Effect of Nanobubble Evolution on Hydrate Process: A Review

As a huge reserve for potential energy, natural gas hydrates(NGHs) are attracting increasingly extra attentions, and a series of researches on gas recovery from NGHs sediments have been carried out. But the slow formation and dissociation kinetics of NGHs is a major bottleneck in the applications of NGHs technology. Previous studies have shown that nanobubbles, which formed from melt hydrates, have significant promotion effects on dissociation and reformation dynamics of gas hydrates. Nanobubbles can persist for a long time in liquids, disaccording with the standpoint of classical thermodynamic theories, thus they can participate in the hydrate process. Based on different types of hydrate systems(gas + water, gas +water +inhibitors/promoters, gas + water + hydrophilic/hydrophobic surface), the effects of nanobubble evolution on nucleation, dissociation, reformation process and "memory effect" of gas hydrates are discussed in this paper. Researches on the nanobubbles in hydrate process are also summarized and prospected in this study.

碳捕集能耗分析模型的对比研究（英文）

目的:碳捕集能耗较高的技术瓶颈,亟待热力学理论在交叉研究中解决。热力学理论工具在碳捕集技术能耗水平评估方面的准确性、有效性和局限性都尚未明确,且碳捕集能耗研究的共性规律仍未被把握。本文对现有能耗分析模型进行对比以揭示碳捕集技术能耗的实质,并提出普适性和针对性恰当的能耗分析模型,以明确碳捕集能耗水平的"天花板"。创新点:1.提出热力学碳泵模型,分析碳捕集技术理想能耗;2.对比不同碳捕集能耗分析模型,通过案例分析说明其不同特点和理想化程度的差异。方法:1.通过概念比拟,类比热泵概念,提出热力学碳泵概念,并阐述碳捕集过程是通过热或功驱动的二氧化碳从低浓度向高浓度逆向富集的非自发过程(图2和3),实现碳捕集技术实质的理想化概括;2.通过热力学理论推导,获得基于热力学碳泵模型的碳捕集最小理想能耗(公式(13));3.通过案例分析,论证热力学碳泵模型相对混合气体分离模型和碳泵模型的理想化程度是否更高(图9),以及其中碳源、汇的无限质容假设是否更接近理想状态。结论:1.通过碳泵模型可以得到碳捕集技术的理想能耗,并且碳泵模型相对混合气体分离模型在使用时更便捷。2.热力学碳泵模型相对碳泵模型的理想化程度更高;因为忽略碳源、汇由传质引起的不可逆性,热力学碳泵模型计算所得最小理想能耗比碳泵模型计算所得理想能耗更小。3.通过热力学碳泵模型分析直接空气碳捕集技术表明,其最小理想能耗是相同反应条件下烟气处理技术的4.916倍。