Process for treating cellulosic materials

• US 6,106,888 A
• Filed: 01/19/1999
• Issued: 08/22/2000
• Est. Priority Date: 04/30/1998
• Status: Expired due to Term

• Current Assignee: The Board of Trustees of Michigan State University (Michigan State University)
• Original Assignee: The Board of Trustees of Michigan State University (Michigan State University)
• Inventors: Dale, Bruce E., Weaver, Justin K.
• Primary Examiner(s): Hendricks, Keith D.
• Assistant Examiner(s): BECKER, DREW E
• Application Number:
  US09/232,980
• Time in Patent Office: 581 Days
• Field of Search: 426/635, 426/636, 426/506, 426/516, 426/519, 426/520, 426/807
• US Class Current: 426/636
• CPC Class Codes: A23K 10/32 from hydrolysates of wood or straw
• CPC Class Codes: A23K 40/20 by moulding, e.g. making cakes or briquettes
• CPC Class Codes: A23K 40/25 by extrusion
• CPC Class Codes: A23K 50/15 containing substances which are metabolically converted to proteins, e.g. ammonium salts or urea
• CPC Class Codes: A23P 30/34 by extrusion-expansion
• CPC Class Codes: B29C 48/022 characterised by the choice of material
• CPC Class Codes: B29C 48/09 Articles with cross-sections having partially or fully enclosed cavities, e.g. pipes or channels
• CPC Class Codes: B29C 48/12 Articles with an irregular circumference when viewed in cross-section, e.g. window profiles
• CPC Class Codes: B29C 48/2564 Screw parts
• CPC Class Codes: B29C 48/58 provided with seal ring elements, i.e. elements of generally circular and tapered shape for preventing the back flow of the melt
• CPC Class Codes: B29K 2093/00 Use of natural resins, e.g. shellac, or derivatives thereof, as moulding material B29K2001/00, B29K2003/00, B29K2005/00, B29K2007/00 and B29K2089/00 take precedence
• CPC Class Codes: C12P 2201/00 Pretreatment of cellulosic or lignocellulosic material for subsequent enzymatic treatment or hydrolysis
• CPC Class Codes: Y10S 426/807 Poultry or ruminant feed

Abstract

A process and screw in barrel apparatus (10) for expanding cellulosic materials is described. The expanded cellulosic material is useful as an animal feed and a nutrient source for fermentation processes.

Claims

1. In a process for increasing availability of sugar content and digestibility of a lignocellulosic material by contacting the lignocellulosic material with a liquid ammonia which impregnates the lignocellulosic material and then rapidly reducing the pressure to thereby expand the lignocellulosic material by gaseous expansion of the liquid ammonia to a gas which increases availability of the sugar content and the digestibility of the lignocellulosic material, the improvement which comprises:

(a) injecting the liquid ammonia and the lignocellulosic material into a screw in a heated barrel having a feed throat leading to the screw in rotating contact with the barrel along part of a length of the screw so that the screw is sealed in operation, with an inlet for feeding the liquid ammonia into the feed throat under pressure to the screw and with heated outlet from the barrel adjacent to the screw;

(b) compacting the liquid ammonia and lignocellulosic material by rotation of the screw in the barrel;

(c) removing the liquid ammonia and the lignocellulosic material from the barrel through the outlet from the extruder so that the liquid ammonia expands explosively from the liquid to the gas in the lignocellulosic material; and

(d) recovering the liquid ammonia as the gas from the lignocellulosic material.

2. The process of claim 1 wherein the barrel is at a temperature between about 30°

and 100°

C.

3. The process of claim 1 wherein the lignocellulosic material is corn fodder or stover.

4. The process of claim 1 wherein the lignocellulosic material has been ground to between about 0.01 and 1.0 inch and contains between about 10% to 80% by weight moisture based upon a dry weight of the lignocellulosic material before being introduced into the feed throat of the screw in barrel apparatus.

5. The process of any one of claims 1, 2, 3, or 4 wherein a die means is provided on the barrel which compresses the lignocellulosic material before removal from the screw in barrel apparatus.

6. The process of any one of claims 1, 2, 3 or 4 wherein a die block is provided on the outlet from the barrel of the screw in barrel apparatus and wherein the die block is heated to between 30°

to 100°

C. and wherein a die is provided on the die block which compresses the lignocellulosic material before removal from the screw in barrel apparatus.