The Biosurfactant Surfactin as a Kinetic Promoter for Methane Hydrate Formation

Amino Acids as Kinetic Promoters for Gas Hydrate Applications: A Mini Review

“…Following the initial work by Sa and coauthors, ,, as curiosity around amino acids grew for their potential as benign bioadditives for gas hydrate research, their unique structural makeup, a mix of both hydrophilic and hydrophobic function groups, drew particular attention owing to the high degree of similarity with the chemical structure of surfactants, traditionally the most used class of KHPs. In addition to being toxic synthetic chemicals, the use of surfactants also poses a problem of excessive foam generation, especially during hydrate dissociation, making these additives difficult to handle and unviable for repeat utilization. − Biosurfactants such as Surfactin, which have been proposed to circumvent the issue of chemical toxicity, are cumbersome to produce and present the same challenge of foam generation as conventional synthetic surfactants. , Thus, there was an urgent need to identify a class of additives that may be able to replace synthetic surfactants as competent KHPs, enduring across various gas hydrate systems and engaging through a clean mode of operation (no foam formation), in addition to being inherently ecofriendly and nontoxic entities. As we see in the upcoming sections, amino acids (hydrophobic ones in particular) fit the bill perfectly in this regard, delivering the desired kinetic promotion performance through a clean mode of action, i.e., with no accompanying foam generation whatsoever.…”

“…The various examples of the additives listed in the previous two paragraphs are all synthetic chemicals that are either required in exceedingly large quantities to be effective or are toxic and pose a safety threat to the environment and personnel involved or both. As a result, researchers have now resorted to exploring greener, biodegradable, and benign (nontoxic or low-toxic) additives that may be able to replace the traditional synthetic additives. , …”

“…As a result, researchers have now resorted to exploring greener, biodegradable, and benign (nontoxic or low-toxic) additives that may be able to replace the traditional synthetic additives. 62,63 Amino acids are organic compounds, often labeled as the building blocks (monomer units) of proteins, and a vital component of the human diet. The makeup of an amino acid is a carboxyl (COOH) group, an amino (NH 2 ) group, a hydrogen (H) atom, and a unique organic R group (or side chain).…”

Microbe-Worm Symbiosis Stabilizes Methane Hydrates in Deep Marine Environments

“…The results are plotted in Figure 3c-f. We can clearly see that at the beginning, It is important to note that the equilibrium between the bioreaction and methane hydrate dissociation is also influenced by biosurfactants secreted by microbes and those naturally dissolved in sea water. 27,28 Their predicted influence on the critical temperature was plotted in Figure 4a assuming a mixture of biosurfactant in sea water, with results at other pressures plotted as Figure S2 in Supplementary Infomation.…”

Experimental study on hydrate anti-agglomeration in the presence of rhamnolipid

“… 24 Rhamnolipid biosurfactant in cyclopentane hydrates is similar to THF hydrates, and as a co-surfactant, MeOH can improve the performance of rhamnolipid. 25 Surfactants can generally promote the formation of hydrates, and the effects of the biosurfactant surfactin on methane hydrate formation kinetics have been investigated by Bhattacharjee et al 26 Jadav et al investigated the influence of biosurfactants obtained during the cultivation of microorganisms on the formation kinetics of methane gas hydrate, results showing that biosurfactants are more efficient than sodium dodecylsulfate. 27 Purified biosurfactant rhamnolipids can reduce the surface tension of water, and Arora et al observed that 1000 ppm of rhamnolipid solution in C-type silica gel bed system increased the methane hydrate formation rate by 42.97%, reduced the induction time of hydrate formation by 22.63% and shifted methane hydrate formation temperature to higher values relative to water saturated system.…”