Classifications

• • C—CHEMISTRY; METALLURGY
  • C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
  • C12P—FERMENTATION OR ENZYME-USING PROCESSES TO SYNTHESISE A DESIRED CHEMICAL COMPOUND OR COMPOSITION OR TO SEPARATE OPTICAL ISOMERS FROM A RACEMIC MIXTURE
  • C12P7/00—Preparation of oxygen-containing organic compounds
  • C12P7/02—Preparation of oxygen-containing organic compounds containing a hydroxy group
  • C12P7/04—Preparation of oxygen-containing organic compounds containing a hydroxy group acyclic
  • C12P7/06—Ethanol, i.e. non-beverage
  • C12P7/08—Ethanol, i.e. non-beverage produced as by-product or from waste or cellulosic material substrate
  • C12P7/10—Ethanol, i.e. non-beverage produced as by-product or from waste or cellulosic material substrate substrate containing cellulosic material
• • C—CHEMISTRY; METALLURGY
  • C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
  • C12P—FERMENTATION OR ENZYME-USING PROCESSES TO SYNTHESISE A DESIRED CHEMICAL COMPOUND OR COMPOSITION OR TO SEPARATE OPTICAL ISOMERS FROM A RACEMIC MIXTURE
  • C12P7/00—Preparation of oxygen-containing organic compounds
  • C12P7/02—Preparation of oxygen-containing organic compounds containing a hydroxy group
  • C12P7/04—Preparation of oxygen-containing organic compounds containing a hydroxy group acyclic
  • C12P7/06—Ethanol, i.e. non-beverage
  • C12P7/08—Ethanol, i.e. non-beverage produced as by-product or from waste or cellulosic material substrate
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
  • Y02E50/00—Technologies for the production of fuel of non-fossil origin
  • Y02E50/10—Biofuels, e.g. bio-diesel

Definitions

• the present invention relates to the use of a particular raw material for producing ethanol.
• the invention also covers a process for producing ethanol from this biomass.
• numerous studies have been conducted to replace fossil energy sources with renewable energies.
• research has turned towards the creation of new fuels: agrofuels or eco-fuels.
• An eco-fuel is a fuel produced from renewable and non-fossil organic materials.
• various techniques of production of ecofuels including the production of oil and its derivatives, alcohol or gaseous fuels from plant or animal biomass.
• the development of these fuels has significant drawbacks both in terms of yield and the fact that they compete directly with food crops and ecosystems.
• the production capacity of raw materials is limited compared to the quantities consumed very important fuels. It is therefore necessary to propose new ways of producing ethanol for use as a biofuel.
• the present invention proposes to use a particular cellulosic material: recycled textile cotton.
• Cellulose is an essential element of the plant wall. It is the most abundant polymer on earth. Cellulose is composed of a chain of glucopyranoses. It is known that its hydrolysis by celluloses leads to the production of glucose molecules, simple sugars easily fermentable in ethanol by glycolysis.
• the objective of the present invention is to overcome the disadvantages of the prior art and to propose a new way of producing purely energy-efficient bioethanol, which is more interesting from an environmental standpoint and exhibits better yields.
• the present invention is particularly concerned with a process for producing ethanol from textile cotton comprising the following steps: a) pretreatment of textile cotton:
• pretreatment of milled or unmilled textile cotton by defibration in an extruder b) enzymatic hydrolysis, c) filtration (s), preferably nominal filtration, ultrafiltration and sterile filtration, and d) fermentation.
• textile cotton or recycled textile cotton we mean a raw material collected (end-of-life clothing, clothing industry waste, dust etc.) as waste and made of more than 90% cellulose.
• recycled textile cotton makes it possible to increase the yields of ethanol production, compared with known lignocellulosic raw materials, because of its high cellulose content.
• the particular method which is the subject of the invention makes it possible to further increase the yields.
• this process is very advantageous from the ecological and economic point of view. It is simple to implement and easily industrializable.
• the process comprises a bleaching step before the fermentation step.
• a particularly suitable process according to the invention comprises the following steps: a) pretreatment of recycled textile cotton:
• the pretreatment step a) aims to make the cellulose accessible to facilitate its enzymatic hydrolysis.
• cotton fiber mainly composed of cellulose, has undergone various chemical treatments (mercerization, scraping, nonshrinkable treatment, wrinkle-free treatment and dyes) for their first application in the textile industry.
• the typical chemical composition of a cotton fiber is: - cellulose: 91.2%,
• the pretreatment of the raw material can be chemical and / or mechanical.
• Chemical pretreatment involves hydrolyzing hemicelluloses. It may be, for example, a hydrolysis in a basic hot medium to solubilize the hemicelluloses and a portion of lignin, or in hot weak acid medium to hydrolyze the hemicelluloses.
• the pretreatment of the raw material according to the invention is carried out by defibration of the textile cotton in an extruder.
• Defibering separates the fibers and increases the digestibility of the cellulose.
• the textile cotton is defibrated in an extruder, at a temperature between 60 0 C and 180 0 C and in the presence of a quantity of water representing between 200% and 450% of the mass of said raw material.
• the pretreatment of the raw material by defibration in an extruder makes it possible to increase by a factor of 3 the yield of the enzymatic hydrolysis of the cellulose. It also reduces the amount of enzyme used in step b).
• the pretreatment is preceded by a step of grinding the recycled textile cotton which makes it possible to make the cellulose more accessible for hydrolysis.
• the step of grinding the raw material can be carried out by way of example using a knife mill.
• Step b) consists in hydrolysing the cellulose with the aid of enzymes to obtain a solution rich in glucose.
• the hydrolysis can be carried out using an enzymatic cocktail composed of celluloses and ⁇ -glucosidase.
• the hydrolysis is carried out in a tank maintained at a temperature of between 50 ° C. and 60 ° C., at a pH of between 4 and 5.5 for at least 24 hours.
• the ratio of enzymes per gram of cellulose is between 0.5 and 2.5.
• Step c) consists of filtering the solution obtained after enzymatic hydrolysis of the cellulose.
• step c) comprises the following steps: filtration for the clearance of the medium,
• the reaction medium is composed of a sweet juice, celluloses, non-cellulosic compounds and non-degraded cellulose.
• a centrifugation step prior to filtration eliminates the non-cellulosic compounds and the non-degraded cellulose.
• Ultrafiltration aims to recycle and reuse the enzymes used for hydrolysis.
• the ultrafiltration step makes it possible to considerably reduce the production costs of ethanol, since the cost of the enzymes used for the hydrolysis of the cellulose is very important.
• the ultrafiltration step may be carried out on a membrane such as a polysulfone membrane, with a cutoff threshold of 6KDa, an internal diameter of the fiber of 0.8 mm and an external diameter of 1.4 mm.
• This membrane makes it possible to concentrate and recover the enzymes on the one hand (the concentrate) and the sweet juice on the other hand (permeate).
• the recycled enzymes are then reused to treat another batch of cellulosic biomass. They can be reused up to two cycles without significant loss of activity.
• Reverse osmosis concentrates the permeate without evaporation. This step allows energy saving compared to a conventional evaporation step.
• the discoloration makes it possible to retain the dyes of the textile cotton in a resin.
• the fermentation step d) has the objective of fermenting the glucose contained in the filtered sweet juice in ethanol by glycolysis using a yeast.
• This step is preferably preceded by a cooling of the reaction medium.
• Fermentation can be carried out in a fermenter between 30 0 C and 37 ° C, between 7h and 24h, at a pH between 3.8 and 5.0.
• the yeasts used may be Saccharomyces cerevisiae.
• the yield of the fermentation reaches 0.4 g of ethanol per gram of glucose.
• the yeasts used for fermentation can be recycled by microfiltration, with a cut-off of 6KDa, to be reused.
• the fermentation step is generally followed by a stage e) of distillation / dehydration on a membrane which makes it possible to obtain a 99.9% ethanol.
• An example of a particularly suitable method according to the invention therefore comprises the following steps:
• enzymatic hydrolysis using an enzymatic cocktail composed of celluloses and ⁇ -glucosidase (between 0.1 and Ig of enzyme per gram of cellulose) in a tank maintained at a temperature of between 50 ° C. and 60 ° C. C, at a pH of between 4 and 5.5 for at least 24 hours, filtration for a clearance of the medium,
• the process according to the invention makes it possible to considerably increase the hydrolysis of the cellulose and therefore the yield in terms of ethanol production. At the same time, this process makes it possible to reduce production costs by recycling the enzymes and yeasts used.
• the ethanol obtained can advantageously be used as fuel in a gasoline vehicle, alone or in combination with one or more other fuels.

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• Organic Chemistry (AREA)
• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Zoology (AREA)
• Life Sciences & Earth Sciences (AREA)
• Wood Science & Technology (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Microbiology (AREA)
• General Chemical & Material Sciences (AREA)
• Biotechnology (AREA)
• Health & Medical Sciences (AREA)
• Biochemistry (AREA)
• Bioinformatics & Cheminformatics (AREA)
• General Engineering & Computer Science (AREA)
• General Health & Medical Sciences (AREA)
• Genetics & Genomics (AREA)
• Preparation Of Compounds By Using Micro-Organisms (AREA)

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• 2008
  • 2008-12-05 FR FR0858307A patent/FR2939446B1/fr not_active Expired - Fee Related
• 2009
  • 2009-12-04 CN CN200980148790.5A patent/CN102239263B/zh not_active Expired - Fee Related
  • 2009-12-04 US US13/133,073 patent/US9540665B2/en not_active Expired - Fee Related
  • 2009-12-04 EP EP09802158A patent/EP2364365A2/fr not_active Withdrawn
  • 2009-12-04 WO PCT/FR2009/052417 patent/WO2010063981A2/fr active Application Filing
  • 2009-12-04 BR BRPI0917069-3A patent/BRPI0917069A2/pt not_active Application Discontinuation

Non-Patent Citations (4)

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