Method for producing a sugar syrup from a residual lignocellulosic biomass
The invention relates to a method for producing a sugar syrup comprising fermentable sugars from lignocellulosic biomass containing paper waste, in particular printable paper, printed paper or cardboard, said method comprising the following steps: a. optionally, a step of shredding said lignocellulosic biomass containing paper waste: b.i. a step of impregnating said lignocellulosic biomass containing paper waste or shredded lignocellulosic biomass obtained on completion of step a. in an aqueous medium, and ii. a thermal pretreatment step implemented, without the addition of acid, at a temperature of between 80° C. and 150° C. at a pH between 6.5 and 8.5, in particular between 6.5 and 8, in order to obtain a pretreated product, said impregnation and thermal pretreatment steps being carried out simultaneously or successively according to i. and then ii: c. a step of enzymatic hydrolysis of the pretreated product obtained on completion of step b. in order to convert the cellulose and hemicellulose into a sugar syrup comprising fermentable sugars; and d. a step of recovering the sugar syrup comprising fermentable sugars obtained on completion of step c.
1 . A method for producing a sugar syrup comprising fermentable sugars comprising glucose from lignocellulosic biomass consisting of paper waste, said method comprising:
a. i. an impregnation step of said lignocellulosic biomass in an aqueous medium, and ii. a thermal pre-treatment step of said lignocellulosic biomass performed without addition of acid, at a temperature between 80° C. and 100° C., at a pH of between 6.5 and 8.5, to obtain a pre-treated product, said impregnation step a. i. and said thermal pre-treatment step a. ii. being conducted simultaneously or successively with i. followed by ii.;
b. an enzymatic hydrolysis step of the pre-treated product obtained from step a. to convert cellulose and hemicellulose to said sugar syrup; and
C. a recovery step of said sugar syrup obtained from step b.
2 . The method according to claim 1 , wherein said lignocellulosic biomass, before said impregnation step, has a total dry matter content of between 70% and 100%, by weight of said lignocellulosic biomass and is constituted by said paper waste, or has a total dry matter content comprised between 45% and 96% by weight of said lignocellulosic biomass and at least a portion of said paper waste is composed of a fermentable fraction of household waste.
3 . The method according to claim 1 , wherein said thermal pre-treatment step a. ii. is conducted at a pressure of between 1 bar and 5 bars.
4 . The method according to claim 1 , wherein said thermal pre-treatment step a. ii. is conducted for a time comprised between 10 minutes and 120 minutes.
5 . The method according to claim 1 , wherein said enzymatic hydrolysis step b. is performed by a mixture of cellulolytic enzymes, hemicellulolytic enzymes, or a combination thereof.
6 . The method according to claim 1 , wherein said sugar syrup recovered from step c., has at least one characteristic selected from the group consisting of:
a total dry matter content of between 5% and 25% by weight of said sugar syrup;
a free glucose content of between 60% and 75% by weight of a total dry matter content of said sugar syrup; and
a ratio of glucose to total sugars of between 60% and 90% by weight of a total dry matter content of said sugar syrup.
7 . The method according to claim 1 , wherein said method further comprises:
d. a clarification step of said sugar syrup recovered from step c. to separate solid residues from liquid residues;
e. a purification step of said sugar syrup obtained from step d.; and
f. a recovery step of said purified sugar syrup obtained from step e.
8 . The method according to claim 7 , wherein after said purification step e., said method further comprises:
g. a concentration step of said purified sugar syrup obtained from step e.; and
h. a recovery step of said purified and said concentrated sugar syrup obtained from step g.
9 . The method according to claim 7 , wherein said purification step e. is performed by filtration on activated carbon.
10 . The method according to claim 1 , wherein said paper waste comprises printing paper, office paper, printed paper, chipboard, cardboard, boxes, newspapers, magazines, or a combination thereof.
11 . The method according to claim 1 , wherein said paper waste is provided as a fermentable fraction of household waste (FFHW).
12 . The method according to claim 8 , wherein said sugar syrup recovered from step f. or h. has at least one characteristic selected from the group consisting of:
a total dry matter content of between 50% and 75% by weight of said sugar syrup;
a free glucose content of between 60% and 75% by weight of a total dry matter content of said sugar syrup; and
a ratio of glucose to total sugar sugars of between 70% and 90% by weight of a total dry matter content of said sugar syrup.
13 . The method according to claim 1 , wherein said sugar syrup comprises xylose.
14 . The method according to claim 1 , wherein said sugar syrup recovered from step c. comprises:
a ratio of glucose to total sugars of between 70% and 90% by weight of a total dry matter content of said sugar syrup; and
a content of furfural or hydroxymethylfurfural (HMF) of less than 200 ppm.
15 . The method according to claim 1 , further comprising using said sugar syrup to produce at least one biosourced molecule selected from the group consisting of lactic acid, acetic acid, butyric acid, propionic acid, succinic acid, isopropanol and isobutene.
16 . The method according to claim 1 , further comprising using said sugar syrup to produce biofuels.
17 . A method for producing biofuels comprising:
a. i. impregnating lignocellulosic biomass consisting of paper waste in an aqueous medium, and ii. thermally pre-treating the lignocellulosic biomass without addition of acid, at a temperature between 80° C. and 100° C., at a pH of between 6.5 and 8.5, to obtain a pre-treated product, said impregnating and thermal pre-treating being conducted simultaneously or successively with i. followed by ii.;
b. enzymatic hydrolyzing of said pre-treated product obtained from step a. to convert cellulose and hemicellulose to sugar syrup comprising fermentable sugars comprising glucose;
c. recovering said sugar syrup obtained from step b.; and
d. subsequently fermenting said recovered sugar syrup to convert said recovered sugar syrup to biofuels.
18 . The method according to claim 17 , further comprising fermenting by yeasts, comprising at least one of: (a) a genus Saccharomyces , (b) Saccharomyces cerevisiae , and/or (c) bacteria including Clostridium acetobutylicum or Escherichia coli.
19 . The method according to claim 17 , wherein said sugar syrup comprises a ratio of glucose to total sugars of between 70% and 90% by weight of a total dry matter content of said sugar syrup and a content of furfural or hydroxymethylfurfural (HMF) of less than 200 ppm, and wherein said biofuels include ethanol which is produced with a yield measured by high performance liquid chromatography (HPLC) relative to sugar, that is higher than 40%.
20 . The method according to claim 1 , further comprising: prior to step a., milling said lignocellulosic biomass.
21 . The method according to claim 1 , wherein said thermal pre-treatment step a. ii. is conducted without addition of a chemical catalyst.
22 . The method according to claim 1 , wherein said thermal pre-treatment step a. ii. is conducted at a pH between 6.8 and 8.