Hydrogen solubility measurements in heavy oil and bitumen cuts

An indirect method for measuring gas solubility in liquid media such as hea vy oil, bitumen, petroleum residue and low volatility model hydrocarbons is reported. The method is intended for use with an existing X-ray view cell apparatus. With this apparatus it is possible to verify the number of phase s present and to ensure that the phases are well mixed. For example, vortic es in the impeller region are readily observed using transmitted X-ray imag ing, despite the opacity of heavy hydrocarbons to visible light. Gas solubi lity data is obtained by tracking the location of the liquid-vapour interfa ce. The volume of the view cell, the number of moles of gas added to the ce ll and the mass of the Liquid phase are known. Once the volume of the liqui d is obtained, the dissolved gas fraction is computed by difference. The me thod is applicable over the range of conditions accessible with the view ce ll apparatus - from ambient conditions up to 450 degreesC and 30 MPa. For s paringly soluble gases such as hydrogen, solubilities measured using this m ethod fall within 5% of values reported in the literature for hexadecane an d tetralin at pressures greater than 2 MPa, Measured values are repeatable to within 2%. Hydrogen solubilities in a light virgin gas oil, a heavy virg in gas oil, Athabasca bitumen vacuum bottoms and Gudao atmospheric residuum are reported over a broad range of temperatures (80-380 degreesC) and pres sures (0.5-12 MPa). The solubility values obtained for the four cuts differ significantly at low temperatures but fall within a narrow range at elevat ed temperatures where the values do not differ markedly from values obtaine d for much lighter fluids such as tetralin. (C) 2001 Published by Elsevier Science Ltd.