Process and installation for obtaining ethanol by the continuous acid hydrolysis of cellulosic materials

• US 4,529,699 A
• Filed: 04/27/1982
• Issued: 07/16/1985
• Est. Priority Date: 04/30/1981
• Status: Expired due to Fees

• Current Assignee: Industrias Villares SA A Brazilian Joint-Stock Company
• Original Assignee: Industrias Villares SA
• Inventors: Miller, Joseph, Gerez, Maria D. C. A., Gerez, Jose C. C.
• Primary Examiner(s): Penland, R. B.
• Application Number:
  US06/372,105
• Time in Patent Office: 1,176 Days
• Field of Search: 435/161, 435/163, 435/165, 435/813, 426/626, 426/807, 127/37
• US Class Current: 435/165
• CPC Class Codes: C12P 7/10 substrate containing cellulosic material
• CPC Class Codes: C13K 1/02 obtained by saccharification of cellulosic materials manufacture of fodder A23K10/32
• CPC Class Codes: Y02E 50/10 Biofuels, e.g. bio-diesel

Abstract

Invention patent for a "Process and Installation for Obtaining Ethanol by the Continuous Acid Hydrolysis of Cellulosic Materials", such process comprising the stages of: providing an homogenized aqueous pulp of cellulosic material having 3 to 30% in weight of solids; pumping the cellulosic material pulp, in a substantially continuous way, to the interior of the inlet end of a tubular reactor and restricting its outlet opposite end to maintain a given internal pressure inside the same; heating the pressurized cellulosic material pulp up to the temperature of about 160° to 250° C. before its introduction into the reactor; adding, in a substantially continuous way, a given dose of a concentrated acid to the pressurized and heated cellulosic material pulp, which will be continuously diluted in the reactor, to provide the hydrolysis reaction of said pulp, the acid addition being made inside the reactor at a point longitudinally adjustable from the inlet end of the reactor; discharging in a substantially continuous way through the outlet end of the reactor a given load of hydrolyzed cellulosic material, said discharge being regulated in conjunction with the longitudinal positioning of the point of addition of the acid, thus fixing the reaction time adequate for the cellulosic material pulp; subjecting the hydrolyzed cellulosic material pulp to an abrupt pressure drop and cooling immediately after it leaves the reactor; neutralizing and fermenting the resulting aqueous solution to obtain ethanol; and recovering the resulting byproducts which are methanol, furfural, acetic acid and lignin.

Claims

1. A process for obtaining ethanol by continuous acid hydrolysis of cellulosic materials, consisting essentially of:

(a) providing an aqueous homogenized pulp of cellulosic materials containing about 3 to 30% of solids by weight;

(b) providing a tubular reactor having an inlet at one end therof and an outlet at the opposite end thereof;

(c) maintaining a constant pressure within the reactor by pumping said pulp in a substantially continuous manner into said tubular reactor through the inlet and while controlling outflow of said pulp at the outlet end of said reactor, said pressure ranging between about 10 and about 40 kg/cm² ;

(d) electrically heating said pulp to a temperature ranging between about 160°

C. and about 250°

C. prior to pumping said pulp into said reactor;

(e) providing a point of acid addition into said reactor, said point being continually adjustable longitudinally from the inlet of said reactor towards the outlet of said reactor;

(f) substantially continuously adding into said pressurized and heated pulp concentrated acid selected from the group consisting of sulfuric, sulfurous, hydrochloric, and phosphoric acid in an amount sufficient to cause a hydrolysis reaction to occur;

(g) discharging in a substantially continuous manner through the outlet end of said reactor said hydrolyzed cellulosic material;

(h) during said process, adjusting the retention time of said acid and said cellulosic material to be maintained at an optimum for said hydrolysis reaction, by longitudinally adjusting said point of acid addition and by regulating the rate of said discharge;

(i) immediately upon discharge from the reactor, subjecting the hydrolyzed pulp to an abrupt pressure drop and cooling it, thereby causing the evaporation of volatile components from said pulp and completing said hydrolysis reaction;

(j) subsequently separating the pulp into a solid residue and an aqueous solution supernatant;

(k) neutralizing and fermenting said supernatant to obtain ethanol; and

(l) recovering said volatile components evaporated in said step (i).

2. A process according to claim 1, wherein the reaction time of the cellulosic material pulp inside the reactor is about 20 to 300 seconds.

3. A process according to claim 1, wherein the concentrated acid is sulfuric acid, said acid being added in an amount such that, when diluted by the water of the cellulosic material pulp, it is present in a concentration of about 0.1 to 3%.