APPARATUS AND METHOD FOR MANUFACTURING A PRODUCT

Abstract

The present invention concerns an apparatus and a method for manufacturing a product from a raw material. The apparatus comprises a rotary kiln having a first rotary kiln end and a second rotary kiln end, and a cooling unit which is connected to the second rotary kiln end, wherein a process direction is provided leading through the rotary kiln from the first rotary kiln end to the second rotary kiln end and further through the cooling unit, wherein the cooling unit is configured to transport the product in the process direction through the cooling unit for cooling the product, the rotary kiln comprising a burning unit at the second rotary kiln end, the burning unit being configured to receive a flammable material and an ignition gas to create heat inside the rotary kiln and to produce a combustion gas containing carbon dioxide, the rotary kiln being configured to transport raw material received at the first rotary kiln end in the process direction towards the second rotary kiln end, and, by using the heat, to transform the raw material into the product and into a resigning gas comprising carbon dioxide, characterized in that the apparatus comprises a gas outlet configured to remove an exhaust gas comprising the resigning gas and the combustion gas from the rotary kiln, and that the cooling unit is configured to transport a cooling gas in the process direction over the product.

Claims

1. Apparatus (1) for manufacturing a product (P) from a raw material (M), said apparatus (1) comprising a rotary kiln (2) having a first rotary kiln end (21) and a second rotary kiln end (22); a cooling unit (4) which is connected to the second rotary kiln end (22), wherein a process direction (x) is provided leading through the rotary kiln (2) from the first rotary kiln end (21) to the second rotary kiln end (22) and further through the cooling unit (4), wherein the cooling unit (4) is configured to transport the product (P) in the process direction (x) through the cooling unit for cooling the product (P), the rotary kiln (2) comprising a burning unit (5) at the second rotary kiln end (22), the burning unit (5) being configured to receive a flammable material (G1) and an ignition gas (G2) to create heat (6) inside the rotary kiln (2) and to produce a combustion gas (G4) containing carbon dioxide, the rotary kiln (2) being configured to transport raw material (M) received at the first rotary kiln end (21) in the process direction (x) towards the second rotary kiln end (22), and, by using the heat (6), to transform the raw material (M) into the product (P) and into a resigning gas (G3) comprising carbon dioxide, characterized in that the apparatus (1) comprises a gas outlet (11) configured to remove an exhaust gas (G5) comprising the resigning gas (G3) and the combustion gas (G4), from the rotary kiln (2), and that the cooling unit (4) is configured to transport a cooling gas (G6) in the process direction (x) over the product (P).

2. Apparatus (1) according to claim 1, characterized in that the apparatus (1) further comprises one or more fans (7, 8) configured to transport the cooling gas (G6) through the cooling unit (4) in the process direction (x).

3. Apparatus (1) according to claim 1 or 2, characterized in that the cooling unit (4) is connected to the second rotary kiln end (22) via a connecting unit (40).

4. Apparatus (1) according to any one of claims 1 to 3, characterized in that the cooling unit (4) is a rotary cooler.

5. Apparatus (1) according to any one of claims 1 to 4, characterized in that the cooling unit (4) and the rotary kiln (2) are configured in such way that the portion of the process direction (x) leading through the cooling unit (4) and the portion of the process direction (x) leading through the rotary kiln are arranged relative to each other at an angle of 90 or below 90.

6. Apparatus (1) according to any one of claims 1 to 5, characterized in that a preheating unit (9) for preheating the raw material (M) is located upstream of the rotary kiln (2) with respect to the process direction (x).

7. Apparatus (1) according to claim 6, characterized in that the cooling unit (4) is connected to said preheating unit (9), said preheating unit (9) is configured to receive at least part of the cooling gas (G6) from the cooling unit (4).

8. Method for producing a product (P) from a raw material (M), wherein a process direction (x) is provided, the process direction (x) leading through a rotary kiln (2) from a first rotary kiln end (21) to a second rotary kiln end (22) and further through a cooling unit (4) being connected to the second rotary kiln end (22), said method comprising the steps of: igniting in a burning unit (5) located at the second rotary kiln end (22) a flammable material (G1) with an ignition gas (G2), the ignition gas (G2) comprising at least 50 vol % of oxygen, to create heat (6) inside the rotary kiln (2) and to produce a combustion gas (G4) containing carbon dioxide, receiving said raw material at the first rotary kiln end (21) and transporting said raw material (M) in the process direction (x) towards the second rotary kiln end (22), manufacturing said product (P) inside the rotary kiln (2) by sintering and/or calcining the raw material (M) by using the heat (6), wherein a resigning gas (G3) comprising carbon dioxide degases from the raw material (M), transporting the product (P) into and through the cooling unit (4) in the process direction (x); cooling the product (P) inside the cooling unit (4) by using a cooling gas (G6); removing the product (P) from the cooling unit (4); characterized in, that the method further comprises the step of removing an exhaust gas (G5) comprising the combustion gas (G4) and the resigning gas (G3), from the rotary kiln (2) via a gas outlet (11); and that the cooling gas (G6) is directed over the product (P) in the process direction (x).

9. The method according to claim 8, characterized in that said raw material (M) comprises one or more inorganic carbonates, preferably said one or more inorganic carbonates are selected from the group consisting of magnesium carbonate, calcium carbonate, magnesium-calcium carbonate, magnesium-calcium carbonate comprising magnesium oxide and mixtures thereof.

10. The method according to claim 8 or 9, characterized in that the flammable material (G1) essentially consists of natural gas.

11. The method according to any one of claims 8 to 10, characterized in that the ignition gas (G2) comprises at least 80 vol % oxygen, preferably at least 90 vol % oxygen, even more preferably at least 95 vol % oxygen.

12. The method according to any one of claims 8 to 11, characterized in that said exhaust gas (G5) comprises at least 70 vol % carbon dioxide, preferably at least 80 vol % or 85 vol % carbon dioxide.

13. The method according to any one of claims 8 to 12, characterized in that said cooling gas (G6) is air.

14. The method according to any one of claims 8 to 13, characterized in that said raw material (M) is preheated in a preheating unit (6) located upstream of the rotary kiln (2) with respect to the process direction (x), preferably by using cooling gas (G6) from the cooling unit (4).

15. The method according to any one of claims 8 to 14, characterized in that said exhaust gas (G5) is purified and/or liquified to obtain a liquid comprising or consisting essentially of carbon dioxide.

Description

[0061] FIGS. 1 to 3 show exemplary, schematic, and non-limiting advantageous embodiments of the invention.

[0062] FIG. 1 shows an apparatus according to a preferred embodiment of the present invention.

[0063] FIG. 2 shows an apparatus according to another preferred embodiment of the present invention.

[0064] FIG. 3 shows an apparatus according to yet another preferred embodiment of the present invention.

[0065] The apparatus 1 as shown in FIG. 1 comprises a rotary kiln 2 with a first rotary kiln end 21 and a second rotary kiln end 22. The burning unit 5 is located at the second rotary kiln end 22. A cooling unit 4 which is connected to the second rotary kiln end 22 is provided. A process direction x leads through the rotary kiln 2 from the first rotary kiln end 21 to the second rotary kiln end 22 and further through the cooling unit 4.

[0066] The cooling unit 4 of the embodiment shown in FIG. 1 is located downstream of the rotary kiln 2 with respect to the process direction x. The portion of the process direction x leading through the cooling unit 4 is by way of example inclined with respect to the portion of the process direction x leading through the rotary kiln 2 with an inclination angle of ca. 90. This can have the advantage of saving space and allowing an efficient transport of the product P through the cooling unit 4. The inclination angle may also be higher than 90. In particular, the inclination angle may be up to 120, or up to 150 or up to 180 C. This arrangement has the advantage of being easy to set up, in case enough space is available.

[0067] If the cooling unit 4 is configured as rotary cooler, the inclination angle describes the longitudinal angle between the longitudinal axis of the rotary kiln 2 and the rotary cooler 4.

[0068] The rotary kiln 2 may be a rotary kiln with a length of 10 m to 200 m, preferably of 30 m to 160 m. The diameter of the rotary kiln may range from 0.5 m to 5 m, preferably from 1.5 to 4 m.

[0069] The rotary kiln may be operated continuously or discontinuously. Preferably, the rotary kiln is operated continuously over several days, weeks or months. A continuous operation allows for stable process conditions and stable product quality and also saves energy for heating up the rotary kiln.

[0070] The rotary kiln 2 is used for manufacturing a product P from a raw material M and comprises a burning unit 5 at the second rotary kiln end 22. The burning unit 5 is configured to receive a flammable material G1 and an ignition gas G2 comprising at least 50 vol % of oxygen to create heat 6 inside the rotary kiln 2 while producing a combustion gas G4.

[0071] The rotary kiln 2 is configured to transport raw material M received at the first rotary kiln end 21 in the process direction x towards the second rotary kiln end 22 and to transform the raw material M into the product P and into a resigning gas G3 comprising or consisting of carbon dioxide. Thus, inside the rotary kiln, the product P is formed from the raw material by sintering and/or calcining the raw material M by using the heat. During the sintering and/or calcination process, the resigning gas G3 comprising or consisting of carbon dioxide degases from the raw material M.

[0072] The apparatus 1 comprises a gas outlet 11 configured to remove an exhaust gas G5 comprising the resigning gas G3 and the combustion gas G4. The exhaust gas outlet 11 can be located near the first rotary kiln end 21.

[0073] The sinter and/or calcination product P formed in the rotary kiln 2 exits the rotary kiln 2 at the second rotary kiln end 22 and is transported into the cooling unit 4 for cooling.

[0074] The cooling unit 4 is configured to transport the product P in the process direction x and to transport a cooling gas G6 in the process direction x over the product P.

[0075] The cooling unit preferably comprises a cooling gas inlet 41, a cooling gas outlet 42 and a product inlet 43 and product outlet 44. The product inlet 43 connects the cooling unit 4 with the second rotary kiln end 22 of the cooling unit 4 and allows the transport of the product into the cooling unit. The cooling gas outlet 42 and the product outlet 44 may be combined, as shown in FIG. 1. The cooling gas inlet 41 is configured to receive the cooling gas G6 into the cooling unit 4.

[0076] In the embodiment shown in FIG. 1, a fan 7 is located upstream of the cooling gas inlet 41 of the cooling unit 4 and a fan 8 is located downstream of the cooling gas outlet 42 of the cooling unit 4 to generate a pressure difference for directing the cooling gas through the cooling unit 4.

[0077] The cooling unit 4 may be a rotary cooler.

[0078] The raw material M can comprise one or more inorganic carbonates, preferably said one or more inorganic carbonates are selected from the group consisting of carbonate, magnesium-calcium carbonate, magnesium-calcium carbonate comprising magnesium oxide and mixtures thereof.

[0079] In a preferred embodiment, the flammable material G1 is natural gas. Therefore, the flammable material preferably comprises methane. The flammable material may also comprise other hydrocarbons such as ethane, propane, butane and/or mixtures thereof.

[0080] The ignition gas G2 comprises at least 50 vol % of oxygen and might even comprise at least 80 vol % oxygen, preferably at least 90 vol % oxygen, even more preferably at least 95 vol %, oxygen.

[0081] Preferably, the cooling gas G6 is air.

[0082] The exhaust gas G5 can be purified and/or liquified to obtain a liquid comprising or consisting essentially of carbon dioxide.

[0083] The apparatus 1 shown in FIG. 2 comprises all the elements of the apparatus shown in FIG. 1 and additionally comprises a connecting unit 40 between the rotary kiln 2 and the cooling unit 4.

[0084] The cooling unit 4 of the embodiment shown in FIG. 2 is by way of example located below the rotary kiln 2 and inclined backwards from the rotary kiln 2 at an angle of below 90. Preferably said angle is below 75, even more preferably below 45 as shown in FIG. 1. In the embodiment shown in FIG. 2, the cooling gas inlet 41 and the product inlet 43 can be combined. In the embodiment shown in FIG. 2, a fan 7 is located upstream of the connecting unit 40.

[0085] The apparatus 1 shown in FIG. 3 comprises all the elements of the apparatus shown in FIG. 2 and additionally comprises a preheating unit 9 located upstream of the rotary kiln 2 with respect to the process direction x.

[0086] The cooling gas outlet 42 can be connected to said preheating unit 9, the preheating unit 9 being configured to receive cooling gas from the cooling unit 4.