Tissue Digestor™ - Introduction

BioSAFE Engineering's patented WR2 process uses alkaline hydrolysis at elevated temperature and pressure to convert the proteins, nucleic acids, and lipids of all cells and tissues, as well as infectious microorganisms, to a sterile aqueous solution of small peptides, amino acids, sugars, soaps, and electrolytes. The alkali itself is consumed in the process by generating the salts of the hydrolysis products. The only byproducts of the process are the mineral constituents (ash) of the bones and teeth of vertebrates. These are soft enough after the organic matter has been degraded to be easily crushed (even by bare hands) and recovered as calcium phosphate powder (sterile bone meal).

BioSAFE Engineering's patented WR2 process:

BioSAFE / WR2 Process solubilizes embalmed or fixed tissues and destroys the fixatives as well. None of the potentially hazardous chemicals used in such fixation processes can be detected after the alkaline hydrolysis process. The BioSAFE / WR2 Process not only compares favorably with incineration, but also is free of its potential for air pollution. By contrast, all products resulting from the BioSAFE / WR2 Process can be truly biodegraded or recycled without stressing the environment in any way.

Anatomy of a Tissue Digestor™

The BioSAFE / WR2 Tissue Digestor™ consists of an insulated stainless steel pressure vessel with a manually or hydraulically clamped lid. The unit is supplied with a basket to contain bone remnants. All wetted parts are 316-L stainless steel alloy, and all vessels are ASME pressure rated and certified. All electrical components are built according to NEMA standards. The system is fully automated; allowing unattended operation after the unit is loaded.


Automatic Treatment Cycle

bonesTo begin the process, the vessel must be loaded with tissue and sealed by the operator.  The operator then presses the START button on the touch screen and the cycle begins.  After the operator has initiated the cycle, the digestion cycle runs completely unattended.

During operation, a measured amount of alkali is pumped from a supply tank and process water is added.  Both are added based on tissue weight measured by the built-in load cells.  Once alkali and water are added, the recirculation pump is turned on and the vessel contents are heated via a steam jacket and/or steam heating coils.  The digestion solution is continuously recirculated during the pre-programmed exposure time.  The tissues rapidly dissolve and are hydrolyzed into smaller and smaller molecules.  When this cycle is complete, a cooling cycle brings the temperature of the hydrolysate to an appropriate temperature for discharge.  The unit is then drained and the remaining inorganic materials are rinsed.

Digestion time is 3-4 hours for processing a fully loaded unit heated to 300˚F (~150˚C) maximum temperature, plus 2-4 hours for heat-up, cool down, rinsing, and draining.  A total process of loading animals, filling, heating, cooking, cooling, rinsing, and draining can take 5-8 hours depending on a number of variables.  Your process time is greatly influenced by the steam pressure provided, type of animal tissue, amount of animal tissue, size of whole animal carcases, and the amount of alkali used in processing.  The temperature, exposure time, water to tissue ratio, and recommended alkali to tissue ratios for particular loads, selected after extensive laboratory testing, result in a sterile, coffee-colored, slightly alkaline, true-solution with a soapy ammonia-like odor.  This solution can be discharged in accordance with local and federal guidelines regarding pH, BOD, and temperature.  If KOH is used as the alkali, the resulting solution may be suitable for direct application as a liquid fertilizer containing Carbon, Nitrogen, and Potassium, for crop or landscape application.  The calcium phosphate of the bones and teeth may also be used as fertilizer.

After the cycle is complete, the operator unseals the vessel and removes the basket with any remaining solids, empties the basket, and returns it to the vessel.  The removed solids are ready for disposal as normal refuse or recycling as described above.