# US 9,435,002 B2 · Continuous processes for hydrolyzing hemicelluloses from ligocellulosic materials with cleaning system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,435,002 B2 - Document ID: US9435002B2 - Status: Granted - Kind: B2 - Application number: 14/714,214 - Filed: 2015-05-15 - Published: 2015-12-10 - Granted: 2016-09-06 - Earliest claimed: 2014-06-07 - Assignees: API Intellectual Property Holdings, LLC - Applicants: API Intellectual Property Holdings, LLC - Inventors: Zheng Dang; Mehmet Sefik Tunc; Ziyu Wang - Web page: https://patentgrep.com/patent/US9435002B2 ## CPC - C13K 13/002: {Xylose} - C07C 51/00: Preparation of carboxylic acids or their salts, halides or anhydrides (of acids by hydrolysis of oils, fats or waxes C11C) - C07D 307/50: Preparation from natural products - C13K 1/02: obtained by saccharification of cellulosic materials (manufacture of fodder A23K10/32) - C13K 13/00: Sugars not otherwise provided for in this class - Y02E 50/10: Biofuels, e.g. bio-diesel - C13K: SACCHARIDES OBTAINED FROM NATURAL SOURCES OR BY HYDROLYSIS OF NATURALLY OCCURRING DISACCHARIDES, OLIGOSACCHARIDES OR POLYSACCHARIDES (chemically synthesised sugars or sugar derivatives C07H; polysaccharides, e.g. starch, derivatives thereof C08B; malt C12C; fermentation or enzyme-using processes for preparing compounds containing saccharide radicals C12P19/00; production of sucrose C13B) - C07C: ACYCLIC OR CARBOCYCLIC COMPOUNDS - C07D: HETEROCYCLIC COMPOUNDS (macromolecular compounds C08) - Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION ## Abstract A continuous process for producing hemicellulose sugars from a biomass extraction liquor is provided. A system is configured for continuously producing hemicellulose sugars and/or hemicellulose derivatives from a biomass extraction liquor, the system comprising at least a first hydrolysis reactor and a second hydrolysis reactor. Each of the hydrolysis reactors is in switchable communication with (i) an operating feed stream of a biomass extraction liquor containing water, hemicellulose oligomers, and dissolved or suspended lignin, and (ii) a cleaning feed stream of a cleaning agent selected from the group consisting of steam, an alkaline solution, an organic solvent, and combinations thereof. The cleaning agent dissolves precipitated lignin formed from the lignin under the hydrolysis reaction conditions. ## Claims ### Claim 1 A continuous process for producing hemicellulose sugars from a biomass extraction liquor, said process comprising: (a) providing or obtaining a biomass extraction liquor containing water, hemicellulose oligomers, and dissolved or suspended lignin; (b) optionally introducing an acid catalyst to said biomass extraction liquor; (c) for a first period of time, feeding said biomass extraction liquor through a first hydrolysis reactor under effective hydrolysis reaction conditions to hydrolyze said hemicellulose oligomers into hemicellulose monomers; (d) at a first switching time, diverting said biomass extraction liquor from said first hydrolysis reactor to a second hydrolysis reactor; (e) for a second period of time, feeding said biomass extraction liquor through said second hydrolysis reactor under said effective hydrolysis reaction conditions; (f) during said second period of time, cleaning said first hydrolysis reactor by introducing a cleaning agent selected from the group consisting of steam, an alkaline solution, an organic solvent, and combinations thereof, wherein said cleaning agent is effective to dissolve precipitated lignin formed from said lignin under said effective hydrolysis reaction conditions; (g) at a second switching time, diverting said biomass extraction liquor from said second hydrolysis reactor back to said first hydrolysis reactor or to a third hydrolysis reactor for hydrolyzing said hemicellulose oligomers into hemicellulose monomers, while concurrently cleaning said second hydrolysis reactor by introducing said cleaning agent to dissolve said precipitated lignin; and (h) repeating steps (c) to (g) a plurality of times, thereby continuously producing hemicellulose sugars from said biomass extraction liquor. ### Claim 2 (depends on 1) The process of claim 1, wherein said biomass extraction liquor is obtained from steam or liquid hot-water extraction of biomass. ### Claim 3 (depends on 1) The process of claim 1, wherein said biomass extraction liquor is obtained from acidic liquid extraction of biomass. ### Claim 4 (depends on 1) The process of claim 1, wherein said biomass extraction liquor is obtained from fractionation of biomass in the presence of water, a solvent for lignin, and an acid. ### Claim 5 (depends on 1) The process of claim 1, wherein said process employs two hydrolysis reactors consisting of said first hydrolysis reactor and said second hydrolysis reactor. ### Claim 6 (depends on 1) The process of claim 1, wherein said process employs three or more hydrolysis reactors comprising said first hydrolysis reactor, said second hydrolysis reactor, and said third hydrolysis reactor. ### Claim 7 (depends on 1) The process of claim 1, wherein each of said hydrolysis reactors is, or is integrated with, a heat exchanger with indirect steam heating. ### Claim 8 (depends on 1) The process of claim 1, wherein said biomass extraction liquor has a pH from about 0 to about 6. ### Claim 9 (depends on 8) The process of claim 8, wherein said biomass extraction liquor has a pH from about 1 to about 4. ### Claim 10 (depends on 1) The process of claim 1, wherein said biomass extraction liquor provided or obtained in step (a) contains suitable acidity for hydrolysis, and wherein step (b) is not performed. ### Claim 11 (depends on 10) The process of claim 10, wherein said suitable acidity arises from the presence of lignosulfonic acid. ### Claim 12 (depends on 1) The process of claim 1, wherein step (b) is performed, and wherein said acid catalyst is a sulfur-containing compound selected from the group consisting of sulfur dioxide, sulfurous acid, sulfur trioxide, sulfuric acid, sulfonic acid, lignosulfonic acid, and combinations thereof. ### Claim 13 (depends on 1) The process of claim 1, wherein said effective hydrolysis reaction conditions include an acid content from about 0.1 wt % to about 20 wt %, a temperature from about 100° C. to about 220° C., and a residence time from about 2 minutes to about 4 hours. ### Claim 14 (depends on 13) The process of claim 13, wherein said effective hydrolysis reaction conditions include an acid content from about 0.5 wt % to about 2 wt %, a temperature from about 120° C. to about 180° C., and a residence time from about 5 minutes to about 90 minutes. ### Claim 15 (depends on 1) The process of claim 1, wherein each of said hydrolysis reactors is operated at the same reaction conditions. ### Claim 16 (depends on 1) The process of claim 1, wherein said first period of time and said second period of time are each independently selected from about 1 day to about 3 months. ### Claim 17 (depends on 1) The process of claim 1, wherein said cleaning agent includes said steam to mechanically dislodge said precipitated lignin. ### Claim 18 (depends on 1) The process of claim 1, wherein said cleaning agent includes said alkaline solution to chemically dissolve or react with said precipitated lignin, wherein said alkaline solution comprises a base selected from the group consisting of sodium hydroxide, potassium hydroxide, calcium oxide, magnesium hydroxide, ammonia, and combinations thereof. ### Claim 19 (depends on 1) The process of claim 1, wherein said cleaning agent includes said organic solvent to chemically dissolve said precipitated lignin, wherein said organic solvent comprises a compound selected from the group consisting of an aliphatic alcohol, an aromatic alcohol, a ketone, an aldehyde, and combinations thereof. ### Claim 20 (depends on 1) The process of claim 1, wherein said cleaning agent includes said steam to mechanically dislodge said precipitated lignin, followed by said alkaline solution to chemically dissolve or react with said precipitated lignin or with mechanically dislodged lignin. ### Claim 21 (depends on 1) The process of claim 1, wherein said cleaning agent includes said steam to mechanically dislodge said precipitated lignin, followed by said organic solvent to chemically dissolve said precipitated lignin or mechanically dislodged lignin. ### Claim 22 (depends on 1) The process of claim 1, wherein said cleaning agent includes steam, said alkaline solution, and said organic solvent, introduced in any sequence.