--------+-------------------------------+-------------------------------- | Crude[1] | Refined +----------+------------+-------+----------+-------------+------- Year | | | Value | | | Value | Quantity | Value | per | Quantity | Value | per | | | pound | | | pound --------+----------+------------+-------+----------+-------------+------- | _1,000 | | | _1,000 | | | pounds_ | |_Cents_| 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 1931[2]| 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.