Optimal synthesis of heat-integrated distillation configurations using the two-column superstructure

In the realm of the synthesis of heat-integrated distillation configurations,the conventional approach for exploring more heat integration possibilities typically entails the splitting of a single column into a twocolumn configuration.However,this approach frequently necessitates tedious enumeration procedures,resulting in a considerable computational burden.To surmount this formidable challenge,the present study introduces an innovative remedy:The proposition of a superstructure that encompasses both single-column and multiple two-column configurations.Additionally,a simultaneous optimization algorithm is applied to optimize both the process parameters and heat integration structures of the twocolumn configurations.The effectiveness of this approach is demonstrated through a case study focusing on industrial organosilicon separation.The results underscore that the superstructure methodology not only substantially mitigates computational time compared to exhaustive enumeration but also furnishes solutions that exhibit comparable performance.

Process synthesis for the separation of coal-to-ethanol products

The coal-to-ethanol process,as the clean coal utilization,faces challenges from the energy-intensive distillation that separates multi-component effluents for pure ethanol.Referring to at least eight columns,the synthesis of the ethanol distillation system is impracticable for exhaustive comparison and difficult for conventional superstructure-based optimization as rigorous models are used.This work adopts a superstructure-based framework,which combines the strategy that adaptively selects branches of the state-equipment network and the parallel stochastic algorithm for process synthesis.High-performance computing significantly reduces time consumption,and the adaptive strategy substantially lowers the complexity of the superstructure model.Moreover,parallel computing,elite search,population redistribution,and retention strategies for irrelevant parameters are used to improve the optimization efficiency further.The optimization terminates after 3000 generations,providing a flowsheet solution that applies two non-sharp splitting options in its distillation sequence.As a result,the 59-dimension superstructure-based optimization was solved efficiently via a differential evolution algorithm,and a high-quality solution with a 28.34%lower total annual cost than the benchmark was obtained.Meanwhile,the solution of the superstructure-based optimization is comparable to that obtained by optimizing a single specific configuration one by one.It indicates that the superstructure-based optimization that combines the adaptive strategy can be a promising approach to handling the process synthesis of large-scale and complex chemical processes.

Effect of Measurement Error on the Multivariate CUSUM Control Chart for Compositional Data

Control charts(CCs)are one of the main tools in Statistical Process Control that have been widely adopted in manufacturing sectors as an effective strategy for malfunction detection throughout the previous decades.Measurement errors(M.E’s)are involved in the quality characteristic of interest,which can effect the CC’s performance.The authors explored the impact of a linearmodel with additive covariate M.E on the multivariate cumulative sum(CUSUM)CC for a specific kind of data known as compositional data(CoDa).The average run length(ARL)is used to assess the performance of the proposed chart.The results indicate that M.E’s significantly affects themultivariate CUSUM-CoDaCCs.The authors haveused theMarkov chainmethod to study the impact of different involved parameters using six different cases for the variance-covariance matrix(VCM)(i.e.,uncorrelated with equal variances,uncorrelated with unequal variances,positively correlated with equal variances,positively correlated with unequal variances,negatively correlatedwith equal variances and negatively correlated with unequal variances).The authors concluded that the error VCM has a negative impact on the performance of themultivariate CUSUM-CoDa CC,as the ARL increases with an increase in the value of the error VCM.The subgroup size m and powering operator b positively impact the proposed CC,as the ARL decreases with an increase in m or b.The number of variables p also has a negative impact on the performance of the proposed CC,as the values of ARL increase with an increase in p.For the implementation of the proposal,two illustrated examples have been reported formultivariate CUSUM-CoDaCCs inthe presence ofM.E’s.Onedealswith themanufacturingprocessof uncoated aspirin tablets,and the other is based on monitoring the machines involved in the muesli manufacturing process.

Analysis of Multiple Annular Pressure in Gas Storage Well and High-Pressure Gas Well

In gas storage or high-pressure gas wells,annular pressure is an unavoidable threat to safe,long-term resource production.The more complex situation,however,is multiple annular pressure,which means annular pressure happens in not only one annulus but two or more.Such a situation brings serious challenges to the identification of well integrity.However,few researches analyze the phenomenon of multiple annular pressure.Therefore,this paper studies the mechanism of multi-annular pressure to provide a foundation for its prevention and diagnosis.Firstly,the multi-annular pressure is classified according to the mechanism and field data.Then the failure mechanism and function of the wellbore safety barriers in the process of passage formation are analyzed.Finally,some suggestions are put forward for identifying and controlling multi-annular pressure.The results show that gas storage wells and high-pressure gas wells have the conditions to generate pressure channels,which leads to the expansion of annular pressure from a single annulus to multiple annuli.The pressure channel is composed of the tubing string,casing string,and a cement mantle,and the failures among the three have causal and hierarchical relationships.According to the channel direction,it can be divided into two types:tubing-casing annulus to casing annulus and casing annulus to the tubing-casing annulus,of which the former is more harmful.Some measures can be considered to prevent pressure channeling,including improvement of cementing quality,revision of maximum allowable annular pressure,and suitable frequency of pressure relief.

Novel Water-Based Drilling and Completion Fluid Technology to Improve Wellbore Quality During Drilling and Protect Unconventional Reservoirs

The efficient exploration and development of unconventional oil and gas are critical for increasing the self-sufficiency of oil and gas supplies in China.However,such operations continue to face serious problems(e.g.,borehole collapse,loss,and high friction),and associated formation damage can severely impact well completion rates,increase costs,and reduce efficiencies.Water-based drilling fluids possess certain advantages over oil-based drilling fluids(OBDFs)and may offer lasting solutions to resolve the aforementioned issues.However,a significant breakthrough with this material has not yet been made,and major technical problems continue to hinder the economic and large-scale development of unconventional oil and gas.Here,the international frontier external method,which only improves drilling fluid inhibition and lubricity,is expanded into an internal-external technique that improves the overall wellbore quality during drilling.Bionic technologies are introduced into the chemical material synthesis process to imitate the activity of life.A novel drilling and completion fluid technique was developed to improve wellbore quality during drilling and safeguard formation integrity.Macroscopic and microscopic analyses indicated that in terms of wellbore stability,lubricity,and formation protection,this approach could outperform methods that use typical OBDFs.The proposed method also achieves a classification upgrade from environmentally protective drilling fluid to an ecologically friendly drilling fluid.The developed technology was verified in more than 1000 unconventional oil and gas wells in China,and the results indicate significant alleviation of the formation damage attributed to borehole collapse,loss,and high friction.It has been recognized as an effective core technology for exploiting unconventional oil and gas resources.This study introduces a novel research direction for formation protection technology and demonstrates that observations and learning from the natural world can provide an inexhaustible source of ideas and inspire the creation of original materials,technologies,and theories for petroleum engineering.

Fabrication of a Hydrophobic Hierarchical Surface on Shale Using Modified Nano-SiO_(2)for Strengthening the Wellbore Wall in Drilling Engineering

Wellbore stability is essential for safe and efficient drilling during oil and gas exploration and development.This paper introduces a hydrophobic nano-silica(HNS)for use in strengthening the wellbore wall when using a water-based drilling fluid(WBF).The wellbore-strengthening performance was studied using the linear swelling test,hot-rolling recovery test,and compressive strength test.The mechanism of strengthening the wellbore wall was studied by means of experiments on the zeta potential,particle size,contact angle,and surface tension,and with the use of a scanning electron microscope(SEM).The surface free energy changes of the shale before and after HNS treatment were also calculated using the contact angle method.The experimental results showed that HNS exhibited a good performance in inhibiting shale swelling and dispersion.Compared with the use of water,the use of HNS resulted in a 20%smaller linear swelling height of the bentonite pellets and an 11.53 times higher recovery of water-sensitive shale—a performance that exceeds those of the commonly used shale inhibitors KCl and polyamines.More importantly,the addition of HNS was effective in preventing a decrease in shale strength.According to the mechanism study,the good wellbore-strengthening performance of HNS can be attributed to three aspects.First,the positively charged HNS balances parts of the negative charges of clay by means of electrostatic adsorption,thus inhibiting osmotic hydration.Second,HNS fabricates a lotus-leaf-like surface with a micro-nano hierarchical structure on shale after adsorption,which significantly increases the water contact angle of the shale surface and considerably reduces the surface free energy,thereby inhibiting surface hydration.Third,the decrease in capillary action and the effective plugging of the shale pores reduce the invasion of water and promote wellbore stability.The approach described herein may provide an avenue for inhibiting both the surface hydration and the osmotic hydration of shale.

Editorial for the Special Issue on Unconventional and Intelligent Oil and Gas Engineering

A key global challenge in the 21st century is how to secure sustainable access to energy for a growing global population—set to reach 10 billion by 2035—while coping with the threat of dangerous climate change.The oil and gas industry will still play an essential role in the energy transition by providing affordable and reliable energy to improve living conditions.Meanwhile,producing this energy with decreasing emissions supports a net-zero world.

Influence of Orifice Position Deviations on Distribution Performance of Gravity-Type Liquid Distributor Analyzed Through Mathematical Pathway

The distribution performance of the gravity-type liquid distributor(GTLD) significantly affects column operation efficiency and the consequent product quality. In industrial settings, maldistribution is normally considered to be caused by vertical positional or coplanarity errors stemming from deflections associated with manufacture and installation, or even by excessive weight. The lack ofestimation protocols or standards impedes the description ofthis error, which influences the corresponding outflow rates. Given this situation, the paper proposes a lumped parameter, orifice position deviation(OPD), to facilitate the calculation of the relative discharge rate error(RDRE)based on a formula derivation, which allows the systematic analysis of the influence ofa single orifice or weir OPD.The paper introduces a sensitivity factor K as a concise and unified expression in theoretical RDREs for calibrating the influence of OPD on the RDREs ofgeometrically different orifices and weirs. With respect to the GTLD, a larger K indicates the need for more strict OPD requirements. The paper verifies that the extent of GTLD outflow nonuniformity is associated with diverging tendencies regarding its morphology, especially in the orifice and weir, which can be determined using our proposed procedures.

Three-Dimensional Hexagram Gold Nanoparticles: Synthesis and Growth Mechanism

This study explained a procedure to synthesize 3 D hexagram gold nanoparticles using a specific morphologically controlled gold precursor reduction. Acetaldehyde acted as the reducing agent along with polyvinyl pyrrolidone as the stabilizing agent with a limited reaction temperature range observed to be near to 25 °C. The resulting special gold nanoparticles were physically characterized and observed to possess an average planar size of 420 nm, an average central thickness of 200 nm, and an average edge thickness of 18 nm. Furthermore, a mechanism model was proposed to describe the oriented growth of gold nanoparticles employing published accounts of the mechanisms involved in the growth of gold hexagonal nanoplates. Moreover, the two major factors that controlled the morphology of synthesized gold nanoparticles were elaborated to provide reference for future fabrication methods of metal nanoparticles in both academia and industry.

Morphological Control of Gold Nanoparticles by Green Synthesis Using L-Tryptophan and Other Additives

This study focuses on shape-controlled synthesis of gold nanoparticles, using the green reducing agent L-Tryptophan(L-Trp), which is non-toxic and eco-friendly. This specific agent was investigated to realize certain morphology controlling effects by changing the relative growth rates among various crystal planes. Experimental samples were characterized by transmission electron microscope, UV-Vis spectrophotometer and X-ray diffraction(XRD) for size and morphological information. The effects of the specific additives of PVP((C_6 H_9 NO)_n), CTAB(C_(16)H_(33)(CH_3)_3 NBr), and KBr were examined for their morphological control individually and synergistically in this system. Hexagonal gold nanoparticles were successfully obtained via the PVP/CTAB and PVP/KBr systems. Particular amounts of PVP/KBr produced various polyhedron structures, such as cubes, and others with triangular and rhombic straight-side cross sections.

Gold Nanoparticles of Multiple Shapes Synthesized in L-Tryptophan Aqueous Solution

In this paper, we describe a simple and efficient synthesis of gold nanoparticles(GNPs) of various shapes(spherical, rod-like, hexagonal, truncated triangular, and triangular) using Au(Ⅲ) reduction in aqueous solutions by L-tryptophan. We evaluated the influences of reaction temperature, foreign metal ions Ag(Ⅰ), and surfactants of nonionic(polyethylene glycol, PEG), anionic(sodium dodecyl sulfate, SDS), and cationic(cetyltrimethyl ammonium bromide, CTAB) on GNPs synthesis. We characterized the resultant GNPs using UV–visible adsorption spectroscopy, transmission electron microscopy/high-resolution transmission electron microscopy, scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, selected-area electron diffraction, and Fourier-transform infrared spectroscopy. We fabricated the variously sized GNPs by controlling the rate of the reduction of gold ions in aqueous solution by varying the reaction temperature: the higher the temperature, the smaller the gold nanospheres. We found the existence of Ag(Ⅰ) to reinforce the reduction of Au(Ⅲ) and to correspond with the appearance of some amorphous bimetallic Au/Ag nanoparticles. Additionally, we found the presence of surfactants to greatly influence the shape of the formed GNPs, especially the presence of CTAB, which results in the anisotropic growth of gold nanocrystals into hexagonal, truncated triangular, and triangular nanoplates. In addition, with the increase in CTAB concentration, we found the amount of gold nanoplates to first increase and then decrease. Finally, we performed preliminary explorations of the reduction process and morphological evolution to propose possible corresponding reduction and morphological evolution pathways.

Review of Denitrogenation of Algae Biocrude Produced by Hydrothermal Liquefaction

Recently, algae biocrude has drawn considerable attention as algae are considered to be one of the major fuel feedstocks of the future. Based on some impressive results achieved under appropriate conditions, the algae hydrothermal liquefaction(HTL) process has proven to be energy efficient. However, the HTL of biocrude is characterized by a high nitrogen content, which prevents its use in the field of transportation due to the associated nitrogen oxide emissions. Despite this toxicity, few research efforts have focused on the denitrogenation of algae biocrude. In this study, we review the effect of different strain-specific operation parameters and process upgrades with respect to the nitrogen content of biocrude. To achieve denitrogenation, chemical engineering may be required, although some improvements in biocrude properties have been achieved in a number of process upgrades. The use of similar successful pathways has the potential to improve the field of HTL biocrude denitrogenation. These methods, including the adsorptive and extractive denitrogenations of fossil fuels and the hydrodenitrogenation of the main nitrogen compounds, are helpful for developing a better understanding of the potential of denitrogenation for algae HTL biocrude. We also recommend the use of some available catalysts and corresponding operation parameters to promote continued research on denitrogenation.

Memory-augmented adaptive flocking control for multi-agent systems subject to uncertain external disturbances

This paper presents a novel flocking algorithm based on a memory-enhanced disturbance observer.To compensate for external disturbances,a filtered regressor for the double integrator model subject to external disturbances is designed to extract the disturbance information.With the filtered regressor method,the algorithm has the advantage of eliminating the need for acceleration information,thus reducing the sensor requirements in applications.Using the information obtained from the filtered regressor,a batch of stored data is used to design an adaptive disturbance observer,ensuring that the estimated values of the parameters of the disturbance system equation and the initial value converge to their actual values.The result is that the flocking algorithm can compensate for external disturbances and drive agents to achieve the desired collective behavior,including virtual leader tracking,inter-distance keeping,and collision avoidance.Numerical simulations verify the effectiveness of the algorithm proposed in the present study.

Distance-based formation tracking control of multi-agent systems with double-integrator dynamics

This paper addresses the distance-based formation tracking problem for a double-integrator modeled multi-agent system（MAS） in the presence of a moving leader in d-dimensional space. Under the assumption that the state of leader can be obtained over fixed graphs, a distributed distance-based control protocol is designed for each double-integrator follower agent. The protocol consists of three terms： a gradient function term, a velocity consensus term, and a leader tracking term.Different shape stabilizing functions proposed in the literature can be applied to the gradient function term. The proposed controller allows all agents to both achieve the desired shape and reach the same velocity with moving leader by controlling the distances and velocity. Finally, we analyze the local asymptotic stability of the equilibrium set with center manifold theory. We validate the effectiveness of our approach through two examples.

Correction to: Influence of Orifice Position Deviations on Distribution Performance of Gravity-Type Liquid Distributor Analyzed Through Mathematical Pathway

Correction to:Transactions of Tianjin University https://doi.org/10.1007/s12209-017-0078-6 In the original publication of the article,the authorization or reference of Fig.1 cited for describing the installation location of liquid distributor(pink)in column wasn’t nor-matively provided.Considering that many literatures can provide information like Fig.1,and the relationship between this picture and the contents can be negligible,Fig.1 will be deleted.Meanwhile,the words“as shown in Fig.1”in the first sentence of the introduction will also be deleted.

Optimization and simultaneous heat integration design of a coal-based ethylene glycol refining process by a parallel differential evolution algorithm

Coal to ethylene glycol still lacks algorithm optimization achievements for distillation sequencing due to high-dimension and strong nonconvexity characteristics,although there are numerous reports on horizontal comparisons and process revamping.This scenario triggers the navigation in this paper into the simultaneous optimization of parameters and heat integration of the coal to ethylene glycol distillation scheme and double-effect superstructure by the self-adapting dynamic differential evolution algorithm.To mitigate the influence of the strong nonconvexity,a redistribution strategy is adopted that forcibly expands the population search domain by exerting external influence and then shrinks it again to judge the global optimal solution.After two redistributive operations under the parallel framework,the total annual cost and CO_(2) emissions are 0.61%/1.85%better for the optimized process and 3.74%/14.84%better for the superstructure than the sequential optimization.However,the thermodynamic efficiency of sequential optimization is 11.63%and 10.34%higher than that of simultaneous optimization.This study discloses the unexpected great energy-saving potential for the coal to ethylene glycol process that has long been unknown,as well as the strong ability of the self-adapting dynamic differential evolution algorithm to optimize processes described by the high-dimensional mathematical model.

Development and performance evaluation of a high temperature resistant, internal rigid, and external flexible plugging agent for water-based drilling fluids

During the drilling process for oil and gas production,a larger number of drilling fluids invade the formation,causing severe formation damage and wellbore collapsing,which seriously hinders the efficient production of deep oil and gas.Although several plugging agents have been developed for efficient fracture sealing in recent years,the development of high-performance plugging agents with self-adaptive ability and high-temperature resistance remain a challenge.Herein,we report the synthesis of an internal rigid and external flexible plugging agent PANS by reversed-phase emulsion polymerization with nano-silica as the rigid core and poly(acrylamide-co-N-vinylpyrrolidone)as a flexible shell.The plugging agent has a median particle size of 10.5μm and can self-adapt to seal the microfractures and fractures in the formation,leading to an effective reduction in the filtration loss of bentonite water-based drilling fluid under both low temperature and low pressure(LTLP)and high temperature and high pressure(HTHP)conditions.In addition,compared with the neat nano-silica(500 nm),the sealing efficiency of PANS toward 100–120 mesh sand bed was increased by 71.4%after hot rolling at 180°C.