Geographical maldistribution of coal and water resource has led to huge water consumption, posing great challenges to the development of coal chemical industries in China. In this study, based on the ...obtained unit product data of water withdrawal, consumption, and wastewater effluent capacity, the wastewater quantitative information about water quality and relevant energy and reagents consumption for several coal chemical industries were analyzed. Then, the life cycle costs of different types of coal chemical wastewater were analyzed when achieving ICIWD (1st category integrated wastewater discharge) and ZLD (zero liquid discharge) standards. According to the results, the life cycle cost of ICIWD was average 0.94 US$/t water less than that of the wastewater meeting ZLD, because the life cycle boundaries focused on coal chemical industries. Given surface water treatment cost and environment damages value, ICIWD's total cost was 1.07 US$/t water higher than ZLD's. Besides, the consumed water of planning advanced coal chemical projects of 2018 took up 2.8% of total industrial water. Such proportion could even reach over 30% in north and northwest regions. It is suggested that ZLD water policies and water resources appraisal should be introduced to improve and strengthen the rational layout of coal chemical projects.
•Full analysis of water utilization and wastewater treatment is accomplished.•The life cycle costs of wastewater treatment systems are analyzed.•ICIWD's cost is average 1.07 US$/t higher than ZLD's given ecological factors.•Coal chemical projects plan 2018 conflicts with ZLD water policies.•Detailed pathways for achieving ZLD are suggested.
The regulations of the international maritime organization (IMO) on ship emission are becoming increasingly strict. Liquefied natural gas (LNG) is an ideal alternative fuel for vessels, considering ...its environmental and economic advantages. In this paper, comparative life cycle cost (LCC) analysis of low pressure fuel gas supply systems (FGSS) for LNG fueled ships was performed. Nine cases with different ship scale and FGSS configurations were compared and analyzed, in which the BOG was handled by gas combustion units (GCU), auxiliary engines or reliquefaction devices. The variation of utility cost of FGSS during different stages of voyage was particularly considered. Moreover, sensitivity analysis was performed to investigate the influences of sailing time index, LNG price and lifetime on LCC. The study revealed that the LCC of FGSS depends strongly on ship scale, LNG fuel price and ship operation. BOG reliquefaction onboard is a feasible solution when the sailing time index is low and LNG price is high, especially for large scale ship. On the contrary, when the sailing time index is high and LNG price is low, it is more economic to supply the BOG to auxiliary engines after compression.
•Nine cases with different ship scale and FGSS configurations were compared and analyzed based on LCC.•The BOG is handled by gas combustion units, auxiliary engines or reliquefaction devices.•The variation of utility cost of FGSS during different stages of voyage was particularly considered.•Influences of the ship scale, sailing time index, LNG price and lifetime on LCC were revealed.•Configuration strategies of efficient and economical low pressure FGSS for LNG fueled ships were proposed.
Off-grid solar/diesel systems have been widely utilized in remote and rural settings. Some of the main challenges for solar-diesel energies are determining the appropriate capacity and location in ...rural areas. Therefore, an efficient framework is needed for using off-grid solar/diesel systems. For the optimal sizing and location of off-grid photovoltaic (PV)-diesel schemes in rural areas, a new framework is proposed. In this framework, a geographic information system module is utilized to identify the best location based on technical, economic, reliability, social, and environmental criteria. Then, a hybrid optimization algorithm is utilized to determine the appropriate capacity for continuously meeting of the load via total life cycle cost minimization. A real case study in South Khorasan is considered, in order to illustrate the proposed framework and its effectiveness. The effectiveness of the applied approach is investigated by comparing the outcomes with the results obtained by other heuristic methods. Also, the impacts are investigated of fuel cost variations, initial PV and battery costs, and interest rate on the economics of the hybrid scheme. The simulation results demonstrate that the hybrid algorithm obtains results that are more accurate (by 14.1%) than other applied algorithms, and show that the use of solar energy with a diesel generator, compared to the diesel only system, significantly reduces greenhouse gas emissions (by 59.6%) and supply costs (by 22.2%). The results thus demonstrate the benefits of utilizing the proposed framework for the hybrid system. These results are expected to help enhance acceptance and utilization of cleaner production systems.
•An efficient strategy for optimal sizing and location is presented for a hybrid energy system.•A stand-alone photovoltaic-battery-diesel scheme for a rural area is examined.•Technical, economic, social, and environmental criteria are applied.•Impacts of variations in fuel and initial costs of the PV and battery of the hybrid system and interest rate are discussed.•A hybrid optimization algorithm based on geographic information systems provides the most accurate results.
Supplying electrical energy and drinking water in developing countries, especially in rural areas, is a challenging issue. The main reasons for this may include faulty grid lines, inability to ...fulfill the increasing demand, and inadequate coverage of the national transmission lines due to the distance between the remote villages. Photovoltaic water pumping systems (PVPS) can be the solution to the aforementioned problems. However, the high costs of PVPS and the unpredictability of solar radiation complicate the design of PVPS. This study was conducted considering the drinking water needs of a village located near Khartoum, Sudan. Multi-objective optimization (MOO) in the developed techno-economic model was carried out considering the reliability in terms of loss of load probability (LLP) and life cycle cost (LCC). The PVPS has been optimally sized considering the tilt angle, installed and unused PV power, water tank volume, and excess water. The particle swarm optimization (PSO) algorithm and the new python package, pvpumpingsystem, were combined to simulate the proposed PVPS model. Sensitivity analysis was conducted considering system performance, PV capacity, and tank volume. The optimal sizing results of the proposed model would be satisfactory and feasible, especially in developing countries with infrastructure and energy problems.
•Several local solutions are offered, considering user comfort preferences.•The optimum tilt angle of PV is determined using the PVlib library and PSO.•The sensitivity analyses are realized considering the tank volume and PV power simultaneously.•A greater PV power or tank capacity reduces the LLP's sensitivity to drop after a certain amount.•The interrupted days last only 8 h, and the deficit water is reduced to two m3/year.
The environmental performance of existing buildings can have a major role in achieving significant reductions in CO2 emissions: In the UK, around 75% 2050's housing stock has already been built. ...While building performance improvement efforts mostly focus on operational performance, buildings environmental impact is the result of processes that occur throughout their life cycle.
To achieve significant emission reductions in an economically viable way, this study uses Life Cycle Performance approaches to carry a cross-comparison between the refurbishment and replacement of two housing archetypes in London: mid-terrace-house and a bungalow. Specifically, the study integrates Life Cycle Carbon Footprint (LCCF) and Life Cycle Cost (LCC) protocols (EN 15978:2011 and BS ISO 15686–5), thermal simulations (EnergyPlus), building generative design framework (PLOOTO - Parametric Lay-Out Organisation generator) and mathematical optimisation algorithms (NSGA-II).
Results show that the optimal refurbishment archetypes generally performed better than replacements (Refurbishments LCCF ranges between 1,100 and 1,500 kgCO2e/m2 and LCC 440-680 £/m2, compared to that of the replacements scenarios, ranging 1,220-1,850 kgCO2e/m2 and 550-890 £/m2). The study also highlights benefit of incentivising re-use to achieve quicker emissions reductions. The study lastly discusses a range of embodied and operational performance issues.
•Carbon footprint and cost of refurbished and new houses in London were compared.•A breakdown of embodied and operational carbon and cost is presented (60 years).•Refurbishments perform better than replacements, in terms of life cycle performance.•Evidence shows that refurbishment is preferable on short time scale (20 years) too.
•A seismic retrofit scheme was proposed utilizing a friction-damper with disc-springs.•The proposed retrofit technique provides both the self-centering and energy dissipation capability.•The ...effectiveness of the retrofit was investigated through fragility and life cost evaluation.•The proposed retrofit method is effective in increasing seismic safety of existing RC structures.
In this study, concentric braced frame installed with a friction damper-disc-springs is proposed to enhance the seismic performance of RC framed structures. The structural configuration of the retrofit is outlined and the analytical model is explained. A performance-based seismic retrofit procedure combined with a genetic algorithm (GA) optimization is proposed to obtain the optimum design variables of the retrofit. 2D and 3D structural models are used as case studies. The effectiveness of the proposed retrofit is assessed through non-linear time-history response analysis (NLTHA), fragility analysis, and seismic life cycle cost (LCC) estimation. To ensure that concrete stresses after retrofit are within acceptable limits, finite element method is used. The results show that the proposed retrofit technique is effective in reducing the maximum inter-story drift ratio and in eliminating the residual drift of the model structures significantly. In addition, the probabilities of exceeding different limit states and the total seismic LCC are significantly reduced compared to the un-retrofitted cases.
Increasing envelope facet albedos considerably reduces solar heat gain, thus yielding building cooling energy savings. Few studies have explored the potential benefits of utilizing cool coatings on ...building envelopes (“cool-coated buildings”) based on life-cycle cost analysis. A holistic approach integrating the field testing, building energy simulation, and a 20-year life-cycle-based optimization was developed to explore cool-coated building performance and the maximum net savings of optimal building envelope retrofit and design. Experimental results showed that applying cool coatings to a west wall of an office building in Chongqing, China reduced its exterior surface temperature by up to 9.3 °C in summer. Simulation results showed that in Chongqing, making the roof and walls cool could reduce annual HVAC electricity use by up to 11.9% in old buildings (with poorly insulated envelopes) and up to 5.9% in new buildings. Retrofitting old buildings with a cool roof provided the net savings per modified area with present values up to 42.8 CNY/m2; retrofitting a new building with a cool roof or cool walls was not cost-effective. Optimizing both envelope insulation and envelope albedo can achieve 5.6 times the net savings of optimizing the insulation only, and 1.6 times that of optimizing albedo only.
•Potential benefits of cool-coated buildings are comprehensively investigated.•The method integrates field testing, energy simulation and life-cycle-based optimization.•Retrofit and design optimization of cool envelopes are performed based on trade-off options.•The optimal retrofit and design alternatives are presented.•11.9% and 5.9% annual HVAC energy savings for old and new buildings can be achieved.
Although flexible power sources are crucial for the realization next-generation flexible electronics, their application in such devices is hindered by their low theoretical energy density. ...Rechargeable lithium-oxygen (Li-O2) batteries can provide extremely high specific energies, while the conventional Li-O2 battery is bulky, inflexible and limited by the absence of effective components and an adjustable cell configuration. Here we show that a flexible Li-O2 battery can be fabricated using unique TiO2 nanowire arrays grown onto carbon textiles (NAs/CT) as a free-standing cathode and that superior electrochemical performances can be obtained even under stringent bending and twisting conditions. Furthermore, the TiO2 NAs/CT cathode features excellent recoverability, which significantly extends the cycle life of the Li-O2 battery and lowers its life cycle cost.
All costs within the life cycle of a building are known as its life cycle cost (LCC). In the design process of a building, the use of a lower initial cost index to select an option among others with ...similar performance may not lead to an economically optimal alternative during the life cycle. Hence, today, building designers and investors require a tool to estimate life cycle cost at the conceptual design stage to select an economically efficient option. Resilient solutions generally lead to a higher level of complexity and upfront costs and carry additional embodied environmental impact as well. This study aims to support the design of resilient buildings using a sound LCC methodology in the preliminary design stage. The research aims to integrate LCC capabilities directly into a Building Information Model (BIM) and increase the economical relevance and scientific robustness of LCC indicators towards better LCC cost optimization. The plugin, which is developed in the BIM tool is represented to use cost and resiliency factors to predict the whole process cost of building projects to assist designers in selecting a cost-efficient and resilient design option. The LCC of a building includes its initial cost, repair and maintenance cost, operating cost and salvage value at the end of the building's useful life, and all of which were considered in the estimation. The earthquake expected failure and human fatality cost are calculated to consider the resiliency index in building design. The application of the proposed framework to design a residential building is developed and validated on two design options. The application of the actual building project illustrates that by increasing the initial cost in the second alternative by 4.6%, its annual expected failure cost is decreased by 35.4%, and its total life-cycle cost is reduced by almost 10.4% within the first 45 years of operation. The reduction in the cost of the building and human fatality due to failure during an earthquake means the building's resilience would be improved. Using the developed plugin, designers could estimate LCC of the buildings at the early design stages and design more resilient buildings with better economic performance in its life cycle according to the proposed indices.
•The research integrates LCC capabilities directly into a BIM.•Resiliency factors are integrated in predicting the whole cost process.•The earthquake expected failure and human fatality cost are calculated for resiliency index.•By increasing the initial cost by 4.6%, its expected failure cost is decreased by 35.4%.•The proposed BIM-LCC approach results in reduction on cost and resilience improvement.
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