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<br />1)~)Zfiti9 <br /> <br />es were not evaluated, primarily because of lack of data ,for prototype- <br />scaled facilities. A SYNTHANE plant producing 7.1 million cubic metres <br />per day under standard conditions of. temperature and pressure ,was assumed <br />in this analysis. This size plant would util ize about 5.67 mill ion <br />tonnes of coal annually for conversion to pipeline-quality synthetic gas. <br /> <br />As indicated in table 1, one or two coal-gasification plants of the <br />above-specified size and type have been assumed within the set of feasible <br />future coal-resource development alternatives for the Yampa River, basin. <br />Because coal in the Yampa basin has relatively low sulfur content (gener- <br />ally less than 1 percent), a greater proportion of coalutil ization has <br />been allocated to electric-power generation by steam turbines. However, <br />natural gas reserves in the region are decl ining and coal gasification may <br />be proposed in the Yampa River'basin to supply the existing gas-pipeline <br />network. <br /> <br />Substantial quantities of gaseous, liquid, and solid residuals are <br />produced by the SYNTHANE coal-gasification process. With no residuals <br />treatment, an est imated 77 percent of the total residuals from the SYNTHANE <br />coal-gasification plant is in gaseous form. The bulk of liquid residuals <br />is a condensate generated from cooling and char-quenching processes. The <br />liquid residuals contain ammonia, phenols, carbonates,.thiocyanates, cya- <br />nide, and various dissolved-sulfur compounds. In addition, liquid resid- <br />uals containing suspended sol ids and chemical impurities are emItted from <br />the boiler and cooling systems. Nearly 97 percent of the generated'liquid <br />residuals can be transformed into gaseous or sol id residuals by treatment. <br />This modification of residuals can result in an estimated 25-percent re- <br />duction in tot'al residuals loadings, from 26.2 to 21.0 million tonnes per <br />year (I. C. James and others, written commun., 1976). The bulk is trans- <br />formed into a sol id form causing more than a twelvefold increase in dis- <br />cha rged so 1 I d res i dua 1 s. <br /> <br />As with electric-power generation by steam turbines, the major con- <br />sumptive use of water in coal gasification involves dissipation of waste <br />heat. Total consumptive-water use ranges from 2.8 to 32 mill Ion cubic <br />metres per year for a standard-sized plant with a capacity of 7.1 million <br />cubic metres per. day. The factors affecting this range are the type of <br />cool ing system util ized and whether waste-water and flue-gas treatment are <br />imposed. As stated previously, consumptive-water use from a once-through <br />cool ing system is about one-third or less of that from cooling ponds or <br />wet towers, and this is indicated by the lower number of the range given <br />above. The disadvantage of once-through cool ing is the greater require- <br />ment for water. With treatment of waste water and flue gas, liquid resid- <br />uals are modified to other forms, primarily sol ids, and a substantial <br />amount of water (an estimated .4.9 mill ion cubic metres annually) is recov- <br />ered. Total water-circulation rate for a coal-gasification plant is ap- <br />proximatelY'7.5x108 cubic metres per year, which is nearly 40 percent of <br />the mean annual flow from the Yampa River basin. <br /> <br />Coa I Trans port <br /> <br />Traditional modes of transportation of mined coal are either by truck <br /> <br />9 <br />