Kerogen recovery

Soaking at low temperatures without heating above 1000° F results in as much kerogen recovery as direct exposure to high temperatures. (Thirteen percent of the original carbon remains.)... 

Figure 3 shows the residual organic carbon for the range of hydrogen pressures and heat-up rates studied. In all of these runs, the final temperature was 1300°F. Apparently kerogen recovery above 1000° F is extremely pressure sensitive. 

Figure 3. Pressure effect on kerogen recovery from rich shale in pure hydrogen atmospheres...

However, while the carbonate decomposition was repressed, the kerogen recovery was also reduced relative to the pure hydrogen runs. Thus, the net improvement was not as striking as implied by the carbon dioxide repression (Figure 4). 

Figure 4. Correlation of rich shale kerogen recovery and carbonate decomposition in pure hydrogen...

Attempts to devise a kinetic scheme for the low temperature kerogen recovery in hydrogen have been made but have not been successful. The constant temperature data appear capable of being described by a linear combination of first-order exponential terms that might result from the following mechanism ... 

Carbon dioxide generation is suppressed by carbon dioxide in the feed gas, but with a penalty in kerogen recovery. 

Results obtained in the 4-in. diameter reactor have generally verified the trends observed in the laboratory study. Kerogen recoveries using hydrogen have exceeded 90% which is significantly better than recoveries obtained in conventional retorting. 

The recovery of petroleum from sandstone and the release of kerogen from oil shale and tar sands both depend strongly on the microstmcture and surface properties of these porous media. The interfacial properties of complex liquid agents—mixtures of polymers and surfactants—are critical to viscosity control in tertiary oil recovery and to the comminution of minerals and coal. The corrosion and wear of mechanical parts are influenced by the composition and stmcture of metal surfaces, as well as by the interaction of lubricants with these surfaces. Microstmcture and surface properties are vitally important to both the performance of electrodes in electrochemical processes and the effectiveness of catalysts. Advances in synthetic chemistry are opening the door to the design of zeolites and layered compounds with tightly specified properties to provide the desired catalytic activity and separation selectivity. 

In Figure 1, an outline of the product recovery results from phenol-tosyl acid treatment of kerogen is shown. Product recoveries are high (183-193%). Our kerogens are much more reactive toward phenol than is coal. The recovered products were sequentially extracted with toluene, methanol, and pyridine. The... 

Extensive analytical efforts to fully characterize the oil shales are underway at Exxon Research and Engineering Company s Baytown Laboratories. No significant losses of any metals of concern are observed during high temperature ashing. An alternate means of rapid ash determination uses a Parr combustion bomb. The ash can be dissolved by alkaline fusion in a Claisse fluxer or by acid dissolution in a Parr bomb. The solutions thus prepared are analyzed by atomic absorption or by inductively coupled plasma emission spectrometry for major (Al, Ca, Fe, K, Mg, Na, Si, Ti) and trace elements (As, B, Ba, Be, Cd, Co, Cr, Cu, Li, Mn, Mo, Ni, P, Sr, U, V, Zn). Kerogen enriched shales need to be ashed before the dissolution, otherwise low recoveries are obtained. Overall accuracy and precision of metals determination is within... 

Figure 1. Recovery of Marathon Lease kerogen as a function of the number of beneficiation cycles. (Kerogen determined by weight loss on low-temperature ashing.)...

Wish 1 The reactor must be capable of maximum recovery of oil. Oil recovery can be maximized by making sure that high (say, 99% + ) conversion of kerogen is obtained and that the oil vapor once produced does not suffer further cracking and degradation to light gases. 

Kerogen and rock are intimately mixed, and so, are difficult to separate. The shale oil is recovered by heating the shale to about 500° C, when gas, liquid gas and oil are removed and about 20% of the kerogen remains as coke in the rock. Usually, one ton of shale oil yields less than 160 liters of oil, and so large quantities of residue must be handled. Oil recovery from shale also consumes large quantities of water, about 1-3 liters of water per liter oil produced, and is not economic at present because of this. Because of high transport costs, oil production must be carried out at the actual shale source. 

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