US2369372A - Manufacture of soap - Google Patents

Description

j Patented Feb. 13, 1945 UNTITEDSTATES PATENT ICE i 2,369,372 Q 1 t MANUrscTUnn F SOAP:

No Drawing.

Leopold Sender; Baltimore, Md., assignortoflhe Sharples Corporation, P a poration of Delaware y H Application Decemberii, 1941, I ,1, SerialNo. 422,231 I t t hiladelphia, Pa. a corfepoiai is, (minc -pleas) The present invention pertains to the-menu lem of obtaining an improved yield of soap or,

material: which can be saponified by further treatment. More, specifically; a process is pro- I terials in the subsequent soap making operation,

mass from-which the subsequent soaphis'made,

and these impurities must, of course, be removed vided by which soap nigres' may be subjected to purification for removal of material including dirt and other undesired impurities togetherwith a small part of thesoap content of the nigre, 9

from the remainder of the nigre, "and the soap or soap-forming acid content ofthe material, i removedfrom the nigrethereafter recovered from the impurities. i i

Processes for removing impuritie from soap nigres have been proposedheretofore, andI do not'claim anyiparticular process for effecting such removal as a part of the present invention. One method of efiecting. such purification consists in simple centrifugation, preferably by a centrifugal containing peripheral discharge outlets controlled by valves through which theimpurities are-intermittently discharged. In the practice,

wi lson serial No. 389,888, filed April 23, 11941, for Manufacture ofssoap. In accordance iwith this method, the nigre is first treated with a source Another method of purifying,

from this I subsequently made soap in the fitting step performed on ,the saponified mass, if this sistently withproduction'of a soap of satisfactory quality, but a point is inevitably reached in recycling successivebatches of nigre at which the nigre contains such a large proportion of impurities that it canznolonger be recycled consistentl with manufacture ofsatisfactory soap. a N

--oByypurifyin'gthe' nigre by one of the types of operation discussed above before reoyclinglto a subsequent. soap making operation, a substantial proportion of the impurities of the Snigreis re- .moved, with the result that operations of re-:

cycling the i nigre may be continuediin a longer series of operationsithan could be done if such purification were notwaccomplished. 1 The purification of the nigre thus effects an important economy byimaking it possible to repeat therecyclin operation through a longersequence of ofacid, which may-be an organic or inorganic acid or ester (e. g., asoap-forming ester), in order I t to reduce the free alkali content of the nigre and convert it to a condition in which theiimpurities may bemore effectively removed upon subsequent centrifugation; The process covered 35, fication step. In case of separation of the im inthis application constitutesthe best method known to me for efiecting removal of impurities,

and constitutes the preferred operation by which impurities areiremoved from the nigre inmthe practice of the present inventionu i In the conventional manufacture of soap, it is customary to utilize thesoapvalues contained in'thenigre by mixing'the nigre withifat anda utilizing the soap contained inthe nigre in this manner, there are ce'rtain "economic limitations.

In introducing the nigre along with other: ma-

operations than could otherwise be feasibly accomplished. 5 1

While purification of the nigre before recycling .is advantageous for the reasons discussed above, suchipurification is attended by the, draw-hack that a certainamount of soap is inevitably lost inconnection withithe performance of the puri purities centrifugally, for example, the impurities obtained-fbythe centrifugal operation must of necessity contain acertain amount of soap. In i any separating operation, best: results as to puri ficationof one of the :products of the separation can be: attained by permitting the other product gether with the impurities, apart of the soap values or the mere. Any attempt to separate these; impurities without removing. a part of the soapivalues of the 'nigre alongwith the impurities resultstin impairment ofefficiency of separation of'the impurities, withtheresultthat realization of the benefit of efficient removal of the impurities is not attained, and that the number of feasible repetitions of the step of recycling the nigre is correspondingly limited, a result which constitutes partial defeat of the main object of the purification. The operator is thus confronted with the dilemma that, if he effects the best pos-' sible purification of the nigre, substantialquantitles of soap valuesare lost, but that, if he attempts to minimize loss of the soap values in thenigre, the purification operation is relatively inefficient, with the result that attainment of the principal object of the purification step becomes impracticable. The attainment of'the objects of maximum eificiency of purification with minimum loss of soap values with the impurities thus apparently constitutes an attempt to reconcile essentially irreconcilable factors.

A feature of the present invention consists in the fact that it includes a sequence of steps in removal of impurities from the nigr'e and recovcry of soap values by which maximum efiiciency is attained in the purification step, with attendant'removal of a substantial part of the soap from the nigre in this step, and the soap values are subsequently. recovered from the fraction containing the impurities for reuse in the soap making process, or for other appropriate use to which-these soap values or acids derived there with maximum efliciency of purification of the nigre, and'in order to accomplish this object,

the impurities removed from thenigre contain a substantial proportion of soap. By performing the first step of the process in this manner, the main body of the nigre is purified to a degree which will permit it to be mixed with fur ther quantities of soap-forming materials in the manufacture ofa further quantity of soap with a minimum of contamination of the. further quantity of soap by impurities retained. in the nigre from the previous soap making operation.-

The performance of the purification step in the manner discussed above obviously entails substantial loss of soap values from the nigre treated. In the practice of the present invention, this loss is compensated by recovery of these values from the impurities with which they. are removed from the main body of the nigre in the initial purification step. Thus, in case of separation of dirt from soap nigre in a centrifugalseparator of the valve bowl type, impurities are discharged peripherally through the valve-controlled outlets together with a part of the soap of the nigreywith the result that the nigre is satisfactorily purified for reuse, and the peripherally discharged fraction is then subjected to the subsequent steps of the process for recovery of soap contained therein. The removal of the soap .values from the impurities with which they are separated from the main body of the nigre may be accomplished by dilution of these impurities with water to dilute the soap, and subsequent separation of the impurities from the resultant soap solution. The diluted soap solution so ob- CEK tained may be used in the manufacture of 'a further quantity of soap, or in any other manner by which the soap values which it contains may be utilized.

Another method of effecting separation of the soap values from the impurities consists in adding water to the impurities containing the soap values and thereafter saltingthe soap out of solution in the water by addition of a salt or alkali. This operation liberates the dirt, which is next removed from the mixture of soap and Water by appropriate means, such as centrifugation.

As a still further alternative in the practice of the invention, the impurities removed from the nigre and containing the soap may be mixed with a mineral acid capable of springing the soap to form fatty acids. This springing operation will liberate the impurities, with the result that these impurities may be separated from the other constituents of the mixture by appropriate means, such as centrifugation, for example, by treating the resulting mixture in a centrifugal separator of the so-called clarifier type in order to separate the impurities from the mixture of sprung acids and aqueous acid liquor, and then separating the sprung fatty acids and aqueous acid liquor by centrifugation or gravity. Alternatively, the separation may be accomplished in a centrifugal of the so-called separator type in which the impurities may be separated peripherally from the centrifugal at the same time that the sprung acids are separated from theaqueous acid liquor. 1 1

From the above discussion, it will beseen that a separation of the soap values from the impurities may be attained by treatment with water, salts,

alkalies or acids to; liberate the impurities and permit them to be separated from the soap by. appropriate means, such as centrifugation. As a matter of fact, such separation is facilitated by the addition to the impurities of any liquid dil- 'uent, and a feature of the invention consists in the addition of a liquid diluent, followed by centrifugation. While the invention has been discussed above' in connection withan operation involving separation of impurities along with soap values from the nigre after the nigre has been separated from the main portion of the initially saponified mass, it is possible to combine the steps of separation of the nigre from thebulk of the saponified mass and the separation ofimpurities, together with part of the soap values; from the nigre. Thus, by employing a centrifugal sepa-' rator of the valve bowl type in separation of neat soap from nigre, this separation may be accomplished at the same time that impurities containing soap values are discharged centrifugally from the nigre, which forms an outer stratum in the centrifugal rotor. The present invention therefore includes separation of impurities together with soap Values from the nigre, followed by separation of soap values contained in impuri- .ties from those impurities, regardless of whether lowing claims.

Iclaim: x '1 1. In the treatment of soap nigres, the process comprising separating impurities from a soap nigre together with a portionof the soap of the nigre, thereafter diluting the material separated from the nigre to liberate impurities from the resulting diluted mixture and separating the impurities from said mixture. t

2. In the treatment of soap nigres, the process comprising separating impurities from a soap nigre together with a portion of the soap of the nigre, thereafter diluting the material separated from the nigre to liberate impurities from the resulting dilutedmixture and separating the impurities from said mixture by centrifugation.

3. In the treatment of soap nigres, the process comprising separating impurities from a soap nigre together with a portion of the soap of the nigre, thereafter diluting with water the material separated from the nigre to liberate impurities from the resulting diluted mixture and separating the impurities from said mixture.

4. In the treatment of soap nigres, the process comprising separating impurities from a soap nigre together with a portion of the, soap of the mere, thereafter diluting with waterand an electrolyte the material separated from the nigre to ture.

5. In the treatment of soap nigres, the process comprising separating impurities from a soap nigre together with a portion of the soap of the nigre, thereafter diluting with water and a salt the material separated from the nigre to liberate impurities from the resulting diluted mixture and separating the impurities from said mixture.

6. In the treatment of soap nigres, the process liberate impurities from the resulting diluted mix- I ture and separating the impurities from said mixfrom the resulting diluted mixture and separating the impurities from said mixture by centrifuga tion.

8. In the treatment of soap nigres, the comprising separating impurities from a soap nigre together with a portion of the soap or the nigre,. thereafter diluting the material separated from the nigre with a mineral acid to spring the soap separated with the impurities and liberate impurities from the resulting mixture, and epas rating ,the impurities from said mixture.

9. In the treatment of soap nigres, the process comprising separating impurities from a soap nigre together with a portion of the soap of the nigre, thereafter diluting the material separated from the nigre with a mineral acid to spring the soap separated with the impurities and liberate impurities from the resulting mixture, and separating the impurities from said mixture by centrifugation.

LEOPOLD SENDER.

process