Showing papers in "Aiche Journal in 2020"

Model-based equipment design for the biphasic production of 5-hydroxymethylfurfural in a tubular reactor

Abstract: Funding information German Research FoundationDeutsche Forschungsgemeinschaft, Grant/Award Number: EXC2186 Abstract Herein, a novel concept for the acid catalyzed dehydration of fructose (FRC) to 5-hydroxymethylfurfural (5-HMF) in a biphasic tubular reactor is presented. Reaction kinetic models were developed based on experiments performed in a newly developed lab-scale autoclave that enables a decoupled investigation of singlephase reaction and 5-HMF mass transfer. Our reaction kinetic models allow an accurate description of the biphasic reaction. Subsequently, we integrate the reaction kinetic models in the model-based design of a tailored reactor unit. This reactor unit employs the concept of in-situ extraction in a countercurrent flow of a monodisperse droplet swarm within a continuous aqueous phase. From reactor calculations, we obtain a maximum 5-HMF yield of 76% at full FRC conversion. Countercurrent in-situ extraction enables over 99% 5-HMF recovery in the organic phase.

From directed evolution to computational enzyme engineering—A review

Abstract: Funding information Division of Chemical, Bioengineering, Environmental, and Transport Systems, Grant/ Award Number: CBET-1703274 Abstract Nature relies on a wide range of enzymes with specific biocatalytic roles to carry out much of the chemistry needed to sustain life. Enzymes catalyze the interconversion of a vast array of molecules with high specificity—from molecular nitrogen fixation to the synthesis of highly specialized hormones and quorum-sensing molecules. Ever increasing emphasis on renewable sources for energy and waste minimization has turned enzymes into key industrial workhorses for targeted chemical conversions. Modern enzymology is central to not only food and beverage manufacturing processes but also finds relevance in countless consumer product formulations such as proteolytic enzymes in detergents, amylases for excess bleach removal from textiles, proteases in meat tenderization, and lactoperoxidases in dairy products. Herein, we present an overview of enzyme science and engineering milestones and the emergence of directed evolution of enzymes for which the 2018 Nobel Prize in Chemistry was awarded to Dr. Frances Arnold.

Ultrafast water-selective permeation through graphene oxide membrane with water transport promoters

Abstract: Funding information Innovative Research Team Program by the Ministry of Education of China, Grant/Award Number: IRT_17R54; National Natural Science Foundation of China, Grant/Award Numbers: 21606123, 21490585, 51861135203; Natural Science Foundation of Jiangsu Province, Grant/Award Number: BK20160980; Topnotch Academic Programs Project of Jiangsu Higher Education Institutions (TAPP) Abstract Graphene oxide (GO), as a representative two-dimensional material, has shown great prospect in developing high-performance separation membranes via forming ordered and tunable nanochannels. However, for aqueous molecular separations, the implementation of an excellent separation performance remains a critical challenge due to the membrane swelling phenomenon and the trade-off effect between permeation flux and separation factor. Herein, a facile and tunable approach is presented for introducing water transport promoters into GO interlayer channels to construct water transport highways. The combination of covalently cross-linked channel structure, facilitated water-selective sorption, and expedited water-preferential diffusion overcome the trade-off effect, achieving a superior performance from an ultrathin GO membrane with a flux of 5.94 kg/m∙h and a water/butanol separation factor of 3,965, which exceeds the performance of state-of-the-art membranes for water/ butanol separation. The strategy proposed here is straightforward, holding great potential to produce high-efficiency GO and other two-dimensional (2D)-material membranes for precise aqueous molecular separations.

Protic ionic liquid-based deep eutectic solvents with multiple hydrogen bonding sites for efficient absorption of NH3

Abstract: The emerging of ionic liquids (ILs) provides an efficient and sustainable way to separate and recover NH3 due to their unique properties. However, the solid or highly viscous ILs are not suitable f ...

Transport phenomena in electrolyte solutions: Nonequilibrium thermodynamics and statistical mechanics

Abstract: Author(s): Fong, KD; Bergstrom, HK; McCloskey, BD; Mandadapu, KK | Abstract: The theory of transport phenomena in multicomponent electrolyte solutions is presented here through the integration of continuum mechanics, electromagnetism, and nonequilibrium thermodynamics. The governing equations of irreversible thermodynamics, including balance laws, Maxwell's equations, internal entropy production, and linear laws relating the thermodynamic forces and fluxes, are derived. Green–Kubo relations for the transport coefficients connecting electrochemical potential gradients and diffusive fluxes are obtained in terms of the flux–flux time correlations. The relationship between the derived transport coefficients and those of the Stefan–Maxwell and infinitely dilute frameworks are presented, and the connection between the transport matrix and experimentally measurable quantities is described. To exemplify the application of the derived Green–Kubo relations in molecular simulations, the matrix of transport coefficients for lithium and chloride ions in dimethyl sulfoxide is computed using classical molecular dynamics and compared with experimental measurements.

A review of technological advances and open challenges for oil and gas drilling systems engineering

Abstract: The ever-increasing quest to identify, secure, access and operate oil and gas fields is continuously expanding to the far corners of the planet, facing extreme conditions towards exploring, securing and deriving maximum fluid benefits from established and unconventional fossil fuel sources alike: to this end, the unprecedented geological, climatic, technical and operational challenges have necessitated the development of revolutionary drilling and production methods. This review paper focuses on a technological field of great importance and formidable technical complexity that of well drilling for fossil fuel production. A vastly expanding body of literature addresses design and operation problems with remarkable success: what is even more interesting is that many recent contributions rely on multidisciplinary approaches and reusable Process Systems Engineering (PSE) methodologies a drastic departure from ad hoc/one-use tools and methods of the past. The specific goals of this review are to first, review the state of art in active fields within drilling engineering, and explore currently pressing technical problems, which are in dire need, or have recently found, PSE-and/or CFD-relevant solutions. Then, we illustrate the methodological versatility of novel PSE-based approaches for optimization and control, with an emphasis on contemporary problems. Finally, we highlight current challenges and opportunities for truly innovative research contributions, which require the combination of best-in-class methodological and software elements in order to deliver applicable solutions of industrial importance. 1.0 Well drilling in the oil and gas industry The annual increase in global energy demand and the diverse applications of conventional & unconventional oil and gas resources are indicative of the fact that these resources will continuously remain relevant to humanity in the far future. With increasing climate change concerns, natural gas already provides a promising transition between some oil-based fuels and renewables in the long run, despite its well-known transportation difficulties.1 It can be further argued that natural gas represents an economically attractive option for electricity generation (particularly in the US where shale gas is naturally abundant) with significantly reduced greenhouse gas emissions compared to coal; thus increasing its market demand.2 These reasons have warranted the advancements in technologies of

Facile synthesis of ultramicroporous carbon adsorbents with ultra‐high CH4 uptake by in situ ionic activation

Abstract: We introduce a straightforward method for the preparation of novel starch-based ultramicroporous carbons (SCs) that demonstrate high CH4 uptake and excellent CH4/N2 selectivity. These SCs are derived from a combination of starch and 1-6 wt. % of acrylic acid, and the resulting materials are amenable to surface cation exchangeability as demonstrated by the formation of highly dispersed K+ in carbon precursors. Following activation, these SCs contain ultramicropores with narrow pore-size distributions of <0.7 nm, leading to porous carbon-rich materials that exhibit CH4 uptake values as high as 1.86 mmol/g at 100 kPa and 298 K, the highest uptake value for CH4 to date, with the IAST-predicted CH4/N2 selectivity up to 5.7. Both the potential mechanism for the formation of narrow pores and the origin of the favorable CH4 adsorption properties are discussed and examined. This work may potentially guide future designs for carbon-rich materials with excellent gas adsorption properties.