聚乙烯吡咯烷酮在天然气水合物生成中的作用

研究了聚乙烯吡咯烷酮(PVP)在天然气水合物生成中的促进和抑制作用,结果表明PVP作为促进剂时,在确定的反应温度和压力下有一个最佳的浓度,在确定的使用浓度和温度时则有一个最佳反应压力,否则PVP的加入将抑制水合物的生成。认为PVP在低浓度时作为高分子表面活性剂,降低了溶液的表面张力,加速了水合物生成。在高浓度时,其长链上的五元环吸附水合物表面未完成的孔穴,阻止了水合物晶核的增长。

Effects of poly(vinyl pyrrolidone)on formation of natural gas hydrate

The stimulative and inhibitory effects of PVP on tht natural gas hydrate formation were studied.The results show that there exist some optimal concentration at constant pressure and temperature and some optimal pressure at constant temperature and concentration when PVP was used as accelerant,if not,PVP would inhibit hydrate formation.It was supposed that PVP,as the surfactant,would bring down the interfacial tension,and then promote the hydrate formation when PVP's concentration was low.On the contrary,PVP would inhibit hydrate nuclei growth by a long chain of polymer backbone adsorbent with its cyclic ketone-ether groups in the partially-completed cavities on the hydrate surface,And this adsorption slows the nuclei growth.