JPS5912703A - Retort distillation method and apparatus - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

TECHNICAL FIELD OF THE INVENTION This invention relates to a method and apparatus for retort distillation of carbonaceous materials such as oil shale using recirculating high temperature heat carriers such as ceramic spheres.

BACKGROUND OF THE INVENTION It has previously been proposed to retort distill carbonaceous materials, such as oil shale, in a rotating retort using recirculating high temperature heat carriers, such as ceramic spheres, which are fed to the rotating retort along with the carbonaceous material. Ta. As the hot sphere contacts the cold preheated oil shale, the temperature of the oil shale rises to a height that releases volatile liquids and flammable gases. Representative prior art patents disclosing this method include U.S. M. Kitsuki 2,872,886;
, No. 227, No. 8,265,608, and No. 8,9
No. 25,190 is included.

Regarding the weight ratio of spheres to oil shale used,
To date, the optimum weight ratio of spheres or other heat carriers to oil shale has been treated on a haphazard basis (generally 1:1 to 3:1) without a thorough study at the particular temperature used.

With regard to the use of ceramic balls, a problem with sustained operation has been that the balls tend to splinter, crack and break under harsh operating conditions. As a result, some operators have been unwilling to use temperature differences between the thermal circulation bulb and the oil shale feed beyond a certain expected temperature difference. This is based on the fact that even if the heat exchange coefficient of the thread is ignored, if the temperature difference is too large, the thermal shock when each sphere encounters the cold oil shale will crack the ceramic spheres and cause surface cracks. There is.

Accordingly, it is a primary object of the present invention to provide a retort distillation method and apparatus that minimizes cracking and fracturing of recirculating heat carriers, such as ceramic spheres, during high efficiency operation.

SUMMARY OF THE INVENTION The present invention provides for adding a high temperature recirculating heat carrier to a carbonaceous material;
The carbonaceous material and the high-temperature recirculating heat carrier are moved into heat transfer proximity to each other within the retort to raise the temperature of the carbonaceous material to the heat level of retort distillation, and the high-temperature recirculating heat carrier In a method for retort distilling a carbonaceous material having a weight ratio of the high temperature recirculating heat carrier to the carbonaceous material below a weight ratio at which the heat carrier easily cracks or splits,
(a) High temperature recirculating heat carrier versus carbonaceous as a function of continuously increasing temperature difference between carbonaceous material and high temperature recirculating heat carrier with a significantly positive slope as the temperature difference increases (b) sensing the humidity difference between the hot recirculating heat carrier and the carbonaceous material during the process; and (C) determining the critical weight ratio of the material experimentally; A special ζ invention characterized by steps of achieving an optimum weight ratio of high temperature recirculating heat carrier to carbonaceous material of 95 slightly greater than said critical weight ratio, 7. ) the method also includes: (d) sensing a humidity difference between the high temperature recirculating heat carrier and the carbonaceous material as the humidity difference changes during the conduit;
The weight ratio of high temperature recirculating heat carrier to carbonaceous material is changed to a new different optimum weight ratio when said temperature difference changes, and this new different optimum weight ratio is less than said critical weight ratio for the changed temperature difference. Each slightly enlarged stage has its own characteristics.

In the process of the present invention, the feed rate of the high temperature recirculating heat carrier can be varied while the carbonaceous material feed rate can be kept relatively constant to vary the weight ratio. Alternatively, the weight ratio can be varied by varying the carbonaceous material feed rate while keeping the high temperature recirculating heat carrier feed rate relatively constant.

The apparatus of the present invention used in the retort distillation method includes: a retort; an apparatus for supplying a carbonaceous material to the retort; an apparatus for supplying a high temperature recirculating heat carrier to the retort; A device for controlling the amount of high temperature recirculating heat carrier and carbonaceous material supplied to the retort; a device for controlling the amount of high temperature recirculating heat carrier and carbonaceous material supplied to the retort; a device for sensing the temperature difference between; , features an apparatus that responds to a sensed temperature difference between a high temperature recirculating heat carrier and a carbonaceous material.

If the optimal weight ratio has a value within several tens of times larger than the value of the critical type J shear ratio at the sensed temperature difference, for example, a value of 2.1 to 2.8 to 2.0, the optimal weight ratio is the critical weight ratio. considered to be slightly larger.

DETAILED DESCRIPTION OF THE INVENTION The invention will now be explained with reference to the drawings. FIG. 1 is a block diagram showing one embodiment of the thread used as the basis of the present invention. The central part of the invention is the retort 12, which is supplied with pulverized carbonaceous material, such as oil shale, by line 14, and a high temperature recirculating heat carrier, such as small ceramic spheres, by line 16'. Rotation of the retort 12 brings the carbonaceous material and the high temperature recirculating heat carrier into heat transfer proximity to each other without moving within the retort. The input of crushed raw oil shale is indicated by arrow 18, and a conventional preheater for oil shale is indicated by block 20.

Regarding the retort 12, a rotating sieve or rotating cylindrical screen 22 is used at the outlet of the retort 12 to separate oil shale residue from the recirculated ceramic spheres. In this regard, the sphere diameter is typically on the order of 12.7 mm (y2 inches), and the oil shale is crushed to a diameter smaller than this sphere diameter.

Hole 12 of rotating sieve or rotating cylindrical screen 22
．． Since the particles are on the order of 7a+m (% inches) or slightly smaller, the remaining oil shale particles, rather than the spheres, fall through the screen 22 into the accumulator 24. Arrow 26 indicates the removal of accumulated residual Sier solids for further processing. The accumulator 28 rotates the open end of the rotating cylindrical screen 22 to receive and receive the ejected ceramic balls.

The ceramic balls are delivered via line 80, elevator 82 and line 34 to ball heating device 36 where they are reheated to a high temperature. In this regard, air and fuel are supplied to the combustion chamber 42 via lines 38 and 40, respectively;
The ball coming from line 34 is exposed to the resulting heat.

The weight ratio of recycled spheres or other heat carriers to treated oil shale can be varied in any desired manner. In the embodiment of FIG. 1, a feed control unit 44 is provided to vary the amount of balls passed through line 16 to retort 12 during a given period of time. Another supply fljlJ control unit 45 is a preheating block 20
is provided to vary the amount of crushed oil shale supplied to the retort 12 via line 14 from . Therefore,
The weight ratio of ceramic spheres to oil shale can be easily varied.

The temperature of the preheated oil shale is sensed at point 46 and an electrical signal indicative of humidity is transmitted at point 46 to control monitor circuitry 48 via control input lead 50. (The control input leads are shown as dotted lines in this diagram to distinguish them from the supply lines).

Similarly, the temperature of the recirculating ceramic sphere is sensed at point 52;
A corresponding electrical signal is transmitted via control input lead 53 to control monitor circuit 48 .

If desired, instead of sensing at points 46 and 52, the temperature of the oil shale and ceramic spheres can be sensed at the points where lines 14 and 16 feed the oil shale and ceramic spheres directly to rotating retort 12. Appropriate electrical signals are supplied from the control monitor circuit 48 via control output leads 56, 57, respectively, to the control unit 44.4.
5.

Preferably, the temperature of the retort-distilled Meircière is sensed at point 47 or any other convenient location at the point of discharge of the retort 2, and a corresponding electrical signal is likewise sent to the control monitor circuit 48 via the control input lead 49. to be transmitted. Control of the retort distillation process is provided by providing a control monitor circuit 48 with input and output temperatures and appropriate circuitry to ensure that the retort 12
It is possible to maintain an appropriate heat balance of 72. By way of example, bulb heating device 36 is provided via lines 38 and 40, respectively.
If the air and fuel supply to the recirculating bulb supply control unit 44 is maintained constant, the reheating bulb temperature at the temperature sensing point 52 can be maintained constant. Under equilibrium conditions, the heat carrier flow t, ft is kept constant. at the same time,
By changing the flow rate of the raw material oil shale, temperature sensing point 47
The predetermined oil shale discharge humidity can be maintained constant. In response to small changes in the feedstock oil shale feed temperature, sensed at the humidity sensing point 46, the preferred Ni control monitor circuit 48 increases or decreases the feedstock oil shale flow rate and adjusts the heat transfer sphere to oil shale temperature accordingly. The desired discharge temperature is maintained at point 47, which corresponds to the weight ratio.

Ball feed control unit 44 and oil shale feed control unit 45 may be of any form, one or both of which may be, for example, a feed-screw in combination with a variable speed electric motor, US Pat. No. 8,550, US Pat. 9
A flapper valve assembly, such as that disclosed in the '04 patent, or any suitable valve structure, can be used to accurately control the amount and corresponding volume of ceramic spheres or carbonaceous material fed into the retort 12.

Of course, if the temperatures of the oil shale and ceramic spheres are almost constant, the supply rates of the ceramic spheres and oil shale can also be kept constant. Step changes in the flow rate of ceramic spheres or oil shale are necessary when changes are made that affect the heat within the system. Changes of this type include, for example, changes in the heat carrier (i.e. in terms of size or composition), changes in the rotational speed of the retort,
There are changes in the type of carbonaceous feed material being processed, or changes in the structure of the inlet section of the retort. Each change of this kind requires a change that results in a new optimal weight ratio of ceramic spheres to carbonaceous material.

In FIG. 2, the weight ratio of ceramic spheres to oil shale is plotted against the temperature difference between the spheres from sphere heating device 86 and the preheated oil shale from preheat pull 20. First, the ceramic balls whose experimental results are marked ■ had almost no cracks or cracks as a result of thermal shock. However, the ceramic balls marked ■ had significant cracking or crack formation as a result of thermal shock. Therefore, the midline 61 represents the experimentally determined critical weight ratio of hot ceramic spheres to oil shale and has a significantly positive slope with increasing temperature difference. The shaded region 62, slightly to the right of the median line 6, indicates the optimum weight ratio, where cracks or cracks are very small and the recirculating heat carrier foot is minimal for a given amount of oil shale. . In the system of the present invention, reducing the amount of spheres required to retort a given amount of oil shale makes retort distillation more economical. Also, more oil shale can be retorted with a given piece of equipment, and the same amount of oil shale can be retorted with a smaller piece of equipment.

As mentioned above, logically speaking, below a certain predicted temperature difference, cracks or cracks will not form or will be very small, but above a certain temperature difference, cracks will form. It is said that it is large. Of course, this applies to the horizontal line in FIG. 2, but clearly this is not the case as indicated by the experimental data.

For the data used in FIG. 2, the recirculating heat carrier is spherical with a diameter of 12.7 mff1 (% inches) and is based on alumina or aluminum oxide.

Temperature of ball when feeding to rotating retort 482.2~6
It was 76.7°C (900'F to 12507).

In pilot plant operation, the rotating retort has a diameter of 0.6
1-1.52 m (2-5 ft); in industrial operations, diameters of 8.66-4.27 m (12-14 ft) could be used. Rotation speed is 2 per minute
It was about ~5 rotations.

Next, the control monitor circuit 48 and its operation method will be described. As mentioned above, the temperatures for the reheated sphere and preheated oil shale are set at points 52 and 46, respectively.
The temperature at point 47 can be sensed at the output of retort 12 or directly at the input to retort 12 . Of course, there is a small temperature drop between point 46,52 and the input to the retort 12, and a correction factor can be introduced to compensate for these differences.

As an exemplary set of steady state conditions, the temperature of the reheated sphere is about 676.7°C (1250"F") and the temperature of the preheated oil shale is about z60. o°C (500″F'
), and the temperature at the output from the retort is approximately 4
The temperature was 900″F.

As shown in Figure 2, the difference between the input temperatures at the two locations was approximately 398.9°C (750″F) and the ceramic sphere to oil shale weight ratio was approximately 1.7. taking into account the heat losses within the retort and the heat content of the volatile products obtained from the retort, the output temperature at point 47 is approximately 482.2°C, as discussed above.
(900″F).

The control monitor circuit 48 can be operated in any number of ways to maintain the operating point of the process at the desired optimum shaded region 62, as shown in FIG. In particular, when indicating a temperature change from the temperature sensing point 52146.47, deviations far from normal values can be easily detected and changed or adjusted accordingly. Further, the control monitor circuit 48 can be operated to supply the reheated spheres at a relatively constant rate, and the supply control unit 45 can provide control by varying the rate of supply of the preheated oil shale. This is done using a "forward" sub-control system sensitive to the temperatures of the sphere and oil shale sensed at points 52 and 46, and the desired optimum shaded region 62 of the ceramic sphere/oil shale of FIG. The feed rate to the oil shale can be varied (with a relatively constant recirculating ceramic sphere feed rate) to achieve an elbow ratio of 9. Point 4
The temperatures monitored at 7 demonstrate that the process is operating within the desired optimum shaded region 62.

Additionally, along with the predetermined temperature and flow rate of the recirculating ceramic sphere, a relatively long time constant (greater than the transit time through the retort 12) as a servo or feedback thread, and the output power of the retort 12 indicates the predetermined temperature at point 47. It can be operated with an oil shale flow through the feed control unit 45 varying as follows: If the temperature at point 47 increases, the flow rate through the feed control unit 45 increases and vice versa. Furthermore, monitoring can ensure the verification of the correction operating point within the f?+ line region 62 of FIG. has the initial effect of lowering the output temperature at point 47. As a result, the supply of oil shale through the control unit 45 is slowed, which causes the ceramic sphere/oil shale weight ratio to increase as shown in FIG. Similarly, of course, both the forward and feedback operating methods can be used to keep the oil shale feed rate relatively constant and vary the feed rate of recirculated ceramic spheres by the control unit 44. and can be easily met.

The parameters described above are just one example for retort distilling oil shale, and conditions and materials can be varied. For example, supply iG'lJ? MJ units 44 and 4.5, respectively, with ceramic balls IJII
The i-equipped Wt86 and the oil shale preheating block 20 can be combined. We also offer ceramic balls of different diameters, such as i9.05mm (Vi inches) or 25.
A diameter of 4111ffi (1 inch) was used to successfully utilize smaller dimensions for the crushed carbonaceous material to facilitate separation. Successfully retorted carbonaceous materials include oil shale as well as rubber and coal. For rubbers that are retort distilled without preheating, the optimum weight ratio of ceramic spheres to rubber is determined by the partial Generally speaking, lIn of about 1 to 10:1 was required. Therefore, the present invention is not limited to the conditions shown in FIG.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of a thread showing the basics of the present invention, Fig. 2 shows the ceramic sphere/oil shale weight ratio of various high temperature recirculating heat carriers, including the critical weight ratio and the optimum weight ratio.
1 is a graph plotted against the temperature difference between a sphere and a retort distilling oil shale. 12... Retort 14... Oil Sealer 1. I @ line 16...7 lamic sphere supply line 18...raw oil shale input 20...preheating block 22...rotating cylindrical screen 24.28...accumulator 26...carrying out the remaining shale solid 30.34...Ceramic ball delivery line 32...Elevator-36...Ball heating device 38...Air supply line 40...Fuel supply line 42...Combustion chamber 44.45...Supply Control unit 46, 47, 52...Temperature sensing point 48...Control monitor circuit

Claims (1)

[Claims] 1. A high temperature recirculating heat carrier is added to the carbonaceous material, and the carbonaceous material and the high temperature recirculating heat carrier are moved in heat transfer proximity to each other in a retort to lower the temperature of the carbonaceous material. to the heat level of retort distillation, and the high temperature recirculating heat carrier has a weight ratio of less than the weight ratio of the high temperature recirculating heat carrier to the carbonaceous material, which easily causes cracking and cracking of the high temperature recirculating heat carrier. A method for retort distilling a carbonaceous material having a ratio of: (a) continuously increasing the temperature difference between a high temperature recirculating heat carrier and the carbonaceous material having a significantly positive slope as the temperature difference increases; Experimentally determine the critical weight ratio of high temperature recirculating heat carrier to carbonaceous material expressed as a function; (b
) detecting a humidity difference between the high temperature recirculating heat carrier and the carbonaceous material during the process; (C) detecting the humidity difference between the high temperature recirculating heat carrier and the carbonaceous material during the process; A method for retort distillation of carbonaceous materials characterized by stages that provide an optimal weight ratio of carbonaceous materials to carbonaceous materials. 2. Each stage further: (d) senses a temperature difference between the hot recirculating heat carrier and the carbonaceous material as the temperature difference changes during the process; (e) sensing the temperature difference between the hot recirculating heat carrier and the carbonaceous material; The weight ratio of the quality substances is changed to a new different optimum weight ratio when said temperature difference changes, and this new different optimum weight ratio is slightly larger than said critical weight ratio for the changed temperature difference. The method described in paragraph 1. & While varying the feed rate of the high temperature recirculating heat carrier,
3. The method of claim 2, wherein the feed rate of carbonaceous material is maintained relatively constant while the weight ratio is varied. 3. The method of claim 2, wherein the feed rate of the carbonaceous material is varied while the feed rate of the high temperature recirculating heat carrier is maintained relatively constant to vary the weight ratio. 5. The method according to claim 1, wherein the carbonaceous material is oil shale and the high temperature recirculating heat carrier is a ceramic sphere. 6. Retort; A device for supplying carbonaceous material to the retort; A device for supplying a high temperature recirculating heat carrier to the retort; A device for moving the carbonaceous material and the high temperature recirculating heat carrier within the retort in heat transfer proximity to each other. a device for controlling the amount of high temperature recirculating heat carrier and the amount of carbonaceous material supplied to the retort; a device for sensing the temperature difference between the high temperature recirculating heat carrier and the carbonaceous material supplying the retort; and In response to the sensed humidity between the high temperature recirculating heat carrier and the carbonaceous material, the high temperature recirculating heat carrier to the carbonaceous material is adjusted at an optimal weight ratio slightly greater than the critical weight ratio for the sensed temperature difference. A retort distillation apparatus comprising a device for controlling the weight ratio of.