United States production.

The output of both the crude and the refined has increased in recent years, reaching new highs in 1937. Chemically pure glycerin constitutes about 60 percent of the total refined output and dynamite and other grades about 40 percent. In the production statistics shown in table [48], grades such as yellow distilled are included with the dynamite grade. Since large soap makers refine their own crude glycerin, the sale of crude is only a small part of the total output.

Table [48] shows domestic production of glycerin by grades and table [49] production for sale.

Table 48.—Glycerin: United States production by grades, in specified years, 1919-37

[In thousands of pounds]
Census year	Crude 80 percent basis	Refined
Census year	Crude 80 percent basis	Chemically pure grade	Dynamite grade	Total
1919	61,793	36,693	25,655	62,348
1920	54,688	32,860	31,571	64,431
1923	99,579	47,992	52,369	100,361
1924	95,154	53,243	37,368	90,611
1925	103,407	55,448	52,658	108,106
1926	116,369	64,460	49,579	114,039
1927	128,209	59,126	49,266	108,392
1928	130,499	66,419	46,622	113,041
1929	140,080	66,791	58,981	125,772
1930	138,675	69,654	50,974	120,628
1931	140,002	70,528	43,366	113,894
1932	133,919	63,624	41,539	105,163
1933	119,812	58,585	45,534	104,119
1934	153,115	80,359	48,553	128,912
1935	141,185	74,705	48,685	123,390
1936	154,096	85,386	47,535	132,921
1937	167,882	92,889	51,794	144,683

Source: Bureau of the Census, U. S. Department of Commerce.

Table 49.—Glycerin: United States production for sale, in specified years, 1919-35

Year	Crude¹			Refined
Year	Quantity	Value	Value per pound	Quantity	Value	Value per pound
	1,000 pounds		Cents	1,000 pounds		Cents
1919	18,228	$2,482,779	13.6	47,377	$11,461,213	24.2
1923	27,444	3,124,470	11.4	74,105	12,214,012	16.5
1925	30,735	4,258,351	13.9	94,303	16,991,213	18.0
1927	27,000	3,942,991	14.6	89,585	19,184,806	21.4
1929	28,790	2,358,031	8.2	113,140	12,715,641	11.2
1931	27,530	1,673,733	6.1	102,510	10,316,347	10.1
1931²	25,964	1,551,573	6.0	101,615	10,222,850	10.1
1933	22,161	1,191,000	5.4	107,853	7,915,000	7.3
1935	24,042	2,366,481	9.8	121,262	12,984,684	10.7

¹ By chemical and soap manufacturing plants only.

² Adjusted for comparison with 1933.

Source: Bureau of the Census, U. S. Department of Commerce.

Crude glycerin is produced by about 200 soap makers and by about 12 producers of fatty acids. Soap factories are located in more than half the States, the principal ones being in Ohio, New York, Massachusetts, New Jersey, Illinois, California, and Pennsylvania; the fatty acid plants are located in five or six States, Ohio being of chief importance. Most of the smaller producers sell their output of crude glycerin. Refiners of glycerin are few in number compared to the producers of crude. The larger soap plants refine their own crude glycerin and in addition purchase crude from other plants for refining.

The process of recovering glycerin consists of chemically treating weak glycerin solutions separated from the soap or fatty acids, and then concentrating and distilling under reduced pressures. The average yield is less than 10 percent but varies from about 9 to 12 percent, depending upon the kinds of oils and fats used. When prices are high every effort is made to recover the maximum yield of glycerin; when prices are low, cost of chemical treatment and distillation makes it advisable to allow more glycerin to remain in the soap or to discard the weak solutions.

Production in other countries.

As in the United States, glycerin is produced in foreign countries, as a byproduct of the soap and fatty acid industries. The United Kingdom, Germany, and France, and recently the Soviet Union, are the leading producers. The output in each of these countries is estimated to be less than a third of the output in the United States. The British Census of 1930 reports the production of crude glycerin in the United Kingdom at 44 million pounds. Authentic statistics on production in other leading countries are not available, but most estimates show lower figures than for the United Kingdom. In some European countries the normal production of soap results in more glycerin than can be utilized.