TABLE I.-Potential advantages of proposed sulfur control by coal gasification 1. The gas volume to be processed is 10 percent or less of that of the final flue gases.

2. The sulfur is present largely as hydrogen sulfide which is more readily removed chemically than the sulfur oxides.

3. More efficient thermal cycles based on gas turbines, pressurized boilers and top heat cycles are more easily integrated with these systems and may thereby help offset the cost of equipment.

4. Gas firing should allow a more efficient steam cycle than that of present coal firing practice since coal ash corrosion and not thermal resistance is the present limiting factor on super-heat and reheat temperatures in coal fired units.

5. Although utilities are naturally hesitant to enter the chemicals industry, this eventuality may be inevitable; in addition to organic chemicals from coal the proposed systems aid the recovery of sulfur as elemental sulfur which is the most useful form.

Fourthly, by burning coal as gas one has less coal ash corrosion and one can work at a little higher temperature and have a somewhat more efficient steam cycle.

Fifth, more efficient thermal cycles based on gas turbines and top heat cycles are more easily integrated. Finally, sulfur is only one diagnostic contaminant. There may be others that we will learn of as air pollutions are studied nationwide and worldwide. Our scheme is more readily adapted to removing other pollutants as contrasted with burning coal and then looking at the great volume of exhaust gases to remove other materials.

This project began in its first phase at the end of December and we have in 4 months created a laboratory which I would like to show briefly.

COAL GASIFICATION

The plate I (exhibit 4) shows the laboratory for the study of coal gasification and desulfurization. In the center is the pyrolysis furnace and gas-handling equipment. On the left is a gas liquid chromatograph double column, modified from a commercial device.

The rest of the equipment was designed and constructed by our staff with a few commercial components. On the right is the plasma spectograph, an invention which this staff made last spring.

Behind the plasma spectrograph is a special mass spectrometer. For example, gases can be taken from the pyrolysis furnace through the gas chromatograph on the left which separates them into different chemical compounds or groups. They pass then across to the plasma spectograph on the right and by this device, which is shown in plate II (exhibit 5) more clearly, with the plasma operating in the ring in the center we can tell just what molecules are present and what the ratios of atoms in the molecules are.

Now in the plate III (exhibit 6) we see the mass spectrometer more clearly. In a given run on coal we developed one-tenth of a mile of chart record if you take the chart shown and divide it and put it end to end as a single record.

BASIC SCIENCE

This laboratory shows the application of basic science to a very practical problem. What have we learned in this less than 5-month period?

First of all, if one looks into the literature one finds that generally

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speaking the literature among this tonnage of papers and documents and reports can be broken into a very few documents that are really of value for practical application of such a scheme.

SULFUR REMOVAL KINETICS

We need to know the kinetics, the rate of the reactions, because in order to be economic it must go fast enough for a continuous process. If we look at the literature we find that the practical coal-sulfur kinetics papers are prior to 36 years ago and three papers summarize the known knowledge then, two by a man named Powell in 1920 and one by a man named Snow in 1932.

Looking at these works we find that first we must check these older results. We took the same kind of coal and put it through a series of tests which led to the submission to the Center a week ago Friday of a first draft paper for publication entitled "Studies on Coal Gasification I. Isothermal Desulfurization Experiments."

In this publication we graphed the Snow data in a different way as defined as the sulfur removal factor and then compared with our new data.

Exhibit 7 is a graph taken from our paper showing this comparison. We see in the circles the Snow data plotted as sulfur removal factors at different temperatures. We see that slow heating gives-on the right of the graph-at a thousand centigrade quite adequate removal but practically too slowly.

Our points-crosses and squares-check the earlier work. We can accept the entire data of Snow now. It is interesting that our data plotted as the square point was obtained several times in the series of 16 runs and corresponds to a percentage removal of approximately 90 percent of the sulfur by gasification.

The question remains how can we make the reactions go fast enough to use in a practical and economic plant. To answer, we have completed a first series of kinetic measurements using a very powerful tool developed recently in Germany by Juntgen and coworkers. In December, having identified the Juntgen papers, we did a translation from the German and submitted it in January to the National Center, we have designed and built the apparatus and applied this technique now to coal.

In this technique of nonisothermal kinetics, one heats at a known rate from room temperature up to, say, 1,100° centigrade and measures continuously the rate of emission of each

gas.

Exhibit 8 is one result which was taken from a paper submitted Friday, several days ago, to the Center, called "Studies on Coal Gasification II: Non-Isothermal Desulfurization Kinetics." This is one plot from those data, from the tenth of a mile chart record, showing in the black circles the experimental measurements with the mass spectrometer of hydrogen sulfide emission as coal is heated from 100° centigrade up to 1,100.

There are many more experimental points in between but they all fall on the smooth continuous curve. At the same time all gases were trapped in a series of batch traps and these were subsequently analyzed by different techniques. The rectangular lines represent the measure