(72f) Enhancing Hydrate Inhibition Performance of Biomolecules By Doping with Synergents

Khraisheh, M. - Presenter, Qatar University
Enhancing hydrate inhibition performance of biomolecules by doping with synergents

M. Fahed Qureshi , Tausif Al-Tamash , Mert Atilhan and Majeda Khraisheh

Corresponding Author: m.Khraisheh@qu.edu.qa

Department of Chemical Engineering, Qatar University


The formation of gas hydrates in offshore subsea lines is a matter of constant threat to flow assurance in oil and gas industry. These gas hydrates are ice-liked crystalline compounds that are formed under high pressure and low temperature conditions. In order to prevent the risk of hydrate formation annually the industry spends over 100 million dollars on thermodynamic hydrate (THI) inhibitors. These THI mitigate hydrate formation by shifting hydrate vapour equilibrium curve (HLVE) to lower temperatures under standard pipeline operating conditions. The thermodynamic inhibitors (THI) like Mono-ethylene glycol (MEG) and Methanol are widely used to prevent the risk of hydrate formation. However, these inhibitors are highly flammable, toxic and required in bulk quantities (>30wt%) causing environmental and safety concerns. Therefore, there is a strong market need for finding low dosage hydrate inhibitors that are non-toxic and environmentally friendly.

In the last decade, the research interest has grown towards kinetic hydrate inhibitors (KHI) that prevent hydrate formation by delaying the hydrate formation time. These KHI are required in low dosage and can be designed as per the process requirement. Amino acids (AAs) are new class of KHI that biological exists in nature composed of amine (-NH2) and carboxylic acid functional groups (-COOH). AAs have been previously used as corrosion inhibitors and are reported to be environmentally friendly. So the suitability of using AAs as potential hydrate inhibitors have been tested on pure methane gas at different operating pressure conditions and varying concentration of AAs.

The amino acids tested include: L-Alanine, L-Phenylalanine, Glycine, Histadine and L-Asparagine. The experimental results show that amino acids with lower hydrophobicity tend to act as both KHI and THI at the same time. The novel part of the study involves the doping of synergent compounds with the selected AAs. By doping synergents with AAs, the overall kinetic inhibition performance of AAs was enhanced significantly and at low pressure conditions (~40 bars) the methane hydrate crystal formation was delayed up to 24 hrs. Similarly, the significant delay in hydrate formation was also observed at high pressure operating conditions (80-120 bars).



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