EP1844107A1 - Process for the preparation of bio-tanning agent - Google Patents
Process for the preparation of bio-tanning agentInfo
- Publication number
- EP1844107A1 EP1844107A1 EP04816683A EP04816683A EP1844107A1 EP 1844107 A1 EP1844107 A1 EP 1844107A1 EP 04816683 A EP04816683 A EP 04816683A EP 04816683 A EP04816683 A EP 04816683A EP 1844107 A1 EP1844107 A1 EP 1844107A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- bio
- tanning agent
- acid
- hide
- range
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
- 238000000034 method Methods 0.000 title claims description 34
- 238000002360 preparation method Methods 0.000 title claims description 9
- 239000003795 chemical substances by application Substances 0.000 claims description 33
- 239000000843 powder Substances 0.000 claims description 23
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 22
- 239000000463 material Substances 0.000 claims description 20
- 238000009966 trimming Methods 0.000 claims description 16
- 239000002699 waste material Substances 0.000 claims description 13
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 claims description 12
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 claims description 12
- 239000002253 acid Substances 0.000 claims description 12
- BDAGIHXWWSANSR-UHFFFAOYSA-N methanoic acid Natural products OC=O BDAGIHXWWSANSR-UHFFFAOYSA-N 0.000 claims description 10
- 239000002002 slurry Substances 0.000 claims description 10
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 claims description 8
- 239000007788 liquid Substances 0.000 claims description 7
- OSWFIVFLDKOXQC-UHFFFAOYSA-N 4-(3-methoxyphenyl)aniline Chemical compound COC1=CC=CC(C=2C=CC(N)=CC=2)=C1 OSWFIVFLDKOXQC-UHFFFAOYSA-N 0.000 claims description 5
- 238000001035 drying Methods 0.000 claims description 5
- 235000019253 formic acid Nutrition 0.000 claims description 5
- 229910052799 carbon Inorganic materials 0.000 claims description 4
- 239000012736 aqueous medium Substances 0.000 claims description 3
- 238000002036 drum drying Methods 0.000 claims description 3
- 238000001694 spray drying Methods 0.000 claims description 3
- 238000004519 manufacturing process Methods 0.000 abstract description 7
- 239000000243 solution Substances 0.000 description 24
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 18
- 238000003756 stirring Methods 0.000 description 18
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 15
- 239000010985 leather Substances 0.000 description 14
- 229910052804 chromium Inorganic materials 0.000 description 12
- 239000011651 chromium Substances 0.000 description 12
- 235000018102 proteins Nutrition 0.000 description 8
- 108090000623 proteins and genes Proteins 0.000 description 8
- 102000004169 proteins and genes Human genes 0.000 description 8
- CDBYLPFSWZWCQE-UHFFFAOYSA-L Sodium Carbonate Chemical compound [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 description 6
- 239000000047 product Substances 0.000 description 6
- 238000005303 weighing Methods 0.000 description 6
- 102000008186 Collagen Human genes 0.000 description 5
- 108010035532 Collagen Proteins 0.000 description 5
- 229920001436 collagen Polymers 0.000 description 5
- 238000005903 acid hydrolysis reaction Methods 0.000 description 4
- 239000000203 mixture Substances 0.000 description 4
- 238000012545 processing Methods 0.000 description 4
- 230000007065 protein hydrolysis Effects 0.000 description 4
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 description 3
- 239000007795 chemical reaction product Substances 0.000 description 3
- 230000007071 enzymatic hydrolysis Effects 0.000 description 3
- 238000006047 enzymatic hydrolysis reaction Methods 0.000 description 3
- 229910000029 sodium carbonate Inorganic materials 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- 231100000331 toxic Toxicity 0.000 description 3
- 230000002588 toxic effect Effects 0.000 description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- 108010009736 Protein Hydrolysates Proteins 0.000 description 2
- 239000003513 alkali Substances 0.000 description 2
- 238000001816 cooling Methods 0.000 description 2
- 239000002609 medium Substances 0.000 description 2
- 239000003531 protein hydrolysate Substances 0.000 description 2
- 239000002910 solid waste Substances 0.000 description 2
- 239000007921 spray Substances 0.000 description 2
- 231100000027 toxicology Toxicity 0.000 description 2
- MTCFGRXMJLQNBG-REOHCLBHSA-N (2S)-2-Amino-3-hydroxypropansäure Chemical compound OC[C@H](N)C(O)=O MTCFGRXMJLQNBG-REOHCLBHSA-N 0.000 description 1
- DCXYFEDJOCDNAF-UHFFFAOYSA-N Asparagine Natural products OC(=O)C(N)CC(N)=O DCXYFEDJOCDNAF-UHFFFAOYSA-N 0.000 description 1
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- 239000001828 Gelatine Substances 0.000 description 1
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- DCXYFEDJOCDNAF-REOHCLBHSA-N L-asparagine Chemical compound OC(=O)[C@@H](N)CC(N)=O DCXYFEDJOCDNAF-REOHCLBHSA-N 0.000 description 1
- LEVWYRKDKASIDU-IMJSIDKUSA-N L-cystine Chemical compound [O-]C(=O)[C@@H]([NH3+])CSSC[C@H]([NH3+])C([O-])=O LEVWYRKDKASIDU-IMJSIDKUSA-N 0.000 description 1
- ZDXPYRJPNDTMRX-VKHMYHEASA-N L-glutamine Chemical compound OC(=O)[C@@H](N)CCC(N)=O ZDXPYRJPNDTMRX-VKHMYHEASA-N 0.000 description 1
- AYFVYJQAPQTCCC-GBXIJSLDSA-N L-threonine Chemical compound C[C@@H](O)[C@H](N)C(O)=O AYFVYJQAPQTCCC-GBXIJSLDSA-N 0.000 description 1
- QIVBCDIJIAJPQS-VIFPVBQESA-N L-tryptophane Chemical compound C1=CC=C2C(C[C@H](N)C(O)=O)=CNC2=C1 QIVBCDIJIAJPQS-VIFPVBQESA-N 0.000 description 1
- IMSOBGJSYSFTKG-PKPIPKONSA-N Lysinoalanine Chemical compound OC(=O)[C@@H](N)CCCCNCC(N)C(O)=O IMSOBGJSYSFTKG-PKPIPKONSA-N 0.000 description 1
- 206010028980 Neoplasm Diseases 0.000 description 1
- MTCFGRXMJLQNBG-UHFFFAOYSA-N Serine Natural products OCC(N)C(O)=O MTCFGRXMJLQNBG-UHFFFAOYSA-N 0.000 description 1
- AYFVYJQAPQTCCC-UHFFFAOYSA-N Threonine Natural products CC(O)C(N)C(O)=O AYFVYJQAPQTCCC-UHFFFAOYSA-N 0.000 description 1
- 239000004473 Threonine Substances 0.000 description 1
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 1
- QIVBCDIJIAJPQS-UHFFFAOYSA-N Tryptophan Natural products C1=CC=C2C(CC(N)C(O)=O)=CNC2=C1 QIVBCDIJIAJPQS-UHFFFAOYSA-N 0.000 description 1
- QCWXUUIWCKQGHC-UHFFFAOYSA-N Zirconium Chemical compound [Zr] QCWXUUIWCKQGHC-UHFFFAOYSA-N 0.000 description 1
- 230000002378 acidificating effect Effects 0.000 description 1
- 150000001252 acrylic acid derivatives Chemical class 0.000 description 1
- 238000005904 alkaline hydrolysis reaction Methods 0.000 description 1
- 239000004411 aluminium Substances 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 235000001014 amino acid Nutrition 0.000 description 1
- 229940024606 amino acid Drugs 0.000 description 1
- 150000001413 amino acids Chemical class 0.000 description 1
- 229960001230 asparagine Drugs 0.000 description 1
- 235000009582 asparagine Nutrition 0.000 description 1
- 230000003139 buffering effect Effects 0.000 description 1
- 239000004566 building material Substances 0.000 description 1
- 239000006227 byproduct Substances 0.000 description 1
- 201000011510 cancer Diseases 0.000 description 1
- 230000030833 cell death Effects 0.000 description 1
- 231100000481 chemical toxicant Toxicity 0.000 description 1
- 238000004587 chromatography analysis Methods 0.000 description 1
- 150000001844 chromium Chemical class 0.000 description 1
- DSHWASKZZBZKOE-UHFFFAOYSA-K chromium(3+);hydroxide;sulfate Chemical class [OH-].[Cr+3].[O-]S([O-])(=O)=O DSHWASKZZBZKOE-UHFFFAOYSA-K 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 229960003067 cystine Drugs 0.000 description 1
- 230000006378 damage Effects 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000010790 dilution Methods 0.000 description 1
- 239000012895 dilution Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 230000002255 enzymatic effect Effects 0.000 description 1
- 238000006911 enzymatic reaction Methods 0.000 description 1
- 239000003797 essential amino acid Substances 0.000 description 1
- 235000020776 essential amino acid Nutrition 0.000 description 1
- 239000000835 fiber Substances 0.000 description 1
- 235000013305 food Nutrition 0.000 description 1
- 239000013505 freshwater Substances 0.000 description 1
- 229920000159 gelatin Polymers 0.000 description 1
- 235000019322 gelatine Nutrition 0.000 description 1
- 239000003292 glue Substances 0.000 description 1
- ZDXPYRJPNDTMRX-UHFFFAOYSA-N glutamine Natural products OC(=O)C(N)CCC(N)=O ZDXPYRJPNDTMRX-UHFFFAOYSA-N 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 230000007062 hydrolysis Effects 0.000 description 1
- 238000006460 hydrolysis reaction Methods 0.000 description 1
- 230000003301 hydrolyzing effect Effects 0.000 description 1
- 239000005457 ice water Substances 0.000 description 1
- 239000010842 industrial wastewater Substances 0.000 description 1
- 239000012212 insulator Substances 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 239000010808 liquid waste Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 229910021645 metal ion Inorganic materials 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 238000006386 neutralization reaction Methods 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 231100000252 nontoxic Toxicity 0.000 description 1
- 230000003000 nontoxic effect Effects 0.000 description 1
- 230000000050 nutritive effect Effects 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 238000012552 review Methods 0.000 description 1
- 230000001225 therapeutic effect Effects 0.000 description 1
- 239000010936 titanium Substances 0.000 description 1
- 229910052719 titanium Inorganic materials 0.000 description 1
- 239000003440 toxic substance Substances 0.000 description 1
- 231100000419 toxicity Toxicity 0.000 description 1
- 230000001988 toxicity Effects 0.000 description 1
- 239000011782 vitamin Substances 0.000 description 1
- 235000013343 vitamin Nutrition 0.000 description 1
- 229940088594 vitamin Drugs 0.000 description 1
- 229930003231 vitamin Natural products 0.000 description 1
- 229910052726 zirconium Inorganic materials 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L89/00—Compositions of proteins; Compositions of derivatives thereof
- C08L89/04—Products derived from waste materials, e.g. horn, hoof or hair
- C08L89/06—Products derived from waste materials, e.g. horn, hoof or hair derived from leather or skin, e.g. gelatin
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08H—DERIVATIVES OF NATURAL MACROMOLECULAR COMPOUNDS
- C08H1/00—Macromolecular products derived from proteins
- C08H1/06—Macromolecular products derived from proteins derived from horn, hoofs, hair, skin or leather
Definitions
- the present invention relates to a process for the preparation of bio-tanning agent. More particularly, the present invention provides a simple process for preparing bio-tanning agent from collagenous source. It is envisaged to have enormous potential application in leather processing industry as an environment friendly option for tanning hides/skins, whereby the pollution load would be significantly reduced compared to that of the conventional tanning process.
- Background of the Invention Commercially skins/hides are tanned, stabilized against microbes and heat, using chromium salts.
- Conventional chrome tanning is a popular and mostly practiced technique in the world and employs basic chromium sulfate salt, a progenitor of several chromium species.
- tanned wastes are many fold such as the manufacture of bonded leather, leather boards, fibrous sheets grafted with acrylates, insulators and building materials, composites for footwear, sound-proof roofing material, etc as discussed by Rao et al (Journal of the American Leather Chemists Association, 99, 170, 2004).
- the non-tanned wastes such as raw hide/skin trimmings, limed hide splits, hair, hide/skin fleshings, delimed wastes/trimmings have been processed in to various useful products such as glue, gelatine, pet treats and collagen for medical use as described by Mann (Processing and utilization of animal byproducts, FAO, 1962).
- the obtained compounds are particularly used in the therapeutic field.
- the drawback of this method is the use of very high temperature and stringent control of parameters such as pH and pressure.
- the main objective of the present invention is to provide a process for the preparation of bio-tanning agent, which precludes the drawbacks stated above.
- Another objective of the present invention is to provide a process for preparing bio- tanning agent that does not require very high temperature.
- Yet another objective of the present invention is to provide a process for preparing bio-tanning agent that does not require strict control measures such as pH and pressure.
- Still another objective of the present invention is to provide a process for preparing bio-tanning agent that does not require any buffering medium.
- the present invention provides a process for the preparation of bio- tanning agent, which comprises
- step (b) adjusting the pH of the slurry, as formed in step (i), in the range of 5.5-7.0 by known method to obtain the bio-tanning agent in liquid form,
- the collagenous material used may be selected from raw hide/skin trimmings, limed hide splits, green fleshings, limed skin/hide fleshings, delimed pelt wastes/trimmings, hide powder either alone or in any combination.
- the amount of water used may be in the range of 50-200% by volume on the wet weight of the collagenous material.
- the acid used may be selected from sulfuric acid, formic acid, acetic acid, hydrochloric acid either alone or in any combination.
- the known method of drying may be such as spray drying, drum drying. Description of the Invention
- the invention provides a process for the preparation of a bio-tanning agent by: i. treating collagenous material in aqueous medium, to a temperature in the range of 80-98 0 C at a pH not exceeding 3.0 for a period not less than 30 minutes by known method using known acid, to obtain a slurry followed by adjusting the temperature of the slurry in the range of 20-40 0 C, ii. adjusting the pH of the slurry, as formed in step (i), in the range of 5.5-7.0 by known method to obtain the bio-tanning agent in liquid form, iii. drying the bio-tanning agent liquid at 130-260 0 C, as formed in step (ii), by known method as an optional step, to obtain the bio-tanning agent in the dry powder form.
- the collagenous material used is selected from raw hide/skin trimmings, limed hide splits, green fleshings, limed skin/hide fleshings, delimed pelt wastes/trimmings, hide powder either alone or in any combination.
- the amount of water used may be in the range of 50- 200% by volume on the wet weight of the collagenous material.
- the acid used is selected from sulfuric acid, formic acid, acetic acid, hydrochloric acid either alone or in any combination. Drying is achieved by known methods such as spray drying or drum drying.
- Collagenous material is added to 50-200% by volume of water, measured on the wet weight of the collagenous source and treated with known acid to adjust the pH at not more than 3 at a temperature in the range of 80-98 0 C for a period not less than 30 minutes.
- the temperature of the mixture is then adjusted in the range of 20-40 0 C.
- pH of the resulting slurry is adjusted in the range of 5.5-7.0 by adding known alkali to obtain the bio-tanning agent in liquid form. This is optionally dried by known method at a temperature in the range of 130-
- the inventive step of the present invention lies in treating collagen material with a known acid, adjusting the pH at less than
- Raw hide/skin trimmings were washed in 12 lit water for 2 hrs in a pit. Then the trimmings were again washed in 12 lit fresh water for 2 hrs. The washed trimmings were sliced into small pieces using mechanical slicer. The sliced material ' weight was found to be 4.8 kg and charged into a reactor. 7.2 lit water and 60 gms concentrated sulfuric acid was added to the reactor with stirring. Then the reactor was heated to 98 0 C with continuous stirring for a period of 120 minutes. The pH of the solution was found to be 1.5. Obtained viscous solution was air cooled to 4O 0 C. The cooled solution was neutralized to a pH 7.0 using 48 gms sodium hydroxide with continuous stirring.
- Example 2 Limed hide splits, weighing 6 kg, were sliced into small pieces using mechanical slicer. The weight of the sliced material was found to be 5.6 kg. The sliced materials were washed with 11.2 lit water for 15 minutes in a reactor. Then, the water was drained from the reactor. 2.8 lit water and a mixture of 84 gms concentrated sulfuric acid, 56 gms formic acid and 28 gms hydrochloric acid were added to the reactor with stirring. Then the reactor was heated to 95 0 C with continuous stirring for a period of 30 minutes.
- the pH of the solution was found to be 1.3. Obtained viscous solution was cooled to 37 0 C using water cooling system. The cooled solution was neutralized to a pH 5.5 using 140 gms sodium hydroxide and 28 gms sodium carbonate with continuous stirring. Then the solution was spray dried at a temperature of 26O 0 C and the resulting bio-tanning agent powder was stored in a plastic container. Total weight of the dried powder was found to be 1550 gms.
- the raw hide/skin trimmings and green hide fleshings were washed in 12 lit water for 2 hrs in a pit. Then the trimmings and green fleshings were again washed in 12 lit water for 2 hrs. The washed trimmings and green fleshings were sliced into small pieces using mechanical slicer. The sliced material weight was found to be 7.4 kg and charged into a reactor. 14.8 lit water and a mixture of 92.5 gms concentrated sulfuric acid, 18.5 gms acetic acid and 37 gms formic acid were added to the reactor with stirring. Then the reactor was heated to 98 0 C with continuous stirring for a period of 60 minutes. The pH of the solution was found to be 1.2.
- Delimed pelt wastes/trimmings and limed fleshings were sliced into small pieces using mechanical slicer.
- the sliced weight of the material was found to be 6.6 kg.
- the sliced materials were washed with 19.8 lit water for 15 mins in a reactor. Then, the water was drained from the reactor. 6.6 lit water and 99 gms concentrated sulfuric acid was added to the reactor with stirring. Then the reactor was heated to 92 0 C with continuous stirring for a period of 90 minutes.
- the pH of the solution was found to be 1.6. Obtained viscous solution was cooled to 2O 0 C using ice water cooling system.
- Hide powder weighing 2 kgs, was washed with 4000 ml water in a pit for 3 hrs. The weight of the washed wet hide powder was found to be 7.8 kg.
- the wet hide powder was charged into a reactor. To this, 7.8 lit water and 78 gms concentrated sulfuric acid was added to the reactor with stirring. Then the reactor was heated to 8O 0 C with continuous stirring for a period of 30 minutes. The pH of the solution was found to be 1.2. Obtained viscous solution was air cooled to 37 0 C. The cooled solution was neutralized to a pH 7.0 using 58.4 gms sodium hydroxide and 19.6 gms sodium carbonate with continuous stirring. Then the solution was spray dried at a temperature of 260 0 C and the resulting bio-tanning agent powder was stored in a plastic container. Total weight of the dried powder was found to be 1900 gms. The following are the advantages of the present invention:
- the developed product has wide applications in leather industry, especially as a bio- tanning agent, thereby replaces toxic or hard biodegradable conventional tanning agents.
Landscapes
- Chemical & Material Sciences (AREA)
- Health & Medical Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Organic Chemistry (AREA)
- Dermatology (AREA)
- Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Biochemistry (AREA)
- Materials Engineering (AREA)
- Treatment And Processing Of Natural Fur Or Leather (AREA)
Abstract
The present invention provides a process for preparing a bio-tanning agent from collagenous source.
Description
PROCESS FOR THE PREPARATION OF BIO-TANNING AGENT Field of the Invention
The present invention relates to a process for the preparation of bio-tanning agent. More particularly, the present invention provides a simple process for preparing bio-tanning agent from collagenous source. It is envisaged to have enormous potential application in leather processing industry as an environment friendly option for tanning hides/skins, whereby the pollution load would be significantly reduced compared to that of the conventional tanning process. Background of the Invention Commercially skins/hides are tanned, stabilized against microbes and heat, using chromium salts. Conventional chrome tanning is a popular and mostly practiced technique in the world and employs basic chromium sulfate salt, a progenitor of several chromium species. The kinetic inertness of certain chromium species lends itself to poor exhaustion of chrome tanning. Thus the commercial chrome tanning activities release chromium in the range of 2000-5000 ppm. As reported by Baral and Engelken (Environmental Science & Policy, 5, 121, 2002), the discharge of industrial wastewater containing chromium into water bodies has a significantly polluting impact on the environment. It has been proved that chromium has the ability to cause cancer, as reported by Tsou et al (Chemical Research in Toxicology, 10, 962, 1997) and cell death, as reported by Blankenship et al (Toxicology and Applied Pharmacology, 126, 75, 1994). The wide ecological concern as well as economic loss has prompted the researchers to look for suitable alternatives for chromium. Several methods have been evolved over the years for better management of chromium in leather industry as reported by Chandrasekaran (Leather Science, 34, 91, 1987). Among them the development of alternative tanning agent to chromium has been gaining momentum. Covington (Chemical Society Reviews, 26, 111, 1997) has reported the use of metal ions like aluminium, titanium, zirconium and iron for tanning. However, the major disadvantages with these products are that the tanning is not complete and some of the metals are toxic to humans. In addition, these products lack the ability to withstand pH conditions above 5.5, as described by Bienkiewicz (Physical Chemistry of Leather Making, Krieger RE Publishing Company, Florida, Chapter 15, 1983). Though several efforts have been taken to overcome these drawbacks, universal availability, toxicity and high cost have forced the researchers to look for other alternatives as well. Several attempts are therefore being made to replace the toxic chemical based auxiliary with non-toxic bio based product for tanning skins/hides. This is because the potential bio resource is available abundantly.
Leather processing leads to the generation of large amounts of solid and liquid wastes. Protein based solid wastes acquire much attention due to its high value. Skin/hide losses its mass up to 70% during leather making processes. The tanned wastes primarily consist of chromium and protein. Historically, the tanned wastes were disposed of in landfills. However, due to stringent restriction on the disposal of chromium bearing wastes as well as the presence of valuable protein source, the tanning industry seeks alternatives to dumping as reported by Lipsett (Journal of the American Leather Chemists Association, 77, 291, 1982). Reference may be made to Brown et al (Journal of the American Leather Chemists Association, 89, 215, 1994), who subjected the leather wastes to chemical as well as enzymatic treatment for separating the protein-bound chromium and using the protein and chromium fractions for several applications. Direct application of tanned wastes is many fold such as the manufacture of bonded leather, leather boards, fibrous sheets grafted with acrylates, insulators and building materials, composites for footwear, sound-proof roofing material, etc as discussed by Rao et al (Journal of the American Leather Chemists Association, 99, 170, 2004). The non-tanned wastes such as raw hide/skin trimmings, limed hide splits, hair, hide/skin fleshings, delimed wastes/trimmings have been processed in to various useful products such as glue, gelatine, pet treats and collagen for medical use as described by Mann (Processing and utilization of animal byproducts, FAO, 1962).
Commercial preparation of protein hydrolysates, for reducing the molecular size of the protein, is accomplished by one of three methods namely acid, alkaline or enzymatic hydrolysis by breaking peptide bonds. Acid and alkali hydrolysis of protein leads to decreased nutritive value because of recemisation and destruction of essential amino acids, production of toxic constituents like lysino-alanine as stated by Swamylingappa et al (United States Patent 6,589,574, 2003). Enzymatic methods accomplish protein hydrolysis selectively without causing structural changes in the amino acids that make up the proteins. There are several reports and patents available for enzymatic hydrolysis of proteins due to its high selectivity thereby yielding high end products used in food or pharmaceutical industries, as reported by Milan et al (United States Patent 5,948,766, 1999) and Blortz et al (United States Patent 5,985,337, 1999). Acid hydrolysis of proteins is usually not recommended for high end products due to several reasons. Tryptophan is usually totally lost in an acid hydrolysis as shown by Levine (Journal of Chromatography A, 236, 499, 1982). Cystine, serine and threonine are partially broken down and asparagine and glutamine are converted to their acidic forms. Vitamins are mostly destroyed by acid hydrolysis. However, low end industries such as leather processing
do not need high end products. Enzymatic hydrolysis not only has the disadvantage of being relatively expensive, but also requires strictly controlled process conditions to achieve maximum results.
An alkaline or acid pressure protein-hydrolysis process was developed by Vaille (Great Britain Patent 1,227,534, 1971) and followed by many of the researchers and commercial protein hydrolysate manufacturers for the past three decades. The process consists of subjecting natural collagen to the action of a pH modifying agent which is acid or alkaline and which establishes, alone or in conjunction with a buffer medium, a pH of 3 to 3.5 or of 8 to 8.5 respectively at a temperature as high as 1100C at normal pressure and as high as 15O0C under elevated pressure, for a period of 45 to 90 minutes, followed by neutralization.
The obtained compounds are particularly used in the therapeutic field. The drawback of this method is the use of very high temperature and stringent control of parameters such as pH and pressure.
No prior art is available on hydrolysing collagen at a temperature not exceeding 980C for using as a tanning agent. Objects of the Invention
The main objective of the present invention is to provide a process for the preparation of bio-tanning agent, which precludes the drawbacks stated above.
Another objective of the present invention is to provide a process for preparing bio- tanning agent that does not require very high temperature.
Yet another objective of the present invention is to provide a process for preparing bio-tanning agent that does not require strict control measures such as pH and pressure.
Still another objective of the present invention is to provide a process for preparing bio-tanning agent that does not require any buffering medium. Summary of the Invention
Accordingly, the present invention provides a process for the preparation of bio- tanning agent, which comprises
(a) treating collagenous material in aqueous medium, to a temperature in the range of 80- 980C at a pH not exceeding 3.0 for a period not less than 30 minutes by known method using known acid, to obtain a slurry followed by adjusting the temperature of the slurry in the range of 20-400C,
(b) adjusting the pH of the slurry, as formed in step (i), in the range of 5.5-7.0 by known method to obtain the bio-tanning agent in liquid form,
(c) drying the bio-tanning agent liquid at 130-2600C, as formed in step (ii), by known
method as an optional step, to obtain the bio-tanning agent in the dry powder form. In an embodiment of the present invention, the collagenous material used may be selected from raw hide/skin trimmings, limed hide splits, green fleshings, limed skin/hide fleshings, delimed pelt wastes/trimmings, hide powder either alone or in any combination. In another embodiment of the present invention, the amount of water used may be in the range of 50-200% by volume on the wet weight of the collagenous material.
In yet another embodiment of the present invention, the acid used may be selected from sulfuric acid, formic acid, acetic acid, hydrochloric acid either alone or in any combination. In still another embodiment of the present invention, the known method of drying may be such as spray drying, drum drying. Description of the Invention
The invention provides a process for the preparation of a bio-tanning agent by: i. treating collagenous material in aqueous medium, to a temperature in the range of 80-980C at a pH not exceeding 3.0 for a period not less than 30 minutes by known method using known acid, to obtain a slurry followed by adjusting the temperature of the slurry in the range of 20-400C, ii. adjusting the pH of the slurry, as formed in step (i), in the range of 5.5-7.0 by known method to obtain the bio-tanning agent in liquid form, iii. drying the bio-tanning agent liquid at 130-2600C, as formed in step (ii), by known method as an optional step, to obtain the bio-tanning agent in the dry powder form.
The collagenous material used is selected from raw hide/skin trimmings, limed hide splits, green fleshings, limed skin/hide fleshings, delimed pelt wastes/trimmings, hide powder either alone or in any combination. The amount of water used may be in the range of 50- 200% by volume on the wet weight of the collagenous material. The acid used is selected from sulfuric acid, formic acid, acetic acid, hydrochloric acid either alone or in any combination. Drying is achieved by known methods such as spray drying or drum drying.
The process of the present invention is described below in detail. Collagenous material is added to 50-200% by volume of water, measured on the wet weight of the collagenous source and treated with known acid to adjust the pH at not more than 3 at a temperature in the range of 80-980C for a period not less than 30 minutes. The temperature of the mixture is then adjusted in the range of 20-400C. pH of the resulting slurry is adjusted in the range of 5.5-7.0 by adding known alkali to obtain the bio-tanning agent in
liquid form. This is optionally dried by known method at a temperature in the range of 130-
26O0C to obtain the bio-tanning agent in dry powder form. The inventive step of the present invention lies in treating collagen material with a known acid, adjusting the pH at less than
3.0 to facilitate preparation of bio-tanning agent in solution form at a relatively low temperature in the range of 80-980C and without controlling pressure.
The invention is described in detail in the following illustrative examples, and should not be construed to limit the scope of the present invention. Example 1
Raw hide/skin trimmings, weighing 4 kg, were washed in 12 lit water for 2 hrs in a pit. Then the trimmings were again washed in 12 lit fresh water for 2 hrs. The washed trimmings were sliced into small pieces using mechanical slicer. The sliced material' weight was found to be 4.8 kg and charged into a reactor. 7.2 lit water and 60 gms concentrated sulfuric acid was added to the reactor with stirring. Then the reactor was heated to 980C with continuous stirring for a period of 120 minutes. The pH of the solution was found to be 1.5. Obtained viscous solution was air cooled to 4O0C. The cooled solution was neutralized to a pH 7.0 using 48 gms sodium hydroxide with continuous stirring. Then the mixture was drum dried at 1300C and the resulting bio-tanning agent powder was stored in a plastic container. Total weight of the dried powder was found to be 1300 gms. Example 2 Limed hide splits, weighing 6 kg, were sliced into small pieces using mechanical slicer. The weight of the sliced material was found to be 5.6 kg. The sliced materials were washed with 11.2 lit water for 15 minutes in a reactor. Then, the water was drained from the reactor. 2.8 lit water and a mixture of 84 gms concentrated sulfuric acid, 56 gms formic acid and 28 gms hydrochloric acid were added to the reactor with stirring. Then the reactor was heated to 950C with continuous stirring for a period of 30 minutes. The pH of the solution was found to be 1.3. Obtained viscous solution was cooled to 370C using water cooling system. The cooled solution was neutralized to a pH 5.5 using 140 gms sodium hydroxide and 28 gms sodium carbonate with continuous stirring. Then the solution was spray dried at a temperature of 26O0C and the resulting bio-tanning agent powder was stored in a plastic container. Total weight of the dried powder was found to be 1550 gms. Example 3
The raw hide/skin trimmings and green hide fleshings, weighing 4 kgs and 2 kgs, were washed in 12 lit water for 2 hrs in a pit. Then the trimmings and green fleshings were again washed in 12 lit water for 2 hrs. The washed trimmings and green fleshings were sliced
into small pieces using mechanical slicer. The sliced material weight was found to be 7.4 kg and charged into a reactor. 14.8 lit water and a mixture of 92.5 gms concentrated sulfuric acid, 18.5 gms acetic acid and 37 gms formic acid were added to the reactor with stirring. Then the reactor was heated to 980C with continuous stirring for a period of 60 minutes. The pH of the solution was found to be 1.2. Obtained viscous solution was air cooled to 360C. The cooled solution was neutralized to a pH 6.5 using 74 gms sodium hydroxide and 18.5 gms potassium hydroxide with continuous stirring. Then the solution was drum dried at 13O0C and the resulting bio-tanning agent powder was stored in a plastic container. Total weight of the dried powder was found to be 1700 gms. Example 4
Delimed pelt wastes/trimmings, weighing 8 kgs, were sliced into small pieces using mechanical slicer. The weight of the sliced material was found to be 7.5 kg. The sliced material was washed with 22.5 lit water for 15 mins in a reactor. Then, the water was drained from the vessel. 7.5 lit water and 75 gms concentrated sulfuric acid was added to the reactor with stirring. Then the reactor was heated to 970C with continuous stirring for a period of 50 minutes. The pH of the solution was found to be 1.5. Obtained viscous solution was air cooled to 380C. The cooled solution was neutralized to a pH 7.0 using 56.2 gms sodium hydroxide and 18.7 gms sodium carbonate with continuous stirring. Then the solution was drum dried at 13O0C and the resulting bio-tanning agent powder was stored in a plastic container. Total weight of the dried powder was found to be 2150 gms. Example 5
Delimed pelt wastes/trimmings and limed fleshings, weighing 5 kgs and 2 kgs, were sliced into small pieces using mechanical slicer. The sliced weight of the material was found to be 6.6 kg. The sliced materials were washed with 19.8 lit water for 15 mins in a reactor. Then, the water was drained from the reactor. 6.6 lit water and 99 gms concentrated sulfuric acid was added to the reactor with stirring. Then the reactor was heated to 920C with continuous stirring for a period of 90 minutes. The pH of the solution was found to be 1.6. Obtained viscous solution was cooled to 2O0C using ice water cooling system. The cooled solution was neutralized to a pH 6.5 using 66 gms sodium hydroxide with continuous stirring. • Then the solution was drum dried at 13O0C and the resulting bio-tanning agent powder was stored in a plastic container. Total weight of the dried powder was found to be 2050 gms. Example 6 /
Hide powder, weighing 2 kgs, was washed with 4000 ml water in a pit for 3 hrs. The weight of the washed wet hide powder was found to be 7.8 kg. The wet hide powder was
charged into a reactor. To this, 7.8 lit water and 78 gms concentrated sulfuric acid was added to the reactor with stirring. Then the reactor was heated to 8O0C with continuous stirring for a period of 30 minutes. The pH of the solution was found to be 1.2. Obtained viscous solution was air cooled to 370C. The cooled solution was neutralized to a pH 7.0 using 58.4 gms sodium hydroxide and 19.6 gms sodium carbonate with continuous stirring. Then the solution was spray dried at a temperature of 2600C and the resulting bio-tanning agent powder was stored in a plastic container. Total weight of the dried powder was found to be 1900 gms. The following are the advantages of the present invention:
1. This process does not require very high temperature for the hydrolysis of collagen wastes/fibers
2. This process hardly requires any complicated control measures such as pH and pressure.
3. The process leads to significant reduction in time and power.
4. Suitable for all kinds of raw materials.
5. The developed product has wide applications in leather industry, especially as a bio- tanning agent, thereby replaces toxic or hard biodegradable conventional tanning agents.
Product characteristics
Appearance Pale brown powder Moisture (%) 1.5±0.5 pH (10% dilution) 5.5±O. l Carbon (%) 27+0.5 Hydrogen (%) 4.7±0.1 Nitrogen (%) 9.6±0.2
Comparative advantages over the prior art
Claims
1. A process for the preparation of bio-tanning agent, which comprises: i. treating a collagenous material in aqueous medium with an acid at a temperature in the range of 80-980C and at a pH not exceeding 3.0 for a period not less than 30 minutes to obtain a slurry followed by adjusting temperature of the slurry to a range of 20-400C, ii. adjusting pH of the slurry formed in step (i) to a range of 5.5-7.0 to obtain the bio- tanning agent in liquid form.
2. A process as claimed in claim 1 wherein the bio-tanning agent in liquid form obtained in step (ii) is dried at a temperature in the range of 130-2600C to obtain the bio-tanning agent in dry powder form.
3. A process as claimed in claim 1 wherein the collagenous material used is selected from the group consisting of raw hide/skin trimmings, limed hide splits, green hide fleshings, limed skin/hide fleshings, delimed pelt wastes/trimmings, hide powder either alone or in any combination thereof.
4. A process as claimed in claim 1 wherein the amount of water used is in the range of 50-
200% by volume on wet weight of the collagenous material.
5. A process as claimed in claim 1 wherein the acid used is selected from the group consisting of sulfuric acid, formic acid, acetic acid, hydrochloric acid either alone or in any combination thereof.
6. A process as claimed in claim 2 wherein the drying is achieved by spray drying or drum drying.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| PCT/IN2004/000435 WO2006070398A1 (en) | 2004-12-30 | 2004-12-30 | Process for the preparation of bio-tanning agent |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| EP1844107A1 true EP1844107A1 (en) | 2007-10-17 |
Family
ID=34960559
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| EP04816683A Withdrawn EP1844107A1 (en) | 2004-12-30 | 2004-12-30 | Process for the preparation of bio-tanning agent |
Country Status (5)
| Country | Link |
|---|---|
| EP (1) | EP1844107A1 (en) |
| CN (1) | CN101090946A (en) |
| BR (1) | BRPI0419261A (en) |
| CA (1) | CA2592856C (en) |
| WO (1) | WO2006070398A1 (en) |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1227534A (en) * | 1967-08-31 | 1971-04-07 | ||
| RU1823879C (en) * | 1991-08-02 | 1993-06-23 | Киевский технологический институт легкой промышленности | Method of tanning out of collagen-containing waste of chrome tanning for protein substance preparing |
| RU2085592C1 (en) * | 1995-11-16 | 1997-07-27 | Центральный научно-исследовательский институт кожевенно-обувной промышленности | Process for preparing synthetic tanning agent |
| IT1320175B1 (en) * | 2000-12-22 | 2003-11-26 | Artoni S A S Di Artoni Giancar | PROCESS FOR THE EXTRACTION OF JELLY AND RECOVERY OF CHROMODAL SALTS SHAVING OF TANNED SKIN. |
-
2004
- 2004-12-30 EP EP04816683A patent/EP1844107A1/en not_active Withdrawn
- 2004-12-30 CA CA2592856A patent/CA2592856C/en not_active Expired - Fee Related
- 2004-12-30 WO PCT/IN2004/000435 patent/WO2006070398A1/en not_active Ceased
- 2004-12-30 BR BRPI0419261-3A patent/BRPI0419261A/en not_active IP Right Cessation
- 2004-12-30 CN CNA200480044740XA patent/CN101090946A/en active Pending
Non-Patent Citations (1)
| Title |
|---|
| See references of WO2006070398A1 * |
Also Published As
| Publication number | Publication date |
|---|---|
| BRPI0419261A (en) | 2007-12-18 |
| WO2006070398A1 (en) | 2006-07-06 |
| CA2592856C (en) | 2012-09-11 |
| CA2592856A1 (en) | 2006-07-06 |
| CN101090946A (en) | 2007-12-19 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| John Sundar et al. | Recovery and utilization of proteinous wastes of leather making: a review | |
| Krishnamoorthy et al. | Greener approach to leather tanning process: D-Lysine aldehyde as novel tanning agent for chrome-free tanning | |
| Cabeza et al. | Processing of leather waste: pilot scale studies on chrome shavings. Isolation of potentially valuable protein products and chromium | |
| Mu et al. | Towards zero discharge of chromium-containing leather waste through improved alkali hydrolysis | |
| Sundar et al. | Recovery and utilization of chromium-tanned proteinous wastes of leather making: a review | |
| Wang et al. | An integrated cleaner beamhouse process for minimization of nitrogen pollution in leather manufacture | |
| Puhazhselvan et al. | Recycling of tannery fleshing waste by a two step process for preparation of retanning agent | |
| Kandasamy et al. | Anaerobic biovalorization of leather industry solid waste and production of high value-added biomolecules and biofuels | |
| US4179333A (en) | Method for making water-soluble elastin hydrolyzates | |
| CA2706325C (en) | Agent and process for the tanning of hides and skins | |
| Zainescu et al. | A new concept of complex valorization of leather wastes | |
| CA2592856C (en) | Process for the preparation of bio-tanning agent | |
| Aftab et al. | Biodegradation of leather waste by enzymatic treatment | |
| US20060137103A1 (en) | Process for the preparation of bio-tanning agent | |
| CN102030994A (en) | Shoe-heel regenerated leather | |
| US6352714B1 (en) | Method of producing a metal nutrient for an animal feed | |
| AU656448B2 (en) | Use of silica sols for obtaining a hide which is called a stabilized pickled white or stabilized white | |
| KR102643029B1 (en) | chromium tanner | |
| CN1928123A (en) | Hair-protection and hair-removing composition of organosilicon and enzyme and method for hair-protection and hair-removing animal skin by the same | |
| RU2116350C1 (en) | Method of manufacturing porous fibrous material | |
| US20040214309A1 (en) | Method for preparing leather using protease and method for treating wastes derived from leather processing | |
| Constantinescu et al. | Retanning bioagent used in leather processing and process of obtaining thereof | |
| AU2002308063A1 (en) | Improvements in leather processing | |
| NZ529172A (en) | Improvements in leather processing | |
| WO2001042440A1 (en) | Enzymatic treatment of proteinaceous animal by-product materials to impart cohesion and strength |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
Free format text: ORIGINAL CODE: 0009012 |
|
| 17P | Request for examination filed |
Effective date: 20070730 |
|
| AK | Designated contracting states |
Kind code of ref document: A1 Designated state(s): DE GB IT |
|
| DAX | Request for extension of the european patent (deleted) | ||
| RBV | Designated contracting states (corrected) |
Designated state(s): DE GB IT |
|
| 17Q | First examination report despatched |
Effective date: 20080430 |
|
| GRAP | Despatch of communication of intention to grant a patent |
Free format text: ORIGINAL CODE: EPIDOSNIGR1 |
|
| GRAS | Grant fee paid |
Free format text: ORIGINAL CODE: EPIDOSNIGR3 |
|
| STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN |
|
| 18D | Application deemed to be withdrawn |
Effective date: 20090825 |