Membrane-based dissolved gas extraction from transformer oil has been gaining importance in dissolved gas analysis (DGA). However, there lacks a systematic study on the transport of dissolved gases from oil. This paper reports an experimental study of dissolved-gas-in-oil extraction by Teflon AF2400 membranes on bare α-Al₂O₃ and modified γ-Al₂O₃/α-Al₂O₃ hollow fiber supports. Dense, ultrathin, and durable Teflon AF2400 top-coating layer can be synthesized on the modified γ-Al₂O₃/α-Al₂O₃ support but not the bare α-Al₂O₃ support. The long-term stability of the composite membranes strongly depends on the microstructure of the Teflon AF2400 top-coating layers. Mass transfer in the liquid phase is the rate-limiting step for extraction by the fresh membranes. The measured gas permeances in the extraction process are lower than that in the gas separation process. During extraction, the gas extraction rate decreases exponentially with on-stream time due to an increase in the membrane transport resistance caused by oil infiltration into the membrane. The overall mass transfer rate is determined by gas-in-oil solubility constant, mass transfer coefficient in the liquid phase, and the membrane permeance. The effects of these equilibrium and rate parameters on overall mass transport are sensitive to operating temperature due to the difference temperature dependence of these parameters.

中文翻译：

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铁氟龙AF2400 /陶瓷复合中空纤维膜在油中溶解气中的输气特性

从变压器油中提取基于膜的溶解气体在溶解气体分析（DGA）中已变得越来越重要。但是，目前尚缺乏对石油中溶解气体传输的系统研究。本文通过特氟隆AF2400膜在裸的α-Al报告溶解气体的油提取的实验研究₂ ö ₃和改性的γ-Al ₂ ö ₃ /α-Al系₂ ö ₃中空纤维载体。密，超薄，耐用特氟龙AF2400顶涂层可以在改性来合成的γ-Al ₂ ö ₃ /α-Al系₂ ö ₃的支持，但没有裸露的α-Al ₂ ö ₃支持。复合膜的长期稳定性在很大程度上取决于Teflon AF2400面漆的微观结构。液相中的传质是新鲜膜萃取的限速步骤。在提取过程中测得的气体渗透率低于在气体分离过程中测得的气体渗透率。在萃取过程中，由于油渗入膜中引起的膜传输阻力增加，气体萃取率随运行时间呈指数下降。总的传质速率由油中气体溶解度常数，液相中的传质系数和膜渗透率决定。