Toward more cost‐effective and greener chemicals production from shale gas by integrating with bioethanol dehydration: Novel process design and simulation‐based optimization

A novel process design for a more cost‐effective, greener process for making chemicals from shale gas and bioethanol is presented. The oxidative coupling of methane and cocracking technologies are considered for converting methane and light natural gas liquids, into value‐added chemicals. Overall, the process includes four process areas: gas treatment, gas to chemicals, methane‐to‐ethylene, and bioethanol‐to‐ethylene. A simulation‐optimization method based on the NSGA‐II algorithm for the life cycle optimization of the process modeled in the Aspen HYSYS is developed. An energy integration model is also fluidly nested using the mixed‐integer linear programming. The results show that for a “good choice” optimal design, the minimum ethylene selling price is $655.1/ton and the unit global‐warming potential of ethylene is 0.030 kg CO₂‐eq/kg in the low carbon shale gas scenario, and $877.2/ton and 0.360 kg CO₂‐eq/kg in the high carbon shale gas scenario. © 2014 American Institute of Chemical Engineers AIChE J, 61: 1209–1232, 2015     

Comparison of Oleo‐ vs Petro‐Sourcing of Fatty Alcohols via Cradle‐to‐Gate Life Cycle Assessment

Alcohol ethoxylates surfactants are produced via ethoxylation of fatty alcohol (FA) with ethylene oxide. The source of FA could be either palm kernel oil (PKO) or petrochemicals. The study aimed to compare the potential environmental impacts for PKO‐derived FA (PKO‐FA) and petrochemicals‐derived FA (petro‐FA). Cradle‐to‐gate life cycle assessment has been performed for this purpose because it enables understanding of the impacts across the life cycle and impact categories. The results show that petro‐FA has overall lower average greenhouse gas (GHG) emissions (～2.97 kg CO₂e) compared to PKO‐FA (～5.27 kg CO₂e). (1) The practices in land use change for palm plantations, (2) end‐of‐life treatment for palm oil mill wastewater effluent and (3) end‐of‐life treatment for empty fruit bunches are the three determining factors for the environmental impacts of PKO‐FA. For petro‐FA, n‐olefin production, ethylene production and thermal energy production are the main factors. We found the judicious decisions on land use change, effluent treatment and solid waste treatment are key to making PKO‐FA environmentally sustainable. The sensitivity results show the broad distribution for PKO‐FA due to varying practices in palm cultivation. PKO‐FA has higher impacts on average for 12 out of 18 impact categories evaluated. For the base case, when accounted for uncertainty and sensitivity analyses results, the study finds that marine eutrophication, agricultural land occupation, natural land occupation, fossil depletion, particulate matter formation, and water depletion are affected by the sourcing decision. The sourcing of FA involves trade‐offs and depends on the specific practices through the PKO life cycle from an environmental impact perspective.     

Conceptual design of ammonia‐based energy storage system: System design and time‐invariant performance

Chemicals‐based energy storage is promising for integrating intermittent renewables on the utility scale. High round‐trip efficiency, low cost, and considerable flexibility are desirable. To this end, an ammonia‐based energy storage system is proposed. It utilizes a pressurized reversible solid‐oxide fuel cell for power conversion, coupled with external ammonia synthesis and decomposition processes and a steam power cycle. A coupled refrigeration cycle is utilized to recycle nitrogen completely. Pure oxygen, produced as a side‐product in electrochemical water splitting, is used to drive the fuel cell. A first‐principle process model extended by detailed cost calculation is used for process optimization. In this work, the performance of a 100 MW system under time‐invariant operation is studied. The system can achieve a round‐trip efficiency as high as 72%. The lowest levelized cost of delivered energy is obtained at 0.24 $/kWh, which is comparable to that of pumped hydro and compressed air energy storage systems. © 2016 American Institute of Chemical Engineers AIChE J, 63: 1620–1637, 2017     

A target‐oriented solid‐gas thermochemical sorption heat transformer for integrated energy storage and energy upgrade

An innovative target‐oriented solid‐gas thermochemical sorption heat transformer is developed for the integrated energy storage and energy upgrade of low‐grade thermal energy. The operating principle of the proposed energy storage system is based on the reversible solid‐gas chemical reaction whereby thermal energy is stored in form of chemical bonds with thermochemical sorption process. A novel thermochemical sorption cycle is proposed to upgrade the stored thermal energy by using a pressure‐reducing desorption method during energy storage process and a temperature‐lift adsorption technique during energy release process. Theoretical analysis showed that the proposed target‐oriented thermochemical sorption heat transformer is effective for the integrated energy storage and energy upgrade, and the low‐grade thermal energy can be upgraded from 87 to 171^°C using a group of sorption working pair MnCl₂‐CaCl₂‐NH₃. Moreover, it can give the flexibility of deciding the temperature magnitude of energy upgrade by choosing appropriate sorption working pairs. © 2012 American Institute of Chemical Engineers AIChE J, 59: 1334–1347, 2013     

Experimental validation of hybrid distillation‐vapor permeation process for energy efficient ethanol–water separation

BACKGROUND: The energy demand of distillation‐based systems for ethanol recovery and dehydration can be significant, particularly for dilute solutions. An alternative separation process integrating vapor stripping with a vapor compression step and a vapor permeation membrane separation step, termed membrane assisted vapor stripping (MAVS), has been proposed. The hydrophilic membrane separates the ethanol–water vapor into water‐rich permeate and ethanol‐enriched retentate vapor streams from which latent and sensible heat can be recovered. The objective of this work was to demonstrate experimentally the performance of a MAVS system and to compare the observed performance with chemical process simulation results using a 5 wt% ethanol aqueous feed stream as the benchmark. RESULTS: Performance of the steam stripping column alone was consistent with chemical process simulations of a stripping tower with six stages of vapor liquid equilibria (VLE). The overhead vapor from the stripper contained about 40 wt% ethanol and required 6.0 MJ of fuel‐equivalent energy per kg of ethanol recovered in the concentrate. Introduction of the vapor compressor and membrane separation unit and recovery of heat from both membrane permeate and retentate streams resulted in a retentate ethanol concentrate containing ca 80 wt% ethanol, but requiring only 2.2 MJ fuel kg^?1 ethanol, significantly less than steam stripping alone. CONCLUSION: Performance of the experimental unit with a 5 wt% ethanol feed liquid corroborated chemical process simulation predictions for the energy requirement of the MAVS system, demonstrating a 63% reduction in the fuel‐equivalent energy requirement for MAVS compared with conventional steam stripping or distillation. Published 2009 by John Wiley & Sons, Ltd.     

Advances in Organic Liquid‐Gas Chemical Heat Pumps

Compared with inorganic chemical heat pumps (CHPs), organic liquid‐gas CHPs are more amenable to be run as a continuous process because the reactants and products can be fed or removed continuously. Therefore, increasing attention has been paid to investigations of CHPs using the organic liquid‐gas reaction system. Relevant research topics involved reaction catalyst, chemical reaction kinetics, reactive distillation, energy efficiency evaluation, economic analysis, etc. Nevertheless, the research on an organic liquid‐gas CHP system is still in the elementary stage. A detailed review on the current research status of catalyst‐assisted CHPs employing an organic liquid‐gas reaction system has been performed. Existing problems are identified and future research directions are proposed.     

Targeting climate-neutral hydrogen production: Integrating brown and blue pathways with green hydrogen infrastructure via a novel superstructure and simulation-based life cycle optimization

This article addresses the sustainable design of hydrogen (H₂) production systems that integrate brown and blue pathways with green hydrogen infrastructure. We develop a systematic framework to simultaneously optimize the process superstructure and operating conditions of steam methane reforming (SMR)-based hydrogen production systems. A comprehensive superstructure that integrates SMR with multiple carbon dioxide capture technologies, electrolyzers, fuel cells, and working fluids in the organic rankine cycle is proposed under varying operating conditions. A life cycle optimization model is then developed by integrating superstructure optimization, life cycle assessment approach, techno-economic assessment, and process optimization using extensive process simulation models and formulated as a mixed-integer nonlinear program. We find that the optimal unit-levelized cost of hydrogen ranges from $1.49 to $3.18 per kg H₂. Moreover, the most environmentally friendly process attains net-zero life cycle greenhouse gas emissions compared to 10.55 kg CO₂-eq per kg H₂ for the most economically competitive process design.     

Hybrid‐Bridged Silsesquioxane as Recyclable Metathesis Catalyst Derived from a Bis‐Silylated Hoveyda‐Type Ligand

The synthesis of a bis‐silylated Hoveyda‐type monomer is described as well as the preparation of several organic‐inorganic hybrid materials derived from it by a sol‐gel process (with and without tetraethyl orthosilicate) and by anchoring to MCM‐41. The resulting materials were treated with second generation Grubbs' catalyst to generate second generation Hoveyda–Grubbs‐type alkylideneruthenium complexes covalently bonded to the silica matrix. These materials are recyclable catalysts for the ring‐closing metathesis reaction of dienes and enynes.     

Hydrolysis,polycondensation, and catalytic properties of Ru(II) complex of 3‐4,5‐dihydroimidazol‐1‐yl‐propyltriethoxysilane

The preparation and measurements of some properties of organic–inorganic hybrid materials derived from Ru(II)‐3‐4,5‐dihyroimidazol‐1‐yl‐propyltriethoxysilane inside a polysiloxane network have been achieved. The hydrolysis and polycondensation of Ru(II)‐3‐4,5‐dihyroimidazol‐1‐yl‐propyltriethoxysilane were performed in different experimental conditions, producing a new organic–inorganic silica. The alkoxysilyl groups available were used for the construction of inorganic backbone by the sol‐gel process, and the imidazole group was found suitable for incorporating Ru(II) by coordination. The coordination of metal complex is retained because there is no leaching from the metal complex containing gels. To ensure sufficient catalytic properties, a series of hybrid materials from tetraethoxysilane was prepared. These materials were identified and catalytic activities were tested for cyclization of (Z)‐3‐methylpent‐2‐en‐4‐yn‐1‐ol to 2,3‐dimethylfuran. Heterogeneous Ru(II) catalyst can also be recycled and reused without significant loss of selectivity or activity. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1329–1334, 2001     

无机盐工业面临碳达峰碳中和的挑战与创新发展机遇

传统的无机化学品均是采用独自的矿产资源分别进行加工,生产资源与能源未能实现循环经济再利用、循环和分级利用的生产原则,全生命周期能源消耗无效率高。要实现碳达峰、碳中和,满足新产业的需要,就需要开发无机盐化工资源性耦合低碳的新技术新工艺。在钛、磷、硫资源耦合生产钛白粉与湿法磷酸盐先进工艺技术模式的基础上,以储能材料磷酸铁锂为例,提出将钛铁矿-磷灰石矿-锂灰石矿三矿耦合,按“元素经济”的绿色工艺技术路线生产储能材料磷酸铁及磷酸铁锂产品,论述了磷酸铁锂三元素上游磷化工、钛化工、锂化工面临节能减碳的挑战与耦合新技术创新的机遇及市场发展前景。     

Hybrid Organic‐Inorganic Materials Derived from a Monosilylated Hoveyda‐type Ligand as Recyclable Diene and Enyne Metathesis Catalysts

The synthesis of a monosilylated Hoveyda‐type monomer is described as well as the preparation of several organic‐inorganic hybrid materials derived from it by sol‐gel processes and by anchoring to commercial silica gel and MCM‐41. The resulting materials were treated with first and/or second generation Grubbs’ catalyst to generate Hoveyda–Grubbs’ type alkylidene ruthenium complexes covalently bonded to the silica matrix. These materials are efficient recyclable catalysts for the ring‐closing metathesis reaction of dienes and enynes, even for the formation of tri‐ and tetrasubstituted olefins.     

Semicrystalline Shape‐Memory Elastomers: Effects of Molecular Weight,Architecture, and Thermomechanical Path

Poly(caprolactone) networks are well‐studied shape‐memory polymers owing to their high fixity and recovery, their ability to store large amounts of elastic energy, and their tunable shape‐triggering temperature. To elucidate the influence of network structure on shape‐memory features, poly(caprolactone) networks are prepared by reacting different molecular weight diacrylate prepolymers with trifunctional (trimethylolpropane tris(3‐mercaptopropionate), 3T ) or tetrafunctional (pentaerythritol tetrakis(3‐mercaptopropionate), 4T ) crosslinkers. Networks from 4T crosslinkers generally exhibit higher gel fractions, more elastically active strands, and superior shape‐memory properties compared with networks from 3T . Melted elastomers exhibit stress–strain behavior well described by the neo‐Hookean model. How the state of crystallization during the cold‐drawing process has a large effect on the draw stress, the network's shape fixity, and its elastic storage capacity is shown. Finally, the working strain range of networks is evaluated. Cured elastomers prepared from prepolymers with different molecular weights can store and release large amounts of elastic energy (>2 MJ m⁻³), over different ranges of tensile strain.     

Membrane‐assisted vapor stripping: energy efficient hybrid distillation–vapor permeation process for alcohol–water separation

BACKGROUND: Energy efficient alternatives to distillation for alcohol recovery from dilute solution are needed to improve biofuel sustainability. A process integrating steam stripping with a vapor compression step and a vapor permeation membrane separation step is proposed. The objective of this work is to estimate the energy and process costs required to make a fuel grade ethanol (0.5 wt% water) from 1 and 5 wt% ethanol aqueous streams using the proposed process. RESULTS: Using process simulation and spreadsheeting software, the proposed membrane‐assisted vapor stripping process was estimated to require as little as 8.9 MJ of fuel‐equivalent energy per kg of fuel grade ethanol recovered from a 1 wt% ethanol feed stream, 2.5 MJ kg^?1 for a 5 wt% ethanol solution. This represents an energy saving of at least 43% relative to standard distillation producing azeotropic ethanol (6 wt% water). Process costs were also found to be lower than for distillation at the 3.0 × 10⁶ kg‐ethanol year^?1 scale modeled. CONCLUSION: In this hybrid system, the stripping column provides high ethanol recoveries and low effluent concentrations while the vapor compression‐membrane component enables the efficient recovery of latent and sensible heat from both the retentate and permeate streams from the membrane system. Published in 2008 by John Wiley & Sons, Ltd.     

Phase‐separation prevention and performance improvement of poly(vinyl acetate)/TEOS hybrid using modified sol‐gel process

The formation of covalent bonds between silanols in copolymer and those in silica prevents organic–inorganic phase separation. Two series of hybrid composite materials, poly(vinyl acetate‐co‐vinyl trimethoxysilane)/TEOS and poly[vinyl acetate‐co‐3‐(trimethoxysilyl)propyl methacrylate]/TEOS, were fabricated using a modified sol‐gel process. The hybrids were transparent. Two kinds of silane coupling agents, vinyl trimethoxysilane (VTS) and 3‐(trimethoxysilyl)propyl methacrylate (γ‐MPS), were used to prevent macrophase separation through formation of covalent bonds. Thermal analysis showed that γ‐MPS was more effective than VTS for the formation of covalent bonds. Enhancement of thermal stability of the hybrids was investigated by thermogravimetric analysis. Photomicrographs of scanning electron microscopy and images of atomic force microscopy indicated that inorganic silica particles were homogeneously dispersed in less than 50 nm in organic matrix. The morphological properties of hybrids were strongly dependent on the organic–inorganic composition. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 2310–2318, 2001     

Experimental methods in chemical engineering: Micro‐reactors

Whereas the bulk chemical industry has historically sought economic advantage through economies of scale, a paradigm shift has researchers developing systems on smaller scales. Nano‐cages and nano‐actuators increase selectivity and robustness at the molecular scale. In parallel, micro‐contactors with sub‐millimetre lateral dimensions are decreasing boundary layers that restrict heat and mass transfer and thus meet the objectives of process intensification with great increases in productivity with a smaller footprint. These contactors continue to serve chemical engineers and chemists to synthesize fine chemicals and characterize catalysts; however, they have now been adopted for sensors in biological and biochemical systems. A bibliometric analysis of articles indexed in the Web of Science in 2016 and 2017 identified five major clusters of research: catalysis and bulk chemicals; nanoparticles; organic synthesis and flow chemistry; systems and micro‐fluidics applied to biochemistry; and micro‐channel reactors and mass transfer. In the early 1990s, less than 100 articles a year mentioned micro‐reactors, while over 943 articles mentioned it in 2017. Here, we introduce micro‐reactors and their role in the continuous synthesis of fine chemicals across the various scales to commercialization.     

Self‐healing polymeric materials towards non‐structural recovery of functional properties

Self‐healing of polymers and polymer composites initially represented a process capable of autonomic restoration of mechanical strength upon cracking of the materials, but it is moving into the area of restoration of functionality. This mini‐review is focused on recent efforts to develop functional polymers with built‐in stimuli‐responsive ability to heal for recovery of their specific physical or chemical properties. Molecular design and synthesis, compounding and assembly of organic and inorganic species, inherent reversibility, etc., are summarized. It is hoped that much more interest will be aroused in this emerging and promising frontier topic. © 2014 Society of Chemical Industry     

Characterization and properties of UV‐curable polyurethane‐acrylate/silica hybrid materials prepared by the sol‐gel process

UV‐curable, transparent hybrid material of urethane‐acrylate resin was prepared by the sol‐gel process using 3‐(trimethoxysilyl)propylmethacrylate (TMSPM) as a coupling agent between the organic and inorganic phases. The effects of the content of acid and silica on the morphology and mechanical properties of UV‐curable polyurethane‐acrylate/silica hybrid (UA‐TMSPM)/SiO₂ materials have been studied. The results of thermogravimetric analysis for the (UA‐TMSPM)/SiO₂ hybrid materials indicated that the thermal stability of the hybrids is greatly improved. It was found that with the increase of HCl content, the interfacial interaction between organic and inorganic phases had been strengthened, as demonstrated by field emission scanning electron microscopy. Without sacrificing flexibility, the hybrid materials showed improved hardness with increasing content of acid and silica. Compared with the pure organic counterpart UA/hexanediol diacrylate (UA/HDDA) system, abrasion resistance of the hybrids improved with increasing acid content, at low silica content. Copyright © 2004 Society of Chemical Industry     

Cation‐exchange kinetics and electrical conductivity studies of an ‘organic‐inorganic’ composite cation‐exchanger: Polypyrrole Th(IV) phosphate

Polypyrrole Th(IV) phosphate, an electrically conducting ‘organic‐inorganic’ cation‐exchange composite material was prepared by the incorporation of an electrically conducting polymer, i.e., polypyrrole, into the matrix of a fibrous type inorganic cation‐exchanger thorium(IV) phosphate. The composite cation‐exchanger has been of interest because of its good ion‐exchange capacity, higher chemical and thermal stability, and high selectivity for heavy metal ions. The temperature dependence of electrical conductivity of this composite system with increasing temperatures was measured on compressed pellets by using four‐in‐line‐probe dc electrical conductivity measuring instrument. The conductivity values lie in the semiconducting region, i.e., in the order of 10^?6 to 10^?4 S cm^?1 that follow the Arrhenius equation. Nernst–Plank equation has been applied to determine some kinetic parameters such as self‐diffusion coefficient (D₀), energy of activation (E_a), and entropy of activation (ΔS*) for Mg(II), Ca(II), Sr(II), Ba(II), Ni(II), Cu(II), Mn(II), and Zn(II) exchange with H⁺ at different temperatures on this composite material. These results are useful for predicting the ion‐exchange process occurring on the surface of this cation‐exchanger. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Response of a sequential‐valve‐gate system used for thin‐wall injection molding

Sequential injection molding using a valve‐gate‐controlled hot runner system has attracted attention for industrial applications in recent years. Because of the complexity of the operation mechanisms, a commercial valve gate usually delays for about 0.3–0.5 s once the valve‐opening command is given. The signal‐to‐operation delay is acceptable for the conventional injection molding of large parts. However, this operation delay limits its application to thin‐wall molded parts for computer, communication, and consumer electronics, for which the required filling time is very short. In this study, a gas‐driven fast‐response sequential‐valve‐gate system was developed for thin‐wall injection molding by the adoption of valve‐gate control performance. The characteristics and verifications of the valve‐gate opening were monitored with a charge‐coupled device (CCD) camera (nonmelt condition) and cavity pressure transducers and an accelerometer (melt‐filled condition). The influence of the tolerance between the inner piston and cylinder and the gas pressure on the valve‐gate opening was investigated in detail. Tensile bar parts 1 mm thick were used for the molding experiments. The delay time has been found to be intimately related to the response of the gas‐pressure delivery controlling the valve‐gate movement. In a nonmelt environment, the delay time of the valve‐gate opening decreases with increasing driven gas slightly. In a melt‐filled environment, the delay time is quite sensitive to the operating gas pressure because of the extra resistance between the shaft and the melt. A threshold pressure as high as 100 bar is required to keep the delay time below 15 ms. With the proper choice of the piston size and driven gas pressure, the delay time can be reduced to about 8 ms in a nonmelt environment and to about 12 ms in a melt‐filled environment. Molding using this improved system for sequential valve opening can provide thin‐wall injection parts without a weld line, and good cosmetic quality and better tensile strength require a lower injection pressure than molding using single‐gate and concurrent‐valve‐gate opening. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 1969–1977, 2005     

Treating Methanol‐to‐Olefin Quench Water by Minihydrocyclone Clarification and Steam Stripper Purification

In the chemical industry, methanol‐to‐olefin (MTO) technology is a novel process for producing ethylene and propylene from naphtha thermal cracking. The process of recovering MTO quench water by minihydrocyclone and steam stripping treatment was successfully applied in industrial plants. The fine catalyst in the quench water is removed by the two‐stage minihydrocyclone separation. The method and equipment for this system present various advantages: the quench water can be recycled in the cooling system and prevents heat loss in heat transfer systems; and the stripping tower can be blocked by the catalyst. Maintenance activities are reduced and a stable operation cycle is extended. The proposed treatment process improves the economic efficiency of the MTO device.