US3123626.Pdf

3,123,626 United States Patent Office Fatented Mar. 3, 1964 2 contrary, generally have a broader plastic range and re 3,123,626 quire temperatures above 104 F. to effect complete lique SELECTWE HYDROGENATECBN OF FATS AND faction. The factors of considerable importance in the FATTY OLS control of these physical attributes in decreasing order Francis William Kirsch, Wilmington, Del, assignor to 5 are: first, the relationship of the unsaturates, mono-, di-, Air Products and Chericais, Inc., a corporation of and tri-forms, to the completely saturated forms inasmuch Delaware as the hardness increases with a decrease in unsaturation Fied Sept. 30, 1960, Ser. No. 59,613 and particularly with an increase in saturates; secondly, 9 Claims. (C. 269-409) the double bond characteristics in the trans- and cis-forms This invention concerns fat hydrogenation. It is more 0. (for example, the trans-form triolein (or trielaidin) has a particularly concerned with the selective hydrogenation melting point of approximately 42 C. whereas the cis of edible fats and oils and with a procedure of the type form material has a melting point of about 5 C.); thirdly, in which hydrogen and fatty charge are passed continu the position of the double bonds with respect to their ously over a fixed bed of catalyst conducive to the satis separation from the carboxyl groups affects the hardness factory production of commercially acceptable, partially 5 in that the melting point decreases with increasing dis hydrogenated fats of the type suitable for use in shorten tance of separation (it is of interest to note that with Ca ings and/or margarine. fatty acids a shift of double bond position of at least 7-8 The preparation and use of hydrogenated vegetable carbon atoms is equivalent in effect on the melting point oils and the like has a respected history of development to one change from the cis- to the trans-position); and covering more than half a century. Many methods of 20 lastly, though somewhat little established by firm informa operation and large numbers of agents for the catalysis tion, is the positioning of fatty acid groups in the alpha, of the hydrogenation to achieve the desired end products beta and alpha prime positions of the glyceride. have been proposed during this period. Naturally only As indicated above, most commercial operation has a relative few of both operational methods and catalysts been limited to the batch type operations, but many seri have proven commercially acceptable and successful. At 25 ous efforts have been made to permit the development of the present time substantially all of the commercial opera Some suitable continuous process in which the charge is tions utilize "batch operation' methods of effecting the introduced, processed, and recovered without discontinu desired type and degree of hydrogenation. In such batch ance such as is necessary in a batch type operation. One operations the customary procedure involves the admix variation, of Such systems, which has probably come the ture with the fat of a reasonably small quantity of hydro 30 closest to commercial usage is that in which catalyst is genation catalyst which may or may not be supported and circulated through the system with and suspended in the which may or may not be associated with a type of ab fats, and the catalyst is continuously recycled through the sorbent material, such as natural earths and clays includ System after being separated from hydrogenated product ing diatomaceous earth and kieselguhr, which act more as by final filtration. Filtration problems, however, are or less entirely as filter aids. 35 of considerable magnitude because of the extremely fine Inasmuch as nickel is one of the most widely used cata size of the catalyst and the necessity of removing sub lytic agents and in its commercially effective state is of stantially all of the catalyst from the product. Substan practically colloidal nature, the absorbent filter aid mate tially all of the known catalysts have been tried in at rial is a necessary adjunct in aiding in the flocculation tempts to develop a continuous process without, however, and congolomeration of such nickel for its necessary re 40 reaching the final state of a really acceptable commercial moval, usually by filtration, from the final hydrogenation method equalling or supplanting batch type operation. product. It appears that the associated absorbent mate The reasons in back of the drive to develop a suitable rial or support agents usually have little effect on the continuous process of the kind represented by this inven catalytic nature of the nickel or other catalystic agent tion included substantial labor savings, space and time associated therewith or carried therein and that the main 45 savings, simplified equipment and operating conditions, purpose therefore is that of a filter aid and flocculation the avoidance of the need to filter the catalyst out of the agent. final product and perhaps some saving in the catalyst Typical catalysts employed in such systems are usually quantity requirements per unit amount of fat and oil available in a form prepared by suspending the active treated. catalytic agents in a relative small amount of a suitable 50 It has now been found that a continuous process for oil which is hardened to protect the catalyst from deac selective hydrogenation of edible fats and oils is possible tivants before and during storage, transportation and in with all of the attendant benefits mentioned above, and troduction to the hydrogenation system. As is readily with the attainment of at least the quality of product here understood, the batch operation is of the unitary operation tofore known to be available only in batch type operation. type wherein the batch of ingredients is introduced into 55 One of the chief requirements of a hydrogenation proc a confined zone, reacted therein, and then removed. In ess applicable to edible oils is “selectivity” of reaction. such batch operations the controllable variables are gen Selectivity concerns and depends on the conversion of erally limited to the pressure, temperature, time, and the poly-unsaturate groups within the glyceride molecule degree of agitation. A factor of somewhat less appreci to a lower degree of unsaturation without producing any able control as a variable is the kind and quantity of the 60 Substantial amount of attendant total hydrogenation. catalytic agents employed in the system. For example, a linoleate (C18, with two double bonds) Edible oils must meet certain rather stringent specifica may be said to be selectively hydrogenated when the chief tions in their hydrogenated form and included in those product is an oleate (C18, with one double bond) rather specifications are certain physical attributes which are than a stearate (C8, with no double bonds). It is now demanded by the trade. Of these the melting point and 65 possible with this invention to continuously hydrogenate plastic range are of considerable importance. In general, edible fats and oils to products of acceptable partial satu it may be said that the margarines have a relatively high ration and of commercially desirable iodine value without melting point in order to maintain shape and consistency substantial increase in the amount of total saturates in at normal room temperatures and must have a relatively the product. One of the reasons making this process pos short plastic range before they become liquid. Mar 0 sible resides in the discovery of a nickel-containing cat garines generally melt completely by or preferably below alyst of unique form and preparation as well as composi a temperature of 104 F. The shortening agents, on the tion. 3,123,626 g s In accordance with this invention continuous hydro well established in that with the use thereof continuous genation with improved selectivity, including the capacity operation is now possible in hydrogenation of edible fats to selectively conjugate the polyethenoid bonds to Se and oils. lectively hydrogenate edible fats and oils, is obtained un In an earlier filed co-pending application, Serial No. der closely controlled conditions and in the presence of 812,138, filed May 11, 1959, the description of the manu a unique hydrogenation catalyst. The contacting con facture and use of a superior fat hydrogenation catalyst ditions include temperatures in the range of 100-400 is set forth. In such identified application it is shown F.; pressures, measured as free hydrogen, in the range of that nickel, obtained from nickel formate impregnating 10 to 150 lbs./sq. in... gauge (p.s.i.g.); contact time in the solution, supported on a powder-included silica gel of order of 0.25 to 10 hours controlled by liquid hourly large pore size is superior to previously available ma space velocity in the range of 0.1 to 4.00 (LHSV). The terials in certain aspects in the provision of a highly ac charge at these conditions is contacted with a fixed bad ceptable catalyst material for the hydrogenation of cer of catalyst which comprises a powder-included macro tain fats and oils. However, the present catalyst is su porous silica support associated with an active hydro perior in its particular field even to this material. Where genation component obtained from nickel sulfate con the nickel formate catalyst is used in a continuous sys prising nickel with anionic sulphur present in a ratio of tem for the hydrogenation of edible fats and oils with 5 to 30 parts by weight nickel to one of sulfur (i.e., 0.13 their strict product specifications, such catalyst is found to 4.99% by weight of sulfur based on the final catalyst) to be relatively non-selective and indiscriminate in the and further characterized in that the pore structure of reactions therein promoted so that the product which be the catalyst contains at least 15% of its pores with an 20 comes hydrogenated contains a substantially larger average diameter in the order of at least 100 A.

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