Scenario-Based Assessment of the Water-Energy-Food Nexus in Kuwait: Insights for Effective Resource Management

The interdependency among water, food, and energy (WEF) in the GCC countries is strongly and closely interlinked, and is intensifying as demand for resources increases with population growth and changing consumption patterns, and are expected to be further compounded by the impacts of climate change. Therefore, integrated management of the three sectors is crucial to reduce trade-offs and build synergies among them. This paper presents a comprehensive framework to assess the WEF nexus in Kuwait as a representative case for the GCC countries. The framework consists of three main steps: 1) evaluating the influence of socio-economic development and climate change on water, energy, and food resources;2) generating scenario-based projections;and 3) conducting an extensive quantitative nexus analysis. The WEF interlinkages in Kuwait are modelled quantitatively using the Q-Nexus model, and current critical interdependencies are evaluated. Then, various WEF-Nexus scenarios were conducted for the year 2035 to explore the effects of management interventions in one sector on the other two sectors. The main findings are that per capita municipal water consumption is a major influencer on the WEF-nexus due to the heavy reliance on thermal desalination in municipal water supply in Kuwait, which is attributed to its energy intensity, financial cost, GHGs emissions, and environmental impacts on the marine and air environments. To reduce WEF trade-offs, mitigate risks, and build synergies among the three sectors, it is important to shift the current policy focus on supply-side management approach to the demand-side management and efficiency approaches.

Towards a new avenue for rapid synthesis of electrocatalytic electrodes via laser-induced hydrothermal reaction for water splitting

Electrochemical production of hydrogen from water requires the development ofelectrocatalysts that are active,stable,and low-cost for water splitting.To address these challenges,researchers are increasingly exploring binder-free electrocatalytic integratedelectrodes (IEs) as an alternative to conventional powder-based electrode preparation methods,for the former is highly desirable to improve the catalytic activity and long-term stability for large-scale applications of electrocatalysts.Herein,we demonstrate a laser-inducedhydrothermal reaction (LIHR) technique to grow NiMoO4nanosheets on nickel foam,which is then calcined under H2/Ar mixed gases to prepare the IE IE-NiMo-LR.This electrode exhibits superior hydrogen evolution reaction performance,requiring overpotentials of 59,116 and143 mV to achieve current densities of 100,500 and 1000 mA·cm-2.During the 350 h chronopotentiometry test at current densities of 100 and 500 m A·cm-2,the overpotentialremains essentially unchanged.In addition,NiFe-layered double hydroxide grown on Ni foam is also fabricated with the same LIHR method and coupled with IE-NiMo-IR to achieve water splitting.This combination exhibits excellent durability under industrial current density.The energy consumption and production efficiency of the LIHR method are systematicallycompared with the conventional hydrothermal method.The LIHR method significantly improves the production rate by over 19 times,while consuming only 27.78%of the total energy required by conventional hydrothermal methods to achieve the same production.

Energy Consumption in Comminution of Mica with Cavitation Abrasive Water Jet

We have studied the efficiency of energy consumption in the comminution of mica powder with cavitation abrasive water jet technology. The energy required to create new surfaces in the comminution of mica powder with cavitation abrasive water jet was calculated,in order to estimate its efficiency of energy consumption. The particle size distribution and the specific surface area were measured by applying a JEM-200CX transmission electron microscope and an Autosorb-1 automatic surface area analyzer. The study results show that the efficiency of energy consumed in creating new surface areas is as high as 2.92%,or 4.94% with the aid of cavitation in the comminution of mica powder. This efficiency will decrease with an increase in the number of comminutions. After three comminutions,the efficien-cies will become 1.91% and 2.29% for comminution without cavitation and with cavitation,respectively. The abrasive water jet technology is an effective way for comminution of mica powder.

Optimal Scheduling Strategy for Energy Consumption Minimization of Hydro-Thermal Power Systems

A comparison analysis based method for computing the water consumption volume needed for electric energy production of optimal scheduling in hydro-thermal power systems is presented in this paper. The electric energy produced by hydroelectric plants and coal-fired plants is divided into 4 components: potential energy, kinetic energy, water-deep pressure energy and reservoir energy. A new and important concept, reservoir energy, is proposed, based on which is divided into a number of water bodies, for example 3 water bodies, and a reservoir is analyzed in a new way. This paper presents an optimal scheduling solution of elec-tric energy production of hydro-thermal power systems based on multi-factors analytic method, in which some important factors, such as load demand, reservoir in-flow, water consumption volume increment rate of hydroelectric plants or converted from coal-fired plants, and so on are given to model the objective function and the constraints. A study example with three simulation cases is carried out to illustrate flexibility, adapta-bility, applicability of the proposed method.

INVESTIGATION ON NEW TYPE OF DOUBLY BLENDING ABRASIVE WATER JET NOZZLE SYSTEM WITH HIGHER PERFORMANCE

Based on the two existing abrasive water-jet（AWJ） systems, the dia-jet （or pre-jet） and the post-jet, a new type of abrasive water-jet system is put forward, which combines the dia-jet＇s advantage, low operating system pressure, slender stream jet, and more concentrative abrasive in the blended stream, with merits of post-jet, the less sophisticate apparatus, successive supply of abrasives. The theoretic analysis is brought out in detail, and the nozzle system structure is concisely illustrated. Its relevant experiment results are demonstrated, proving that this new system is effective in various aspects, enlarging penetrating capability without raising system pressure, saving machining power supply, lessening energy loss, etc.

Analysis of Energy Consumption and Energy Conservation Measures for RFCCU at Shengli Petrochemical Company

This article introduces a string of energy conservation measures adopted over the past sev- eral years by the RFCC unit at Shengli Petrochemical Complex, including the optimization of feedstock properties, the adoption of high-efficiency atomizing nozzles, the revamp of CO boiler, the atomization by means of dry gas, the post-burning of flue gas as well as the application of frequency converting machines and pumps, resulting in ideal effects. The energy consumption of the RFCC unit was gradually decreased to 2984.25 MJ/t from the original level of 3716.99 MJ/t. After comparing basic energy con- sumption values with actual consumption values, the authors have set forward measures for further energy conservation, such as the recovery of low-temperature excess heat contained in oil/gas streams exiting from the fractionation tower top, addition of the fourth cyclone, delivery of hot oil slurry, and heat tracing with hot water.

Space heating and hot water demand analysis of dwellings connected to district heating scheme in UK

To achieve CO2 emissions reductions,the UK Building Regulations require developers of new residential buildings to calculate expected CO2 emissions arising from their energy consumption using a methodology such as Standard Assessment Procedure(SAP 2005) or,more recently SAP 2009.SAP encompasses all domestic heat consumption and a limited proportion of the electricity consumption.However,these calculations are rarely verified with real energy consumption and related CO2 emissions.This work presents the results of an analysis based on weekly heat demand data for more than 200 individual flats.The data were collected from a recently built residential development connected to a district heating network.A method for separating out the domestic hot water(DHW) use and space heating(SH) demand has been developed and these values are compared to the demand calculated using SAP 2005 and SAP 2009 methodologies.The analysis also shows the variation in DHW and SH consumption with size of flats and with tenure(privately owned or social housing).Evaluation of the space heating consumption also includes an estimate of the heating degree day(HDD) base temperature for each block of flats and compares this to the average base temperature calculated using the SAP 2005 methodology.

电化学水处理技术降低循环水硬度的实验研究

使用电化学法处理某焦化企业实际循环水的实验,探究了循环水的硬度和碱度去除率随处理时间的变化情况。分析了电流密度、水力停留时间、极板间距等实验操作参数以及商用阻垢剂对电解效果和能耗的影响。结果表明:硬度和碱度去除率随处理时间呈现先上升后平稳的趋势,且碱度去除率总是高于硬度去除率;电流密度为70 A/m^(2)、水力停留时间为6 min、极板间距为3 cm时电解效果最佳,硬度和碱度去除率可达27%以上,单位能耗低至13 kWh/kg;商用阻垢剂对电解效果具有阻碍作用。

老油田掺水工艺能耗分析及节能优化技术研究

为实现老油田地面掺水工艺的简化优化,在水力和热力计算的基础上,利用Pipesim软件实现了双管掺水工艺、首端环状掺水工艺和末端环状掺水工艺的建模,研究了不同掺水方式、掺水量及掺水温度对能耗和运行费用的影响,并以总运行费用最低为目标函数,对不同工况下的最佳运行参数进行了求解。研究结果表明:随着掺水温度的升高,掺水系统的耗电量有所下降,随着掺水比的增加,耗电量呈先增加后降低再增加的趋势;耗气量与掺水温度和掺水比均呈正相关,在掺水比1.4之后的耗气量增幅不大;双管掺水工艺的运行费用最高,末端环状掺水工艺的运行费用最低。通过最优化求解,获得了不同月份的最优掺水温度和掺水量,工艺简化后,运行费用降低了63.3%~68.8%,年运行费用降低了37.31万元,节能潜力巨大。研究结果可为同类老油田地面方案的实施提供实际参考。

GA与分层优化结合的掺水集油工艺参数优化

为降低进入特高含水阶段油田的掺水集油能耗,对掺水集油工艺参数进行优化。以掺水温度、掺水量、掺水压力为外层决策变量,加热炉和掺水泵运行方案为内层决策变量,以掺水集油工艺综合能耗最低为目标函数,建立掺水集油工艺参数优化模型。提出了一种遗传算法(Genetic Algorithm,GA)与分层优化结合的求解策略,将掺水温度作为染色体上的基因,先优化个体对应加热炉和掺水泵运行方案,得到个体对应的最小集油能耗,再通过种群的不断迭代进化,得到掺水集油工艺的最优参数。研究结果表明,与优化前相比,掺水温度降低8.3℃,掺水量减少131.6 m^(3)/d,掺水压力降低0.15 MPa,集输吨液综合能耗降低13.64%,优化效果良好。研究成果可为进入特高含水阶段油田降低掺水集油能耗提供借鉴。

杏北油田掺水系统全流程能量优化方法的研究与应用

油田含水率的上升和产液规模的不断增大,导致集输能耗逐年增加,如何保持开发效益,降低集输能耗,成为高含水开发阶段面临的一大难题。随着节能工作不断深入,潜力已得到很大程度的挖掘,常规技术节能空间小,能耗管控压力大。因此开展能量系统优化技术研究,该方法转变原来区域优化的方式,统筹采油井、计量间、转油站、脱水站四个环节,通过确定末端能耗需求,逐级推导前端各环节能供给的方式,指导集输系统精细化、低能耗生产运行。杏北油田自2017年应用能量优化运行技术,由点及面逐步扩大规模,已实现水驱转油站全覆盖,截至目前累计节气5 621×10^(4)m^(3),节电3 275×10^(4)kWh,为油田集输系统降本增效提供了指导依据。

高安屯再生水厂碳中和实践措施及效果

高安屯再生水厂位于北京市,水处理规模20万m^(3)/d,主体工艺为AAO+砂滤池,污泥处理中心规模1836 t/d(污泥含水率80%),主体工艺为热水解+厌氧消化+板框脱水。对比了不同碳核算标准,确定了高安屯再生水厂碳排放计算边界。高安屯再生水厂碳中和项目采用节能降耗、回收能源、利用清洁能源的方法,是泥水共治、餐厨协同、多能耦合、能源自给的大型碳中和示范工程。

集输系统双管掺水工艺节能优化运行研究

某区块采用双管掺水集油工艺流程,由于现场无法判断掺水参数与现场工况的关系,导致回液温度远高于原油凝点,造成能源浪费,超出了经济运行成本区间。针对上述问题,利用Pipesim软件实现工艺建模,分析了掺水参数与工艺热能损失、井口回压、回液温度、工艺压能损失及能耗损失占比等参数的定量关系,得到了符合现场调控的一般性规律,并通过建立目标函数和约束条件,利用萤火虫算法实现了掺水比和掺水温度的自动调控。结果表明:掺水温度建议不超过75℃,掺水比不宜过高,现场调控应采用先调节掺水温度再调节掺水比的操作方式;随着掺水比和掺水温度的增加,单井运行费用存在最低值;经算法优化后,不同单井掺水比和掺水温度均有不同程度下降,预计每天可节约运行费用0.5万元~1万元。

水能风机在循环水冷却系统的应用

介绍了循环水冷却系统中采用水能风机代替大功率电动机实现节能降耗的实施措施,分析了改造后带来的经济效益。

某大型纳滤工艺地表水厂优化运行及不可逆膜污染分析

依托江苏省某大型纳滤工艺地表水深度处理工程,围绕纳滤工艺在实际工程应用中的运行优化方法、膜污染情况及能耗和碳排放计算开展研究。该纳滤工程采用国产疏松型纳滤膜,产水高锰酸盐指数低于0.5 mg/L,总硬度(CaCO_(3)计)为77~107 mg/L。同时在采取一系列优化改进措施缓解膜污染问题后,纳滤系统电耗由0.239 kW·h/m^(3)降低至0.194 kW·h/m^(3)。结果表明选择适宜的阻垢剂类型和投加方式对膜污染的控制效果最为明显。研究发现纳滤膜在长期运行后均存在一定程度的不可逆污染。受到进水格网和膜元件位置的影响,其中无机污染以AlPO_(4)为主,主要发生在系统后段,并且可能与腐殖酸、富里酸存在相互作用,形成腐殖酸/富里酸-Al-P络合物。纳滤工艺在实际应用中需注意磷酸盐类阻垢剂的使用,同时应尽可能降低进水中残余铝的浓度。

风光消纳对梯级水库群运行水位的影响

水风光多能互补系统大多聚焦协同调度和提高新能源消纳研究,却忽略了风光能源消纳对水库水位的潜在影响。构建了考虑短期弃电特征的水风光互补系统中长期优化调度模型。首先,根据实际水风光出力模拟可能的弃电情景,拟合弃电损失函数,将其嵌套在中长期优化调度模型中;其次,模拟接入风光前后的水库调度运行过程;最后,分析风光消纳对梯级水库群年际、年内、月运行水位的影响。以黄河上游龙羊峡至刘家峡梯级水电站水风光互补系统为实例,研究表明:①接入风光后,梯级水库群的年均出力降低约0.5%,可促进风光消纳,保证系统总出力更大,可提高风光上网出力和系统总出力约2.2%;②风光消纳导致梯级水库群的年际和月水位波动增加,龙羊峡和刘家峡水库的年末消落水位和年均水位的波动范围分别增加2.5%、101.6%、0.8%和78.9%,龙羊峡的月水位波动变幅为0,刘家峡月水位下限降低14.7%;③在丰水年,接入风光后梯级水库水位显著下降;平水年,龙羊峡水库水位稍有降低,刘家峡水库的水位表现为汛前春季水位降低,汛后秋季水位升高;枯水年,风光消纳对水库水位几乎没有影响。这些研究结果对于更好地理解风光能源与水库运行之间的复杂关系以及优化水风光互补系统的运行策略具有重要的实际意义。

复水量对新型真空升华-复水解冻影响的实验研究

真空升华-复水解冻方法作为一种新型解冻方法,具有广阔前景。为深入了解新型真空升华-复水解冻方法的过程机理并优化其解冻工艺,采用新鲜猪里脊肉为对象,研究了复水量对解冻时间、解冻效果和系统比能耗等解冻性能的影响,并与传统真空蒸汽解冻方法进行对比研究。结果表明:在真空升华-复水解冻方法中复水量对复水解冻阶段中传热传质过程有重要影响,不同复水量下表现出的解冻性能差异较大。当进入单位容积真空箱的复水量为0.0135 mL/cm^(3)时,解冻效率和能耗及解冻后冻品品质效果最优。与传统真空蒸汽解冻方法相比,该方法可将解冻时间缩短55%,解冻损失率、总色差和系统比能耗可分别降低85%、77%、47%,且能保证解冻后猪肉更好的质构参数。

光热膜蒸馏水处理技术与应用研究进展

利用高效的水处理技术对海水、苦咸水脱盐淡化,以及将工业废水循环再利用,是解决水资源短缺及水污染问题的关键。目前应用较多的膜分离技术尚存在高能耗、低热效率、二次污染等问题。因此,新型的膜分离技术受到广泛关注。光热膜蒸馏技术具有热效率高、能耗低、零排放等特点,在海水淡化、水资源再利用等领域的应用已展现出良好前景。文章综述了光热膜蒸馏的基本过程和原理,光热膜材料的研发和光热膜蒸馏系统的设计研究进展,并对光热膜蒸馏的综合实际应用进行详细阐述。另外,还探讨了当前光热膜蒸馏技术的局限性及未来的挑战,以期为光热膜蒸馏系统的进一步发展及应用提供参考。

基于油藏化学驱能耗分配原理的理想流度控制型驱油剂研究Ⅰ:聚/表二元复合驱油体系的渗流阻力调控机理及应用

针对驱油剂的深部流度控制能力与近井地带注入性之间的矛盾,提出了理想流度控制型驱油剂应满足低黏度配制/输送、近井地带低吸附量长期稳定注入和低浓度产出液的技术要求,同时,在渗流过程中能够在储层深部不同位置建立多级渗流阻力峰值,并且前缘后驱替相渗流阻力应始终保持在较低水平。基于固/液界面吸附作用与分子间相互作用的协同效应,设计了在渗流过程中具备动态改变体系组成和微观溶液结构,从而改变其渗流阻力特征的疏水缔合聚合物/阴离子型表面活性剂二元体系。相较于HP-1(1500 mg/L),表观黏度相近、组成不同的二元体系HP-1(1500 mg/L)/SDSB(150 mg/L)和HP-1(1500 mg/L)/SDSB(200 mg/L),在段塞注入及其后续水驱过程中可以在多孔介质的中、后部构建数值更高、空间分布更优的动态渗流阻力,说明二元体系具备运移增黏特征和延迟突破特征,其前缘的流度控制能力更强,并且渗流阻力在储层的空间分布更合理,从而延长了段塞整体突破时间,有利于提高波及体积和驱油效率。在相对稠油、强非均质性和水驱含水率为80%的渤海某油田油藏条件下,采用基本相同剂量、相近成本的化学剂工业产品进行的驱油实验表明:二元体系后续水驱突破之前驱油剂段塞渗流阻力的空间动态分布特征是影响驱油效率的关键因素,二元体系(AP-P4(1400 mg/L)/ZX-27(300 mg/L),黏度为6.4 mPa·s)比疏水缔合聚合物AP-P4(1750 mg/L,黏度为62.9 mPa·s)多提高10%的原油采收率。

吉林油田典型集输接转站场提质提效研究

吉林油田地面工程系统中接转站存在高能耗问题。通过分析接转站的主要工作流程,计算出每个流程中用能环节的能耗占比,找出接转站产生高能耗的主要原因为加热炉的能耗过高。对加热炉出口温度进行调整,降低加热炉能耗,最终达到接转站能耗降至最低的效果。优化计算结果表明,当海118接转站冬季、夏季外输流程加热炉出口温度分别为43.8℃和37.2℃,冬季、夏季掺输流程加热炉出口温度分别为51℃和44℃时,接转站全年能耗最低,可减少使用碳307 t/a;当新民6接转站冬季、夏季外输流程加热炉出口温度分别为44.4℃和44.2℃,冬季、夏季掺输流程加热炉出口温度分别为54.5℃和49.5℃时,接转站全年能耗最低,可减少使用碳375 t/a;当让47接转站冬季、夏季外输流程加热炉出口温度分别为47.9℃和46.6℃,冬季、夏季掺输流程加热炉出口温度分别为57℃和56℃时,接转站全年能耗最低,可减少使用碳333 t/a。