Method and apparatus for conversion of cellulosic material to ethanol

• US 20100041119A1
• Filed: 07/19/2006
• Published: 02/18/2010
• Est. Priority Date: 07/19/2005
• Status: Active Grant

• Current Assignee: Inbicon A/S
• Original Assignee: Holm Christensen Biosystemer ApS
• Inventors: Gerlach, Lena Holm, Christensen, Børge Holm
• Granted Patent: US 8,123,864 B2
• Time in Patent Office: Days
• US Class Current: 435/162
• CPC Class Codes: B01J 19/245 placed in series
• CPC Class Codes: B01J 2219/00006 Large-scale industrial plants
• CPC Class Codes: C08B 1/003 Preparation of cellulose solutions, i.e. dopes, with different possible solvents, e.g. ionic liquids solutions used in the manufacture of monocomponent artificial filaments or cellulose or derivatives thereof D01F2/02
• CPC Class Codes: C08B 15/00 Preparation of other cellulose derivatives or modified cellulose , e.g. complexes
• CPC Class Codes: C08B 37/0057 beta-D-Xylans, i.e. xylosaccharide, e.g. arabinoxylan, arabinofuronan, pentosans; (beta-1,3)(beta-1,4)-D-Xylans, e.g. rhodymenans; Hemicellulose; Derivatives thereof
• CPC Class Codes: C08H 6/00 Macromolecular compounds derived from lignin, e.g. tannins, humic acids
• CPC Class Codes: C08H 8/00 Macromolecular compounds derived from lignocellulosic materials pretreatment thereof B27N
• CPC Class Codes: C12M 21/12 for producing fuels or solvents C12M21/04 takes precedence; liquid carbonaceous fuels C10L1/00, solid fuels C10L5/00
• CPC Class Codes: C12M 45/02 by mechanical forces; Stirring; Trituration; Comminuting crushing, pulverizing, disintegrating in general B02C
• CPC Class Codes: C12M 45/04 Phase separators; Separation of non fermentable material; Fractionation
• CPC Class Codes: C12M 45/09 by enzymatic treatment
• CPC Class Codes: C12M 45/20 Heating; Cooling heating or cooling apparatus for laboratory uses B01L7/00
• CPC Class Codes: C12P 19/02 Monosaccharides 2-ketogulonic acid C12P7/60
• CPC Class Codes: C12P 19/14 produced by the action of a carbohydrase (EC 3.2.x), e.g. by alpha-amylase , e.g. by cellulase, hemicellulase
• CPC Class Codes: C12P 21/00 Preparation of peptides or proteins single cell protein C12N1/00
• CPC Class Codes: C12P 2201/00 Pretreatment of cellulosic or lignocellulosic material for subsequent enzymatic treatment or hydrolysis
• CPC Class Codes: C12P 2203/00 Fermentation products obtained from optionally pretreated or hydrolyzed cellulosic or lignocellulosic material as the carbon source ethanol C12P7/10
• CPC Class Codes: C12P 7/10 substrate containing cellulosic material
• CPC Class Codes: C12P 7/14 Multiple stages of fermentation; Multiple types of microorganisms or re-use of microorganisms
• CPC Class Codes: C12P 7/56 Lactic acid
• CPC Class Codes: C13B 20/165 : using membranes, e.g. osmosis, ultrafiltration electrodialysis C13B20/18
• CPC Class Codes: C13K 1/02 : obtained by saccharification of cellulosic materials manufacture of fodder A23K10/32
• CPC Class Codes: D21C 9/18 : De-watering de-watering in general F26B; Elimination of cooking or pulp-treating liquors from the pulpD21C9/002, D21C9/02 take precedence; paper-making machines D21F; strainers in digesters D21C7/00; presses in general B30B
• CPC Class Codes: Y02E 50/10 : Biofuels, e.g. bio-diesel

Abstract

The present invention provides an apparatus and a method for conversion of cellulosic material, such as chopped straw and corn stover, and household waste, to ethanol and other products. The cellulosic material is subjected to continuous hydrothermal pre-treatment without addition of chemicals, and a liquid and a fibre fraction are produced. The fibre fraction is subjected to enzymatic liquefaction and saccharification. The method of the present invention comprises:

• • performing the hydrothermal pre-treatment by subjecting the cellulosic material to at least one soaking operation, and conveying the cellulosic material through at least one pressurised reactor, and subjecting the cellulosic material to at least one pressing operation, creating a fibre fraction and a liquid fraction;
  • selecting the temperature and residence time for the hydrothermal pretreatment, so that the fibrous structure of the feedstock is maintained and at least 80% of the lignin is maintained in the fibre fraction.

Claims

1-84. -84. (canceled)

85. A method of continuous hydrothermal pretreatment of lignocellulosic biomass feedstock comprising:

(i). treating the feedstock so as to drive out air and ensure that all of the feedstock is saturated with liquid, while avoiding heating of unnecessary liquid, without adding acids, bases or other chemicals which must be recovered, followed by

(ii). pressurized treatment of the material at temperatures between 170°

C. and about 230°

C. wherein the pretreated feedstock is subsequently pressed while it is still under pressure or after it has been unloaded from the pretreatment reactor to create a fibre fraction and a liquid fraction, and wherein temperature and residence time for hydrothermal pretreatment are selected so that greater than 80% of the original lignin content of the feedstock remains in the fibre fraction.

86. The method of claim 85 wherein fibrous structure with cavities in the particles of the cellulosic material is maintained.

87. The method of claim 85 wherein the feedstock is cleaned for sands, stones and other undesirable heavy objects by wet cleaning using the liquid fraction as wash water.

88. The method of claim 85 further characterized in that at least a part or a fraction of the liquid fraction is used to lower the dry matter content in sugar and/or starch feedstock of an ethanol-production process based on starch and/or sugar, such as a grain mashing process.

89. The method of claim 85 further characterized in that at least a part or a fraction of the liquid fraction is used as feedstock for the production of enzymes and C5 fermenting microorganisms.

90. The method of claim 85 further characterized in that feedstock is soaked in liquid fraction at ambient pressure before pressurized treatment.

91. The method of claim 85 further characterized in that at least a part or a fraction of the liquid fraction is used to obtain a ruminant animal feed.

92. The method of claim 85 further characterized by enzymatic liquefaction of the fibre fraction.

93. The method of claim 92 further characterized by SSF of the liquefied fraction.

94. The method of claim 85 further characterized by SSF of the fibre fraction.

95. The method of claim 93 or 94 further characterized by leaving lignin microparticles in the fermentation mixture.

96. The method of claim 93 or 94 further characterized in that ethanol production is integrated with an ethanol-production process based on starch and/or sugar.

97. The method of claim 93 or 94 further characterized in that ethanol production is integrated with existing power plants.

98. The method of claim 93 or 94 further characterized in that SSF is integrated with an ethanol stripping process operating with temperatures in the broth close to the fermentation temperature, and wherein the stripped fiber beer with active enzymes and microorganisms is recycled to the fermentation reactor.

99. The method of claim 93 or 94 further characterized in that SSF is integrated with an ethanol stripping process based on gas stripping.

100. The method of claim 93 or 94 further characterized in that lignin microparticles are obtained from the SSF mixture that are suited for co-combustion as solid biofuel with pulverized coal.

101. A method according to claim 85, wherein enzyme-loaded particles of fibre fraction are fed into and moved through an elongated liquefaction reactor, filled with a fluid of liquefied fibre fraction.

102. A method according to claim 101, wherein the liquefied fibre fraction is conveyed to the fermentor after having passed through the incoming fibre fraction.

103. A method for conversion of cellulosic material to ethanol and other products, the cellulosic material comprising at least cellulose, lignin, hemicellulose and ash, in which method the cellulosic material is cleaned and subjected to continuous hydrothermal pre-treatment without addition of acids or bases or other chemicals, which must be recovered, and in which method a liquid and a fibre fraction are produced, the fibre fraction being subjected to enzymatic liquefaction and saccharification, the method including ethanol fermentation and product recovery, the method comprising:

—

performing the hydrothermal pre-treatment by subjecting the cellulosic material to at least one soaking operation, and conveying the cellulosic material through at least one pressurised reactor defining a reactor pressure zone at an elevated pressure;

the cellulosic material being heated to a temperature between 170 and 230°

C., and subjecting the cellulosic material to at least one pressing operation, creating a fibre fraction and a liquid fraction, either while it is still under pressure or after it has been unloaded from the pretreatment reactor;

—

selecting the temperature and residence time for the hydrothermal pretreatment, so that the fibrous structure of the feedstock is maintained and at least 80% of the lignin is maintained in the fibre fraction.

104. A solid biofuel suited for co-combustion with pulverized coal comprising a combustible residue of lignin microparticles obtained from hydrothermal pretreatment of lignoellulosic biomass.

105. The solid biofuel of claim 104 derived from fermentation mixtures obtained using the method of claim 93 or 94.

106. A ruminant animal feed comprising C5 sugars obtained from hydrothermal pretreatment of lignocellulosic biomass.

107. The ruminant animal feed of claim 106 derived from liquid fraction obtained using the method of claim 85.