Laserfiche WebLink
<br />ExxonMobil Global Services Page 6 <br />Colony Shale Oil Project <br />ESR Reclamation Studies <br />Weighing Lysimeter Performance 1990-2003 <br />Project No. 353 <br />thick soil cover similar to Colony's then pemutted design. Further, the requirement to salvage <br />5 feet of soil materials might have been problematic at Colony. As a minimum, it would have <br />required acceptance of lower grade (rockier) materials. <br />3.1.4 Impacts of Transition to Higher Temperature (Fluid bed) Combusting Retorts <br />in the early 1980's Exxon was developing afluid-bed combusting retort called ESR <br /> <br /> <br />Exxon constructed and operated a pilot scale 5 ton/day fluid bed combusting retort at <br />Baytown, Texas. Similaz to Chevron's STB (staged turbulent bed) fluid bed combusting retort <br />in Salt Lake City, and Unocal's fluid bed combustor Unishale-C add-on to its then <br />commercial Unocal-B retort, the shale processed through afluid-bed combustor lost its black <br />residual cazbon coating, was generally firmer grained, was pozzolonic, and had higher pH and <br />salt content than the TOSCO low temperature retorted shale. The ESR combusted shale was a <br />non plastic fine grained material that would also classify agronomically as a sHt or silt loam. <br />Greenhouse tests were conducted by Exxon to detemmine if the ESR combusted shale could be <br />economically transformed into a suitable plant rooting medium, but concluded that simple <br />water leaching would not be sufficient. Attempts were made to modify the combusted shale <br />minerals with the addition of CO2 with some success, although the commercial viability of <br />that was considered problematic at the time. However, the pozwlonic nature of the material <br />had some significant advantages with respect to the other environmental considerations of the <br />pile, those being pile stability and control of leachate originating as surface precipitation <br />passing through the pile. Lab studies (WWL, 198' showed that the ESR shale had a <br />significant capacity to absorb and hold water. Unlike the limited water holding capacity of the <br />silt sized non-pozzolonic TOSCO II spent shale, where the capacity was simple capillary <br />suction, some of the water introduced to ESR combusted shale became pemmanently fixed <br />through hydration of the minerals in the combusted shale. Further, in the process of hydration <br />and growth of cement crystals and tobermorite gel, at least for compacted ESR combusted <br />LACHEL FELICE & Associates <br />