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<br /> the ...,ater require.'"nen ts fer reveqetating the spent shale from the Parana <br />l-' <br />en Indirect retort are larger than those from the paraho Direct retort a"d t;o,e <br />Gl of the higher residual in the former. ~orecve=, <br />0 Tasca II retort because carbon <br /> <br />since the wastewaters evolved curing the retorting and upgrading operations i~ <br />the Paraho process are much larger t~an the water requirements for disposing <br />of the spent shale, they will have to be treated for recycle and reuse within <br />the plant or disposed of in evaporation ponds. The wastewater cannot ze used <br />directly for revegetation because ies quality must be similar to the quality <br />of river water. Since the latter is wasteful of ~ater, we will assume t~at <br />the wastewaters will be treatea :or use in a cooling tower, i~ a manner similar <br />to that for a coal gasification plant as described i~ Section 2. The process <br />wastewaters evolved in retorting range from about 10 to 25 percent 0: the <br />water requirements fer cooling in the Paraho process. <br /> <br />Figures 3-1 and 3-2 show the major parts of the two wate~ management <br />scn~~es discussed above for an oil shale ~onversion ccmplex ~n which t~e <br />source water is river ~at~r. In Figure 3-1, which wculd be characteristic of <br />that used for an oil shale process in which t~e spent shale is disposed c: _.. <br />a ~anner 3~~ilar to ~~at for Tasco !I, the retor~ing ~~d upgrading ~as~~waters <br />are treated to remove odorous, volatile substances ~~C ~~en, ~i~~ other 91~'t <br />wastewaters, completely ~sed to moisturize the spent shale. In the scheme <br />shown in Figure 3-2, which is characteristic of a process in whic~ t~e spent <br />shale is disposed of in a manner similar to ~1at for Paraho, the retorting anc <br />~pgradinq wastewaters are treated for cooling tower makeup, similar to t~e <br />scheme presented in Section 2 (see Figure 2-1) for coal gasifica~ion. If the <br />source water is brackish or high in suspended soli~s, it mus~ be treatec :or <br />service use within the mine-plant complex. The service water is generally or <br />potable water quality. Figures 3-3 and 3-4 sho'", the major water streams far a <br />Tasca II plant producing 50,000 barrels/day of synthetic crude (upgraded shale <br />oil) and for a Parana Direct plant producing 50,000 barrels/day of synthetic <br />crude, respectively. These detailed desi9ns were made recently by Water <br />Purification Associates and are dif:erent in some respects ~~an the designs <br />reported :n Ref~ 4. As a result there may be some discrepar.cies in flow rates <br />between ~~e ~alues shown en Figures 3-3 and 3-4 and the values :ou~d in Ref. 4 <br />and also repeated in this sec~ion. <br />It should be noted ~~at in the proposed White River oil shale desig,,3 <br />although 85 pe~cent of the oil shale will be processed in paraho retorts and <br /> <br />55 <br />