on these questions.

Modular Equipment for Chemical Process Development and Small‐Scale Production in Multipurpose Plants

AbstractSmall‐scale, continuous‐flow processes are currently discussed in the chemical industry for rapid process development and manufacturing of small product amounts. This contribution describes an equipment toolbox system for continuously operated chemical reactors consisting of microfluidic chip or plate reactors for rapid mixing, capillary or coil tube reactors for defined mixing and residence time, as well as continuously stirred tank reactors. The involved phases of the physico‐chemical system determine the successfully deployed elements or modules and therefore enable the setup of a flexible multipurpose plant. The platform strategy with modules of similar flow throughput as well as temperature or pressure range allow for consistent scale‐up. Several examples show the current development level, while first experiences from plant engineering indicate the implementation status and open issues.

Toward the Development and Deployment of Large-Scale Carbon Dioxide Capture and Conversion Processes

In light of the depletion of fossil fuels and the increased daily requirements for liquid fuels and chemicals, CO2 should indeed be regarded as a valuable C1 additional feedstock for sustainable manufacturing of liquid fuels and chemicals. Development and deployment of CO2 capture and chemical conversion processes are among the grand challenges faced by today’s scientists and engineers. Very few of the reported CO2 capture and conversion technologies have been employed for industrial installations on a large scale, where high-efficiency, cost/energy-effectiveness, and environmental friendliness are three keys factors. The CO2 capture technologies from stationary sources and ambient air based on solvents, solid sorbents, and membranes are discussed first. Transforming CO2 to liquid fuels and chemicals, which are presently produced from petroleum, through thermochemical, electrochemical, photochemical, and biochemical routes are discussed next. The relevant state-of-the-art computational methods and tools a...

INES – An Interface Between Experiments and Simulation to Support the Development of Robust Process Designs

AbstractThe development of chemical processes is based on both experiments and process simulations. Data evaluation and reconciliation, model development and validation, and design of experiments are essential steps in this procedure. The different tools and approaches available are usually not supported in an integrated way in the process developer's workflow. Therefore, a framework for process design was created and integrated in a tool box which supports process design comprehensively. It contains methods for data selection and reconciliation, sensitivity analysis, model validation and model adjustment.

Inherently safer design review and their timing during chemical process development and design

This paper discusses the enhancement of inherent safety review and its implementation in the chemical process development and design. The aim is to update and improve the existing inherently safer design review (ISDR) practices during design of chemical process plant by exploiting major accident cases from the U.S. Chemical Safety Board (CSB) and Failure Knowledge Database (FKD). Although the basic guidelines to conduct ISDR during design phase are available, however they are too general and incomplete. The review criteria and their best timing for application are still missing. This paper attempts to develop the accident-based ISDR for chemical process plant design. The proposed accident-based ISDR is supported with detail review criteria for each phase of process design. The timing of ISDR application is corresponding to the common design tasks and decisions made in the design project. Therefore, timely design review could be done at the specific design task and the findings help designer to make a correct decision making.

Application of ICH Q11 Principles to Chemical Process Development

Application of ICH Q11 Principles to Chemical Process Development

Group Contribution Methods for Phase Equilibrium Calculations.

The development and design of chemical processes are carried out by solving the balance equations of a mathematical model for sections of or the whole chemical plant with the help of process simulators. For process simulation, besides kinetic data for the chemical reaction, various pure component and mixture properties are required. Because of the great importance of separation processes for a chemical plant in particular, a reliable knowledge of the phase equilibrium behavior is required. The phase equilibrium behavior can be calculated with the help of modern equations of state or g(E)-models using only binary parameters. But unfortunately, only a very small part of the experimental data for fitting the required binary model parameters is available, so very often these models cannot be applied directly. To solve this problem, powerful predictive thermodynamic models have been developed. Group contribution methods allow the prediction of the required phase equilibrium data using only a limited number of group interaction parameters. A prerequisite for fitting the required group interaction parameters is a comprehensive database. That is why for the development of powerful group contribution methods almost all published pure component properties, phase equilibrium data, excess properties, etc., were stored in computerized form in the Dortmund Data Bank. In this review, the present status, weaknesses, advantages and disadvantages, possible applications, and typical results of the different group contribution methods for the calculation of phase equilibria are presented.

ChemInform Abstract: Review of Hydrogen Production from the Steam‐Iron Process by Chemical‐Looping Combustion

AbstractReview: 44 refs.

ChemInform Abstract: Cellulose Sulfuric Acid (CSA) and Starch Sulfuric Acid (SSA) as Solid and Heterogeneous Catalysts in Green Organic Synthesis: Recent Advances

AbstractReview: 61 refs.

Magnetic and dendritic catalysts.

The recovery and reuse of catalysts is a major challenge in the development of sustainable chemical processes. Two methods at the frontier between homogeneous and heterogeneous catalysis have recently emerged for addressing this problem: loading the catalyst onto a dendrimer or onto a magnetic nanoparticle. In this Account, we describe representative examples of these two methods, primarily from our research group, and compare them. We then describe new chemistry that combines the benefits of these two methods of catalysis. Classic dendritic catalysis has involved either attaching the catalyst covalently at the branch termini or within the dendrimer core. We have used chelating pyridyltriazole ligands to insolubilize catalysts at the termini of dendrimers, providing an efficient, recyclable heterogeneous catalysts. With the addition of dendritic unimolecular micelles olefin metathesis reactions catalyzed by commercial Grubbs-type ruthenium-benzylidene complexes in water required unusually low amounts of catalyst. When such dendritic micelles include intradendritic ligands, both the micellar effect and ligand acceleration promote faster catalysis in water. With these types of catalysts, we could carry out azide alkyne cycloaddition ("click") chemistry with only ppm amounts of CuSO4·5H2O and sodium ascorbate under ambient conditions. Alternatively we can attach catalysts to the surface of superparamagnetic iron oxide nanoparticles (SPIONs), essentially magnetite (Fe3O4) or maghemite (γ-Fe2O3), offering the opportunity to recover the catalysts using magnets. Taking advantage of the merits of both of these strategies, we and others have developed a new generation of recyclable catalysts: dendritic magnetically recoverable catalysts. In particular, some of our catalysts with a γ-Fe2O3@SiO2 core and 1,2,3-triazole tethers and loaded with Pd nanoparticles generate strong positive dendritic effects with respect to ligand loading, catalyst loading, catalytic activity and recyclability. In other words, the dendritic catalysts were more efficient and more stable than their nondendritic γ-Fe2O3@SiO2 analogues. The bulk at the dendritic periphery helps to localize the metal nanoparticles at the SPION core surface, which confers these advantages. We could also use sonification as a remarkably simple and efficient method to impregnate the SPIONs with dendrimer-encapsulated PdNPs. Catalysis within the hydrophobic dendrimer pockets that include ligands leads to rapid turnover with or without a γ-Fe2O3@SiO2 core. In addition, catalytically active metal nanoparticles are more robust when they are loaded onto the surface of a γ-Fe2O3@SiO2 dendritic core. Herein, we illustrate this chemistry with examples including olefin metathesis, click chemistry, cross carbon-carbon bond forming reactions, and selective alcohol oxidation.

Method for identifying errors in chemical process development and design base on accidents knowledge

It has been claimed that the high accident rate in the chemical process industry is due to poor dissemination of accident knowledge that affects directly the level of learning from accidents. In response to this situation, this paper utilized past accident knowledge as a basis to develop a safety oriented design tool whereby the accident information were directly disseminated into plant design. The method was developed based on our previous accident analysis of design error in which the common design errors were ranked in accordance to their frequency and its origins during normal plant design project. Based on the design error ranking and its origin at a specific design phases, a method for design error detection is proposed. The method is expected to be able to identify the possible design error and its causes throughout chemical process development and design. The main objective is to trigger safe design thinking at the specific design phases so that appropriate action for risk reduction could be timely implemented. The Bhopal and BP Texas tragedies are used as case studies to test and verify the method. The proposed method can detect up to 74% of design errors.

Argon–germane in situ plasma clean for reduced temperature Ge on Si epitaxy by high density plasma chemical vapor deposition

Demand for integration of near infrared optoelectronic functionality with silicon complementary metal oxide semiconductor (CMOS) technology has for many years motivated the investigation of low temperature germanium on silicon deposition processes. This work describes the development of a high density plasma chemical vapor deposition process that uses a low temperature (<460 °C) in situ germane/argon plasma surface preparation step for epitaxial growth of germanium on silicon. It is shown that the germane/argon plasma treatment sufficiently removes SiOx and carbon at the surface to enable germanium epitaxy. The use of this surface preparation step demonstrates an alternative way to produce germanium epitaxy at reduced temperatures, a key enabler for increased flexibility of integration with CMOS back-end-of-line fabrication.

Combination of chemical and biological transformation for the sustainable manufacturing of bulk chemicals

Bulk chemicals, also called commodity chemicals, occupy an important position within the national economy. At present, the preparation of bulk chemicals in China is mainly based on chemical transformation using petroleum, coal, natural gas and other non-renewable fossil resources as the raw materials. The development of chemical processes is unsustainable and the existence of serious pollution accompanied by a considerable number of carbon dioxide emissions has caused environmental problems. The future trends of Chinas bulk chemicals manufacturing will be diversified feedstocks and green synthesis processes. The use of renewable biomass as raw materials and biotransformation will become research hotspots in bulk chemicals preparation. Chemical transformation and biotransformation have their respective advantages but cannot avoid their shortcomings. The effective integration of chemical transformation and biotransformation can fully exert each advantage, thus resulting in a high-performance green process. This review discusses the key scientific problems of combined chemical and biological transformation to prepare bulk chemicals, including feedstocks fusion, process fusion and integrated system fusion. Measures and suggestions on the development of related fields are also put forward.

Cellulose sulfuric acid (CSA) and starch sulfuric acid (SSA) as solid and heterogeneous catalysts in green organic synthesis: recent advances

The use of heterogeneous solid acid catalysts is important to the development of sustainable chemical processes. To this end, cellulose sulfuric acid (CSA) and starch sulfuric acid (SSA) have been developed and used for a wide range of organic transformations, including the synthesis of pharmaceutically important heterocyclic compounds. These heterogeneous catalysts are easily recovered and reused several times without loss of their activity. In this review, we mainly summarize applications of these catalysts in synthetic organic chemistry.

Copper‐ and Ligand‐free Heteroannulation of o‐Halohydroxypyridine with Terminal Alkynes Using Pd/C Catalyst: One‐Pot Synthesis of 2‐Substituted Furopyridines and their Functionalization

Three types of isomeric 2‐substituted furo[3,2‐b]pyridine, furo[2,3‐b]pyridine and furo[3,2‐c]pyridine were prepared using Pd/C‐catalyzed heteroannulation of o‐halopyridinols and terminal alkynes under copper‐ and ligand‐free conditions. We also demonstrated that double functionalization yielding 2,3‐disubstituted furopyridines could be achieved through heteroannulation followed by bromination and Suzuki/Heck reactions. In addition, the use of recoverable Pd/C in the absence of a cocatalyst and ligand can aid in the development of greener chemical processes.

Microscopic silicon-based lateral high-aspect-ratio structures for thin film conformality analysis

Film conformality is one of the major drivers for the interest in atomic layer deposition (ALD) processes. This work presents new silicon-based microscopic lateral high-aspect-ratio (LHAR) test structures for the analysis of the conformality of thin films deposited by ALD and by other chemical vapor deposition means. The microscopic LHAR structures consist of a lateral cavity inside silicon with a roof supported by pillars. The cavity length (e.g., 20–5000 μm) and cavity height (e.g., 200–1000 nm) can be varied, giving aspect ratios of, e.g., 20:1 to 25 000:1. Film conformality can be analyzed with the microscopic LHAR by several means, as demonstrated for the ALD Al2O3 and TiO2 processes from Me3Al/H2O and TiCl4/H2O. The microscopic LHAR test structures introduced in this work expose a new parameter space for thin film conformality investigations expected to prove useful in the development, tuning and modeling of ALD and other chemical vapor deposition processes.

Extension and application of energy-minimization multi-scale (EMMS) theory for full-loop hydrodynamic modeling of complex gas–solid reactors

Virtual reality in chemical engineering features real-time simulation of complex industrial processes by utilizing multi-scale computation paradigm, and its realization is premised on global hydrodynamic modeling of the processes. Initial energy-minimization multi-scale (EMMS) model, though originally proposed for gas–solid fast fluidization, is extended to bubbling fluidization and in both axial and radial directions, so as to enable unified modeling of the entire gas–solid fluidization regime and theoretical computation of axial and radial heterogeneities in gas–solid flow. By applying the EMMS and its extension models to the segments divided from complex gas–solid reactors, an EMMS-based general method is proposed for global hydrodynamic calculation of the complex systems. Compared with traditional empirical schemes, the EMMS-based method avoids pre-separating the complex systems into various reaction zones until each has a single and simple flow state. And its feasibility is demonstrated by performing full-loop computation of an industrial-scale circulating fluidized bed, but its flexibility to the complexities of industrial processes in configuration and hydrodynamics still needs to be increased further in order to develop a software package for chemical process and virtual reality technology development.

COSMO-SAC Sigma Profile Generation with Conceptual Segment Concept

Solvation thermodynamics-based models for predicting liquid-phase nonidealities and fluid-phase equilibria are gaining attention in modern chemical process and product development. Among this class of thermodynamic models, COSMO-RS and COSMO-SAC are two variants used extensively in industry. A key input to these models is the so-called sigma profile, i.e., a histogram of charge density distribution over the molecular surface. Typically, sigma profiles are generated from quantum mechanical calculations with molecular structure and conformation information as inputs to the calculation. We present an alternative approach for generating sigma profiles from experimental fluid-phase equilibrium data, i.e., solubility. Specifically, we incorporate the conceptual segment concept of NRTL-SAC activity coefficient model into sigma profile generation. We generate “apparent” sigma profiles from linear combination of sigma profiles of conceptual segments represented by reference molecules selected for hydrophobic, pola...