NL2029981B1

NL2029981B1 - Local calcium looping and pure-oxygen (enriched-oxygen) combustion coupled cement production c02 capture process and device

Info

Publication number: NL2029981B1
Application number: NL2029981A
Authority: NL
Inventors: Peng Hui; Zhang Tongsheng; Gou Yiqun; Yu Qijun; Wei Jiangxiong; Wang Wei
Original assignee: Univ South China Tech
Priority date: 2021-12-01
Filing date: 2021-12-01
Publication date: 2023-06-19

Abstract

The present invention discloses a local calcium looping and pure-oxygen (enriched- oxygen) combustion coupled cement production C02 capture process and device. The C02 capture device includes a pure-oxygen (enriched-oxygen) combustion calciner module, a preheater-carbonatization furnace-rotary kiln module, and an auxiliary and purification device. The C02 capture process is characterized in that Ca0 generated by calciner transports to a carbonatization furnace to capture C02, and the generated CaC03 transports to the calciner. Then the C02 is released, and the low-activity Ca0 enters into the rotary kiln to participate in clinkerization. The calciner and the carbonatization furnace are designed to be separated, and local calcium looping of the calciner and the carbonatization furnace are simultaneously coupled to capture C02 generated by kiln system, so that self-enrichment of C02 with high concentration in ﬂue gas is achieved, impurities such as $02, chloride, sulphur, and alkali in the kiln system are avoided, and the difﬁculty of C02 purification and utilization is reduced remarkably.

Description

LOCAL CALCIUM LOOPING AND PURE-OXYGEN (ENRICHED-OXYGEN)

COMBUSTION COUPLED CEMENT PRODUCTION CO: CAPTURE

PROCESS AND DEVICE

5S TECHNICAL FIELD

[01] The present invention belongs to the technical field of crossing of cement production and calcium looping to achieve CO: capture, and particularly relates to a local calcium looping and pure-oxygen (enriched-oxygen) combustion coupled cement production CO: capture process and device.

BACKGROUND ART

[02] Cement industry is one of the main emission sources of CO: (accounting for about 10% of total emissions), and reducing carbon emissions in the cement industry is important and very urgent. At present, the common methods to capture CO: include: chemical absorption, membrane separation, pure-oxygen combustion, and calcium looping method. When the chemical absorption method and the membrane separation method are used for CO: capture, a large amount of chemical reagents and membrane materials are needed, and the pressurization and decompression operations are applied on flue gas, so that the cost for CO: capture is greatly improved. In addition, due to large content of dust and acid gas in flue gas, the membrane separation cannot separate CO: at high flux continuously, and the cycle life of an absorbent is also greatly shortened. In comparison, the pure-oxygen combustion and the calcium looping are beneficial to the efficient utilization of fuel, which help improving the concentration of CO: in the flue gas of the cement kiln essentially, and show significant CO; capture potential. In general process of calcium looping, the activity of calcium-based absorbent drops sharply, indicating the low capture efficiency. Moreover, the cost for providing a pure-oxygen environment of the whole system of the cement kiln is extremely high.

SUMMARY

[03] In order to overcome the shortcomings of the prior art, the coupling of local pure-oxygen (enriched-oxygen) combustion and local calcium looping is utilized, and the devices for desulphurization, denitration, and water condensation are applied, then the self-purification and efficient capture of CO: in flue gas of the cement kiln are achieved. The technical solution is as follows:

[04] A local calcium looping and pure-oxygen (enriched-oxygen) combustion coupled cement production CO: capture system is composed of a preheater- carbonatization furnace-rotary kiln module, a pure-oxygen (enriched-oxygen) combustion calciner module, and auxiliary and purification devices. The preheater- carbonatization furnace-rotary kiln module includes first series of cyclone preheaters, carbonatization furnace, second series of cyclone preheaters, smoke chamber, rotary kiln, tertiary air pipe, cooler, combustor. The pure-oxygen (enriched-oxygen) combustion calciner module includes a calciner, third series of cyclone preheaters, gas distribution device, a booster fan. The auxiliary and purification devices include selective non-catalytic reduction (SNCR) devices, selective catalytic reduction (SCR) device, booster fan, gas distribution device, solid distribution device, a heat-exchange device, a water condensation device, and CO: collection device.

[05] According to the gas flow direction in the CO: capture device, in the preheater- carbonatization furnace-rotary kiln module:

[06] An outlet of the tertiary air pipe of the rotary kiln is connected with an outlet of the smoke chamber.

[07] Anair inlet of the second series of cyclone preheaters is connected with an outlet of the smoke chamber.

[08] An air inlet of the carbonatization furnace is connected with an air outlet of the second series of cyclone preheaters.

[09] Anair inlet of the first series of cyclone preheaters is connected with an air outlet of the carbonatization furnace.

[10] An air outlet of the first series of cyclone preheaters is sequentially connected with the heat-exchange device, a dust removal device, and the SCR device.

[11] In the pure-oxygen (enriched-oxygen) calciner module:

[12] An air outlet of the calciner is connected with an air inlet of the third series of cyclone preheaters.

[13] An air outlet of the third series of cyclone preheaters is connected with the gas distribution device.

[14] One outlet of the gas distribution device is connected with the booster fan and is connected with an air inlet of the calciner, and the other outlet of the gas distribution device is sequentially connected with the heat-exchange device, the water condensation device, and the CO: collection device.

[15] According to a flow direction of solid materials in the CO: capture device:

[16] Raw materials are fed into an air inlet pipe of a first cyclone separator of the first series of cyclone preheaters through a feeding device, and a material outlet of a second- to-last cyclone separator of the first series of cyclone preheaters is connected with the carbonatization furnace. Preferably, the raw materials may be fed at multiple locations, so that the heat-exchange efficiency is improved, and heat released by a carbonatization reaction is fully utilized to preheat the raw materials.

[17] A material outlet of a last cyclone separator of the first series of cyclone preheaters is connected with an air inlet pipe of a last cyclone separator of the second series of cyclone preheaters.

[18] A material outlet of the last cyclone separator of the second series of cyclone preheaters is connected with the calciner through the solid distribution device.

Preferably, multi-point feeding is used, so that the decomposition reaction rate and efficiency of calcium carbonate are improved.

[19] An outlet of the calciner is connected with an air inlet pipe of the third series of cyclone preheaters, and a material outlet of the third series of cyclone preheaters is respectively connected with the carbonatization furnace and a kiln tail of the rotary kiln through the solid distribution device, so that the proportion of calcium oxide used in local calcium looping is controlled.

[20] Preferably, the SNCR devices are additionally arranged at the calciner and the third series of cyclone preheaters, so that nitrogen oxide emission is reduced.

[21] A lower part of the smoke chamber is connected with the kiln tail of the rotary kiln, and a kiln head of the rotary kiln is connected with the combustor and the cooler.

[22] A local calcium looping and pure-oxygen (enriched-oxygen) combustion coupled cement production CO: capture process includes:

[23] Raw materials are fed into the air inlet pipe of the first cyclone separator of the first series of cyclone preheaters, and the raw materials and flue gas in the first series of cyclone preheaters and the carbonatization furnace are fully subjected to heat-exchange.

[24] After gas-solid separation of the flue gas through the first series of cyclone preheaters, hot raw materials are fed into the air inlet pipe of the second series of cyclone preheaters. SO; released by thermal decomposition of sulphates contained in the raw materials is discharged along with the flue gas in a preheating process, so that the amount of impurity gas such as SO: is reduced before entering the pure-oxygen (enriched- oxygen) combustion calciner module.

[25] The solid distribution device is arranged on a pipeline connecting the second series of cyclone preheaters with the calciner and configured to adjust the amount of hot raw materials entering different parts of the calciner.

[26] According to an embodiment, a large amount of CO: is generated by decomposing in a pure-oxygen (enriched-oxygen) combustion calciner environment. A small amount of fuel-NO, is removed by the SNCR device. After gas-solid separation via the third series of cyclone preheaters, the flue gas enters the gas distribution device, and it is divided into two paths. One path sequentially passes through the heat-exchange device and the water condensation device to obtain high-purity CO: which enters a CO: storage system. The other path re-enters the calciner for flue gas cycle through the booster fan.

[27] According to an embodiment, after the hot raw materials containing a large amount of CaO are subjected to gas-solid separation via the third series of cyclone preheaters, the hot raw materials are divided into two paths through the solid distribution device. The first path of hot raw materials is fed into the air inlet pipe of the carbonatization furnace, and CO: in the flue gas is rapidly captured in a flue gas environment of 600-850°C. The second path of hot raw materials is fed into the kiln tail of the rotary kiln to participate in clinker sintering.

[28] After flue gas discharged from the carbonatization furnace is subjected to gas- solid separation by the first series of preheaters, hot raw materials are fed into the air inlet pipe of the second series of preheaters, perform heat-exchange with high- temperature flue gas discharged from the smoke chamber, and enter the calciner.

[29] Compared with the prior art, the present invention has the advantages that local calcium looping of partial hot raw materials is adopted, so that CO: generated by a kiln system can be captured, then the significant reduction of cycle-activity of calcium-based absorbent is avoided. Only offline calciner pure-oxygen (enriched-oxygen) combustion is carried out in present system, so that the operation cost is reduced. Meanwhile, volatile substances such as chlor-alkali sulphur and impurity gas such as SO; are prevented from entering the calciner, so that the self-enrichment of CO: with ultra-high concentration in flue gas of a cement kiln is realized. And the difficulty of CO: capture and utilization is reduced economically.

BRIEFT DESCRIPTION OF THE DRAWINGS

[30] FIG. 1 is a local calcium looping and pure-oxygen (enriched-oxygen) combustion coupled cement production CO: capture process and device in Example 1 of the present invention. In the drawings, 1-first series of cyclone preheaters, 2-second series of cyclone preheaters, 3-third series of cyclone preheaters, 4-carbonatization furnace, S-SNCR device A, 6-SNCR device B, 7-smoke chamber, 8-rotary kiln, 9-rotary kiln combustor, 10-cooler, 11-solid distribution device A, 12-solid distribution device B, 13-calciner, 14-calciner combustor, 15-gas distribution device, 16-heat-exchange device

A, 17-heat-exchange device B, 18-water condensation device, 19-CO; storage device, 20-booster fan, 21-raw material feeding device, 22-dust removal device, 23-SCR device, 24-flue gas outlet, 25-tertiary air pipe.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[31] Hereinafter, the present invention will be described in further detail with reference to specific examples, but embodiments of the present invention are not limited thereto.

[32] As shown in FIG. 1, the local calcium looping and pure-oxygen (enriched- oxygen) combustion coupled cement production CO: capture device includes a first series of cyclone preheaters (1), a second series of cyclone preheaters (2), a third series of cyclone preheaters (3), a carbonatization furnace (4), an SNCR device A (5), an SNCR device B (6), a smoke chamber (7), a rotary kiln (8), a rotary kiln combustor (9), a cooler (10), a solid distribution device A (11), a solid distribution device B (12), a calciner (13), a calciner combustor (14), an gas distribution device (15), a heat-exchange device A (16), a heat-exchange device B (17), a water condensation device (18), a CO: storage device (19), a booster fan (20), a raw material feeding device (21), a dust removal device (22), an SCR device (23), a flue gas outlet (24), and a tertiary air pipe (25).

[33] In the local calcium looping and pure-oxygen (enriched-oxygen) combustion coupled cement production CO; capture device, an outlet of the tertiary air pipe (25) of the rotary kiln is connected with an outlet of the smoke chamber (7). An air inlet of the second series of cyclone preheaters (2) is connected with the smoke chamber (7). An air inlet of the carbonatization furnace (4) is connected with an air outlet of the second series of cyclone preheaters (2). An air inlet of the first series of cyclone preheaters (1) 1s connected with an air outlet of the carbonatization furnace (4). An air outlet of the first series of cyclone preheaters (1) is sequentially connected with the heat-exchange device (17), the dust removal device (22), and the SCR device (23).

[34] An air outlet of the calciner (13) is connected with an air inlet of the third series of cyclone preheaters (3). An air outlet of the third series of cyclone preheaters (3) 1s connected with the gas distribution device (15). One outlet of the gas distribution device (15) 1s connected with the booster fan (20) and is connected with an air inlet of the calciner (13). The other outlet of the gas distribution device (15) is sequentially connected with the heat-exchange device (16), the water condensation device (18), and the CO: collection device (19).

[35] Raw materials are fed into an air inlet pipe of a first cyclone separator of the first series of cyclone preheaters (1) by the feeding device (21). A material outlet of a second- to-last cyclone separator of the first series of cyclone preheaters (1) is connected with the carbonatization furnace (4). A material outlet of a last cyclone separator of the first series of cyclone preheaters (1) is connected with an air inlet pipe of the second series of cyclone preheaters (2). A material outlet of the second series of cyclone preheaters (2) 1s connected with the calciner (13) through the solid distribution device B (12). An outlet of the calciner (13) is connected with an air inlet pipe of the third series of cyclone preheaters (3). A material outlet of the third series of cyclone preheaters (3) is respectively connected with the carbonatization furnace (4) and a kiln tail of the rotary kiln (8) through the solid distribution device A (11). SNCR devices are additionally arranged at the calciner (13) and the third series of cyclone preheaters (3). A lower part of the smoke chamber (7) is connected with the kiln tail of the rotary kiln (8). A kiln head of the rotary kiln is connected with the combustor (9) and the cooler (10).

[36] In a local calcium looping and pure-oxygen (enriched-oxygen) combustion coupled cement production CO: capture process, raw materials enter the air inlet pipe of the first cyclone separator of the first series of cyclone preheaters (1). The raw materials and flue gas are subjected to heat-exchange in the first series of cyclone preheaters (1).

The raw materials enter the carbonatization furnace (4) from a third cyclone separator of the first series of cyclone preheaters (1) for further heat-exchange. After the flue gas is subjected to gas-solid separation by a fourth cyclone separator of the first series of cyclone preheaters (1), hot raw materials enter the air inlet pipe of the second series of cyclone preheaters (2).

[37] The solid distribution device B is arranged on a pipeline connecting the second series of cyclone preheaters (2) with the calciner (14) and configured to adjust the amount of hot raw materials entering the calciner (13).

[38] According to an embodiment, the combustors (14) are arranged at different parts of the calciner, fuel and oxygen are injected, and the calciner is in a local pure-oxygen

(enriched-oxygen) combustion state.

[39] According to an embodiment, a large amount of CO: is generated by decomposing hot raw materials in the pure-oxygen (enriched-oxygen) combustion calciner module. A small amount of thermal and fuel-NOx is removed by the SNCR device. After gas-solid separation via the third series of cyclone preheaters (3), the flue gas enters the gas distribution device (15) and is divided into two paths. One path sequentially passes through the heat-exchange device A (16) and the water condensation device (18) to obtain high-purity CO: which enters the CO; storage system (19). The other path re-enters the calciner (13) through the booster fan (20) to participate in gas cycle.

[40] The gas distribution device (15) is arranged at an air outlet of the third series of cyclone preheaters (3) and is configured to adjust the amount of gas entering the pure- oxygen (enriched-oxygen) combustion calciner module and the CO: storage system (19).

[41] According to an embodiment, after the hot raw materials containing a large amount of CaO are subjected to gas-solid separation via the third series of cyclone preheaters (3), the hot raw materials are divided into two paths through the solid distribution device A (11). The first path is fed into the air inlet pipe of the carbonatization furnace (4) and rapidly carbonized in a flue gas environment of 600- 850°C, and CO: in the flue gas is captured by local calcium looping between the carbonatization furnace (4) and a calciner (13). The second path is fed into the kiln tail of the rotary kiln (8) to participate in clinker sintering.

[42] Flue gas is discharged from the carbonatization furnace (4) and enters a last cyclone separator of the first series of preheaters (1). After gas-solid separation, hot raw materials are fed into the air inlet pipe of the second series of preheaters (2), perform heat-exchange with high-temperature flue gas discharged from the smoke chamber, and enter the calciner (13).

[43] The above examples are preferred embodiments of the present invention, but the embodiments of the present invention are not limited by the above examples. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit essence and principle of the present invention should be equivalent replacements, which are all included within the protection scope of the present invention.

Claims

Conclusions l. Device for CO2 capture in cement production coupled to local calcium looping and pure oxygen (enriched oxygen) combustion, characterized in that the device consists of a preheater-carbonization kiln-rotary kiln module, a pure oxygen (enriched oxygen) incinerator roaster module, and a auxiliary and purification device, wherein the roaster module and the preheater carbonization furnace rotary kiln module have a separate design, and a pure oxygen (enriched oxygen) combustion of a roaster and a local calcium loop are coupled.

A device for CO2 capture in cement production coupled to local calcium looping and pure oxygen (enriched oxygen) combustion according to claim 1, wherein the preheater-carburizing kiln-rotary kiln module consists of a raw material introduction device (21), a first series of cyclone preheaters (1 ), a carbonization furnace (4), a second series of cyclone preheaters (2), a smoke chamber (7), a rotary furnace (8), a tertiary air pipe (25), a combustor (9), and a cooler (10).

The apparatus for CO 2 capture in cement production coupled to local calcium looping and pure oxygen (enriched oxygen) combustion according to claim 1, wherein the pure oxygen (enriched oxygen) combustion roaster module consists of a roaster (13), a combustor (14) , a third set of cyclone preheaters (3), a gas distribution device (15), and blower fan (20).

A device for CO 2 capture in cement production coupled to local calcium looping and pure oxygen (enriched oxygen) combustion according to claim 1, wherein the auxiliary and purification device consists of selective non-catalytic reduction (SNCR) devices (5) and (6), a gas distribution device (15), solid matter distribution devices (11) and (12), heat exchange devices (16) and (17), a water condensation device (18), a CO2 collecting device (19), a dust removal device (22) , a selective catalytic reduction (SCR) device (23), and a flue gas exhaust system (24).

A device for CO 2 capture in cement production coupled to local calcium looping and pure oxygen (enriched oxygen) combustion according to claim 1, characterized in that the tertiary air pipe (25) of the rotary kiln is connected to an outlet of the smoke chamber (7), an air inlet of the second series of cyclone preheaters (2) is connected to the smoke chamber (7), an air inlet of the carbonization furnace (4) is connected to the second series of cyclone preheaters (2), an air inlet of the first series of cyclone preheaters (2) is connected to an air outlet of the carbonization furnace (4), and an air outlet of the first series of cyclone preheaters (1) is successively connected to the heat exchange device (17), the dedusting device (22), and the SCR device ( 23); an air outlet of the roaster (13) is connected to an air inlet of the third series of cyclone preheaters (3), an air outlet of the third series of cyclone preheaters (3) is connected to the gas distribution device (15), one outlet of the gas distribution device (15 ) is connected to the booster fan (20) and connected to an air inlet of the roaster (13), and the other outlet of the gas distribution device (15) is successively connected to the heat exchange device (16), the water condensing device (18), and the CO: collecting device (19); and a material outlet of a penultimate cyclone separator of the first series of cyclone preheaters (1) is connected to the carbonization furnace (4), a material outlet of a last cyclone separator of the first series of cyclone preheaters (1) is connected to an air inlet pipe of the second series of cyclone preheaters (2), a material outlet of the second series of cyclone preheaters (2) is connected to the roaster (13) through the solids distribution device (12), the roaster (13) is connected to a material inlet of the third series of cyclone preheaters (3),

a material outlet of the third series of cyclone preheaters (3) is respectively connected to the carbonization furnace (4) and a furnace tail of the rotary kiln (8) through the solids distribution device (11), air inlets of the roasting furnace (13) and the second series of cyclone preheaters (2) both are connected to a denitration device, a lower part of the smoke chamber (7) is connected to the furnace tail of the rotary kiln (8), and a furnace head of the rotary kiln (8) is connected to the combustor (9) and the cooler (10).

The device for CO 2 capture in cement production coupled to local calcium looping and pure oxygen (enriched oxygen) combustion according to claim 2, wherein the carbonization furnace (2) comprises a multi-stage neck structure in which an introduction device is arranged at a neck for introducing hot raw materials at multiple locations.

An apparatus for CO 2 capture in cement production coupled to local calcium looping and pure oxygen (enriched oxygen) combustion according to claim 3, wherein the roaster (13) comprises a multi-necked structure in which an inlet device is arranged at a neck for the perform pure oxygen (enriched oxygen) combustion and for hot feedstock injection at multiple sites; and the gas distribution device (15) is arranged at an air outlet pipe of the third series of cyclone preheaters and is configured to adjust the amount of gas entering the CO₂ collecting device (19) and the roaster with respect to a flue gas cycle.

A device for CO 2 capture in cement production coupled to local calcium looping and pure oxygen (enriched oxygen) combustion according to claim 4, wherein the solids distribution device (13) is arranged on a pipeline connecting the second series of cyclone preheaters (2) to the roaster (13) and configured to adjust the amount of hot raw materials entering different parts of the roaster (13).

A method of CO capture in cement production coupled to local calcium looping and pure oxygen (enriched oxygen) combustion, characterized in that the raw material input device (21) is arranged at an air inlet of a first cyclone separator of the first series of cyclone preheaters (1), and raw materials and flue gas enter the carbonization furnace (4) after being separated by the penultimate cyclone separator of the first series of cyclone preheaters (1); raw materials enter the last cyclone separator of the first series of cyclone separators (1) pass through a carbonization furnace (4), and then enter the second series of cyclone preheaters together with exhaust gas from the smoke chamber (7), and hot raw materials are injected into different parts of the roasting furnace (13) by the solids distribution device (12); the combustors (14) are arranged at different parts of the roaster (13), pure oxygen (enriched oxygen) gases are injected, the SNCR denitration device (6) is adopted to remove NOx in flue gas, the flue gas the third series of cyclone preheaters (3), then enters the gas distribution device (15) after gas-solid separation, and is divided into two paths, one path passing through the heat exchange device (16) and the water condenser (18) sequentially goes to obtain high purity CO: which enters the collector (19), and the other path is accelerated by the booster fan (20) and re-enters the roaster to participate in a gas cycle; and hot raw materials (containing a large amount of CaO) separated from the third series of cyclone preheaters (3) are divided into two paths by the solids distribution device (11), with one path entering the carbonization furnace (4) to achieve local calcium looping between the carbonization furnace (4) and the roasting furnace (13), and the other path enters the furnace tail of the rotary furnace (8) to participate in clinker sintering.