Modeling and Optimization of Ethane Steam Cracking Process in An Industrial Tubular Reactor with Improved Reaction Scheme

Ethane steam cracking process in an industrial reactor was investigated.An one-demsional(1D)steady-state model was developed firstly by using an improved molecular reaction scheme and was then simulated in Aspen Plus.A comparison of model results with industrial data and previously reported results showed that the model can predict the process kinetics more accurately.In addition,the validated model was used to study the effects of different process variables,including coil outlet temperature(COT),steam-to-ethane ratio and residence time on ethane conversion,ethylene selectivity,products yields,and coking rate.Finally,steady-state optimization was conducted to the operation of industrial reactor.The COT and steam-to-ethane ratio were taken as decision variables to maximize the annual operational profit.

Data-driven intelligent modeling framework for the steam cracking process

Steam cracking is the dominant technology for producing light olefins,which are believed to be the foundation of the chemical industry.Predictive models of the cracking process can boost production efficiency and profit margin.Rapid advancements in machine learning research have recently enabled data-driven solutions to usher in a new era of process modeling.Meanwhile,its practical application to steam cracking is still hindered by the trade-off between prediction accuracy and computational speed.This research presents a framework for data-driven intelligent modeling of the steam cracking process.Industrial data preparation and feature engineering techniques provide computational-ready datasets for the framework,and feedstock similarities are exploited using k-means clustering.We propose LArge-Residuals-Deletion Multivariate Adaptive Regression Spline(LARD-MARS),a modeling approach that explicitly generates output formulas and eliminates potentially outlying instances.The framework is validated further by the presentation of clustering results,the explanation of variable importance,and the testing and comparison of model performance.

A Comparison Study between the Newly Developed Vertical Wells Steam Assisted Gravity Drainage and the Conventional SAGD Process

A numerical simulation study using the CMG-STAR Simulator was performed to compare the performance of the newly developed process (VWSAGD) utilizing vertical wells to enhance heavy oil recovery during steam assisted gravity drainage against the conventional steam assisted gravity drainage process which utilized horizontal wells (HWSAGD) under the same operating conditions. Two identical reservoir models were simulated for the two processes using 3-Dimensional, black heavy oil model (14° API). Each reservoir type consists of 49 × 49 × 20 grid blocks on a 5-acre model, which incorporated a typical heavy oil reservoir rock and fluid properties taken from the SPE case study, stspe001.dat (CMG 2015 release). A sensitivity analysis for both processes was performed for the grid density, soaking time, steam quality, bottom hole producing pressure, steam injection rate, reservoir thickness, reservoir area, and horizontal to vertical permeability anisotropy. More preferable reservoir conditions are those such as high horizontal to vertical permeability ratio, thick reservoir oil zones, as well as improved reservoir recovery for the VWSAGD process. Under unfavorable conditions such as thin reservoir oil zones, an improved reservoir recovery response was limited for the VWSAGD process and could be uneconomical in real field cases. Finally, the simulation results from this study include cumulative recoveries, Steam oil ratios, produced water-oil ratios, pressure and temperature distributions, and production rates. In addition, the results from this study have shown that the new VWSAGD process is more favorable than the conventional HWSAGD process.

The application of cellulosic-based materials on interfacial solar steam generation for highly efficient wastewater purification: A review

The world's population is growing,leading to an increasing demand for freshwater resources for drinking,sanitation,agriculture,and industry.Interfacial solar steam generation(ISSG)can solve many problems,such as mitigating the power crisis,minimizing water pollution,and improving the purification and desalination of seawater,rivers/lakes,and wastewater.Cellulosic materials are a viable and ecologically sound technique for capturing solar energy that is adaptable to a range of applications.This review paper aims to provide an overview of current advancements in the field of cellulose-based materials ISSG devices,specifically focusing on their applications in water purification and desalination.This paper examines the cellulose-based materials ISSG system and evaluates the effectiveness of various cellulosic materials,such as cellulose nanofibers derived from different sources,carbonized wood materials,and two-dimensional(2D)and 3D cellulosic-based materials from various sources,as well as advanced cellulosic materials,including bacterial cellulose and cellulose membranes obtained from agricultural and industrial cellulose wastes.The focus is on exploring the potential applications of these materials in ISSG devices for water desalination,purification,and treatment.The function,advantages,and disadvantages of cellulosic materials in the performance of ISSG devices were also deliberated throughout our discussion.In addition,the potential and suggested methods for enhancing the utilization of cellulose-based materials in the field of ISSG systems for water desalination,purification,and treatment were also emphasized.

Short wet-steam dyeing process of cotton fabrics with reactive dyes

The effects of Reactive Black 5 utilized to cotton fabrics by short wet-steam process on the dyeing properties were investigated. This study will provide a theoretical reference for short wet-steam process of cotton fabrics with bifunctional reactive dyes. The optimal amount of Selilao agent was 20 g/L, while the soaping and rubbing fastness of the dyed cotton fabrics were both reached to 4-5 rating.

Development of Tuckahoe (Poria cocos) Purple Potato Steamed Sponge Cake

This study was conducted to find the optimum process conditions for tuck- ahoe （Poria cocos） purple potato steamed sponge cake. The results showed that the best production process conditions of tuckahoe purple potato steamed sponge cake were as follows： ratio of wheat flour to tuckahoe power at 8：2, 10% purple potato starch, 25% white granulated sugar, and 1.5% yeast powder.

Effects of steaming process on rare saponins and efficacy of Panax ginseng, Panax notoginseng and Panax quinquefolium

The steamed Panax ginseng C. A. Mey., Panax notoginseng(Burk.) F. H. Chen, and Panax quinquefolium L. not only facilitate storage, but also increase the content of rare saponins and enhance their clinical application value. The traditional steaming process has high energy consumption, low efficiency, and lacks standardized operating procedures and unified standards. This paper retrieves the research literature on the steaming process parameters, rare saponin increments, and efficacy enhancement results of ginseng plants. By summarizing the effects of different steaming processes on rare saponins and pharmacodynamics in P. ginseng, P. notoginseng and P. quinquefolium, we explored new steaming methods and established a new quality evaluation system to provide guarantee for the effectiveness and safety of clinical medication and provide scientific basis for its rational use.

Targeted Catalytic Cracking to Olefins(TCO):Reaction Mechanism,Production Scheme,and Process Perspectives

Light olefins are important organic building blocks in the chemicals industry.The main low-carbon olefin production methods,such as catalytic cracking and steam cracking,have considerable room for improvement in their utilization of hydrocarbons.This review provides a thorough overview of recent studies on catalytic cracking,steam cracking,and the conversion of crude oil processes.To maximize the production of light olefins and reduce carbon emissions,the perceived benefits of various technologies are examined.Taking olefin generation and conversion as a link to expand upstream and downstream processes,a targeted catalytic cracking to olefins(TCO)process is proposed to meet current demands for the transformation of oil refining into chemical production.The main innovations of this process include a multiple feedstock supply,the development of medium-sized catalysts,and a diameter-transformed fluidizedbed reactor with different feeding schemes.In combination with other chemical processes,TCO is expected to play a critical role in enabling petroleum refining and chemical processes to achieve low carbon dioxide emissions.

STEAM教育理念在高考化学复习中的应用——以“无机工艺流程题”为例

根据最新的普通高中化学课程标准所提出的核心素养的教育内涵,高考的命题方式也将更加灵活,以真实情境为解决问题的载体,注重科学方法的迁移和应用。在高考化学模块复习中,基于STEAM教育理念的项目式教学方式跳出了传统的题海模式,教师通过创设真实情境,学生采用自主、合作和探究的学习方式,能够较好地让学生完成深度复习的理念,逐步培养出较强的证据推理能力和逻辑思维能力。以无机工艺流程题为例,分析了STEAM教育理念在高考化学中的应用。

The riddles of number nine in Chinese medicine processing method

The“nine cycles of steaming and shining”,“nine making”,“nine turns”and“nine cycles of calcining and quenching”methods that are recorded and used since ancient times are merely one aspect of the unique processing methods of traditional Chinese medicine.Inducing the Chinese medicine processing method“nine cycles of steaming and shining”from historical review and summarizing the practical wisdom based on the canonical aspects of traditional Chinese medicine and the experiences of ancient Chinese medicine sages to promote the new development of traditional Chinese medicine.After the long-term and multiple“nine”processing,the materials of traditional Chinese medicine exhibit significant beneficial changes in terms of taste,efficacy,and chemical composition contents,thus emphasizing that Chinese medicine processing plays a significant role in their efficacy enhancement and toxicity reduction.Heshouwu(Polygoni Multiflori Radix),Dihuang(Rehmanniae Radix),Huangjing(Rhizoma Polygonati),Dahuang(Radix et Rhizoma Rhei),and Xixiancao(Herba Siegesbeckiae)are representatives of Chinese medicinal materials prepared using the“nine-system”processing method.This review discovers the aim and the molecular mechanism of“nine”processing of the abovementioned herbs from the viewpoints of modern pharmacochemistry and pharmacology to provide a theoretical support for the“nine”processing method of traditional Chinese medicine and to promote the international market of traditional Chinese medicine.

Simulation and Optimization of Cracked Gasoline Hydrofining Process

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Steam教育理念下戏剧活动对儿童学习过程与创造力的影响研究

研究以Steam教育理念下戏剧活动为干预项目,以61名大班儿童为研究对象。实验班儿童在教师带领下进行Steam教育理念下的戏剧活动,运用过程性量表和评价性量表对儿童进行学习过程和创造力测试,借助SPSS21.0统计软件进行前测和后测对比分析。经过为期1年的实验,得出以下结论:儿童的创造力得到显著提升;儿童正向学习兴趣增强,学习过程中的问题得到改观和控制;在学习方式上,儿童自主性提升。

STEAM教育理念对高职院校项目式教学流程的重构

STEAM教育理念引入国内已经多年,目的是培养高素养劳动者的创新能力,以提升国家竞争力。高职项目式教学旨在强调学生的实践能力以及分析问题与解决问题能力的培养,实现学生高质量更充分就业,二者出发点相同。我们依据高职办学定位,遵循高职学生学习特点,从当前项目式教学中普遍存在的问题出发,运用STEAM教育核心特征,提出对项目式教学流程各环节的重构策略,为职业院校教师教学创新提供新思路。

Process Control for Dissolving Pulp by SuperBatch Cooking

The process of producing dissolving pulp with SuperBatch cooking was introduced. The factors that affected the quality of the dissolving pulp and the corresponding operations were investigated.

STEAM教育理念下中职机械加工类专业学生职业能力模型构建

STEAM教育是一种以跨学科整合知识的方式培养学生综合素养的教育理念,符合中职教育培养目标.将该理念应用于中职教育,提炼出知识迁移与整合能力、实践探索与协调能力及学科融通与延展能力为模型元素,构建出学生职业能力模型.通过分析各元素,阐明该理念下中职机械加工类专业学生应具备的知识与技能.

九蒸九制对黄精中AGEs含量、多糖结构及体外活性的影响

为初步判断九蒸九制黄精多糖含量下降的主要原因及九蒸九制对黄精多糖体外活性的影响,本文测定了九蒸九制黄精中5-羟甲基糠醛(5-HMF)及晚期糖基化终产物(AGEs)的含量,考察了九蒸九制前后黄精纯化多糖的结构变化,并分析这些变化对黄精体外活性的影响。结果表明九蒸九制黄精发生了美拉德反应,5-HMF含量为(631.3±21.5)μg/g,羧甲基赖氨酸(CML)和羧乙基赖氨酸(CEL)含量分别为(342.4±11.3)μg/g和(63.7±9.8)μg/g。并对黄精多糖的结构及组成产生了不同程度的影响,葡萄糖(Glc)含量有所增长,甘露糖(Man)及半乳糖醛酸(GalUA)的含量有明显降低,Man从34.53%降至17.06%,GalUA从9.59%降至1.77%。研究表明,黄精在九蒸九制的加工过程中发生了美拉德反应,并产生了一定量的AGEs,同时,九蒸九制法在一定程度提高了黄精多糖的体外降糖活性。

STEAM理念在“化妆品科学与鉴赏--冷法制皂”实验教学中的应用

“化妆品科学与鉴赏”是浙江工业大学开设的一门以化学为基础,涉及生命科学、天然产物化学、皮肤科学及精细化工等专业的通识选修课。为更好地实现课程实践性特征,基于STEAM理念开发了该课程的“冷法制皂”实验项目。该项目的综合评估结果表明:基于实际项目小组合作的学习方式及跨学科实验方案的设计与实施,有助于提高学生的学习兴趣和科学探究能力,受到学生的喜爱。课程具有教学硬件和教学资源的普适性,有利于STEAM教育的普及。

甘薯生全粉添加量对馒头制作工艺及品质的影响

以甘薯-小麦混粉为原料,探究甘薯生全粉馒头制作配方工艺以及甘薯生全粉添加量对馒头基本成分和物化特性的影响。结果表明,甘薯馒头制作配方最优工艺为甘薯生全粉添加量30%、加水量55%、α-淀粉酶添加量0.02%、普鲁兰酶添加量0.75%,此时甘薯生全粉馒头感官评分最高为84.9。随着甘薯生全粉添加量增加,甘薯馒头淀粉和总膳食纤维含量逐渐增大,蛋白质含量逐渐减小,可溶性糖呈不规律变化趋势且变化幅度较小。随着甘薯生全粉添加量增加,甘薯馒头色度WH值、比容逐渐减小,硬度和胶黏性逐渐增加,黏性、回复性、黏聚性和弹性逐渐减小。随着甘薯生全粉添加量增加,冻藏后复蒸馒头比容逐渐减小,硬度逐渐增大;在相同添加量的情况下,随着冻藏时间的延长,比容呈逐渐减小的变化趋势,硬度呈逐渐增大的变化趋势。综上所述,适当添加甘薯生全粉可制作出品质较好的馒头。

九蒸九制槐角炮制过程主要成分、物性参数及颜色的相关性分析

目的研究九蒸九制槐角炮制过程中主要成分含量、物性参数、颜色的相关性。方法采用高效液相色谱法(HPLC)同时测定槐角苷、染料木苷、芦丁和5-羟甲基糠醛的含量,紫外分光光度法测定多糖的含量;通过测定物性参数和颜色指标(L*、a*、b*),结合系统聚类分析(HCA)、主成分分析(PCA)和偏最小二乘法(PLS)研究主要成分、物性参数及颜色的相关性;采用基于指标相关性的指标权重确定(CRITIC)法对槐角九蒸九制过程的影响进行综合评价。结果含量测定及色度测量方法准确可靠,精密度、稳定性、重复性试验均良好。HCA和PCA结果均表明,槐角饮片炮制过程中一蒸一制至四蒸四制聚为一类,五蒸五制至九蒸九制聚为一类。PLS相关性分析表明,多糖、芦丁的含量与物性参数、颜色均呈显著性相关;吸水膨胀度、相对密度与颜色均呈显著性相关。综合评价显示九蒸九制槐角炮制品最佳。结论九蒸九制槐角炮制过程中主要成分含量、物性参数、颜色的总体变化具有一定规律性,将其内在成分含量与颜色、物性参数结合为揭示槐角九蒸九制炮制机理提供了依据。

温度传感器探头横截面积对压力蒸汽灭菌温度与时间验证关键参数的影响

压力蒸汽灭菌器是利用饱和蒸气对物品进行灭菌的常用设备。灭菌过程验证是确定灭菌过程是否对特定物品具有灭菌效果的测试过程。压力蒸汽灭菌过程验证中的温度与时间验证需要在模拟负载内布置温度传感器测量负载内的温度。但温度传感器探头的横截面积可能影响负载的温度与时间验证结果。该研究通过采用不同横截面积的温度传感器探头进行负载的压力蒸汽灭菌温度与时间验证,探讨温度传感器探头横截面积对压力蒸汽灭菌温度与时间验证关键参数的影响,为实际工作中选择温度传感器类型提供参考。