Under simulated atmospheric condition, photoomdation for HCFC-22 + H2O2, HCFC-22 + H2O2+O2, HFC-134A + H2O2 and HFC-134A + H2O2+ O2 systems were studied.H2O2 was irradiated by low pressure mercury lamp and produced OH...Under simulated atmospheric condition, photoomdation for HCFC-22 + H2O2, HCFC-22 + H2O2+O2, HFC-134A + H2O2 and HFC-134A + H2O2+ O2 systems were studied.H2O2 was irradiated by low pressure mercury lamp and produced OH radicals. The OH radicals can initiate photooxidation of HCFC-22 and 134A. The products of photooxidation were determined by a Fourier Transform infrared Spectroscopy with a 20ml long path cell. The products were COF2,CO2, HCI, H2O and HF for HCFC-22 + H2O2 system, HO, CO2, HCI and HF for HCFC-22 +H2O2 +O2 system, HCOF, CF3OOCF3,CO2, H2O and HF for HFC-134A +H2O2 system, HCOF, CO2, H2O, and HF for HFC-134A + H2O2+ O2 system. Based on those results, the mechanisms of photooxidation were suggested.展开更多
As the major producer and consumer of hydrofluorocarbons (HFCs), China is obligated to phase-down HFCs to mitigate global warming if China ratifies the Kigali Amendment (KA) to the Montreal Protocol. Based on historic...As the major producer and consumer of hydrofluorocarbons (HFCs), China is obligated to phase-down HFCs to mitigate global warming if China ratifies the Kigali Amendment (KA) to the Montreal Protocol. Based on historical HFCs consumption in each sector, here we estimated historical HFCs emissions with a bottom-up method, and projected the consumption baseline and schedule for HFCs phase-down in China under the KA and the corresponding potential for emission reduction. Results showed that China's HFCs consumption and emissions in 2017 were 164,000 t (311 Mt C 2_eq) and 108 Mt C02-eq, respectively. HFCs consumption baseline was projected to be (724 ± 18) Mt C 2-eq in 2024, and China should take measures to phase-down HFCs by 2029, at the latest, to meet the requirements of the KA. HFCs consumption in 2050 under KA would reach the level of 2012 2013. Cumulative reduced consumption was estimated at 10.8 (10.1 11.6) Gt C 02-eq, and cumulative reduced emissions were estimated at 5.38 (4.90 5.64) Gt C 02-eq by 2050.展开更多
While hydrogen fluoride (HF) and hydrogen chloride (HCl) are not considered main air-pollutants in the EU, they have the potential to contribute to acidification. Hydrofluorocarbons (HFCs), hydrofluoro-olefins (HFOs) ...While hydrogen fluoride (HF) and hydrogen chloride (HCl) are not considered main air-pollutants in the EU, they have the potential to contribute to acidification. Hydrofluorocarbons (HFCs), hydrofluoro-olefins (HFOs) and hydrochlorofluoro-olefins (HCFOs) are used as refrigerants and for other applications. They break down in the atmosphere to produce HF and HCl (for HCFOs) and some of these fluorocarbons also break down to produce trifluoroacetic acid (TFA). For the emissions of these fluorocarbons in the EU, a worst-case scenario estimates their theoretical potential contribution to acidification and compares it to the acidification potential for the main air pollutants contributing to acidification, which are nitrous oxides (NOx), sulphur oxides (mainly SO2), and ammonia (NH3). The Acidification Potential from these fluorocarbons in 2016 is estimated at 2, NOx, NH3, and it can be concluded that this is insignificant in the context of the main acidification air-pollutants. Assuming that the EU targets for emissions of SO2, NOx and NH3 by 2030 are achieved, the Acidification Potential from HFCs, HFOs and HCFOs in 2030 is also estimated at 2, NOx, NH3 and will remain insignificant.展开更多
氢氟烃(HFC)/氢氟烃和氢氟烃/碳氢(HC)混合物是两类重要的制冷工质。采用PR状态方程结合Horon-Vidal(HV)混合规则对7种HFC/HFC和7种HFC/HC二元混合物的气液相平衡性质进行了计算,并与PR状态方程结合van der Waals(vdW)混合规则的计算结...氢氟烃(HFC)/氢氟烃和氢氟烃/碳氢(HC)混合物是两类重要的制冷工质。采用PR状态方程结合Horon-Vidal(HV)混合规则对7种HFC/HFC和7种HFC/HC二元混合物的气液相平衡性质进行了计算,并与PR状态方程结合van der Waals(vdW)混合规则的计算结果进行了对比。结果表明,HFC/HFC体系组元性质比较接近,非理想性不强,vdW混合规则即可达到较理想计算效果,HV混合规则对计算精度的提升有限;对非理想性较强的HFC/HC体系,vdW混合规则对共沸性质的描述不够理想,HV混合规则可以显著提升相平衡的计算精度。展开更多
采用20 L爆炸球装置开展了典型氢氟烃化合物(HFCs)对丙烷气体抑爆特性实验研究,得出爆炸压力、火焰传播速度的变化,分析不同H/F比例下氢氟烃的抑爆特性变化规律。实验起始压力为10~500 k Pa,实验温度为室温至200℃。实验结果表明:对于...采用20 L爆炸球装置开展了典型氢氟烃化合物(HFCs)对丙烷气体抑爆特性实验研究,得出爆炸压力、火焰传播速度的变化,分析不同H/F比例下氢氟烃的抑爆特性变化规律。实验起始压力为10~500 k Pa,实验温度为室温至200℃。实验结果表明:对于可燃气体丙烷,氢氟烃类抑爆剂微量加入初期导致最大爆炸压力升高,火焰传播速度加快,存在过压现象;随着H/F比例增大,五氟丙烷、五氟乙烷和七氟丙烷火焰传播速度抑制效果依次减弱,且最大爆炸压力来临时间相对缩短。展开更多
文摘Under simulated atmospheric condition, photoomdation for HCFC-22 + H2O2, HCFC-22 + H2O2+O2, HFC-134A + H2O2 and HFC-134A + H2O2+ O2 systems were studied.H2O2 was irradiated by low pressure mercury lamp and produced OH radicals. The OH radicals can initiate photooxidation of HCFC-22 and 134A. The products of photooxidation were determined by a Fourier Transform infrared Spectroscopy with a 20ml long path cell. The products were COF2,CO2, HCI, H2O and HF for HCFC-22 + H2O2 system, HO, CO2, HCI and HF for HCFC-22 +H2O2 +O2 system, HCOF, CF3OOCF3,CO2, H2O and HF for HFC-134A +H2O2 system, HCOF, CO2, H2O, and HF for HFC-134A + H2O2+ O2 system. Based on those results, the mechanisms of photooxidation were suggested.
文摘As the major producer and consumer of hydrofluorocarbons (HFCs), China is obligated to phase-down HFCs to mitigate global warming if China ratifies the Kigali Amendment (KA) to the Montreal Protocol. Based on historical HFCs consumption in each sector, here we estimated historical HFCs emissions with a bottom-up method, and projected the consumption baseline and schedule for HFCs phase-down in China under the KA and the corresponding potential for emission reduction. Results showed that China's HFCs consumption and emissions in 2017 were 164,000 t (311 Mt C 2_eq) and 108 Mt C02-eq, respectively. HFCs consumption baseline was projected to be (724 ± 18) Mt C 2-eq in 2024, and China should take measures to phase-down HFCs by 2029, at the latest, to meet the requirements of the KA. HFCs consumption in 2050 under KA would reach the level of 2012 2013. Cumulative reduced consumption was estimated at 10.8 (10.1 11.6) Gt C 02-eq, and cumulative reduced emissions were estimated at 5.38 (4.90 5.64) Gt C 02-eq by 2050.
文摘While hydrogen fluoride (HF) and hydrogen chloride (HCl) are not considered main air-pollutants in the EU, they have the potential to contribute to acidification. Hydrofluorocarbons (HFCs), hydrofluoro-olefins (HFOs) and hydrochlorofluoro-olefins (HCFOs) are used as refrigerants and for other applications. They break down in the atmosphere to produce HF and HCl (for HCFOs) and some of these fluorocarbons also break down to produce trifluoroacetic acid (TFA). For the emissions of these fluorocarbons in the EU, a worst-case scenario estimates their theoretical potential contribution to acidification and compares it to the acidification potential for the main air pollutants contributing to acidification, which are nitrous oxides (NOx), sulphur oxides (mainly SO2), and ammonia (NH3). The Acidification Potential from these fluorocarbons in 2016 is estimated at 2, NOx, NH3, and it can be concluded that this is insignificant in the context of the main acidification air-pollutants. Assuming that the EU targets for emissions of SO2, NOx and NH3 by 2030 are achieved, the Acidification Potential from HFCs, HFOs and HCFOs in 2030 is also estimated at 2, NOx, NH3 and will remain insignificant.
文摘氢氟烃(HFC)/氢氟烃和氢氟烃/碳氢(HC)混合物是两类重要的制冷工质。采用PR状态方程结合Horon-Vidal(HV)混合规则对7种HFC/HFC和7种HFC/HC二元混合物的气液相平衡性质进行了计算,并与PR状态方程结合van der Waals(vdW)混合规则的计算结果进行了对比。结果表明,HFC/HFC体系组元性质比较接近,非理想性不强,vdW混合规则即可达到较理想计算效果,HV混合规则对计算精度的提升有限;对非理想性较强的HFC/HC体系,vdW混合规则对共沸性质的描述不够理想,HV混合规则可以显著提升相平衡的计算精度。
文摘采用20 L爆炸球装置开展了典型氢氟烃化合物(HFCs)对丙烷气体抑爆特性实验研究,得出爆炸压力、火焰传播速度的变化,分析不同H/F比例下氢氟烃的抑爆特性变化规律。实验起始压力为10~500 k Pa,实验温度为室温至200℃。实验结果表明:对于可燃气体丙烷,氢氟烃类抑爆剂微量加入初期导致最大爆炸压力升高,火焰传播速度加快,存在过压现象;随着H/F比例增大,五氟丙烷、五氟乙烷和七氟丙烷火焰传播速度抑制效果依次减弱,且最大爆炸压力来临时间相对缩短。
