Fluid thermal processing of Mongolian oil sands
17 July 2011
A study by a team from the State Key Laboratory of Heavy Oil Processing, China University of Petroleum found that fluid thermal processing of il sands is a feasible process for the production of an upgraded bitumen-derived liquid from Inner Mongolian oil sand. The study appears in the ACS journal Energy & Fuels.
| Oil sands exploration in Xing’an region |
|---|
| Israel’s Brack Capital Energy (BCE) is exploring for oil sands reserves in the Xing’an region of Inner Mongolia. |
| In 2005, the company acquired some 261 square kilometers of exploration rights and expects to generate an estimated 150,000 tons of oil-sands derived crude oil annually from the site. |
| According to Brack Capital, geological surveys show significant oil sands reserves are present and contain quality heavy oils. |
| BCE says its vision is to become the pioneer of the oil sands industry in China. |
The bitumen products from oil sands can be recovered through open-pit and underground mining processes. Open-pit mining recovery includes oil sand mining and subsequent surface processing to recover bitumen from the sand matrix.
Hot water extraction method is the most widely used process for separating and recovering bitumen from oil sand; however, note Zhang et al., hot-water extraction is limited by the type of oil sand, and high bitumen recovery yields can only be obtained from water-wet oil sands. A solvent extraction process can increase the bitumen recovery yields of oil-wet oil sand but, requires a large amount of organic solvent, resulting in high treatment costs and potential environmental pollution.
Direct thermal conversion can be a more feasible process to obtain bitumen-derived liquid products from oil-wet oil sand, they say.
However, for different types of oil sands, the bitumen reaction behaviors of fluid thermal conversion show different cracking performances because oil sands are deposited in differing geological environments and have noticeably discrepant properties. Therefore, the thermal reaction behaviors of oil sand bitumen in a fluid thermal reactor are also worthy of investigation to widen the feedstock resources for fluid thermal processing. Oil sand bitumen is a complex compound containing a large number of different functional groups, molecular structures, and fairly broad molecular-weight distributions. Therefore, the composition of bitumen has a great significance because of its vital role in determining its fluid thermal processing and performance-related properties.
...At present, the comprehensive study of oil sand use is only just beginning in China, and there is a dearth of information available regarding the fluid thermal reaction behaviors of Inner Mongolia oil sand bitumen. Studies on the chemical structural change of oil sand bitumen are indispensable to better understand the reaction behaviors of oil sand bitumen during fluid thermal conversion and improve their performance.
—Zhang et al.
Zhang et al. investigated the thermal reaction performances of Inner Mongolia oil sand bitumen in a confined fluid-bed reactor. To select the subsequent processes for upgrading and/or refining, the liquid products of fluid thermal conversion were analyzed and compared to native bitumen.
They found that the optimal reaction temperature was 485–495 °C and the optimal reaction time was 5 minutes. Under the optimal operation conditions,they obtained maximum liquid yields of 79.87, 78.93, and 85.64 wt % for three oil sands samples from different parts of the Songliao Basin of Inner Mongolia in northeastern China.
(The Songliao basin is one of 12 geological basins (on- and off-shore) in China reporting deposits of heavy oil and/or natural bitumen, according to a 2007 report by the US Geological Survey (USGS).)
The quality of the liquid products from the thermal conversion of oil sand was significantly better than that of the native bitumen, indicating that it would be an excellent feedstock for further processing and use in a refinery.
—Zhang et al.
Resources
An-gui Zhang, Jinsen Gao, Gang Wang, Chunming Xu, Xinying Lan, Guoqing Ning, Yongmei Liang (2011) Reaction Performance and Chemical Structure Changes of Oil Sand Bitumen during the Fluid Thermal Process. Energy & Fuels Article ASAP doi: /10.1021/ef200644
Heavy Oil and Natural Bitumen Resources in Geological Basins of the World (USGS Open File-Report 2007-1084)
Hot centrifugal processing with low volatile hydrocarbon liquids will remove most of the hydrocarbons. Hot water in the centrifuge might free even more hydrocarbons. The remainder can be removed with low temperature wet air oxidation in the form of simple organic acids. The oxidation can provide process heat and electrical energy. Of course a heavy water reactor designed for the production of low temperature hot water alone should be built to supply the additional heat.
Completely deuterated heavy paraffin should be the moderator and coolant for a subsequent reactor built to produce low temperature heat for bitumen extraction. There can be no worries about the melting of fuel cladding and dispersal of water dissolved fission products. Heat from the hot paraffin can be used to produce small amounts of electricity with multiple sets of the the machinery usually used for geothermal energy. This can continue at a reduced level with the heat produced by fission products after a chain reaction shut down. Excess heat is easily transferred to the air from the paraffin with several possible arrangements.
A kilogram of thorium used in such a reactor can produce the heat energy of three million kilograms of coal, two million kilograms of oil or a million kilograms of natural gas.
..HG..
Posted by: Henry Gibson | 17 July 2011 at 11:54 AM
Unanswered: the toxicity of the residues on the thermally-processed sands.
Posted by: Engineer-Poet | 17 July 2011 at 02:02 PM