Accurate simulation of water distillation system for oxygen-18(18O) isotope separation is necessary to guide industrial practice, since both deuterium(D) and oxygen-18 isotope get enriched and interfere with each othe...Accurate simulation of water distillation system for oxygen-18(18O) isotope separation is necessary to guide industrial practice, since both deuterium(D) and oxygen-18 isotope get enriched and interfere with each other. In the present work, steady-state and dynamic distillation models are established based on a classic method and a cascade distillation system with 5 towers is introduced to test the models. The theoretical expressions of separation factor αH/Dfor protium/deuterium and separation factor α^(16)O/^(18) O.for oxygen-16/oxygen-18 were derived,with the existence of deuterium and oxygen-18, respectively. The results of the steady-state simulation by the classical method proposed in the present work agreed well with the results of the lumping method. The dynamic process could be divided into 5 stages. Impressively, a peak value of product withdraw was observed before the final steady state, which was resulted from the change of ^(16)O/^(18) O separation factor and isotope distribution. An interesting low concentration zone in the towers of T2–T5 existed at the beginning of the dynamic process and it required industrial evidence.展开更多
In this study, life cycle assessment of oxygen-18 by using cryogenic distillation of oxygen is performed using SimaPro 8.3 software. Life cycle assessment is performed to understand the environmental profile and hotsp...In this study, life cycle assessment of oxygen-18 by using cryogenic distillation of oxygen is performed using SimaPro 8.3 software. Life cycle assessment is performed to understand the environmental profile and hotspots of this process in order to be used in design and development. Simulation of oxygen-18 process is executed by Hysys software, and the required inputs and outputs for inventory of life cycle were acquired. By doing life cycle assessment and considering achieved results after characterization and normalization of inventory data it has been investigated that in the majority of environmental impacts electricity consumption has a huge contribution relative to other parts of the system like liquefied oxygen production from air separation unit,required facilities for air separation and oxygen-18 units, and needed transportation. Also, among 17 impact categories investigated in ReCiPe impact assessment method, fossil depletion, climate change(human health),particulate matter formation, climate change(ecosystem), human toxicity, and metal depletion have the most contribution in entire environmental loads respectively. Furthermore, sensitivity analysis showed that changing life cycle impact assessment method from ReCiPe to IMPACT 2002+ has no significant effect on acquired results and results are confident. In addition, assumption of market for depleted oxygen from heavy isotopes which is withdrawn from top of distillation columns showed some positive effects compared to first case and environmental impacts resulted from liquefied oxygen production(feed) reduced but because of huge contribution of electricity consumption compared to other sections, this positive effect has no remarkable influence on entire environmental loads of product system.展开更多
Tho Gudui geothermal field records the highest temperature at equivalent borehole depths among the lainland hydrothermal systems in China's Mainland.Located about 150 km southeast of Lhasa City,the capital of Tibe...Tho Gudui geothermal field records the highest temperature at equivalent borehole depths among the lainland hydrothermal systems in China's Mainland.Located about 150 km southeast of Lhasa City,the capital of Tibet,the Gudui geothermal field belongs to the Sangri-Cuona rift belt,also known as the Sangri-Cuona geothermal belt,and is representative of the non-volcanic geothermal systems in the Himalayas.In this study,oxygen-18 and deuterium isotope compositions as well as 87Sr/86Sr ratios of water samples collected from the Gudui geothermal field were characterized to understand the origin and mixing processes of the geothermal fluids at Gudui.Hydrogen and oxygen isotope plots show both,deep and shallow reservoirs in the Gudui geothermal field.Deep geothermal fluids are the mixing product of magmatic and infiltrating snow-melt water.Calculations show that the magma fluid component of the deep geothermal fluids account for about 21.10%-24.04%;magma fluids lay also be a contributing source of lithium.The linear relationship of the 87Sr/86Sr isotopic ratio versus the 1/Sr plot indicates that shallow geothermal fluids form from the mixing of deep geothermal fluids with cold groundwater.Using a binary mixing model with deep geothermal fluid and cold groundwater as two end-members,the nixing ratios of the latter in most surface hot springs samples were calculated to be between 5% and 10%.Combined with basic geological characteristics,hydrogen and oxygen isotope characteristics,strontium concentration,87Sr/(86)Sr ratios,and the binary mixing model,we infer the 6 th-Class Reservoirs Evolution Conceptual Model(6-CRECM) for the Gudui geothermal system.This model represents an idealized summary of the characteristics of the Gudui geothermal field based on our comprehensive understanding of the origin and mixing processes of the geothermal fluid in Gudui.This study may aid in identifying the geothermal and geochemical origin of the Gudui high-temperature hydrothermal systems in remote Tibet of China,whose potential for geothermal development and utilization is enormous and untapped.展开更多
基金Supported by the Jiangsu Province Transformation of Sci-tech Achievements Project(BA2012080)
文摘Accurate simulation of water distillation system for oxygen-18(18O) isotope separation is necessary to guide industrial practice, since both deuterium(D) and oxygen-18 isotope get enriched and interfere with each other. In the present work, steady-state and dynamic distillation models are established based on a classic method and a cascade distillation system with 5 towers is introduced to test the models. The theoretical expressions of separation factor αH/Dfor protium/deuterium and separation factor α^(16)O/^(18) O.for oxygen-16/oxygen-18 were derived,with the existence of deuterium and oxygen-18, respectively. The results of the steady-state simulation by the classical method proposed in the present work agreed well with the results of the lumping method. The dynamic process could be divided into 5 stages. Impressively, a peak value of product withdraw was observed before the final steady state, which was resulted from the change of ^(16)O/^(18) O separation factor and isotope distribution. An interesting low concentration zone in the towers of T2–T5 existed at the beginning of the dynamic process and it required industrial evidence.
文摘In this study, life cycle assessment of oxygen-18 by using cryogenic distillation of oxygen is performed using SimaPro 8.3 software. Life cycle assessment is performed to understand the environmental profile and hotspots of this process in order to be used in design and development. Simulation of oxygen-18 process is executed by Hysys software, and the required inputs and outputs for inventory of life cycle were acquired. By doing life cycle assessment and considering achieved results after characterization and normalization of inventory data it has been investigated that in the majority of environmental impacts electricity consumption has a huge contribution relative to other parts of the system like liquefied oxygen production from air separation unit,required facilities for air separation and oxygen-18 units, and needed transportation. Also, among 17 impact categories investigated in ReCiPe impact assessment method, fossil depletion, climate change(human health),particulate matter formation, climate change(ecosystem), human toxicity, and metal depletion have the most contribution in entire environmental loads respectively. Furthermore, sensitivity analysis showed that changing life cycle impact assessment method from ReCiPe to IMPACT 2002+ has no significant effect on acquired results and results are confident. In addition, assumption of market for depleted oxygen from heavy isotopes which is withdrawn from top of distillation columns showed some positive effects compared to first case and environmental impacts resulted from liquefied oxygen production(feed) reduced but because of huge contribution of electricity consumption compared to other sections, this positive effect has no remarkable influence on entire environmental loads of product system.
基金This work was financially supported by the China Geological Survey(Grant No.DD20160054)the National Natural Science Foundation of China(Grant No.U1407207)the National Key Research and Development Program of China(Grant No.2017YFC0602802).
文摘Tho Gudui geothermal field records the highest temperature at equivalent borehole depths among the lainland hydrothermal systems in China's Mainland.Located about 150 km southeast of Lhasa City,the capital of Tibet,the Gudui geothermal field belongs to the Sangri-Cuona rift belt,also known as the Sangri-Cuona geothermal belt,and is representative of the non-volcanic geothermal systems in the Himalayas.In this study,oxygen-18 and deuterium isotope compositions as well as 87Sr/86Sr ratios of water samples collected from the Gudui geothermal field were characterized to understand the origin and mixing processes of the geothermal fluids at Gudui.Hydrogen and oxygen isotope plots show both,deep and shallow reservoirs in the Gudui geothermal field.Deep geothermal fluids are the mixing product of magmatic and infiltrating snow-melt water.Calculations show that the magma fluid component of the deep geothermal fluids account for about 21.10%-24.04%;magma fluids lay also be a contributing source of lithium.The linear relationship of the 87Sr/86Sr isotopic ratio versus the 1/Sr plot indicates that shallow geothermal fluids form from the mixing of deep geothermal fluids with cold groundwater.Using a binary mixing model with deep geothermal fluid and cold groundwater as two end-members,the nixing ratios of the latter in most surface hot springs samples were calculated to be between 5% and 10%.Combined with basic geological characteristics,hydrogen and oxygen isotope characteristics,strontium concentration,87Sr/(86)Sr ratios,and the binary mixing model,we infer the 6 th-Class Reservoirs Evolution Conceptual Model(6-CRECM) for the Gudui geothermal system.This model represents an idealized summary of the characteristics of the Gudui geothermal field based on our comprehensive understanding of the origin and mixing processes of the geothermal fluid in Gudui.This study may aid in identifying the geothermal and geochemical origin of the Gudui high-temperature hydrothermal systems in remote Tibet of China,whose potential for geothermal development and utilization is enormous and untapped.
