Energy-water nexus in seawater desalination project: A typical water production system in China

Exploring energy-saving potentials in seawater desalination engineering from the energy-water nexus perspective

Given the context of the global energy shortage and the deterioration of the ecological environment, this paper uses industrial linkage as a starting point to deeply explore the energy consumption of different sectors and its transfer characteristics. First, a dual evaluation of energy consumption in various sectors is conducted from the perspectives of production and demand to realize an integrated analysis from the energy consumption perspective. Second, based on industrial linkage, the economic input-output life cycle assessment (EIO-LCA) model is used to quantify the net transfer of energy consumption and identify the transfer of energy consumption pressure embodied in economic activities by various sectors. Finally, the energy consumption of various sectors is decomposed, and the transfer flow of energy consumption is measured to accurately quantify the degree of linkage in the energy consumption of sectors. The results show that the current direct energy consumption intensity of various sectors in China is continuously decreasing, but this decrease is insufficient to reverse the upward trend in energy consumption demand. From the perspective of production and demand, non-energy industrial sector is a key sector for reducing energy consumption, and the intersectoral linkage between the subsectors caused by product trade flows has a greater impact on the level of direct and embodied energy consumption. Direct and embodied energy consumption in the same sector can be ranked quite differently, and their levels may not be equal. Energy sector is the main net outflow sector of energy consumption, and the level of its direct energy consumption is much higher than that of its embodied energy consumption. It is worth noting that the scale of embodied energy consumption in construction industry is much higher than the scale of direct energy consumption. Construction is the sector with the greatest net inflow of energy consumed and is the main driver of the energy consumption transfer of energy sector and non-energy industrial sector.

Identifying greenhouse gas emission reduction potentials through large-scale photovoltaic-driven seawater desalination

Australian building sector contributes 23% of the total greenhouse gas (GHG) emissions. This is particularly important for Western Australia (WA) as the houses here are made of energy- and carbon-intensive clay bricks. This research has utilized life cycle assessment (LCA) approach and cleaner production strategies (CPS) to design low-carbon houses in 18 locations in regional WA. An integrative LCA analysis of clay brick house has been conducted by incorporating energy efficiency rating tool (i.e., AccuRate) to capture the regional variation in thermal performance of houses in 18 locations in WA under five climatic zones. The data bank provided information on energy and materials for mining to material production, transportation of construction materials to the site of construction, and construction stages, while an energy rating tool has been utilized to generate location-specific information on energy consumption during use stage for developing a life cycle inventory for estimating life cycle GHG emissions and embodied energy consumption of a typical 4 × 2 × 2 detached house (i.e., 4 bed rooms, 2 bathrooms, and 2 cars/double garage). This approach has enabled us to determine the location-specific hotspot of a house in order to select suitable CPS for achieving reduced level of GHG emissions and embodied energy consumption. Except for two hottest locations, the average life cycle GHG emissions and embodied energy consumption of houses at 16 locations in regional WA have been estimated to be 469 t of CO2 equivalent (or CO2 e-) and 6.9 TJ, respectively. Home appliances and water heating have been found to be the top two hotspots. The CPS options, including rooftop solar photovoltaic panels (PV), solar water heaters (SWH) integrated with gas based water heaters, cast in situ concrete sandwich wall, fly ash as a partial replacement of cement in concrete, and polyethylene terephthalate (PET) foam made of post-consumed polyethylene terephthalate bottles, have been considered to reduce GHG emissions and embodied energy consumption of a typical house in18 locations in regional WA. Excluding above two hottest locations, these CPS provide an opportunity to reduce GHG emissions and embodied energy consumption per house by an average value of 320 t CO2 e- and 3.7 TJ, respectively. Considering the alarming growth rate of the housing industry in WA, the incorporation of optimum house orientation, rooftop solar PV, roof top SWH, cast in situ sandwich wall, partial replacement of cement in concrete with fly ash, and PET foam insulation core could reduce the overall GHG emissions and embodied energy consumption associated with the construction and use of clay brick wall house which in turn will assist in achieving Australia’s GHG emission reduction target by 2050. The findings provide useful data for architects, designers, developers, and policy makers to choose from these CPS options based on existing resource availability and cost constraints.

Embodied water consumption between typical desalination projects: Reverse osmosis versus low-temperature multi-effect distillation

Achieving environmentally friendly building envelope for Western Australia’s housing sector: A life cycle assessment approach

This paper proposes a new life cycle assessment (LCA) statistics method to calculate the energy consumption of Chinese buildings from the perspective of LCA under the sustainable supply chain system. We divide the life cycle of buildings into the materialization stage, the construction stage, and the operation stage. Based on the new LCA statistics method, we obtain the following findings. First, the growth of total building energy consumption has slowed down since 2014, and its share of the Chinese total energy consumption levels off, remaining at about 40%. In 2018, the stages of materialization, construction, and operation account for about 34.02%, 4.65%, and 61.33% in total building energy consumption, respectively. Second, the materialization and operation stages are the main sources of energy consumption in the whole supply chain. Energy consumption in the materialization stage has been declining year by year since 2014, due to the impact of energy-saving policy. Moreover, we find that energy consumption in the operation and construction stages has been increasing year by year. Finally, in the life cycle of Chinese buildings, energy consumption in the operation stage plays a dominant role. This paper puts forward some managerial suggestions to relevant departments and provides some measures to optimize energy consumption in the Chinese building industry.

With the rapid development of economy, energy demand is increasing in Hebei. Therefore, prediction of energy consumption and structure in Hebei province has importance of actual meaning significance. In this paper, total energy, coal, oil and natural gas consumption data are selected in Hebei province between 2001 and 2013. First, energy consumption and structure in Hebei province are analyzed. Second, GM(1,1)forecast model is established. Then, according to the established forecast model, energy consumption and structure between 2014 and 2021 in Hebei province is predicted. Last, related suggestions on energy optimization are put forward. The results are expected to provide important scientific basis for energy utilization and planning in Hebei province. Introduction Grey prediction is a method that can predict the systems containing uncertainties. To find the laws of system changes, original data is generating processed by identifying development trend of dissimilarity degree between system factors. Thus, data sequence with high regularity is generated. And then the corresponding differential equation model is established to predict future development trend of things. GM (1,1) prediction model with a variable and first-order differential is an important model of grey prediction. It is commonly used in energy and environment prediction because this model requires less modeling information, operates easily, forecasts precisely and is easy to test. In this paper, total energy, coal, oil and natural gas consumption data in Hebei province between 2001 and 2013 are selected as original sequence. GM (1, 1) model is constructed to predict energy consumption and structure in following 20 years in Hebei province. It hopes to provide reference and scientific basis for energy development strategy and the establishment of energy planning in Hebei. Analysis of energy consumption and structure in Hebei province The energy data in Hebei province between 2000 and 2012 are from China energy statistical yearbook. In this paper, all the energy consumption data have been converted into standard coal and the unit is ten thousand tons of standard coal. Table one shows the energy consumption and consumption structure in Hebei province. As shown in table 1, the total energy consumption in Hebei province seems to be increasing annually from 2000 to 2012 and its average annual growth rate is 7.95%. However, the speed of total energy consumption growth is different during the period and it has periodic growth characteristic. From the table, we can see that the growth speed is rapid from 2001 to 2007. Energy consumption structure in Hebei province is basically stable in recent years because of restriction on resources endowment and consumption structure of energy relying mainly on coal cannot be changed. Coal accounts for about 90 percent in energy consumption before 2011, but oil, gas and electricity such clean energy consumption occupies 10 percent of the total energy consumption. This shows that there is no variety in energy consumption structure in Hebei province and energy consumption has many defects. It depends heavily on coal which is non-renewable International Conference on Computational Science and Engineering (ICCSE 2015) © 2015. The authors Published by Atlantis Press 34 energy, so the renewable clean energy strengthened the large market demand, and the development of solar energy utilization technology has a broad prospect. Table.1 Energy consumption and consumption structure in Hebei province Year Total energy consumption Coal Oil Natural gas Electric power Total Proportion Total Proportion Total Proportion Total Proportion 2001 11195.71 10181.38 90.94 914.69 8.17 94.04 0.84 5.60 0.05 2002 12114.29 11125.76 91.84 898.88 7.42 84.80 0.70 4.85 0.04 2003 13404.53 12214.21 91.12 1092.47 8.15 93.83 0.70 4.02 0.03 2004 15297.89 14193.38 92.78 992.83 6.49 100.97 0.66 10.71 0.07 2005 17347.79 15810.78 91.14 1389.56 8.01 130.11 0.75 17.35 0.1

This study investigates household-scale seawater desalination to address freshwater shortages, particularly in coastal areas or during emergencies. The process involves heating seawater to evaporate it and then condensing the vapor into freshwater. The research compares the efficiency of pure water and salt production from seawater desalination using two heating methods which is gas stoves and induction stoves. Gas stoves which use fossil fuel combustion and induction stoves which use electromagnetic fields to generate heat have different characteristics and efficiencies in the desalination process. After the heating, the seawater then cooling down by using 3 different speed of fan speed.This study evaluates the differences in the amount of pure water and salt produced by these two methods, considering factors such as energy consumption and operational costs. The results of this research are expected to provide useful insights for selecting more efficient and economical heating methods in the seawater desalination process.The results indicate that freshwater production is higher when using an induction stove compared to a gas stove. Freshwater production at low fan speeds yielded 157 g/hour on an induction stove with 600 W power and 147 g/hour on a gas stove with equivalent power of 658.75 W; 168 g/hour on an induction stove with 600 W power and 88 g/hour on a gas stove with equivalent power of 632.92 W; and 153 g/hour on an induction stove with 600 W power and 105 g/hour on a gas stove with equivalent power of 646.58 W. The heating with an induction stove produces more freshwater compared to heating with a gas stove due to its Energy Efficiency, Precise Temperature Control, Heating Speed, Reduced Heat Loss which is better than gas stove.In terms of salt production, both induction and gas stoves produced nearly identical amounts of salt: 34 g/liter on the induction stove and 36 g/liter on the gas stove at low fan speeds; 36 g/liter on the induction stove and 34 g/liter on the gas stove at medium fan speeds; and 34 g/liter on the induction stove and 36 g/liter on the gas stove at high fan speeds. The power required to produce 1 gram of freshwater at low fan speed was 3.57 watts for the induction stove and 7.18 watts for the gas stove; at high fan speed, it needs 3.92 watts for the induction stove and 6.15 watts for the gas stove. Therefore, it can be concluded that the power consumption for the induction stove is significantly lower than that for the gas stove to produce 1 gram of freshwater.

Tracing and excavating critical paths and sectors for embodied energy consumption in global supply chains: A case study of China

The occurrence of global climate change is caused by the rising temperature of the earth as a result of high CO2 emissions due to excessive energy consumption in the construction sector. Energy consumption in construction activities starts from the pre-construction stage, then the construction stage and finally the post-construction stage. This study aims to find assessment indicators in reducing energy consumption based on literature studies within the scope of the project life cycle (PLC). The method applied here is a qualitative approach by identifying and reviewing some of the literature on reducing energy consumption in construction projects. The literature study found that there are 5 parts in the building life cycle that can be used to identify sources of energy consumption in construction projects, namely the building materials production stage, the construction process, the building use stage, the end of the building's life and disassembly stage. We identified that there are 3 stages of energy calculation in buildings, namely the stages of Manifest Energy, Operational Energy and Demolition Energy. We find that optimizing indirect energy at the production and planning stage has a significant impact on reducing energy consumption at a later stage through building policy and design. While direct energy optimization can be carried out at the construction and operation stages through energy efficiency in each activity.

Embodied and operational energy and carbon emissions of passive building in HSCW zone in China: A case study

The Beijing-Shanghai High-Speed Railway (HSR) is one of the most important railways in China, but it also has impacts on the economy and the environment while creating social benefits. This paper uses a life cycle assessment (LCA) method and a life cycle cost (LCC) analysis method to summarize the energy consumption, carbon emissions and costs of the Beijing-Shanghai HSR from the perspective of life cycle, and proposes some corresponding suggestions based on the results. The research objective of this paper is to analyse the carbon emissions, energy consumption, and costs of the rail system which includes the structure of the track and earthwork of the Beijing-Shanghai HSR during four stages: conception stage, construction stage, operation and maintenance stage, and disposal stage. It is concluded that the majority of the carbon emissions and energy consumption of the entire rail system are from the construction stage, accounting for 64.86% and 54.31% respectively. It is followed by the operation and maintenance stage with 31.60% and 35.32% respectively. In contrast, the amount of carbon emissions and energy consumption from the conception stage is too small to be considered. Furthermore, cement is the major contributor to the carbon emissions and energy consumption during the construction stage. As for the cost, the construction stage spends the largest amount of money (US$4614.00 million), followed by the operation and maintenance stage (US$910.61 million). Improving production technologies and choosing construction machinery are proposed to reduce the cost and protect the environment.

Energy use for membrane seawater desalination – current status and trends

Energy–water nexus under energy mix scenarios using input–output and ecological network analyses