Accelerated tissue dissolution

Abstract

Methods for the chemical dissolution of human and other cadavers (e.g., pets) using ethanol potassium hydroxide (KOH) or aqueous ethanol KOH at atmospheric pressure are described. Upon acid neutralization to the neutral pH range, the resulting solution can be applied in soil as a fertilizer treatment, or further treated using hydrogen peroxide. It has been found that for high concentrations of KOH, the use of ethanol can reduce the dissolution time of a cadaver to approximately two hours.

Description

[0001] Cross-references to related applications

[0002] This application claims the benefit of U.S. Provisional Patent Application No. 62 / 931050, filed November 5, 2019, by Richard M. Hyslop et al., concerning “accelerating tissue digestion,” the entire contents of which are hereby specifically incorporated by reference for disclosure and teaching. Background Technology

[0003] Tissue dissolution is increasingly being used as an alternative to incineration for the disposal of tissues, proteins, animal carcasses, and human remains. Tissue is dissolved using a strong alkaline solution, a process known as alkaline hydrolysis. The resulting wastewater is either discharged into sanitary sewers or dried and transported to landfills. After the dissolution process, approximately 6% of the original carcass weight remains as bones and teeth. The remaining bones are sterile and easily processed into shapes suitable for use as soil additives, or can be placed in urns according to family instructions. Summary of the Invention

[0004] According to the purposes of the invention, as embodied and broadly described herein, an embodiment of a method for chemically dissolving tissue from a cadaver comprises: preparing an alkaline solution in a mixture of ethanol or potassium hydroxide having a selective amount of potassium hydroxide, or sodium hydroxide, or a mixture of potassium hydroxide and sodium hydroxide, or a mixture of sodium hydroxide, or sodium hydroxide and potassium hydroxide, water and ethanol; contacting the tissue with the alkaline solution; heating the tissue and the alkaline solution to a desired temperature; determining when the tissue is completely dissolved; and reacting the resulting solution with nitric acid or carbonic acid or a mixture of nitric acid and carbonic acid or another acid to a selected pH value.

[0005] The advantages and benefits of the present invention include, but are not limited to, providing a method for chemically dissolving a corpse using a strong base of hydroxide dissolved in ethanol or a mixture of ethanol and water, the method being carried out for about two hours at atmospheric pressure and a selected temperature. Attached Figure Description

[0006] The accompanying drawings, which are included in and form part of this specification, illustrate embodiments of the invention and, together with the specification, serve to explain the principles of the invention.

[0007] The attached figure shows the dissolution time (in hours) of mice in 10% KOH (curve (a)); 25% KOH (curve (b)); and 40% KOH (curve (c)) solutions in 100% ethanol, 50% ethanol and 50% water, and 100% water. Detailed Implementation

[0008] In summary, embodiments of the present invention provide a method for chemically solubilizing tissue from human and other cadavers (e.g., pets) using ethanol potassium hydroxide (KOH) and aqueous ethanol KOH heated to a desired temperature at atmospheric pressure. After neutralization, the resulting solution can be applied to soil for disposal within the neutral pH range. Additionally, the solution can be treated with an oxidizing agent (e.g., hydrogen peroxide) to further break down lipids, thereby eliminating the need for a waste disposal facility to handle the biological oxygen demand of the lipids. Using an acid (e.g., nitric acid) to reduce the pH of the heated solution to a level suitable for application to soil, results in a crystalline material that can be easily separated from the solution once cooled, thereby reducing the biological oxygen demand of the waste disposal facility. It was discovered that adding nitric acid to a hot solubilization solution (between about 100°F and 165°F) forms a crystalline material when the pH of the solution is reduced to greater than about 6, and the resulting solution temperature is between about 80°F and 100°F.

[0009] Hereinafter, the term “tissue” includes medical waste from humans and animals, as well as parts and whole bodies.

[0010] Carbon dioxide, as carbonic acid, can also be used to reduce the pH of disposal in sewer and waste water treatment facilities, which is currently the practice of alkaline hydrolysis. See, for example, U.S. Patent No. 9,233,405 for “Methods And Apparatuses For Digesting Tissue” by Joseph H. Wilson et al., issued January 12, 2016. It has been discovered that using ethanol can reduce the time for solubilization of cadavers with high concentrations of KOH to about 2 hours, as opposed to 18-24 hours for systems using only water and base.

[0011] At room temperature, about 40 g of KOH will dissolve in 100 mL of ethanol, while about 121 g of KOH dissolves in 100 mL of water. Potassium hydroxide also dissolves in other low molecular weight alcohols, such as methanol and propanol, but has a lower solubility in isopropanol than in ethanol and methanol. The alcohol can participate in acid-base equilibria; in the case of ethanol, potassium ethoxide (ethanolate) forms: KOH + CH3CH2OH → CH3CH2OK + H2O. Additionally, as a nucleophile in organic chemistry, KOH is a source of OH - in both inorganic and organic materials. Aqueous KOH also saponifies esters: KOH + RCOR' → RCOOK + R'OH. When aqueous KOH is used in hydrolysis reactions, amides are another example of saponification.

[0012] Alternatively, when the reaction is sensitive to water or performs an elimination reaction (e.g., dehydration), KOH is used in anhydrous form, such as ethanol KOH (KOH dissolved in ethanol).

[0013] In embodiments of the present invention, ethanol is initially thought to contribute to a more homogeneous solution to more effectively perform the alkaline hydrolysis of triglycerides. Furthermore, since alcohol-type KOH can react by an elimination-type reaction mechanism as opposed to a substitution-type mechanism with aqueous KOH, the present inventors anticipate that the microenvironment of alcohol-type KOH within the cadaver tissue will cause further degradation of lipids by the elimination of hydrogen by the ethoxide salt.

[0014] Methanol when oxidized forms formaldehyde and formic acid, neither of which are as well suited for disposal as acetaldehyde and acetic acid, which are oxidation products of ethanol. Acetone, which is highly flammable, can be formed from the oxidation of isopropyl alcohol.

[0015] Bases, such as Ca(OH)2or Ba(OH)2, are less water and alcohol soluble. NaOH can be used as well as mixtures of NaOH and KOH, but the presence of sodium in the dissolution product is not thought to be a good fertilizer when NaOH is used. However, if the neutralized dissolution solution is intended to be disposed of in the ocean, the use of NaOH alone or in combination with KOH would be a good substitute for KOH. In addition, salted (containing NaCl) water and / or clean seawater can be used to prepare the potassium hydroxide and sodium hydroxide solutions during the dissolution process, as well as solutions containing mixtures of sodium and potassium hydroxides if such disposal is anticipated.

[0016] Dissolution is thought to be complete when all tissue is digested, leaving only bone and / or teeth. This can be determined by visual observation when bone is observed without tissue, or based on reaction times from prior experience with similar cadaver tissue dissolution or digestion. Dissolution times depend on the initial body weight, the amount and concentration of chemicals used, and the temperature of the cadaver and chemicals during the dissolution process. Bone can be dissolved by further reaction with KOH.

[0017] At the request of the deceased’s family, bone can be separated from the dissolution solution and provided to the family for burial. Other arrangements, the deceased’s skeleton, crystalline material, and / or liquid effluent can be returned. Upon completion of cadaver tissue dissolution, the skeleton is observed to be soft.

[0018] Reference will now be made in detail to the present embodiments of the application, examples of which are illustrated in the accompanying drawings. Understanding that the drawings are presented for the purpose of describing particular embodiments of the application and are not intended to limit the application thereto, now turning to the drawings, a graph is shown of the corrected dissolution time in hours for mice in 10 wt% KOH (curve (a)); 25 wt% KOH (curve (b)), and 40 wt% KOH (curve (c)) for KOH solutions in 100 wt% ethanol, 50 wt% ethanol and 50 wt% water, and 100 wt% water.

[0019] The table provides data used in the graphs for dissolution times of mice using KOH. The temperature for all experiments was between 155°F and 170°F.

[0020] Table

[0021]

[0022]

[0023] As can be seen from the graphs and table, the dissolution times of mouse carcasses depend on the concentration of KOH in water, ethanol, and mixtures of water and ethanol, and the amount of ethanol in the KOH solution. For example, in the absence of ethanol in the KOH / water solution, a 40% by weight KOH solution dissolved 1.37 times faster than a 10% by weight KOH solution, while a 100% ethanol, 10% by weight KOH solution dissolved 2.23 times faster than a 10% by weight KOH solution without ethanol. The entries in the column containing the correction time in hours have not been adjusted for the different weights of mice, but have been corrected for the different amounts of KOH in grams used in the tables and graphs. For example, the 2.68 hour dissolution time for Test 9 multiplied by 4.59 / 4.19 gives 2.94 hours.

[0024] The shortest dissolution time measured was 1.63 hours for a 40% KOH solution in 100% ethanol.

[0025] Solutions of 10%, 25%, and 40% by weight KOH in 100% H2O, 50% H2O and 50% ethanol, and 100% ethanol were prepared, with the weight of solvent equal to the weight of the carcass (mouse) in grams. All experiments were conducted in glass jars. Light agitation (shaking or shaking the jar or container) or stirring was used. Ultrasonic treatment or ultrasonic treatment in combination with shaking of the solution can also be used. At least one heating element external to the container was used to raise the temperature from room temperature to the desired temperature for about 1 hour; however, the temperature can be raised more quickly if desired. The temperature was kept below 200°F. The carcass can be contacted with the fully mixed alkaline solution, or with the desired volume of H2O, followed by the addition of ethanol (or ethanol followed by H2O) with the appropriate weight of KOH added; that is, in the preparation of the alkaline solution. The carcass does not necessarily have to be covered with the solution. The dissolution process is open to environmental conditions, and the reaction is terminated when only bone is left in the solution as determined by visual inspection. Covering the jar with the heated solution without actually sealing the glass container used is determined to be helpful in that it at least partially prevents the evaporation of the alcohol.

[0026] After dissolution is complete, the solution is dark in color, not thick, and has an ammonia odor. After the tissue has reacted, the bone can be collected in a strainer basket, either before or after neutralization. The implants can also be collected, as can the teeth.

[0027] After dissolution, the solution is neutralized (pH ~ 7) while being heated with a 67% nitric acid solution. A pH meter is used to measure the pH. Other mineral acids, such as HC1 and H2SO4, are not used because these acids are not good fertilizers, but can be used. Phosphoric acid was found to be very slow in neutralizing the dissolution mixture. If the solution will be accepted for further treatment at a waste water treatment facility, carbon dioxide can be used to neutralize the solution to an acceptable level, usually a maximum pH of 10.5.

[0028] As mentioned above, the neutralization is done while the solution is still hot. If the solution is neutralized after it has cooled, a high viscosity solution with a fatty surface layer results. However, if the warm solution is neutralized and the pH is kept above about 6, an aqueous solution of crystalline material can be filtered as a product.

[0029] After the reaction is complete, hydrogen peroxide (H2O2(30%)) is added to the dissolution solution and the solution is neutralized in pH. To bleach the long chain fatty acids, the volume of H2O2 added is about 70-100% of the weight of the body. The resulting solution can be used directly as a soil fertilizer. Hydrogen peroxide can also be added to the dissolution solution before neutralization.

[0030] The foregoing description of the application is presented for the purpose of illustration and description. It is not intended to be exhaustive or to limit the application to the precise form disclosed, and obviously many modifications and variations are possible in light of the above teachings. The embodiments were chosen and described in order to best explain the principles of the application and its practical application to thereby enable others skilled in the art to best utilize the application in various embodiments and with various modifications as are suited to the particular use contemplated. The scope of the application is defined by the following claims.

Claims

1. A method of chemically dissolving a cadaver comprising: preparing a potassium hydroxide ethanol solution having a potassium hydroxide by weight of 10%, 25% or 40% in a mixture of potassium hydroxide, water and ethanol, and a mass ratio of water to ethanol in the potassium hydroxide ethanol solution of 1 : 1; contacting the cadaver with the potassium hydroxide ethanol solution; heating the cadaver and the potassium hydroxide ethanol solution to a temperature greater than 155°F and less than or equal to 170°F at atmospheric pressure; and determining when the dissolution of the cadaver is complete, whereby the tissue is completely dissolved, resulting in a dissolution solution.

2. The method of claim 1, wherein the pH of the dissolution solution is between 5 and 11.

3. The method of claim 1, further comprising the step of reacting the dissolution solution with carbonic acid to form a solution having a pH lower than the pH of the dissolution solution.

4. The method of claim 3, wherein the pH of the dissolution solution is between 5 and 11.

5. The method of claim 4, further comprising the step of contacting the dissolution solution having a reduced pH with hydrogen peroxide.

6. The method of claim 4, further comprising the step of bringing the pH of the dissolution solution to 7 and applying the resulting solution as a fertilizer to soil.

7. The method of claim 1, further comprising the step of contacting the dissolution solution with hydrogen peroxide.

8. The method of claim 1, further comprising the step of sonicating the dissolution solution to improve the contact of the potassium hydroxide ethanol solution with the cadaver.

9. The method of claim 1, further comprising the step of placing the cadaver and the potassium hydroxide ethanol solution in a container and shaking the container to improve the contact of the potassium hydroxide ethanol solution with the cadaver.

10. The method of claim 9, further comprising the step of heating the container.

11. The method of claim 10, wherein the step of heating the container is accomplished using at least one heater external to the container.

12. The method of claim 1, wherein the step of determining when the dissolution of the cadaver is complete is performed visually.

13. A method of chemically dissolving a cadaver comprising: preparing a hydroxide ethanol solution having a potassium hydroxide by weight of 10%, 25% or 40% in a mixture of potassium hydroxide, water and ethanol, and a mass ratio of water to ethanol in the hydroxide ethanol solution of 1 : 1; contacting the cadaver with the alkali hydroxide solution; heating the cadaver and the alkali hydroxide solution to a temperature greater than 155°F and less than or equal to 170°F at atmospheric pressure; and determining when the dissolution of the cadaver is complete, whereby a dissolution solution having a pH is formed.

14. The method of claim 13, wherein the alkali hydroxide is selected from the group consisting of potassium hydroxide, sodium hydroxide, and mixtures of potassium hydroxide and sodium hydroxide.

15. The method of claim 14, wherein the alkali hydroxide comprises sodium hydroxide and the water comprises saltwater or seawater. ​ ​ 16. The method of claim 13, further comprising the step of reacting the lysing solution with nitric acid or hydrochloric acid to form a solution having a pH value lower than the pH value of the lysing solution.

17. The method of claim 16, wherein the pH value of the lysing solution is between 5 and 11.

18. The method of claim 16, further comprising the step of disposing the lysing solution in an ocean.

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