Assessment of the potential of colloidal fuels in future energy usage. Final report. [97 references]

Pulverized coal has been an increasing important source of energy over the past century. Most large utility boilers, all modern coking plants, and many industrial boilers and blast furnaces employ pulverized coal as a major feed stream. In periods of oil shortages, such as during World Wars I and II, the concept of adding powdered coal to oil for use in combustion equipment originally designed for oil has been actively pursued but rarely used. Over this same period of time, there have been attempts to use air suspensions of coal dust in diesel engines in Germany, and in turbines in various countries. The economic advantages to be enjoyed by substitution of powdered coal in oil are not generally realized. Oil costs at $30/bbl represent a fuel value of about $5.00/10/sup 6/ Btu; coal at $25/ton is equivalent to approximately $1.00/10/sup 6/ Btu. Although capital costs for the use of coal are higher than those associated with the use of oil, coal is clearly becoming the least costly fuel. Not only are considerable cost advantages possible, but an improvement in balance of payments and an increase in reliability of fuel supplies are other potential benefits. It is therefore recommended that increased national attention be given to develop these finer grinds of carbonaceous fuels to be used in various suspending fluids. Technical areas where significant additional support appear desirable are described