Papers by Keyword: Water Consumption

Abstract: Dust deposition may reduce the yield of the PV panels from 10-50% depending upon the amount of dust deposited, particle size and nature. To prevent loss of efficiency of power plant, cleaning of PV panels is generally required in one-two weeks and in summers during dust storms cleaning frequency needs to be increased. Generally, for cleaning de-ionised water is recommended which adds to the cost and even availability of ordinary water for cleaning is a problem with water scarce regions. In the world, most of the high solar potential sites which are ideal for solar PV power plant installation lie in water scarce regions. The attractive locations for solar energy in Asia and Sub-Saharan Africa are water stressed. Therefore, it becomes important to devise methods to reduce the water consumption in cleaning of solar PV panels in solar power plants. There are studies going on several methods, one such option is use of transparent hydrophobic coatings on the solar panel surface to reduce dust deposition and water used in cleaning. The present work is a step in the direction of estimation of reduction of water consumption with the use of transparent hydrophobic coatings. The present paper discusses the characteristics of dust particles deposited on the solar power plant at University of Kota, Kota, India location and compares the water use amount in cleaning dust on five glass samples. The five samples consist of four different transparent hydrophobic coatings available in market and one is the reference uncoated glass sample. Tests have been done and reported for transparency, dust deposition and water use amount in cleaning for the five samples. On the basis of the comparative study, the amount of water saving potential is estimated for solar power plants. The challenges in use of hydrophobic coatings have been discussed and scope for future work in this field has been examined.

Abstract: The water consumption intensity of steel production through BF-BOF technology was decomposed by an innovative process-based water-accounting model, i.e., water-balance model. One ton of steel product was chosen to be the functional unit. The system boundary of the case study included the production processes of coking, sintering, iron making, steel making, continuous casting and rolling. The results showed that the water consumption intensity of steel production was 3.969t/t in this case. The water consumption of evaporation, solidification and wastewater were 2.373t, 0.013t and 1.583t, accounting for 59.79%, 0.33% and 39.88% of the total water consumption, respectively. Steel rolling is the largest contributor to water consumption, and the amount of water consumption is 1.523t, accounting for 38.37% of the total water consumption; followed by coking process and continuous casting process, the amounts of which are 0.814t (20.50%) and 0.634t (15.97%), respectively. This finding can push the utilization of advanced technologies to save water resource in steel industry.

Abstract: The present work assesses water and power consumption, ethanol production and CO₂ emissions in order to evaluate the technical and economic feasibility of a high-scale sugarcane-based biorefinery and propose a scenario of full carbon and capture system, so the complex could become a sustainable carbon withdrawer from the atmosphere. This work is performed with the aid of professional software for a rigorous mass and energy balances simulation to achieve process data for plant technical and economic analysis. The combustion of sugarcane bagasse is the only source of energy of the plant, which provides steam for the distillery and generates electricity through cogeneration system. The ethanol production from sugars fermentation produces CO₂ which, jointly with the CO₂ from combustion, is released directly into the atmosphere contributing to global warming. Results demonstrate that for processing capacity of 1,000 t/h of sugarcane, the plant emits 0.7 tCO₂ per ton of sugarcane, with net water consumption of 3,600 m³/h as make-up water to replace blowdown and evaporation losses in the cooling tower. The cogeneration system generates 320MW of net power for exportation as electricity. The economic analysis reveals a fixed capital investment of 910MMUSD and a net present value of 378MMUSD considering as revenues the ethanol produced and the electricity from cogeneration at an annual discount rate of 10%.

Abstract: Currently, Combined Cycle Power Plants represent the most advanced technology in the domain of high and medium power generation units operating with fossil fuels. Consequently, the interest for their implementation in the propulsion systems field is justified. At this moment, Combined Cycle Units are used for propulsion only on ships (marine propulsion). The present study goes one step further by referring to a small scale Combined Cycle Unit configured for operation as terrestrial propulsion system and based on a two-pressure-levels Steam Cycle. The performances of this unit are analyzed function by the compressor pressure ratio and HRSG feed water temperature.

Abstract: Material balance calculation was adopted to a bubbling desulfurization system of 600MW unit for water-saving measures. Analysis was made on main factors affecting water consumption. Results showed that heat release of desulfurization reaction and water evaporation went up with sulfur content increasing; Free water and bound water in gypsum increased rapidly with calcium improved; When sulfur content enhanced from 0.5% to 3.5%, water evaporation of reactor increased by 28.9% and waste water increased by 7.8%; With inlet flue temperature of WFGD raised from 120°C to 200°C, waste water increased by 25.3% and evaporation of water increased by 102.35%; Once gas-gas heater (GGH) was installed, heat release of original flue gas decreased by 43.72% and the total water consumption decreased by 39.06%. Therefore, with sulfur content and temperature of inlet flue increasing, water consumption raises. Installation of gas-gas heater (GGH) can effectively reduce water consumption of WFGD system.

Abstract: The impact factors of the water consumption changes from 1999 to 2002 and from 2002 to 2007 in China are studied with structural decomposition analysis(SDA) model.Firstly, we combine the classical IPAT model with consumer endogenous input-output local closed model, then decompose the impact factors of water consumption changes with the combined model.Secondly, we analyze the direct effect of final demand on water consumption changes. The main results are as follows: (1) At the structural level, the increase of the GDP per capita is the main factor of water consumption increase, the decrease of water use intensity is the main factor of water consumption decrease.(2)At the final demand level, the total final demand change is the main factor of water consumption change, whose effect exceeds water use intensity decrease and the change of technical level. Among the components of final demand, investment is the main factor of water consumption growth, which exceeds the effects of government consumption and net exports.

Abstract: In order to explore the relationship between water consumption (WC) and economic growth (EG) in China, this paper introduced the concepts related with decoupling in the fields of resources and environmental research to define the decoupling EG from WC. Furthermore, the assessing approach was built up and a coefficient was proposed to estimate the decoupling degree. Afterwards, the relations between WC and EG from 1997 to 2008 were investigated. The results show strong decoupling of agricultural WC from GDP of primary industry and weak decoupling of WC from EG. It can be concluded that agricultural WC plays an important role to improve the decoupling degree between WC and EG.

Abstract: It is widely believed that the economic success in China is achieved at the expense of natural resources and has resulted in severe pollution of the environment, especially water resources. This study applies a hybrid input-output (IO) model linking economic and ecological systems in order to analyze water consumption and wastewater discharge in the Haihe River Basin. Within the environmental IO framework, a series of assessment indicators is calculated to assist in tracking both direct and indirect effects of freshwater consumption and wastewater discharge in the economic sector, as well as to distinguish the economic sectors that have greatest influence on water demand and pollution. Assessment results indicate that water consumption and pollution can be reduced by readjusting the structure of production, consumption and trade in the Haihe River Basin. It is concluded that in order to achieve sustainable development in the Haihe River Basin with its very poor water endowment, not only the direct but also the indirect effects on water demand and pollution should be considered when production, consumption and trade policies are formulated.

Abstract: Rainwater harvesting from roof is considered as valuable water resources. Material Flow Analysis (MFA) of water in Mahasarakham University (Khamriang Campus) shows that rainwater harvesting from roof can reduce water supply production by 7% and save more than 200,000 Bt/year for water treatment cost. The sensitivity analysis suggests that by 5% water supply conservation and 20% additional rainwater harvesting, MSU could have enough water resources. The rainwater is suitable to be substituted water for gardening due to the convenience to assemble an above ground storage tank or a pond to store harvested rainwater from roof. The current practice of rainwater is collected and discharged into drainage system and treated in wastewater treatment plant. Utilisation of rainwater harvested could reduce wastewater amount that must be treated by 9%. Rainwater harvesting and reuse should be promoted in campus in order to encourage sustainable living and water conservation policy.

Abstract: Based on the wet flue gas desulfurization (FGD) system, we had a analysis on water-consuming. Through the detailed heat and quality analysis of the process, the water-consuming of wet FGD can be calculated scientifically and reasonably. The research has a guiding role in the coal-fired power plant desulfurization.