Amir Erfani - School of chemical,gas and petroleum,Semnan university
Farshad Varaminian
Milad Muhammadi

Development and utilization of Low Dosage Hydrate Inhibitors (LDHI) have been attracted researchers and industry for almost two decades. These inhibitors are known to be more effective, more environmental friendly, less corrosive and havelower capital and operational expenses. These inhibitors are usually classified to Kinetic Inhibitors (KI) and Anti-Agglomerants (AA). While kinetic inhibitors prevent hydrate formation by prolonging induction time of hydrate formation more than the residence time of free water in pipeline, anti agglomerants inhibits pipeline plugging acting as a hydrate emulsifier. Environmental aspects of commercial LDHI’s have encouraged researches to look for more environmentally friendly LDHI’s. Considerable efforts have been made to develop non-ionic surfactants e.g. Alkylamide or zwitterionic surfactants, which can be effective inhibitors or to utilize environmentally friendly materials like starch or anti-freeze proteins. In present paper, these research activities, patents and industrial reports are reviewed, including: chemicals with kinetic or anti agglomeration effects, their mechanism of acts, Compatibility, chemical screening and selecting methods like molecular Dynamics simulations, experimental procedures, data reproductivity, stochasticity, inhibitors synergism, multifunction inhibitors, inhibitors surfactant effects and surface interfacial properties, biodegradability, toxicity and environmental impacts.

Gas hydrate, Kinetic inhibitors, Anti-agglomerants, inhibition mechanisms, synergism