Economy, environmental assessment and energy conservation for separation of isopropanol/diisopropyl ether/water multi-azeotropes via extractive distillation coupled pervaporation process

This wok proposed the extraction distillation coupled pervaporation(ED+PV) technology process using two different solvents to separate isopropanol(IPA) and diisopropyl ether(DIPE) from DIPE/IPA/H_(2)O ternary heterogeneous azeotropes in industrial wastewater from the synthesis of isopropanol in this study.Based on strict design specifications, simulation and sequential iteration methods are used for process design and optimization. Compared to the ethylene glycol(EG)-EG+H_(2)O process and the 1,3-propanediol(PDO)-IPA+H_(2)O process, the total annual cost(TAC) of the EG-IPA+H_(2)O process decreased by 20.76% and 7.86%(PDO). Compared to the EG-EG+H_(2)O process, the TAC of the PDO-IPA+H_(2)O process reduced 14%, but the global warming potential(GWP) and human toxicity of the PDO-IPA+H_(2)O process increased 11.3% and 4.07% respectively. Compared to the PDO-IPA+H_(2)O process, the EG-IPA+H_(2)O process saves 7.86%(TAC), 9.78%(GWP) and 9.85%(human toxicity). The ED+PV process with EG is superior to PDO in factors of TAC, energy consumption, human toxicity and environment. The EG-IPA+H_(2)O process changed the separation order of the products of the multi-azeotropic system, reduced the cost and energy conservation of the system, and enhanced the environmental protection evaluation of the process, is the best process through life cycle assessment for analyzing the economy, energy conservation, environmental assessment and human toxicity, designing cleaner products, controlling waste discharge, and promoting the chemical purification industry. This work provides a new process design and optimized separation ideas, will have a good guiding significance for the research and application separation of multi-azeotropic mixture with mixed solvents in organic wastewater from the cleaner chemical production, has been up to standard wastewater discharge process, and realized the development goal of carbon peak and carbon neutrality in the sustainable development of chemical clean industry.

Coupled heat-fluid-solid numerical study on heat extraction potential of hot dry rocks based on discrete fracture network model

Fracture networks within hot dry rock(HDR)geothermal reservoirs are complex,and heat extraction via water injection is thus a coupled process of heat-fluid-solid multifield.In this paper,utilizing the theory of normally distributed random functions,we develop a corresponding pre-processing subprogram to establish a discrete network model of complex fracture distribution in HDR reservoirs;then construct a heat-fluid-solid finite element model for heat extraction via water injection and compare the numerical solution with the analytical solution of the one-dimensional non-isothermal consolidation problem for verification.The numerical simulation results show that the main factors affecting the heat extraction efficiency of HDR reservoirs include fracture width,fracture density,fracture permeability,and matrix permeability.When a HDR reservoir is injected with water for heat extraction,there is a certain threshold value of these influential parameters,beyond which the outlet temperature drops significantly,resulting in an obvious thermal breakthrough.When injecting water for heat extraction,the values of these parameters should be controlled and kept at a reasonable level,otherwise,the HDR reservoir may enter a thermal breakthrough stage in advance,which is not conducive for long-period heat extraction.Influenced by the random distribution of complex fractures,the leading edge of the cold front may present an irregular distribution.During the process of heat extraction,the stress gradually changes from a compressional state to a tensile state,which induces further damage to the HDR reservoir.

Mixed Electric and Magnetic Coupling Design Based on Coupling Matrix Extraction

This paper proposes a design and fine-tuning method for mixed electric and magnetic coupling filters.It derives the quantitative relationship between the coupling coefficients(electric and magnetic coupling,i.e.,EC and MC)and the linear coefficients of frequencydependent coupling for the first time.Different from the parameter extraction technique using the bandpass circuit model,the proposed approach explicitly relatesEC and MC to the coupling matrix model.This paper provides a general theoretic framework for computer-aided design and tuning of a mixed electric and magnetic coupling filter based on coupling matrices.An example of a 7th-order coaxial combline filter design is given in the paper,verifying the practical value of the approach.

Comparative Study on the Acid-Base Indicator Properties of Natural Dye, Turmeric Rhizome (Curcuma longa) and Synthetic Dyes

Acid-Base Indicator, Turmeric Rhizome (Curcuma longa) was extracted from the root of a turmeric plant. The turmeric was peeled, washed and dried in an oven at 60°C. It was ground into powder and soaked in hot and cold ethanol for the extraction. The extract was filtered and part of it was concentrated to yield a reasonable quantity of turmeric indicator. On standardization of acid with a base, 0.05 M base respectively of Sodium hydroxide (NaOH), sodium carbonate (Na2CO3) and Disodium borate (B4Na2O7) were used. Hot and cold extracts of turmeric were used as indicators and were compared with methyl orange and phenolphthalein. On the preliminary test carried out, hot and cold turmeric indicator showed yellow colour in acid medium and orange colour in the base. Methyl orange showed red colour in acid but yellow in the base, phenolphthalein was colourless in acid but pink in the base. During titration there were colour changes at the end points in the entire test carried out. The average volumes at ends points were calculated, the molar concentrations and mass concentrations of the acids used were also determined. The results showed that there was no difference between the natural indicators used and the existing synthetic indicators which are toxic to our environment.

Numerical Study on the Energy Extraction Performance of Coupled Tandem Flapping Hydrofoils

Tidal current energy is a promising renewable energy source for future electricity supply.The flapping hydrofoil is regarded as a useful tool to extract the tidal current energy in shallow water.A concept of coupled tandem flapping hydrofoils under semi-activated mode was proposed in the present study.A two-dimensional numerical model,based on the computational fluid dynamics software ANSYS-Fluent,was established to investigate the power extraction performance of the coupled tandem flapping hydrofoils.The effects of the reduced frequency,pitching amplitude,moment of inertia,damping coefficient,and longitudinal distance between hydrofoils were studied.The vortices,pressure distribution,and kinetic characteristics of hydrofoils under various conditions were analyzed to reveal the interaction between the shedding vortex and hydrofoils.The energy extraction mechanism and hydrodynamic performance were analyzed.The positive interactions for energy harvesting were identified for improvements of the further performance.The peak values of efficiency and power coefficient were achieved at 0.69 and 2.13,respectively.

Soil and Vegetation Spectral Coupling Difference (SVSCD) for Minerals Extraction from Hyperion Data in Vegetation Covered Area

Remote sensing data have been widely applied to extract minerals in geologic exploration, however, in areas covered by vegetation, extracted mineral information has mostly been small targets bearing little information. In this paper, we present a new method for mineral extraction aimed at solving the difficulty of mineral identification in vegetation covered areas. The method selected six sets of spectral difference coupling between soil and plant(SVSCD). These sets have the same vegetation spectra reflectance and a maximum different reflectance of soil and mineral spectra from Hyperion image based on spectral reflectance characteristics of measured spectra. The central wavelengths of the six, selected band pairs were 2314 and 701 nm, 1699 and 721 nm, 1336 and 742 nm, 2203 and 681 nm, 2183 and 671 nm, and 2072 and 548 nm. Each data set's reflectance was used to calculate the difference value. After band difference calculation, vegetation information was suppressed and mineral abnormal information was enhanced compared to the scatter plot of original band. Six spectral difference couplings, after vegetation inhibition, were arranged in a new data set that requires two components that have the largest eigenvalue difference from principal component analysis(PCA). The spatial geometric structure features of PC1 and PC2 was used to identify altered minerals by spectral feature fitting(SFF). The collecting rocks from the 10 points that were selected in the concentration of mineral extraction were analyzed under a high-resolution microscope to identify metal minerals and nonmetallic minerals. Results indicated that the extracted minerals were well matched with the verified samples, especially with the sample 2, 4, 5 and 8. It demonstrated that the method can effectively detect altered minerals in vegetation covered area in Hyperion image.

Feature-Based Fusion of Dual Band Infrared Image Using Multiple Pulse Coupled Neural Network

To improve the quality of the infrared image and enhance the information of the object,a dual band infrared image fusion method based on feature extraction and a novel multiple pulse coupled neural network(multi-PCNN)is proposed.In this multi-PCNN fusion scheme,the auxiliary PCNN which captures the characteristics of feature image extracting from the infrared image is used to modulate the main PCNN,whose input could be original infrared image.Meanwhile,to make the PCNN fusion effect consistent with the human vision system,Laplacian energy is adopted to obtain the value of adaptive linking strength in PCNN.After that,the original dual band infrared images are reconstructed by using a weight fusion rule with the fire mapping images generated by the main PCNNs to obtain the fused image.Compared to wavelet transforms,Laplacian pyramids and traditional multi-PCNNs,fusion images based on our method have more information,rich details and clear edges.

Efficient Solutions of Coupled Matrix and Matrix Differential Equations

In Kronecker products works, matrices are sometimes regarded as vectors and vectors are sometimes made in to matrices. To be precise about these reshaping we use the vector and diagonal extraction operators. In the present paper, the results are organized in the following ways. First, we formulate the coupled matrix linear least-squares problem and present the efficient solutions of this problem that arises in multistatic antenna array processing problem. Second, we extend the use of connection between the Hadamard (Kronecker) product and diagonal extraction (vector) operator in order to construct a computationally-efficient solution of non-homogeneous coupled matrix differential equations that useful in various applications. Finally, the analysis indicates that the Kronecker (Khatri-Rao) structure method can achieve good efficient while the Hadamard structure method achieve more efficient when the unknown matrices are diagonal.

Speciation of Volatile Selenium Species in Plants Using Gas Chromatography/Inductively Coupled Plasma Mass Spectrometry

Gas chromatography/inductively coupled plasma mass spectrometry (GC/ICP-MS) coupled with solid phase micro-extraction can provide a simple, extremely selective and sensitive technique for the analysis of volatile sulfur and selenium compounds in the headspace of growing plants. In this work, the technique was used to evaluate the volatilization of selenium in wild-type and genetically-modified Brassica juncea seedlings. By converting toxic inorganic selenium in the soil to less toxic, volatile organic selenium, B. juncea might be useful in bioremediation of selenium contaminated soil.

萃取/反萃取-电感耦合等离子体发射光谱(ICP-OES)法测定肥料样品中铅、镉、汞、铊、锑、砷

为保障农产品的质量与安全,肥料中的有毒有害物质,尤其是重金属含量被严格限制。为提高肥料中有毒有害物质检测的效率,利用铅、镉、汞、铊、锑、砷在盐酸介质中形成稳定的碘络合物的特性,采用甲基异丁基酮(MIBK)萃取、硝酸溶液反萃取的方法实现肥料样品中基质与待测元素的分离,通过电感耦合等离子体发射光谱法测定肥料样品中的6种重金属元素。通过考察萃取条件及残余基体对分析结果的影响,结果证实,在6 mol/L的盐酸萃取体系中加入5 mL碘化铵(30%)溶液,采用10 mL的MIBK萃取2~3次即可使样品中的铅、镉、汞、铊、锑、砷等被完全萃取,通过萃取/反萃取的方法实现了样品的分离富集,方法的检出限(3σ)为铅0.042 mg/kg、镉0.005 mg/kg、汞0.059 mg/kg、铊0.026 mg/kg、锑0.024 mg/kg、砷0.052 mg/kg,加标回收率在90.1%~108%,可以满足不同肥料样品的质量控制要求。按照实验方法测定6种不同肥料样品中的重金属含量,并采用标准方法进行方法比对,结果表明两种方法的测定结果基本一致。

基于破乳诱导萃取和ICP-MS/MS分析渣油中的微量金属元素

基于破乳诱导萃取提出利用电感耦合等离子体串联质谱(ICP-MS/MS)测定渣油中多种金属元素的新策略。渣油样品经二甲苯稀释降低黏度后采用质量分数6%的Triton X-114乳化,超声水浴破乳25 min,利用体积分数40%的盐酸萃取渣油中金属元素至水相,采用ICP-MS/MS测定其中10种金属元素Na、Mg、Al、Ca、V、Cr、Fe、Ni、Cu、Zn的含量。详细评估了破乳诱导萃取条件对渣油中金属元素萃取效率的影响,在串联质谱(MS/MS)模式下,利用氦碰撞气或不同反应气消除了金属元素的质谱干扰,采用标准参考物质NIST SRM 1634c(燃油中的微量元素)验证了方法的准确性,以微波消解技术处理渣油样品并采用扇形磁场电感耦合等离子体质谱(SF-ICP-MS)进行对比分析验证了方法的可靠性。结果显示,金属元素在各自的含量范围内呈现良好的线性关系(线性相关系数≥0.9997),检出限(LOD)为2.05~31.4 ng/L,NIST SRM 1634c的测定结果与标准参考物质提供的认证值及文献报道的参考值基本一致,置信度水平达到95%,ICP-MS/MS方法与SF-ICP-MS的对比分析结果无显著性差异。所建立的ICP-MS/MS方法操作简单,分析速率快,准确可靠性好,已用于渣油中多种金属元素的质量评价。

广西石漠化与城镇化耦合协调的时空异质性

石漠化是西南喀斯特地区的典型生态环境问题。如何正确认识石漠化与城镇化的耦合关系,是制订石漠化治理政策和指导城镇可持续发展的必要条件。基于Google Earth Engine调用Landsat影像构建石漠化程度评价模型并计算综合石漠化指数。利用熵值法与线性加权法计算综合城镇化指数,借助耦合协调度模型探究2000—2020年石漠化与城镇化耦合协调度演化的时空特征。结果表明:1)石漠化程度呈下降趋势,但区域差异明显,重度和极重度石漠化集中分布在中部和西南部地区。城镇化水平快速发展,东部地区的城镇化水平高于西部地区;2)石漠化与城镇化的耦合协调度不断提高,从2000年的“不协调发展,城镇化滞后”逐步过渡到2020年的“转型发展,石漠化滞后”;3)城镇化水平提升越快的县(区),其石漠化治理效果越明显,相应的耦合协调度越高。研究结果可为当地政府制订可持续发展的城镇化方案、更好地处理城镇化与生态环境保护的关系提供参考。

盐酸超声提取-高分辨电感耦合等离子体质谱法测定食用植物油中11种微量金属元素

提出了盐酸超声提取-高分辨电感耦合等离子体质谱法(HR-ICP-MS)快速测定食用植物油中铝、钡、镉、铜、铁、镁、锰、镍、铅、钒、锌等微量金属元素的方法。取2.0 g食用植物油样品,置于50 mL塑料离心管中,加入800μL ICP溶剂油,于旋涡混匀器上充分混匀,加入10 mL 2.0 mol·L^(-1)盐酸溶液,于70℃超声30 min,冷却。以转速10000 r·min^(-1)离心5 min,在水相与有机相分离后,收集水相,采用HR-ICP-MS测定其中11种元素含量,待测同位素^(51)V、^(56)Fe、^(27)Al、^(63)Cu、^(24)Mg、^(55)Mn、^(60)Ni、^(66)Zn选择中分辨率模式,而^(137)Ba、^(111)Cd和^(208)Pb选择低分辨率模式。结果表明:11种元素的质量浓度在100μg·L^(-1)以内与对应的信号强度呈线性关系,检出限(3s)为0.012~0.173μg·L^(-1);按照标准加入法对食用植物油进行回收试验,回收率为86.9%~107%,测定值的相对标准偏差(n=7)为1.1%~4.9%;方法用于分析3种植物油样品,本方法测定值与标准方法的测定值基本一致。

基于仿生水母的水下机器人结构设计与试验研究

针对水下探测机器人隐蔽性好的需求,设计了一种仿生水母机器人。首先,进行了水母机器人的仿生设计,通过生物特征提取及功能耦合确定了机器人的功能设计要求,基于机构原理图,进行了三维模型设计;其次,对多杆推进机构进行了运动学求解,获得了两个闭环求解方程,并以此为依据,给定了一个尺寸设计案例;然后,采用ANSYS软件对设计案例进行了刚柔耦合分析和模态分析,对关键结构的强度和刚度进行了验证,获得了结构的低阶模态频率及振型,并为声学驱鱼装置的选择提供了依据;最后,根据设计模型制作了实物样机并进行了水下调试,获得了试验参数并验证了机器人的功能。研究结果表明:多杆推进机构在运动过程中最大等效应力约为4.92 MPa,最大变形量约为3.89 mm,该结构满足强度和刚度要求;通过实物样机制作与试验,实现了仿生水母机器人的水下游动和转向等功能,初步验证了方案的可行性;机器人在主驱动电机初设转速的驱动下,直线运动速度约为58.3 mm/s,转向速度约为22.5°/s。

基于高效解离-选择性絮凝耦合作用的煤气化渣提炭实验研究

煤气化渣是由煤气化工艺产生的一种富含铝硅酸盐、灰组分及残炭的大宗工业固体废弃物,其规模化生产对生态环境造成了严重的影响。因此,将煤气化渣进行炭-灰分离是实现其减量化、无害化和资源化利用的关键。以煤气化渣为研究对象,采用高效解离-选择性絮凝耦合作用的工艺,为实现煤气化渣更为合理、高效的资源化利用,减少煤气化渣带来的土壤、空气、水体资源等污染问题,对煤气化渣进行提炭实验研究。首先分析了煤气化渣的理化性质,其次采用单因素变量法探究了磨矿时间、pH、絮凝剂种类、絮凝剂用量、高速剪切转速对煤气化渣提炭实验的影响,以实现残余炭产品的高度富集。结果表明:原煤气化渣灰分质量分数为67.19%,普通湿筛筛上物料灰分质量分数为54.3%,当煤气化渣磨矿时间为5 s, pH为7,絮凝剂聚氧化乙烯用量为0.4 kg/t,在转速为4 000 r/min高速剪切15 min的条件下提炭效果最佳,最终可获得产率为26.6%、湿筛筛上灰分质量分数为43.3%的残炭产品。对比普通湿筛法,基于高效解离-选择性絮凝实验方法在普通湿筛的基础上灰分质量分数降低了11%,降灰效果明显。

永磁同步电机耦合故障特征提取方法仿真

由于永磁同步电机故障的并发性,且耦合故障信号具有较强的关联性,导致永磁同步电机耦合故障特征提取较为困难。为此提出了采用负序电流法和磁链观测法对匝间短路-不均匀退磁耦合故障特征的提取方法。首先推导了正常电机的数学模型,在此基础上搭建仿真模型并验证了其可靠性;其次搭建了匝间短路和不均匀退磁单一故障的仿真模型,验证了负序电流法和磁链观测法在单一故障特征提取时的有效性;最后并对耦合故障的特征进行了对应的提取。结果表明,单一故障特征在耦合故障提取时也有较高的准确性。

基于多级闪蒸与多塔蒸馏耦合的贫氦天然气低温提氦工艺

聚焦从低品位含氦天然气中提纯氦气这一工程问题,在分析已有深冷工艺发展现状与改进方向的基础上,针对原料天然气中氦气浓度低与提氦能耗高的问题,提出一种基于多级闪蒸与多塔蒸馏耦合的贫氦天然气低温提氦工艺,并借助ASPEN HYSYS软件模拟设计了新工艺流程。结果表明:采用设计工艺可从氦摩尔分数为0.05%的贫氦天然气中分离得到纯度(摩尔分数,下同)为99%的氦气,同时得到纯度为99.96%的甲烷和99%的氮气、液化天然气及燃料气,增强了提氦装置的产品方案灵活性;通过工艺内部流股节流膨胀制冷为分离系统提供冷量及工艺内部冷热物流间合理匹配换热,实现了系统的节能降耗;该多级闪蒸+多塔蒸馏耦合工艺的单位压缩功耗为0.058 kW·h kmol,远低于改进型ExxonMobil公司的提氦工艺(1.29 kW·h kmol);综合分析工艺产品纯度及能耗,说明设计的提氦工艺具有一定的应用潜力。

偏硼酸锂熔融-酒石酸络合-超声提取-电感耦合等离子体原子发射光谱法测定岩矿型锆矿石中10种元素的含量

为实现岩矿型锆矿石样品中锆、铪、钾、钙、钠、镁、铝、铁、钛、锰等10种元素含量的准确测定,优化了熔融、提取等试验条件,提出了题示方法。取干燥后的样品0.1 g于铂坩埚中,加入0.5 g偏硼酸锂,搅匀后盖上坩埚盖,于1 000℃熔融30 min。冷却后将铂坩埚置于装有25 mL含20 g·L^(-1)酒石酸的20%(体积分数)盐酸溶液中,超声振荡至熔块完全溶解,用水定容至100 mL,用电感耦合等离子体原子发射光谱仪测定。结果显示:上述10种元素的质量浓度分别在一定范围内与对应的谱线强度呈线性关系,检出限(3s)为1.90~40.8μg·g-1;方法用于由锆含量较低的基性岩岩石标准物质和锆精矿标准物质复配成的以锆石、斜锆石为主的岩矿型锆矿石样品的分析,测定值的相对误差为-1.9%~4.0%,测定值的相对标准偏差(n=12)为0.46%~4.5%,准确度和精密度试验结果的绝对值均优于DZ/T 0130.3-2006规定的控制指标,且方法可拓展应用于砂矿型锆矿石的准确测定。

不同温度-围压-气体压力下煤体蠕变-渗流演化规律

为实现深部煤层气的高效开采,通过研究不同温度、围压和气体压力下煤体蠕变变形和渗透率演化规律,得到多因素作用下煤体蠕变-渗流耦合关系;采用自行设计的岩石三轴蠕变-渗流装置,对焦煤进行多因素变量下的压缩蠕变-渗流试验。结果表明:温度与煤样的蠕变呈正相关性,随温度的增加焦煤煤样径向和轴向应变变化速率增大且高温(110℃)下这种变化会一直持续直至煤样破裂;围压强度3 MPa与4 MPa的焦煤煤样在温度30、70、110℃下其气体渗透率降低率最大和最小差值分别为7.8%、5.2%、6.5%和4.2%、2.1%、1.9%;焦煤煤样的渗透率最大降低率随着温度水平升高而增大,试验温度110、70、30℃下的焦煤煤样的气体渗透率最大降低率均值依次为91%、84.6%、73.25%。

恒温振荡提取-电感耦合等离子体质谱法测定土壤中6种重金属元素可提取态的含量

提出了恒温振荡提取-电感耦合等离子体质谱法(ICP-MS)测定土壤中铬、镍、铜、锌、镉、铅等重金属元素可提取态含量的方法。将土壤样品风干,过2 mm尼龙筛。取过筛后的土壤样品10.0 g置于具塞离心管中,加入100 mL 0.01 mol·L^(-1)氯化钙溶液,置于立式智能精密摇床中,设置提取温度为(20±2)℃,水平振荡速率为(180±20)r·min^(-1),提取时间为120 min。提取后离心、过滤,收集续滤液至10 mL比色管中,在积分时间0.5 s、碰撞池模式条件下,以内标^(72)Ge校正^(53)Cr、^(60)Ni、^(63)Cu、^(66)Zn,^(103)Rh校正^(114)Cd,^(185)Re校正^(208)Pb,采用ICP-MS测定其中6种重金属元素可提取态的含量。结果表明,铬、镍、铜、锌、镉、铅元素的质量浓度均在一定范围内与所对应的信号强度与内标信号强度比呈线性关系,检出限(2.764s)分别为0.076,0.075,0.074,0.15,0.010,0.050 mg·kg^(-1)。方法用于国家标准物质的分析,对于认定值在检出限以上的元素,其测定值与认定值基本一致,高于检出限的测定值的相对标准偏差(n=6)均不大于5.0%。