WO2002020430A1

WO2002020430A1 - In-vessel composting apparatus and method for waste management and soil enhancement

Info

Publication number: WO2002020430A1
Application number: PCT/US2001/027523
Authority: WO
Inventors: Joseph G. Horvath; Loren Schultz
Original assignee: Envirogro Solutions, Inc.
Priority date: 2000-09-05
Filing date: 2001-09-05
Publication date: 2002-03-14
Also published as: AU2001288758A1

Abstract

A composting apparatus (10) and composting methods utilize a rotatable vessel (12). The vessel (12) has an inlet (14) and an outlet (15) communicating with an internal cavity.(16) Compostable material is loaded into the vessel (12) via the inlet (14). The loaded material preferably has at least a 20:1 carbon to nitrogen ratio and a 45 % - 75 % moisture level. When the cavity (16) temperature reaches about 130 °F, the vessel (12) is selectively rotated, preferably 3-4 revolutions per hour, for preferably 72 - 120 hours to compost the material. Internal baffles (20) are preferably provided to assist in the composting process through mixing and aeration. Counter-rotation permits the baffles (20) also to be used to facilitate unloading at the completion of composting.

Description

[0001] IN-VESSEL COMPOSTING APPARATUS AND METHOD FOR

WASTE MANAGEMENT AND SOIL ENHANCEMENT

[0002] The present invention relates to in- vessel compost apparatus and methods useful in waste management and the resultant production of soil enhancement products.

[0003] BACKGROUND

[0004] Composting is a means of recycling organic waste and producing an environmentally stable product, free of disease causing organisms, offensive odors, insects and weeds. On a commercial scale, composting has traditionally occurred in forced aeration of static piles and windrow operations. Both processes create compost in anywhere from five to eighteen months depending on the frequency of turns and the material being composted. Both processes are weather dependent. In particular, static piling requires a storage pit for the waste and odors often build up as do gases that have, on occasion, caused flash explosions. Windrows are land intensive, usually requiring forty or more dedicated acres to be commercially viable. Windrowing also requires the additional investment in compost turning equipment. Further, it is difficult to monitor and control temperatures in windrow operations.

[0005] Chemical treatments also require higher initial investment and higher energy costs to operate. The end result of chemical treatment is that the water can be used in the irrigation system in flushing the barn. The solid nutrients are no longer available for the soil as they are consumed in the process. This results in the farmer potentially increasing his fertilizer need.

[0006] An alternative technique is to spread the raw organic material on the land.

This technique has come under increasing scrutiny and governmental regulation as an environmentally unsound and possibly hazardous practice in that run off of such material into streams, ground water, and aquifers can result in contamination of the nation's water supply. The present invention addresses the growing animal manure problem by providing an apparatus that converts manure and other organic wastes into high quality compost while optimizing aeration and temperature control in a manner that is both economic and expeditious.

[0007] SUMMARY

[0008] The present invention provides an in- vessel composting apparatus and method designed to improve operation, reliability and safety, as well as, accelerate the composting process. The in-vessel composting machine converts animal manure into useable soil amendment products serving the needs of professional produce and nursery stock growers, landscapers and lawn care operators, as well as those of the consumer gardener.

[0009] The apparatus comprises a rotatable tank preferably equipped with baffles .

The tank is preferably mounted on an inclined plane for rotation about a longitudinal axis to facilitate movement of the waste material through the tank. The internal surface of the tank is provided with a series of spaced baffles extending along the tank's longitudinal axis. These baffles circulate the material and improve homogeneity. Materials to be treated are fed into the tank through an upper input end. The tank's baffles are preferably adjusted to direct the material towards the input end during compositing. This arrangement also facilitates unloading since composted material is then directed to an opposing outlet end via reverse rotation.

[0010] Preferably, the apparatus incorporates ports for temperature and moisture gauges for process control, and incorporates an air blower to optimize aeration and control temperature. Push button controls are interfaced with a micro-computer for easy operation. The apparatus requires little operator attention, thus, costs to run the machine are decreased.

[0011] A method of composting is also disclosed. A generally cylindrical vessel is provided having an internal cavity and preferably an array of interior baffles projecting inwardly from an interior cavity wall of said vessel from 15% to 50% of the cavity radius. The vessel has an inlet and an outlet in communication with the internal cavity. Material to be composted is loaded into the internal cavity of said vessel via said inlet such that between 20% to 80%, preferably 40% - 60%, by volume of the internal cavity is filled such that the loaded compostable material is formulated to have a carbon to nitrogen ratio of at least 20: 1 and a moisture level of from 45% to 75%. When the temperature within the loaded cavity exceeds 120°F, the vessel is selectively rotated until the loaded material is composted. Preferably, the vessel is rotated 72 to 120 hours at a steady rate of 3-4 revolutions per hour while maintaining an internal temperature from 130°F to 160°F. [0012] Other objects and advantages of the invention will be apparent to those skilled in the art from the following description of preferred embodiments.

[0013] BRIEF DESCRIPTION OF THE DRAWLNG(S)

[0014] Figure 1 is an elevational view of an in- vessel composting apparatus according to the teachings of the present invention.

[0015] Figure 2 is a perspective view of the upper loading end of the apparatus of

Figure 1.

[0016] Figure 3 is a perspective view of the lower output end of the apparatus of

Figure 1.

[0017] Figure 4 is a schematic diagram of an internal baffle arrangement for an in- vessel composting apparatus made in accordance with the teachings of the present invention.

[0018] Figure 5 is a perspective view of a second embodiment of an in- vessel composting apparatus made in accordance with the teachings of the present invention.

[0019] Figure 6 is a cross-section of the apparatus shown in Figure 5.

[0020] Figure 7 is a partial perspective view of the drive mechanism of the in- vessel composting apparatus shown in Figure 5.

[0021] Figure 8 is a perspective view of a roller support for the in- vessel composting apparatus shown in Figure 5.

[0022] Figure 9 is a perspective view of a vessel retaining member of the in- vessel composting apparatus shown in Figure 5. [0023] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S) [0024] Figures 1 -3 show an in- vessel composting apparatus 10 for converting solid organic waste into compost. The composting apparatus comprises a tank or vessel 12 having an inlet 14 and outlet 15 which communicate with an internal cavity 16. The tank is mounted on two end supports 18, 19 for rotation about a longitudinal axis. The axis of the vessel 12 is preferably inclined from its inlet 14 to its outlet 15 to facilitate movement of the material through the vessel from a higher elevation to a lower elevation as the vessel rotates. This is particularly useful in exploiting gravitational forces to assist in unloading composted material from the vessel 12. Preferably, the incline is five degrees (5°) or less from horizontal.

[0025] Although an incline is preferred, the vessel can be horizontal. In such case it may be desirous to taper the shape of the vessel 12 toward and outlet in order to utilize gravity to assist in unloading the vessel.

[0026] The internal cavity 16 has a plurality of spaced-apart baffles 20 projecting from the wall 21 of the internal cavity 16 defining a mixing area of the tank. There are preferably twelve (12) baffles 20 that agitate, mix, and improve the homogeneity of the waste material being treated. The baffles serve to achieve a uniform material composition and particle size of the organic compost and optimizes aeration and distribution of microbial population through the movement of the material in the tank. [0027] As is best seen in Figure 4 where the cylindrical interior wall 21 of the internal cavity 16 is illustrated as a flat plane, it being understood that illustrated edge 21a is contiguous with illustrated edge 21b in the apparatus, a preferred baffle layout is shown. Preferably, the baffles are affixed to the cavity wall with a 45° pitch from a plane orthogonal with the rotational axis of the vessel and arranged in four rows, each having three baffles spaced equidistant from each other around the interior cavity wall 21. The baffles of each successive row are preferably positioned on the cavity wall 21 midway between the baffles of the preceding row with their leading edge 20a positioned at substantially the same axial location as the trailing baffle edge 20b of the preceding row. Preferably, the leading edge 20a of the baffles 20 of the first row are at least 12 inches from the inlet end 16a of the internal cavity 16 and the trailing baffle ends 20b of the last row of baffles are preferably at least 12 inches from the outlet end 16b of the internal cavity to facilitate both loading and unloading; a mixing area thereby being defined by the location of the baffles in the internal cavity.

[0028] The length and height of the baffles are coordinated with the size of the interior cavity 16. In general, the baffles should be from 15% to 50% of the radius of the internal cavity in the mixing area, preferably 20% to 25% of the radius in height. In a tank having an internal cavity 8 feet long and a radius of 2 feet, the baffles are preferably positioned 18 inches away from both the inlet and outlet cavity ends 16a, 16b, have an 18 inch width, a preferred pitch of 45° and are positioned in four rows of three equally spaced baffles, the mid-point 20m of the baffles between corresponding rows being approximately 22 inches apart. Preferably the tank 12 is made of seven gauge steel with 0.125 inch thick steel baffles welded to the interior surface 21. The baffle height for such a 2 foot radius tank is preferably 5-6 inches having a curved edge attached to the cavity walls 14 and an opposing straight edge.

[0029] With tanks of other dimensions, particularly larger tanks, the preferred baffle height remains 20% - 25% of the radius. However, as the length of the tank increases, the length of the baffles may be increased, additional rows of baffles may be added and/or a combination of both with a significant increase in the radius of the tank, it may be desirable to provide more than three baffles in each row. With small tanks, it may be possible to eliminate the baffles and still produce suitable compost. Additionally, alternate mixing methods without baffles could potentially be employed such as controlling the rotation of the tank to make partial rotations in one or both directions. [0030] Referring to Figures 2 and 3, a cylindrical sleeve 24, 25 may extend from each end of the vessel 10 to define the inlet 14 and outlet 15, respectively. The inlet sleeve 24 preferably rests on 2-4 casters 26, which sit on a pair of plates 27, 28 that permit height adjustment. The plates 27, 28 are supported by a shaft-bearing/A-frame assembly 29 which allows the angle and height of the tank to be set and adjusted. [0031] Preferably, there are several small cylindrical vents 30 on both the upper and lower ends of the vessel as shown by Figures 2 and 3. In the upper end, Fig. 2, these vents 30 act as a gas release in the case of anaerobic digestion and methane generation so as to eliminate the potential for explosion. In the lower end, Fig. 3, the vents 30 allow for drainage.

[0032] A barbell arrangement (not shown) may be placed inside the tank to act as an automatic cleaning device. There are also preferably three ports positioned in a horizontal line along the length of the vessel. These ports serve as points of entry for process temperature and moisture monitoring devices and/or sensors 32. [0033] As shown in Figures 1 and 3, the vessel 12 may have a cone-shaped lower output end extending from the mixing portion of the tank. Where a cone-shaped outlet end is used, either one or two sets of spiral, cement-like flights may be located in the cone at the edge of the lower sleeve to drive the material out of the vessel when it is counter- rotated.

[0034] As best shown in Figure 3, associated with output end of the vessel 12 is a drive system 34 comprising a motor 35 and a transmission assembly 36. The drive motor 35 is interfaced with a heavy duty transmission 36 that drives a series of gears including a large gear 38 enveloping the outlet 15 of the vessel. The rotational interface between the vessel 12 and the drive system is a bronze bearing 39 that surrounds the lower sleeve 25. A computer control 40 interfaces with the motor and sensors 32 to control the rotation of the vessel e.g. speed, direction, time and operation of a blower which directs air into the vessel outlet 15 during the composting operation. The blower is swung away during unloading when the vessel is counter-rotated to drive the composted material toward the outlet 15.

[0035] In one example, the tank is forty-five (45) feet long with a five (5) foot radius and total height of fifteen (15) feet. While empty, the weight of the vessel is thirty- thousand (30,000) pounds. When fully loaded, the tank has a maximum weight of one- hundred thousand (100,000) pounds. The tank rotates at a rate between 3 and 15 revolutions per hour (rph). The tank is maintained at a temperature between 130°- 160° F. The tank requires a 15x30 foot area plus space for material handling equipment, equipment maneuvering and storage.

[0036] Referring to Figures 5-9, there is shown a second embodiment of an in- vessel compost apparatus 50. The apparatus includes a tank 52 mounted on a support structure 53 for rotational movement about the tank's longitudinal axis. The tank/vessel 52 is generally cylindrical with an inlet 54 on one end and an outlet 55 on its opposite end which communicate with an internal mixing cavity 56 of the vessel 52. Projecting from the interior wall 57 of the vessel 52 are preferably a plurality of baffles 60 which are dimensioned and spaced as set forth above in conjunction with the description of the first embodiment.

[0037] A vacuum blower unit 62 is preferably provided to blow air into the vessel outlet during the composting operation and to unload composted material from the vessel in a vacuum mode after the composting operation has been completed. An auxiliary fan may be provided to perform the air circulation function if the power requirements for the vacuum blower are excessive. As discussed above, the vessel is rotated in a first direction during the composting operation and is preferably counter-rotated for unloading such that the pitch of the baffles directs the composted material toward the outlet. The vacuum blower can be associated with a conventional screw conveyor or other conventional solid material handling device to unload the composted material from the vessel to waiting trucks or a storage facility.

[0038] Optionally, the outlet end of the vessel may be provided with hatches from which the composted material may be unloaded. However, a vacuum assembly and/or other material handling devices such as a screw conveyor unloading the vessel from a central outlet opening is preferred.

[0039] The vessel support structure 53 includes two roller support assembly groups

70, 71 which each comprise a plurality of space rollers 73 which engage respective roller channels 75 defined on the exterior of the vessel 52. The rollers 73 of each roller group 70, 71 are preferably axially aligned with the rotational axis of both roller assembly groups 70, 71 being parallel to each other and at a selected angle from horizontal. Accordingly, the roller assembly groups 70, 71 support the tank such that its rotational axis is downwardly inclined from the inlet 54 to the outlet 55. Preferably the angle of the roller assembly group axes and the corresponding angle of the longitudinal rotational axis of the vessel 52 is no more than five degree (5°) from the horizontal. The preferred angle is somewhat dependent upon the length of the vessel since increasing the pitch of the axis of the tank decreases the available processing volume of the composting apparatus since sufficient open volume should be maintained to allow air circulation during processing. [0040] As shown in Figures 5-7, preferably one of the roller assembly groups 70 is operatively associated with a motor 80 and an associated drive assembly which includes a connecting rod 82 which connects the rollers 73 of the roller support assembly 70 with each other and a drive chain or belt 84 which is driven by the motor 80 to rotate the rod 82 thereby driving the rollers 73 to in part rotation to the vessel 52. As shown in Figures 5 and 8, the other roller assembly group 71 comprises several independent roller assemblies 85 having free wheeling rollers 73.

[0041] The roller channels 75 on the vessel 52 preferably have retaining lips 76 to maintain the rollers 73 therein. As shown in Figure 9, the support structure 53 may also include retaining rollers 79 which engage the exterior of the retaining lips 76 to assist in preventing longitudinal displacement of the vessel 52 relative to the support structure 53. Temperature and moisture sensors for the vessel 52 are preferably provided as discussed above with respect to the first embodiment. In addition to temperature and moisture sensors, oxygen and weight sensors can also be provided.

[0042] A computer control unit 86 is provided which is operatively associated with the drive motor 80 and the vacuum blower assembly 62 and the sensors. [0043] Preferably the internal cavity 56 of the vessel 52 has a longitudinal dimension from 6 feet to 60 feet at a radius between 2 feet to 10 feet wherein the ratio of the radius to the longitudinal convention is from 1 :2 to 1 : 10. The size of the drive motor is varied in accordance with the size of the vessel. For example, a vessel having a 2 feet radius and 8 feet length preferably uses a ^lA horsepower drive motor which is capable of rotating the vessel from 3 to 30 revolutions per hour (rph). Such a vessel has a weight of approximately 700 lbs. and a composting material capacity of approximately 1.8 cubic yards. Generally, composting material weighs approximately 1,000 lbs. per cubic yard. [0044] For a vessel having a 4 feet radius and 20 feet length, a 1 horse power motor is preferably provided capable of rotating the vessel from 3-30 rph. Such a vessel weight is approximately 10,000 lbs. and has approximately an 18 cubic yard capacity. [0045] For a vessel having a 4.5 feet radius and 25 feet length, a 2 horse power motor is preferred in order to drive the vessel at 3-30 rph. Such a vessel weighs approximately 15,000 lbs. and has a capacity of approximately 30 cubic yards. [0046] For a vessel having a 5 feet radius and 40 feet length, preferably a 5 horse power motor is provided to drive the vessel at a speed of 3.6 to 26 rph. Such a vessel weighs approximately 30,000 lbs. and has a capacity of approximately 60 cubic yards. With the larger size composting vessel, it is preferred to locate the apparatus on a reinforced concrete pad due to its weight.

[0047] For processing, the vessel is loaded through its inlet end so that between

20% - 80% and, preferably 40% - 60%, of the volume of the cavity is filled. Preferably the material to be composted is chopped and mixed before being processed. Material from most separators works fine as well as material processed in a cutter/mixer/feeder equipment. The vessel can be loaded using a conventional silage blower or any other conventional material handling system.

[0048] Any organic material such as food waste, grass clippings, leaves, manure, etc. is "compostable" as long as an appropriate moisture and carbon to nitrogen ratio is provided. Fats, oils and proteins can be included although they cannot be composted without substantial amounts of other materials that have cellulose, starch and sugars. One of the benefits of utilizing the in-vessel composting apparatus is that it induces composting of items such as dead animals much more rapidly.

[0049] While extremely large particles are not desirable, most manures and bedding are not extremely course grained, but chopping and mixing may be required to get the proper carbon to nitrogen ratio and moisture level.

[0050] With dairy and hog waste, there is usually too much water because many of these operations use water to clean out barns or mature pits. In such cases, the material is preferably processed through a liquid/solid separator and mixed with a bulking agent such as sawdust, shaving or straw to get the proper chemical and moisture composition. Chicken litter is usually very dry and additional water is generally need. Chicken litter also has high nitrogen content requiring extra bulking agents to raise the carbon to nitrogen ration. [0051] The load of material to be composted preferably has an initial moisture content from 50% to 70% and a carbon to nitrogen ratio of about 20:1 to about 30:1 or more, preferably 30:1. With the compostable load within the above parameters, various microbes will begin to feed, grow and reproduce which generates heat. Usually it will take approximately 12 hours for the temperature of the compostable material to exceed 120°F. When the temperature preferably reaches 130°, rotation of the vessel is commenced by the motor. This can automatically be done by setting the computer controller to activate the motor when a temperature sensor indicates a 130° temperature or above. Preferably, the rotation is not commenced until at least 12 hours has passed from loading even if the temperature exceeds 130°F before that time. Once rotational processing is started, it preferably continues for at least 72 hours with the blower operating to maintain temperatures between 130°F and 160°F. Such temperature range ensures that pathogens and seeds are killed without killing off beneficial microbes which assist composting. Higher temperatures can be utilized, preferably no more than 170°F. [0052] The vessel rotation provides both aeration and mixing to assist in composting. While the auxiliary blower is preferred, there are natural air currents which are induced by the temperature and the angle of the vessel while the vessel is rotated. Preferably, rotational processing is effected by a slow steady rotation of 3-4 rph for 72 to 120 hours. Alternatively, standing times may be programmed into the computer controller to periodically start and stop rotation during composting. [0053] Once the material is composted, the vessel can be counter-rotated at its maximum speed to facilitate unloading. Overall, the total composting operation from loading, standing, rotating and unloading can be accomplished within four to six days. Accordingly, the in-line vessel composting apparatus method provide a highly efficient system for waste processing with the beneficial end product of compost which can be sold for subsequent use.

[0054] While specific embodiments and processing parameters have been disclosed, other variations will be apparent to those of ordinary skill in the art and are within the scope of this invention.

Claims

CLAIMS What is claimed is:

1. An in-vessel compost apparatus comprising: a generally cylindrical vessel having: an internal cavity having a longitudinal rotational axis and a selected radius in a mixing area; an inlet on a first end and an outlet on a second end in connection with said internal cavity; and interior baffles arranged in the mixing area for agitating material within said vessel when rotated, said baffles projecting inwardly from an interior cavity wall of said vessel from 15% to 50% of the cavity radius; a support structure for supporting said vessel for rotational displacement about said longitudinal axis; and a motor operatively associated with said vessel for selectively rotating said vessel.

2. An in-vessel compost apparatus according to claim 1 wherein: said baffles are disposed in one or more equally spaced arrays about the interior cavity of said vessel, spaced at least one foot inward of said inlet and outlet, and have a pitch of about 45° from a plane orthogonal with the longitudinal axis; and said internal cavity has a longitudinal dimension from 6 to 60 feet and a radius between 2 to 10 feet wherein the ratio of the radius to the longitudinal dimension is from 1:2 to 1 :10.

3. An in-vessel compost apparatus according to claim 2 wherein said baffles have substantially the same pitch and project inwardly from the interior cavity wall from 20% to 25% of the cavity radius and further comprising a blower operative to selectively circulate air within said vessel when said vessel is rotated.

4. An in-vessel compost apparatus according to claim 1 wherein said baffles project inwardly from the interior cavity wall from 20% to 25% of the cavity radius and further comprising a blower operative to selectively circulate air within said vessel when said vessel is rotated.

5. An in-vessel compost apparatus according to claim 1 wherein said support structure includes an inlet end support and an outlet end support; said inlet end support supporting the vessel inlet higher than the vessel outlet so that the longitudinal axis is angled downwardly from the outlet to the inlet no more than 5° from horizontal; and a rotational drive assembly associated with said motor and one of said end supports for facilitating selective rotation of said vessel.

6. An in-vessel compost apparatus according to claim 1 wherein said support structure comprises first and second substantially parallel roller assembly groups having a plurality of rollers upon which said vessel is disposed for rolling engagement; at least one roller assembly group having a drive assembly associated with said motor for driving rollers of said group to impart rotation to said vessel.

7. An in-vessel compost apparatus according to claim 6 wherein: said baffles are disposed in one or more equally spaced arrays about the interior cavity of said vessel, spaced at least one foot inward of said inlet and outlet, and have a pitch of about 45° from a plane orthogonal with the longitudinal axis; and said internal cavity has a longitudinal dimension from 6 to 60 feet and a radius between 2 to 8 feet wherein the ratio of the radius to the longitudinal dimension is from 1:2 to 1:10.

8. An in-vessel compost apparatus according to claim 6 wherein said first and second roller assembly groups are mounted at a selected angle to horizontal such that said vessel is supported with its longitudinal axis inclined downwardly from said inlet to said outlet no more than 5° from horizontal.

9. An in-vessel compost apparatus according to claim 1 further comprising outlet hatches disposed on the second end of said vessel for facilitating unloading of composted material.

10. An in-vessel compost apparatus according to claim 1 further comprising a vacuum blower unit associated with the vessel outlet for facilitating unloading composted material from the vessel.

11. A method of composting comprising: providing a generally cylindrical vessel having an internal cavity with an array of interior baffles projecting inwardly from an interior cavity wall of said vessel from 15% to 50% of the cavity radius, the vessel having an inlet and an outlet in communication with the internal cavity; loading material to be composted into the internal cavity of said vessel via said inlet such that between 20% to 80% by volume of the internal cavity is filled such that the loaded compostable material is formulated to have a carbon to nitrogen ratio of at least 20:1 and a moisture level of from 45% to 75%; and waiting until the temperature within the loaded cavity exceeds 120°F, then selectively rotating the vessel until the loaded material is composted.

12. A method according to claim 11 wherein between 40% - 60% of the cavity is filled, a blower is utilized to maintain the cavity temperature between 130°F and 160°F during rotation, and the selective rotation commences after the internal temperature reaches at least 130°F.

13. A method according to claim 11 wherein the vessel is steadily rotated at 3 -4 revolutions per hour for at least 72 hours.

14. A method according to claim 11 wherein the vessel is maintained stationary for at least twelve hours before commencing selective rotation.

15. A method according to claim 11 wherein the interior baffles of the cylindrical vessel have a pitch of about 45° from an orthogonal plane intersecting an axis of vessel rotation, said vessel inlet and outlet are separate openings disposed at opposite ends of the vessel, and the vessel is rotated in a first direction for composting, further comprising: rotating the vessel in a second direction after the loaded material has been composted to facilitate unloading of the composted material via said outlet.

16. A method according to claim 15 further comprising unloading composted material from the vessel utilizing vacuum equipment associated with said outlet.

17. A method according to claim 15 wherein said inlet is vertically higher than said outlet and gravity is utilized to assist in unloading the vessel.

18. A method according to claim 15 further comprising providing a blower, a motor driven rotational drive assembly, a temperature sensor, and an associated computer control for controlling the operation of the blower and drive assembly to facilitate the selective rotation of the vessel while maintaining the internal temperature of the vessel cavity between 130° to 160° during composting.

19. A method according to claim 11 further comprising providing a blower, a motor driven rotational drive assembly, a temperature sensor, and an associated computer control for controlling the operation of the blower and drive assembly to facilitate the selective rotation of the vessel while maintaining the internal temperature of the vessel cavity between 130° to 160° during composting.

20. A method of composting comprising: providing a generally cylindrical vessel having an internal cavity, the vessel having an inlet and an outlet in communication with the internal cavity; loading material to be composted into the internal cavity of said vessel via said inlet such that between 20% to 80% by volume of the internal cavity is filled such that the loaded compostable material is formulated to have a carbon to nitrogen ratio of at least 20:1 and a moisture level of from 45% to 75%; and waiting until the temperature within the loaded cavity exceeds 120°F, then selectively rotating the vessel until the loaded material is composted.