Kinetic study of methane hydrate formation in the presence of copper nanoparticles and CTAB

The effects of synthesized copper nanofluids containing CTAB with concentrations ranging from Cu(0.00001 M) + CTAB (0.00015 M) to Cu (0.00018 M) + CTAB (0.0022 M), water-based copper nano fluids with concentrations of 0.0157 M and 0.157 M, and aqueous solutions of CTAB with four concentrations of 0.00015 M, 0.00056 M, 0.0011 M and 0.0022 M are studied on the induction time of methane hydrate formation, the amount of methane consumed in the hydrate formation process, and the hydrate growth rate, in a 390 cm(3) stainless steel stirred-tank reactor under a stirring speed of 800 rpm. The experiments were conducted at initial conditions of 275.15 K and 5.5 MPa. Detailed experimental results show that synthesized copper nanofluids and CTAB solutions reduce the induction time of methane hydrate formation, but CTAB seems to be more effective in this regard. All tested additives have positive effects on the amount of methane consumed in the hydrate formation and the apparent rate constant of methane hydrate growth. However, water-based copper nanofluids with high concentrations of 0.0157 M and 0.157 M seem to be more effective in increasing the amount of methane consumed in hydrate formation. The presence of CTAB in the systems under study is more effective in increasing the average growth rate constant, which means CTAB is more effective in enhancing the growth rate of hydrate formation compared to copper nanoparticles. (C) 2016 Published by Elsevier B.V.