JP2003502135A - Liquid carbon dioxide cleaning using natural and modified natural solvents - Google Patents

Abstract

(57) Abstract: Soiled articles are treated by treating at least a portion of the article with a biodiesel compound and agitating the article in contact with the dense phase carbon dioxide to remove the soil from the article. Washed. The biodiesel compound may be used in a pre-treatment step, during a stirring step, or both. The biodiesel compound may be mixed with at least one of water and a washing enzyme.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD OF THE INVENTION

The present invention relates to cleaning articles, and more particularly to a method of improving carbon dioxide cleaning processes.

[Prior art]

Common organic cleaning solvents historically used in the home, industry and market such as tetrachlorethylene, CFC-113, 1,1,1-trichloroethylene and petroleum based solvents are carcinogenic and highly flammable, Dangerous for health and safety. This solvent is also environmentally detrimental because it depletes ozone and produces smog. As a result of tighter regulations on the manufacture and use of these solvents, operating costs and responsibilities for all market segments associated with these products have skyrocketed.

As a result, alternative cleaning media have been developed and implemented to reduce the health and environmental risks associated with cleaning. Water as a degreasing medium is limited because it requires a drying step after washing, and the washing process is often lengthy and energy intensive. Water also has a low ability to dissolve organic soils, so additives and strong agitation are usually required to remove organic soils. Waste liquid treatment before draining this is expensive.

Carbon dioxide is a low-cost, unlimited natural resource that is non-toxic, non-flammable, does not generate smog, does not deplete ozone. Carbon dioxide is a dense phase in both liquid and supercritical states and exhibits the typical solvation properties of hydrocarbon solvents. Substances dissolved in dense phase carbon dioxide are easily recovered in their concentrated form by vaporizing the carbon dioxide. Secondary waste streams, such as those associated with the use of prior art solvents, do not occur.
Carbon dioxide does not damage textiles or dissolve common dyes, and because of its properties, it is an excellent dry cleaning medium for textiles and clothing. It is also a suitable degreasing / cleaning medium for removing gas oil from commercial and industrial parts and components. Dense-phase carbon dioxide can be obtained, for example, from US Pat.
13,336 specification, 5,316,591 specification, 4,012,194 specification, 5,467,492
In various patent specifications including US Pat. No. 5,267,455, cited as a cleaning liquid for clothing and components.

[Problems to be Solved by the Invention]

The disadvantage of dense phase carbon dioxide is that it is a relatively mild solvent and is not readily suitable for heavy oils and greases. Moreover, it does not remove hydrophilic stains. As a result, for some dense-phase carbon dioxide treatments, hydrophilicity is enhanced by the ability to enhance or adjust the mass-dissolving capacity of carbon dioxide itself for soils that have an affinity for organic soil, or to carry water into the dense-phase carbon dioxide medium. Co-solvation (c
Additives that help to o-solve are incorporated. The use of such additives is described, for example, in U.S. Pat.Nos. 5,683,977, 5,683,473,
References are made to various patent specifications, including 5,676,705, 5,866,005 and 5,789,505.

Typical additives used to enhance the organic solvation power of dense phase carbon dioxide are the same compounds targeted for substitution due to their deleterious properties. Examples include low alkanes, terpenes, alcohols, ketones, benzene, toluene, xylenes and cosolvents such as chlorinated, fluorinated or chlorofluorinated compounds.

Also, in general, the decomposition or removal of ionic or water-soluble soils is enhanced by molecularly-treated surfactants formed to carry water into the carbon dioxide medium. The disadvantage is that these additives require elaborate synthesis and are therefore expensive. It is also necessary to use the above-mentioned cosolvents for the surfactants, which eliminates the health and environmental benefits associated with the use of dense phase carbon dioxide.

The problems associated with removing heavy oils, greases and hydrophilic soils have been improved while improving the efficiency of liquid carbon dioxide scrubbing processes, thereby maintaining the health and environmental benefits of bulk dense phase carbon dioxide solvents. Need to be resolved. The present invention fulfills this need and further provides related advantages.

[Means for Solving the Problems]

The present invention provides methods and apparatus for performing dense phase carbon dioxide cleaning of articles. The method of the present invention retains excellent effectiveness in removing particulate dirt from articles, compared to the use of dense phase carbon dioxide alone in the removal of grease, oil, and hydrophilic dirt. And increase the effect. This method utilizes natural and conditioned natural additives that have excellent solvation properties. The additive is environmentally friendly, non-toxic, biodegradable and free of sulfur and aromatics. They can be rinsed off with water, water, mineral spirits, alcohol,
And forms stable emulsions with other phases such as some terpenes. These additives may be used with known dense phase carbon dioxide scrubbing steps.

According to the present invention, a method of cleaning an article comprises providing an article with soil attached to it, treating at least a portion of the article with a biodiesel compound, and removing the soil from the article in a dense phase. The step of contacting with carbon dioxide is included. After the contacting step is complete, the biodiesel compound, if any, may optionally be rinsed to remove it.

A “biodiesel compound” is an approved class containing alkyl monoesters of vegetable oils, preferably methyl esters of vegetable oils. Examples of suitable vegetable oils are safflower, sunflower, canola and soybean oil. Biodiesel compounds are fully compatible with dense phase (liquid or supercritical) carbon dioxide. "
The term "biodiesel compound" results from the use of such a compound as a component in synthetic diesel fuels without regard to the present invention.

The article to be cleaned may be a woven fabric or it may be another article such as a metal, ceramic or plastic part to be degreased and cleaned. The contacting of the biodiesel compound with the article and stirring of the article may occur wholly or partially in succession, or simultaneously, as appropriate for the particular application.
Thus, for example, the article may be pretreated with a biodiesel compound and then placed in a pool of dense phase carbon dioxide in a pressure chamber and agitated. The biodiesel compound may instead be added to the pool of dense phase carbon dioxide in the original process.
A combination of pretreatment and original treatment may be used. The pretreatment may be a conventional pretreatment such as dipping or a localized pretreatment such as "spotting" of the fabric. The biodiesel compound may be made into an emulsion with at least one of water and enzyme and used in both these pretreatments and the original treatment. Contact and agitation include, for example, liquid jet force of dense phase carbon dioxide introduced into the pool, foaming when some dense phase carbon dioxide evaporates, tumbling action, stirring of the pool by an impeller, circulation of carbon dioxide by a pump, and It may be done by any feasible method, such as ultrasonic cavitation. Thus, various treatments and agitation treatments are carried out using biodiesel compounds within the scope of the present invention.

The present invention provides an improved cleaning treatment method using dense phase carbon dioxide as a cleaning medium. This method focuses on the use of certain natural (eg, enzymes) and conditioned natural additive (eg, biodiesel) compounds that enhance the cleaning efficiency and solvation power of dense phase (liquid) carbon dioxide. . The function of biodiesel compounds, alone or in combination with additives such as at least one of water / enzyme,
The purpose is to dissolve organic matter such as oils and greases and hydrophilic soils to make them mobile so that they can be more easily removed from the article being washed by agitation of dense phase carbon dioxide. These additives, alone or as carriers for at least one of enzymes and water, are environmentally friendly, non-toxic, biodegradable and free of sulfur and aromatics. The method of the present invention enhances the effect of removing heavy oil, grease and hydrophilic stains, while the liquid carbon dioxide cleaning medium retains its health and environmental friendly properties as a solvent. Other features and advantages of the present invention will become apparent with reference to the following detailed description of the preferred embodiments, in which the principles of the invention are illustrated by way of example, and the accompanying drawings. However, the technical scope of the present invention is not limited to this preferred embodiment and embodiment.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 illustrates a preferred method for practicing the present invention. The device is deployed (20). The apparatus can be of any type that can be operated to perform the remaining steps of the process, and Figure 2 shows the preferred apparatus most suitable for commercial fabric washing operations.
40 illustrates one embodiment of 40.

The device 40 includes a cleaning chamber 42 having a pressure container 44 and a pressure door 46 for sealing the container 44.
Is equipped with. The wash chamber 42 generally ranges from about 550 pounds per square inch (psi) to about 1000 psi, and is preferably designed to withstand the internal pressures used in subsequent steps of about 700-800 psi, from steel. Has been formed. A perforated basket 48 having an opening is supported within the wash chamber 42 and has an open end closer to the pressure door 46 so that articles can be placed in and out of the perforated basket 48 when the pressure door 46 is open. Looking at In the illustrated embodiment, the pressure vessel 44 and the perforated basket 48 have a cylindrical shape that is symmetrical about a cylindrical axis 50.

A dense phase carbon dioxide cleaning medium is supplied to the interior of the cleaning chamber 42 by one or more manifolds 52. As explained below, the additive is mixed with the dense phase carbon dioxide.
Each manifold 52 has one or more jet orifices 54 through which dense phase carbon dioxide flows.
have. The jet orifice 54 is preferably positioned such that the wash medium flow from the jet orifice 54 is directed through the openings in the perforated basket 48 towards its interior, and thus around the item being washed.

During operation of the device 40, dense phase carbon dioxide is injected through the manifold 52 into the wash chamber 42 by the main pump 56, which is operated by suitable valves 58 and 60. The dense phase carbon dioxide cleaning medium is first washed by the cleaning chamber 42 to form a pool of liquefied cleaning medium.
Is injected to a preset depth within. When the desired pool depth is reached, additional dense phase carbon dioxide through the jet orifice 54 agitates the pool and the articles therein.

The dense phase carbon dioxide cleaning medium, after passing through the cleaning chamber 42, flows to a lint trap 62 that filters solid material from the washing medium (the lint trap 62 is used when non-woven articles are to be washed). May be removed). The valve 66 allows the dense phase carbon dioxide to be filtered 68
, To a condenser 70 with a cooling system 72 and can be returned to the inlet side of the main pump 56 through a valve 74. When provided with a "bypass," valve 66 enables recovery of the exhausted dense-phase carbon dioxide.

The liquefied cleaning medium is supplied to the main pump 56 from a storage tank 76 operated by a valve 74. Optional additives to the liquefied wash medium, such as water or enzymes, described below, are fed from additive source 78 through additive pump 80 to the inlet side of main pump 56.

The wash medium also flows from the wash chamber 42 to the inlet side of the main pump 56 through a drain line 82 operated by a valve 74 during the “drain” portion of the process.

The device 40 further comprises a ventilation valve 84 by means of which the cleaning chamber 42 can be brought to a pressure equal to the ambient air. Appropriate valves 88, 90 and 91 are provided in the return path for gaseous carbon dioxide from the compressor 86 to the condenser 70 or the storage tank 76.

During cleaning of the article, soluble, non-particulate soil is dissolved in the cleaning medium. A distillation column 92 equipped with suitable valves 94 and 96 to separate soluble, non-particulate soil from the wash medium.
Is provided. Distillation generally occurs independently when the wash chamber 42 is not being used to wash the items.

The device 40 is primarily designed for cleaning fabrics, but may be used for cleaning other items. The device is usually optimized for the type of article to be cleaned.

In a typical cleaning cycle, the material to be cleaned is placed in the perforated basket 48 within the cleaning chamber 42 and the pressure door 46 is closed. Valve 91 is opened and storage tank 76
The pressure between the cleaning chamber 42 and the cleaning chamber 42 is equalized. Valve 74 is in the "chamber" position, storage tank
Fluid from 76 is pumped through valve 58 by main pump 56 into wash chamber 42 until the desired water level is reached (in the "chamber" position). At this point valves 88 and 90 are closed, defining a recirculation loop back through waste trap 62, filter train 68, condenser 70 and back to main pump 58. To agitate the load to be washed by the flow of dense phase carbon dioxide, the main pump 58 produces the necessary flow and pressure drop of dense phase carbon dioxide (and additive, if present) across the orifice 54. . At the end of the agitation cycle, valves 88 and 90 are opened, valve 58 is switched to "drain" and valve 66 is switched to "bypass". Liquid phase carbon dioxide is discharged by the main pump 56 through the discharge line 82 and the valve
It is discharged through 74 and collected from the wash chamber 42 into the storage tank 76 (at which time it is in the "drain" position). At this point, the wash chamber 42 contains the washed load and gaseous carbon dioxide. After the gas compressor 86 collects the carbon dioxide vapor and returns it to the storage tank 76, the cleaning chamber 42 is depressurized to atmospheric pressure. Gaseous residual carbon dioxide is exhausted through the ventilation valve 84, the pressure door 46 is opened, and the washed and cleaned load is removed.

The method of the present invention can be performed by, but is not limited to, the exemplary device 40 when applied to cleaning articles such as fabrics or garments. For example, impellers for agitating the liquid pool in the wash chamber 42, other types of contact and agitation devices such as ultrasonically excited transducers that cause cavitation of the liquid pool, or other techniques described herein. Any of may be used.

Referring to FIG. 1, an article to be cleaned is prepared (22). The article may be of any feasible type and configuration so long as it fits within the perforated basket 48. One preferred application of the present invention is the cleaning of textile articles such as garments, and another preferred application is the cleaning and degreasing of parts or components.

There are several methods that can be implemented to perform cleaning of articles using the present invention. In one method, the article is optionally pretreated (24). During pretreatment, the article is contacted with the pretreatment liquid. Contacting may include, for example, a spot contacted with the pretreatment liquid or immersion in the pretreatment liquid. Generally, 1 so that the pretreatment liquid can solubilize any non-particulate soils that have adhered to the article.
The article is left in contact with the pretreatment liquid for a period of minutes to about 24 hours, preferably about 1 minute to about 60 minutes.

The pretreatment liquid, if used, preferably comprises a biodiesel compound. The biodiesel compounds are alkyl monoesters of vegetable oils or fats (particularly methyl and ethyl esters), preferably methyl esters of vegetable oils. Examples of suitable vegetable oils are rapeseed, safflower, sunflower, canola and soybean oil. Biodiesel compounds may be processed by recycling this waste from used frying cooking oil. Although each vegetable oil consists of glycerides derived from a number of different carboxylic acids, each oil has its unique composition, and these compositions do not differ substantially between samples. Biodiesel compounds are shown in Figure 3.
The glycerin molecule in the untreated vegetable oil is replaced by methanol or ethanol, as represented by the reaction shown in FIG.
Obtained from transesterification where 2 is a saturated or unsaturated long chain fatty acid. Indeed, the chemical reaction of FIG. 3 may occur by mixing the vegetable oil with methanol (or ethanol instead) in the presence of potassium hydroxide and then precipitating the mixture. The biodiesel compound is gently poured from the top of the reactor, leaving heavy glycerin at the bottom. This transesterification reaction is described in the literature (Rober
t T. Morrison, Organic Chemistry, published by Allyn & Bacon, Inc., 1966, pa
ge 686).

Biodiesel compounds have low viscosities and vapor pressures, their concentrations are similar to those of liquid carbon dioxide, are biodegradable and non-toxic, are free of sulfur and aromatic compounds, and are approximately 60 Has a relatively high (compared to about 90 tetrachloroethylene) value for kauributanol and has the advantage of indicating a good organic solvent. Biodiesel compounds can be rinsed off with water and readily form water, mineral spirits, alcohol, and some terpenes and emulsions. They are compatible with dense phase carbon dioxide having about the same specific gravity of 0.9.

The biodiesel pretreatment liquid may optionally be mixed with another compound such as water and / or at least one of the wash enzymes. Enzymes are proteins that promote (catalyze) reactions involving the formation or degradation of covalent bonds. Enzymes act by lowering the temperature below which a given bond is unstable. Although there are numerous instances where a well-defined molecule promotes reactions between other molecules, not all enzymatic reactions are unique. For example, the various enzymes that break down proteins into their amino acids are unique only in the sense that they break peptide bonds. In general, enzymes act in aqueous media and have been used for many years during the cleaning process and in many soap and detergent formulations. Some uses of formulations containing enzymes include spotting compounds that help remove protein-based stains (such as blood) from clothing, as well as unique enzymes that help degrease oils at home. It is a detergent that I have. Recently, enzymes have been used in aqueous detergents to promote degreasing of parts and components. However, enzymes are generally insoluble or poorly miscible in dense-phase carbon dioxide solvents, and thus a "carrier" compound is needed to facilitate introduction of the enzyme into the dense-phase carbon dioxide treatment, which is necessary. Here it is a biodiesel compound.

Any workable relative amounts of biodiesel compound and other compounds can be used. It is preferable that the biodiesel compound or a mixture of the biodiesel compound and the enzyme or water in any proportion is present in the dense phase carbon dioxide in an amount of about 0.01 to about 5% by volume. Less than that would be ineffective, more would be wasteful, and the washed article could be contaminated by residual biodiesel compounds that need to be removed. When using pretreatment,
This may be done in the wash chamber 42 or in another container.

The article, optionally pretreated in step 24, is placed into the cleaning device 40, which in this preferred case is a perforated basket 48 in the cleaning chamber 42 (step 26). The pressure door 46 is closed and sealed. A cleaning medium is introduced into the sealed cleaning chamber 42 and a pool is formed in the cleaning chamber 42 by pumping the cleaning medium from the storage tank 76 using the main pump 56 as described above (step 28). The article is preferably partially or completely submerged in the pool in a perforated basket.

The cleaning medium comprises liquid carbon dioxide spiked with one or more of the biodiesel compounds mentioned above. The composition of the cleaning medium introduced in step 28 may be the same as the pretreatment cleaning medium used in step 24, or a different biodiesel containing medium may be used. Also, other additives such as at least one of water and enzyme described above may be added. This specification includes a prior art description of these various materials. The total amount of additives is generally about 0.01 to about 5.0% of the total carbon dioxide and additives, with a preferred range of about 0.1 to about 1.0%.

The pool and articles are agitated (step 30). Agitation is shown in equipment 40
By the action of the cleaning medium injected through the manifold 52 and the liquid jet orifice 54 in the. To this end, the liquid jet orifice 54 is provided in the perforated basket 48 so that the cleaning medium is impinged on the article to be cleaned in the perforated basket 48.
It is directed into the interior through the opening.

The agitation is continued for a period of time sufficient to remove particulate dirt adhering to the article and to dissolve and remove non-particulate matter such as oils, greases and hydrophilic dirt. . This agitation time will vary depending on the characteristics of the article, how dirty the article is and other factors, but is generally about 5 to about 30 minutes. Agitation is preferably a liquid jet, but not only hydrodynamic cavitation generated by propellers, impellers or blades, circulation by pumps or compressors, transducers, ultrasonic cavitation generated by sonic whistles. , Or by any feasible method such as a combination of these techniques.

When the stirring is completed, the cleaning medium is discharged from the cleaning chamber 42 (step 32). Optionally, a rinse medium such as pure liquid carbon dioxide may be introduced into the wash chamber 42 to rinse the article by agitating the article with unconditioned liquid carbon dioxide (step 34). This step is performed when the cleaning medium is used with additives and it is desirable to completely remove these additives from the article prior to using the article. For example, if the article is a garment-like fabric and the cleaning medium contains a biodiesel compound, it is usually desirable to rinse off the biodiesel compound with unconditioned liquid carbon dioxide. In other cases, such as degreasing an article, it may be desirable to leave the biodiesel compound as a temporary corrosion protection coating on the article. After the rinse step 34 is completed, the rinse medium is discharged from the wash chamber 42.

After recovering most of the liquid and gaseous carbon dioxide in the storage tank, the residual pressure in the wash chamber 42 is made equal to atmospheric pressure using the ventilation valve 84 and the article is removed from the wash chamber 42. It During this ventilation and removal, residual carbon dioxide evaporates, leaving the article dry and clean by the time it is removed from the wash room.

The application of the present invention will be described in the following examples, which do not limit the technical scope of the present invention in any way.

[Example 1] The load of the stainless steel component is CRC industry standard NO.MSDS SL3310, 31
60, 3131, 3141 and various greases such as Exxon L / M487211; H. Threading oil C10 manufactured by Harvey
Type 326 and processed. The part was placed in a liquid carbon dioxide cleaning chamber 42 with a capacity of 12 gallons.

Sufficient liquid carbon dioxide was injected into the wash chamber to completely sink the load. In some cases, the Carbon Group (Huntington Beach, CA) has SSW
A biodiesel compound sold as -1000 was added to chamber 42 in an amount of 0.1%, 0.5%, 1.0% or 2.0% of the total amount of carbon dioxide and biodiesel compound. The liquid carbon dioxide (and biodiesel compound, if present) cleaning medium is agitated for 10 minutes at a temperature in the range of 0 to 85 ° F using cavitation with blades and propellers to facilitate grease and oil removal. Was done. The solvent was then drained, the chamber depressurized, the parts removed, and visually and tactilely tested for residue.

Without the use of biodiesel compounds, only the mineral oil component of the grease could be removed, leaving the drawing soap and other additives in the grease, a form of a viscous thin film coating. Contaminated the parts with. The threading oil remained on the part as a sticky residue.

In the presence of biodiesel compounds, grease and oil removal was improved in all cases. Some improved grease and oil removal was observed for 0.1% biodiesel compound, but at least about 1.0% biodiesel compound was required to completely remove the grease. It was Threading oil residues were removed at> 0.2% biodiesel compounds. After treatment, the parts were dried and no evidence of residual biodiesel compound was found on the parts, even for 2.0% biodiesel compound additive.

Example 2 A load on a stainless steel part was treated with a polishing compound consisting of heavy wax and 20-40 micrometer aluminum powder. The load was pretreated with the same biodiesel compound as the type used in Example 1 for 30 minutes (step 24)
.

After pretreatment, the load was not dried and placed in the same wash chamber as used in Example 1 and treated in the same manner as described for Example 1 (steps 26, 28, 30 and 32).

No substantial removal of polishing compound was observed when no biodiesel compound was used in either the pretreatment or the agitation steps.

When the biodiesel compound was present, removal of the polishing compound was observed even at a concentration of only 0.1%. Greater than 1% biodiesel compound was required for complete removal.

0.1%, 0.5%, 1 in liquid carbon dioxide used in steps 28 and 30
． This example was repeated without pretreatment for biodiesel compounds at concentrations of 0%, 2% and 5%. A 5% concentration of biodiesel compound is required for complete removal of the polishing compound and is substantially 1 if the pretreatment is used.
． Concentrations higher than 0% were required. When a 5% concentration of biodiesel compound was used, a rinse was required after agitation (step 34) as a thin film of biodiesel compound remained on the part after agitation and discharge.

Examples 1 and 2 show that the use of biodiesel compounds enhances the cleaning effect of parts. Example 2 demonstrates that the amount of biodiesel compound required for subsequent treatment and agitation is reduced by the pretreatment, reducing the need for post drainage rinses.

Example 3 A load of stainless steel parts was dipped in a saturated aqueous salt solution, removed and dried. The load was then placed in the wash chamber described in Example 1. Liquid carbon dioxide and biodiesel compound / water (0.5% biodiesel compound plus water, volume ratio of biodiesel compound to water is 1: 1) is introduced into the chamber and the salt is dissolved to produce parts. It was stirred for 10 minutes to remove it. The treatment was carried out under the same conditions as described for Example 1. The chamber was then evacuated, the parts removed and inspected.

[0046]   The same experiment was performed without the biodiesel compound and water.

The salt was removed when the biodiesel compound and water were present in the wash medium. No salt was removed if the biodiesel compound and water were not present in the wash medium.

Example 4 The same polishing compound used in Example 2 was applied to a load of stainless steel parts and this load was placed in the wash chamber described in Example 1.

Liquid carbon dioxide and biodiesel compound / water / Bacto-zyme enzyme (0.5% biodiesel compound / water / Bacto-zyme, with a volume ratio of biodiesel compound: water: Bacto-zyme of 1 :). (1: 1) solution was poured into the chamber and stirred for 10 minutes under the conditions described in Example 1 except the temperature range was 40-85 ° F. Bacto-zyme, described in MSDS 1113, is a versatile natural enzyme agent with a complex non-bacterial organic formulation that promotes the penetration and emulsification of oily or fatty substances.
Sold by on Group.

In the presence of water and Bacto-zyme, the degreasing effect was higher compared to the control test in which they were not present at all.

Example 5 A thread load was applied to a textile load and the stain was treated with a concentrated biodiesel compound liquid and the load was placed in the wash chamber described in Example 1. Liquid carbon dioxide was introduced into the chamber at 55-65 ° F and the load was stirred for 10 minutes. The liquid was drained, the system depressurized, and the fabric removed for evaluation. No residual threading oil was found on the fabric. When removed, the fabric was dry and free of stains.

While particular embodiments of the invention have been described in detail for purposes of illustration, various modifications and enhancements can be made without departing from the scope of the invention. Therefore, the present invention is limited only by the appended claims.

[Brief description of drawings]

[Figure 1]   FIG. 3 is a block flow diagram of a preferred embodiment of the method according to the present invention.

[Fig. 2]   2 is a schematic system diagram of an apparatus used in the method of FIG. 1. FIG.

[Figure 3]   A chemical reaction diagram used to produce a biodiesel compound.

[Procedure amendment]

[Submission date] March 5, 2001 (2001.3.5)

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be amended] Claims

[Correction method] Change

[Contents of correction]

[Claims]

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) C23G 5/00 C23G 5/00 (81) Designated country EP (AT, BE, CH, CY, DE, DK, ES, FI, FR, GB, GR, IE, IT, LU, MC, NL, PT, SE), OA (BF, BJ, CF, CG, CI, CM, GA, GN, GW, ML, MR, NE, SN, TD, TG), AP (GH, GM, KE, LS, MW, SD, SL, SZ, TZ, UG, ZW), EA (AM, AZ, BY, KG, KZ, MD, RU) , TJ, TM), AE, AL, AM, AT, AU, AZ, BA, BB, BG, BR, BY, CA, CH, CN, CR, CU, CZ, DE, DK, D. , EE, ES, FI, GB, GD, GE, GH, GM, HR, HU, ID, IL, IN, IS, JP, KE, KG, KP, KR, KZ, LC, LK, LR, LS, LT, LU, LV, MA, MD, MG, MK, MN, MW, MX, NO, NZ, PL, PT, RO, RU, SD, SE, SG, SI, SK, SL, TJ, TM, TR , TT, TZ, UA, UG, UZ, VN, YU, ZA, ZW (72) Inventor Pula, Edna M. USA, California 90046 Los Angeles, N.C.H.T.S. 828 (72) Inventor Sorbo, Nelson Wake 90277 Redondo Beach, USA United States Emerald Street 605 F Term (Reference) 3B201 AA46 AB01 BB01 BB21 BB45 BB83 BB87 BB92 BB95 CC01 CC11 CD22 4H003 DA01 DA05 DA14 DB0 2 DC02 EA31 EB09 EC02 ED02 ED32 FA01 FA03 4K053 PA03 PA17 QA04 QA07 RA01 RA05 RA12 RA46 RA48 SA09

Claims (20)

[Claims] 1. A method comprising: providing a soiled article, treating at least a portion of the article with a biodiesel compound, and contacting the article with a dense phase of carbon dioxide to remove soil from the article. How to wash items. 2. The method of claim 1, wherein the treating step is initiated prior to initiating the contacting step. 3. The method of claim 1, wherein the treating step is terminated prior to initiating the contacting step. 4. The method of claim 1, wherein at least a portion of the treating step is performed concurrently with the contacting step. 5. The method of claim 1 including the additional step of rinsing the article to remove the biodiesel compound after the contacting step is complete. 6. The method of claim 5, wherein the rinsing step comprises the step of rinsing the article with carbon dioxide in a dense phase after the treating step is completed. 7. The method of claim 1, wherein the article is selected from the group consisting of textiles, metals, ceramics and plastics. 8. The method of claim 1, wherein the contacting step is performed at a pressure above ambient atmospheric pressure. 9. The method of claim 1, wherein the treating step comprises mixing the biodiesel compound with water. 10. The method of claim 1, wherein the treating step comprises the step of mixing the biodiesel compound with a cleaning enzyme and water. 11. The method of claim 1, wherein the article is contacted with a pool containing dense phase carbon dioxide during the contacting step. 12. The method of claim 11, wherein the pool further comprises a biodiesel compound. 13. The step of contacting comprises:   The method of claim 1 including the step of directing a stream of liquefied gas around the article. 14. An article provided with a soiled article, pretreated at least a portion of the article with a biodiesel pretreatment cleaning medium, and in contact with dense phase carbon dioxide to remove the soil from the article. A method of cleaning an article, the method including the step of stirring. 15. The method of claim 14, wherein the dense phase carbon dioxide is mixed with a biodiesel compound. 16. The method of claim 15 wherein the dense phase carbon dioxide is mixed with another additive selected from the group consisting of water, enzymes and mixtures thereof. 17. The method of claim 14 including the additional step of rinsing the article to remove biodiesel compounds after the agitating step is complete. 18. A cleaning of an article comprising the steps of providing a soiled article and agitating the article in contact with a mixture of carbon dioxide in a dense phase and a biodiesel compound to remove the soil from the article. Method. 19. The method of claim 18 including the additional step of rinsing the article to remove biodiesel compounds after the agitating step is complete. 20. The method of claim 18, wherein the treating step comprises mixing the biodiesel compound with another additive selected from the group consisting of water, enzymes and mixtures thereof.