This thesis is based upon work using the stirred batch cell fouling rig at the University of Bath to collect fouling data and investigate the fouling of calcium carbonate and of two crude oils. Research aims were to discover the conditions under which a single crude oil would foul, and to see whether a fouling deposit could be removed by increasing shear stresses exerted by the cylindrical stirrer in the rig. The key purpose of this research was to attempt to record a negative fouling rate and then interpolate between positive and negative fouling rates in order to find the conditions at which the fouling rate would be zero. In conducting the research, a number of issues presented themselves, providing noteworthy observations and new avenues of investigation. The first crude (‘crude 19’) would not foul in the rig, even when temperatures were raised to very high levels. The second crude (‘crude 21’) also initially would not foul, but did foul once a significant proportion of the light ends of the crude were flashed. Initial problems with crude 21 led to an investigation into heat transfer inside the rig with the oil, resulting in a number of findings that have been presented in this thesis. These include the observation that nucleate boiling was occurring in the rig, and the impacts of this finding have been discussed. Data was collected to measure the effect of wall temperature and stirrer speed on fouling rate for crude 21 and the activation energy was found using an Arrhenius plot. Five fouling removal tests were completed and the results were mixed, with some evidence for removal observed, but also several inconclusive results sets. It was, therefore, not possible to record a negative fouling rate and hence use the apparatus to predict the fouling threshold.
|Date of Award||13 Nov 2014|
|Sponsors||Heat Transfer Research Institute Inc|
|Supervisor||Barry Crittenden (Supervisor)|
- Crude oil
- Stirred Batch Reactor
- Nucleate boiling