IIII USOO51 77008A United States Patent (19) 11 Patent Number: 5,177,008 Kampen 45) Date of Patent: Jan. 5, 1993 54 PROCESS FOR MANUFACTURING 5,019,263 5/1991 Haag et al. ..................... 210/500.25 ETHANOL AND FOR RECOVERING GLYCEROL, SUCCINIC ACID, LACTIC ACID, FOREIGN PATENT DOCUMENTS BETAINE, POTASSIUM SULFATE, AND 51-039625 5/1976 Japan ...................................., 101/OO FREE FLOWING DISTILLER'S DRY GRAIN 55-045067 ll/1980 Japan ..................................... 10/2 AND SOLUBLES OR A SOLID FERTILIZER THEREFROM OTHER PUBLICATIONS Chico et al., "L. Alanine as an end product of glycolyi Inventor: Willem H. Kampen, 447 Blue Rock sis in saccharomyces-cerevisiae growing under differ Dr., Charlotte, N.C. 28213 ent hypoxic conditiones," CA79: 177022 Bioss. 1978. Appl. No.: 537,779 "Recovery of Chemicals Such as Glycerol, Dextrose, and Amino Acids from Dilute Broths', Brian D. Burris, Filed: Jun. 18, 1990 pp. 1-39. Related U.S. Application Data Primary Examiner-Robert J. Warden Assistant Examiner-Timothy M. McMahon Continuation-in-part of Ser. No. 381,179, Jul. 18, 1989, which is a continuation-in-part of Ser. No. 136,415, Attorney, Agent, or Firm-Rhodes, Coats & Bennett Dec. 22, 1987, abandoned. (57) ABSTRACT Int. Cl. ................................................ G2P 7/20 This invention relates to the manufacture of ethanol and U.S. C. .................................... 435/139; 435/145 the recovery of economically significant amounts of 435/146; 435/59: 435/16 such by-products therefrom as glycerol, betaine, L (58) Field of Search ............... 435/139, 141, 145, 146, pyroglutamic acid, succinic and lactic acid, potassium 435/159, 161, 163 sulfate and a free flowing distiller's dry grain and solu bles useful as an animal feed or a component of food for (56) References Cited humans or as a premix for agricultural fertilizer and/or U.S. PATENT DOCUMENTS a feed additive. An important aspect of the recovery 2, 69.245 8/1939 Hildebrandt et al. ..............., 195/38 step is the utilization of a crossflow microfiltration sys 2,772.207 1/1956 Frankel et al. ..... ... 195/38 tem which includes inorganic membranes for the classi 4,336,335 6/982 Muller et al. ....................... 435/33 fication of the stillage. 4,359,430 l/1982 Heikkila et al. ... 260/5013 4,689,048 8/1987 Fortsch et al. ...................... 210/650 37 Claims, 2 Drawing Sheets PREPARE MAS CEAN BACKSET OSTELATON ETHANo. (CENTRIFUGING) MICROF TRATION (PARTAL SOFTENING) (HYDROLYSIS OF SOLIDS DRYNG PROTEINACEOUS MAERA (OR) EWAPORATON ION EXCHANGE POTASSUMSUFATE REMOVA CHROMATOGRAPHIC SEPARATION - EWAPORATION KON EXCHANGE - cg3NSSRARS (ION EXCHANGE) EWAPORATION CONCENTRATION PURIFICATION DISTILLATKON EWAPORATION L-PYROG UAMC REFINING ACD SUCCNC BETAINE LACTIC - LACID ACID U.S. Patent Jan. 5, 1993 Sheet 1 of 2 5,177,008 PREPARE MASH CLEAN BACKSET DISTILLATION ETHANOL (CENTRIFUGING) MSEESNPARTIAL SOFTENING SOLDS DRYIN EFSF Sious OLIDS DRYING (OR) SOLID PREMIXFERTLIZER DDG(S) EVAPORATION CONDENSATE ION EXCHANGE POTASSUM SULFATE REMOVAL CHROMATOGRAPHCSEPARATION F EVAPORATION ION EXCHANGE CHROMATOGRAPHC SEPAPARATION(S) EVAPORATION (ON EXCHANGE) CONCENTRATION PURIFICATION DISTILLATION EVAPORATION L-PYROGLUTAMC REFINING ACD acrossGLYCEROL SUCCNC estangBETANE LACTIC F.G. U.S. Patent Jan. 5, 1993 Sheet 2 of 2 5,177,008 PREPARING MASH FROM SUGAR BEET MOLASSES CLEAN BACKSET DISTILLATION ETHANOL MCROFILTRATION SOLDS DRYNG ENZYMATC HYDOLYSS FERTLIZER PRE-MX PROTEINACEOUS MATTER EVAPORATION CONDENSATE K2SO4 REMOVAL CHROMATOGRAPHC SEPARATION I. EVAPORATION EVAPORATION EVAPORATION CHROMATOGRAPHC SEPARATION II BETAINE REMOVAL ION EXCHANGE / EVAPORATION DISTILLATION / REFINING GLYCERNE BETAINE (HC) FIG.2 5,177,008 1 2 "Recovery of Chemicals Such as Glycerol, Dextrose, PROCESS FOR MANUFACTURING ETHANOL and Amino Acids from Dilute Broths' which was AND FOR RECOVERING GLYCEROL, SUCCINIC presented to the "International Conference on Fuel ACID, LACTIC ACID, BETAINE, POTASSIUM Alcohols and Chemical from Biomass' on Nov. 10-12, SULFATE, AND FREE FLOWING DISTILLER'S 5 1986 in Miami Beach, Fla. The process there disclosed DRY GRAIN AND SOLUBLES OR A SOLID includes a very precise sequence of operations including FERTILIZER THEREFROM ultrafiltration (organic membranes with pore size of <0.1 microns), pH adjustment, filtration, ion exclusion, RELATED APPLICATIONS ion exchange, and carbon treatment. This sequence of This application is a continuation-in-part of copend O operations has not proven to provide a commercially ing application Ser. No. 381,179 filed Jul. 18, 1989, feasible glycerol recovery process. which is, in turn, a continuation-in-part of copending Betaine production is, by way of example, discussed application Ser. No. 136,415 filed 22 Dec. 1987, now in U.S. Pat. No. 4,359,430 to Heikkila et al; Japanese abandoned the priority of which is claimed. Patent No. 51/039625; and Japanese Patent No. 15 80/045067. While the production of betaine from sugar FIELD AND BACKGROUND OF THE beet molasses is a known commercially feasible process INVENTION as described in the above listed patents, it is not known This invention relates to the manufacture of glycerol, to produce betaine from stillage. This is because of a betaine, succinic and/or lactic acid, potassium sulfate, serious fouling of the chromatographic resin by yeast and L-pyroglutamic acid. More particularly the inven 20 cells, microorganisms and other compounds. The manu tion relates to the recovery of the above products as a facture of glycerol, betaine, succinic acid and free flow result of the fermentation and distillation of raw materi ing distiller's dry grain, or the production of both beta als into ethanol and stillage, from which a free flowing ine and glycerol from beet molasses stillage, by pro distiller's dry grain or solid fertilizer is produced. cesses such as those to be described hereinafter has not, The manufacture of each of the products named 25 above by other processes has been known heretofore, insofar as is known to the present inventor, been de and all have commercial uses. Ethanol is used as a bev scribed in any prior patent or publication other than erage, a chemical, and a fuel derived from renewable that which has resulted from the aforementioned prior resources, and is typically manufactured by fermenta ity application. tion and distillation processes starting from biological For the first time, it is now possible to recover betaine materials such as corn, wheat or other grain, sugar cane and/or glycerine from stillage of ethanol fermentations or beets, grapes or other fruit. potatoes, cassava, sweet with sugar beet derivatives. The preparation of the feed sorghum, cheese whey or the like. Glycerol, while with microfiltration and the two chromatographic sepa known to be produced in Small quantities as a by-pro ration steps for the production of pure glycerine and duct of ethanol fermentation and distillation processes 35 betaine are critical. Cross-flow microfiltration with or yeast and yeast extract production, has been manu inorganic membranes followed by enzymatic hydrolysis factured commercially only by processes which have of proteinaceous matter and/or removal of potassium soap as the primary product or which synthesize glyc sulfate crystals in the permeate (if required) will yield a erol from petrochemical feed-stocks. Betaine is conven truly clarified stillage. The clarified stillage may now be tionally produced synthetically or by crystallization of 40 concentrated to a very high solids concentration for the aqueous liquors of beet molasses. Succinic acid is further processing in two chromatographic separation conventionally synthesized from maleic or acetic acid steps, each with its own specific resin, yielding high or produced by means of a highly specific fermentation. purity glycerine and betaine streams. This novel process Lactic acid is conventionally produced by fermentation has several advantages over existing and different meth with Lactobacillus delbruecki, B. dextrolacticus, or 45 ods in use as described in the patents listed above, such similar microorganisms. Potassium sulfate is conven as energy and water savings, reduced capitol invest tionally obtained by reacting sulfuric acid with potas ment, very high solids concentrations, high quality sium chloride. Potassium chloride usually occurs in glycerine and betaine. nature as the mineral sylvine or Sylvite. The processes and apparatus of the present invention Distiller's dry grain, characterized as with (DDGS) 50 contemplate the production of each or all or any combi or without (DDG) solubles, is conventionally produced nation of the products mentioned in a commercially as a by-product of fermentation and distillation pro feasible manner in a fermentation and distillation or cesses. As such the resulting DDG or DDGS is usually similar process. infused with sticky by-products such as glycerol so as to BRIEF DESCRIPTION OF THE INVENTION exhibit poor flowing qualities and be difficult to handle. 55 If the substrate from which distillates are produced is a More particularly, it is an object of this invention to sugar cane or beet material, then the residue is typically produce glycerol as a valuable co-product of a fermen used only as a liquid fertilizer, feed additive or treated as tation process such as one which produces ethanol. In a waste. realizing this object of the present invention, the effi The manufacture of ethanol is sufficiently well ciency of the known ethanol producing fermentation known and