阅读说明：本技术 一种用于石油焦气化过程中优化液态排渣的方法 (Method for optimizing liquid-state slag discharge in petroleum coke gasification process ) 是由 王贲 于 2019-09-30 设计创作，主要内容包括：本发明涉及一种用于石油焦气化过程中优化液态排渣的方法,属于环境工程技术领域。将合成灰与石油焦充分混匀,得到待气化混合物；所述合成灰含有V<Sub>2</Sub>O<Sub>5</Sub>、NiO、Fe<Sub>2</Sub>O<Sub>3</Sub>、CaO、SiO<Sub>2</Sub>和Al<Sub>2</Sub>O<Sub>3</Sub>,所述合成灰中SiO<Sub>2</Sub>与Al<Sub>2</Sub>O<Sub>3</Sub>的质量之比为(0.25-4)：1,Fe<Sub>2</Sub>O<Sub>3</Sub>与CaO的质量之比为(0.5-6)：1,V<Sub>2</Sub>O<Sub>5</Sub>与NiO的质量之比为(0.25-4)：1；将得到的待气化混合物在1100℃-1400℃条件下进行气化,所述气化的时间为45min-2h,得到熔融态的残渣。优选地,所述合成灰的质量占待气化混合物的质量小于等于25％。本发明可以有效降低灰的熔融温度,高熔点矿物质大量转化为低熔点矿物质同时转化为液态金属氧化物熔融体,有利于石油焦气化过程中液态排渣。(The invention relates to a method for optimizing liquid state slag discharge in a petroleum coke gasification process, which belongs to the technical field of environmental engineering and comprises the steps of fully and uniformly mixing synthetic ash and petroleum coke to obtain a mixture to be gasified, wherein the synthetic ash contains V 2 O 5 , NiO, Fe 2 O 3 , CaO, SiO 2 and Al 2 O 3 , the mass ratio of SiO 2 to Al 2 O 3 in the synthetic ash is (0.25-4): 1, the mass ratio of Fe 2 O 3 to CaO is (0.5-6): 1, and the mass ratio of V 2 O 5 to NiO is (0.25-4): 1.)

1. a method for optimizing liquid slag discharge in a petroleum coke gasification process is characterized by comprising the following steps:

(1) The synthetic ash contains V ₂ O ₅, NiO, Fe ₂ O ₃, CaO, SiO ₂ and Al ₂ O ₃, the mass ratio of SiO ₂ to Al ₂ O ₃ in the synthetic ash is (0.25-4) to 1, the mass ratio of Fe ₂ O ₃ to CaO is (0.5-6) to 1, and the mass ratio of V ₂ O ₅ to NiO is (0.25-4) to 1;

(2) And (2) gasifying the mixture to be gasified obtained in the step (1) at the gasification temperature of 1100-1400 ℃, wherein the gasification time is 45min-2h, and obtaining molten state residues.

2. the method for optimizing the liquid slag discharge in the petroleum coke gasification process as claimed in claim 1, wherein the mass of the synthetic ash in the step (1) accounts for 25% or less of the mass of the mixture to be gasified.

3. The method for optimizing liquid slag tapping in a petroleum coke gasification process as claimed in claim 1, wherein the mass ratio of SiO ₂ to Al ₂ O ₃ in the synthetic ash is (2-4): 1.

4. The method for optimizing liquid slag discharge in petroleum coke gasification process according to claim 1, wherein the mass ratio of Fe ₂ O ₃ to CaO in the synthetic ash is (0.5-1): 1.

5. The method for optimizing liquid slag discharge in petroleum coke gasification process according to claim 1, wherein the mass ratio of V ₂ O ₅ to NiO in the synthetic ash is (0.25-1): 1.

6. The method for optimizing the liquid slag discharge in the petroleum coke gasification process as claimed in claim 1, wherein the gasification temperature in the step (2) is 1300 ℃ to 1400 ℃.

Technical Field

The invention belongs to the technical field of environmental engineering, and relates to a method for optimizing liquid-state slag discharge in a petroleum coke gasification process.

Background

The petroleum coke entrained flow gasification technology has wide industrial application foundation and is the main direction for cleaning and utilizing petroleum coke in the future. The entrained flow technologies of Texaco, Shell and the like mainly adopt liquid slag discharge. The petroleum coke ash is easy to generate high-melting-point minerals in a gasification furnace under the high-temperature and reducing environment, and the melting characteristic of ash in an entrained flow is directly influenced. The change of ash meltability can bring the problems of refractory material erosion, heating surface contamination, ash deposition and slagging, unsmooth slag discharge and pipeline abrasion and blockage in the operation process of the gasification furnace, and has great influence on the gasification economy and the maintenance cost. The mineral types and components in the petroleum coke control the melting and crystallization process of the petroleum coke ash under the high-temperature reducing atmosphere, so that the control of the mineral composition and properties in the petroleum coke gasification ash has great guiding significance on the design and operation of a gasification device, and data accumulation and theoretical guidance are provided for deep industrial popularization of petroleum coke gasification.

Petroleum coke is a byproduct from the delayed coking process of residual and heavy oils and is the final product of petroleum refining. Petroleum coke is black granular, needle-shaped or columnar solid with irregular shape and compact structure, generally has metallic luster, and can be divided into sponge coke, honeycomb coke and needle coke according to appearance. The petroleum coke is a highly aromatized carbide, mainly comprising aromatic hydrocarbon, long-chain fatty polycondensate and a small amount of inorganic matter, wherein the carbon element content is 90-97%, the hydrogen element content is 1.5-8%, the high-sulfur petroleum coke also contains more than 3% of sulfur, and in addition, a small amount of nitrogen, oxygen and metal elements. The heat value of petroleum coke is very high, the low-level calorific value of the petroleum coke is generally 1.5-2 times of that of coal, the ash content of the petroleum coke is very little and is generally lower than 1%, the ash content comprises elements such as silicon, aluminum, sodium, iron, calcium, vanadium, nickel and the like and compounds thereof, and particularly the content of vanadium and nickel is high; the volatile content is about 11%.

Because vanadium and nickel in petroleum coke are enriched in fly ash or bottom slag in the gasification process, the ash content (Si, Al, Ca, Fe and S) is greatly different from that of the conventional gasified coal, and therefore the ash deposition and slagging conditions are more unpredictable. At present, most industries of petroleum coke gasification are applied to an entrained flow gasification device, the operation temperature is between 1300 ℃ and 1500 ℃, because the flow characteristic of gasified slag is crucial to the slag discharge operation of the entrained flow gasification device, and vanadium and nickel minerals have great influence on the characteristics of ash melting point, viscosity and the like. Therefore, how to modify the petroleum coke ash can ensure that the liquid steam exists in the hearth, and the method plays a good guiding role in controlling the melting point viscosity of ash slag and realizing liquid slag removal in the petroleum coke gasification industry.

The six oxides of V ₂ O ₅, NiO, Fe ₂ O ₃, CaO, SiO ₂ and Al ₂ O ₃ are main components of petroleum coke ash, the migration evolution law of the oxides directly influences the melting characteristic of the gasified ash in the gasification process, and finally determines the liquid-state slag-removing characteristic in the petroleum coke gasification process.

Disclosure of Invention

The method solves the problem of difficult optimization of liquid-state slag discharge in the prior art, and the mineral composition of the gasified ash is identified by performing X-ray diffraction (XRD) representation on the gasified ash, and the mineral composition is compared and verified with the result of Factsage thermodynamic equilibrium simulation calculation, so that the melting temperature of the ash is effectively reduced, a large amount of high-melting-point minerals are converted into low-melting-point minerals and simultaneously into liquid-state metal oxide melts, and liquid-state slag discharge in the petroleum coke gasification process is facilitated.

According to the purpose of the invention, the method for optimizing the liquid-state slag discharge in the petroleum coke gasification process is provided, the petroleum coke gasification process in the gasification furnace and the migration and transformation of mineral matters in petroleum coke ash can be really and effectively simulated, and a proper proportioning scheme is obtained, so that the liquid-state slag discharge is optimized.

According to the object of the present invention, there is provided a method for optimizing liquid slag removal in a petroleum coke gasification process, comprising the steps of:

(1) The synthetic ash contains V ₂ O ₅, NiO, Fe ₂ O ₃, CaO, SiO ₂ and Al ₂ O ₃, the mass ratio of SiO ₂ to Al ₂ O ₃ in the synthetic ash is (0.25-4) to 1, the mass ratio of Fe ₂ O ₃ to CaO is (0.5-6) to 1, and the mass ratio of V ₂ O ₅ to NiO is (0.25-4) to 1;

(2) And (2) gasifying the mixture to be gasified obtained in the step (1) at the gasification temperature of 1100-1400 ℃, wherein the gasification time is 45min-2h, and obtaining molten state residues.

Preferably, the mass of the synthetic ash in step (1) accounts for less than or equal to 25% of the mass of the mixture to be gasified.

Preferably, the mass ratio of SiO ₂ to Al ₂ O ₃ in the synthetic ash is (2-4): 1.

Preferably, the mass ratio of Fe ₂ O ₃ to CaO in the synthetic ash is (0.5-1): 1.

Preferably, the mass ratio of V ₂ O ₅ to NiO in the synthetic ash is (0.25-1): 1.

preferably, in the step (2), the gasification temperature is 1300-1400 ℃.

Generally, compared with the prior art, the above technical solution conceived by the present invention mainly has the following technical advantages:

(1) The invention provides a novel mixing sample preparation method of petroleum coke and synthetic ash, which is characterized in that under the condition that the petroleum coke really exists, the ash content in the petroleum coke is observed in an enlarged mode, the migration and transformation process of mineral substances in the petroleum coke gasification process in a gasification furnace is simulated more really and effectively, a more proper synthetic ash proportioning scheme is obtained through analysis, the method for optimizing liquid state slag removal in the petroleum coke gasification process is obtained, the liquid state slag removal in the petroleum coke gasification process is guided to be optimized, the effect is obvious, and the safe operation of the liquid state slag removal of the gasification furnace is ensured.

(2) The ash content in petroleum coke is obviously different from that of coal, the content of alkali metal and alkaline earth metal is very low, and the content of vanadium and nickel is very high. Therefore, the method obtains the composition of metal oxides in ash by performing X-ray fluorescence spectrum analysis (XRF) on three typical petroleum cokes (respectively from Handan petrochemical company (HD), Jinshan petrochemical company (JS) and Wuhan petrochemical company (WH)), and takes the composition as a reference basis to prepare the synthetic ash corresponding to the components of the metal oxides. On the basis, synthetic ash and petroleum coke with low ash content are mixed and then co-gasified on a fixed bed gasification furnace, the gasified ash is subjected to X-ray diffraction (XRD) representation, mineral composition components of the gasified ash are identified, and the mineral composition components are compared and verified with the result of Factsage thermodynamic equilibrium simulation calculation, so that the melting temperature of the ash is effectively reduced, a large amount of high-melting-point minerals are converted into low-melting-point minerals and simultaneously converted into liquid metal oxide melts, and liquid slag discharge in the petroleum coke gasification process is facilitated.

(3) the method obtains the component composition of the ash sample through XRD analysis, thereby judging the ash fusion characteristic of the petroleum coke, verifying by combining with Factsage simulation, and finally determining the optimal gasification temperature within the range of 1300-1400 ℃. The gasification temperature is controlled in the interval, the molten mass of the liquid metal oxide is rapidly increased, and the slag tapping is more favorably realized.

(4) According to the invention, the crystal structure composition of an ash sample is obtained through XRD analysis, so that the ash fusion characteristic of petroleum coke is judged, and the verification is carried out by combining with facttage simulation, the ash component and the fusion characteristic are integrated, preferably, the mass ratio of SiO ₂ to Al ₂ O ₃ is (2-4): 1, and finally, the optimal mass ratio of SiO ₂ to Al ₂ O ₃ is determined to be 4.

(5) according to the invention, the crystal structure composition of an ash sample is obtained through XRD analysis, so that the ash fusion property of petroleum coke is judged, and the verification is carried out by combining with Factsage simulation, the ash component and the fusion property are integrated, preferably, the mass ratio of Fe ₂ O ₃ to CaO is (0.5-1): 1, the optimal mass ratio of Fe ₂ O ₃ to CaO is finally determined to be 0.5, the mass of Fe ₂ O ₃ is reduced, the mass of CaO is increased, high-melting-point minerals can be reduced, low-melting-point minerals are increased, the ash fusion property is reduced, and the liquid-state slag discharge is more facilitated.

(6) According to the method, the crystal structure composition of an ash sample is obtained through XRD analysis, so that the ash fusion characteristic of petroleum coke is judged, and the method is verified by combining Factsage simulation, the ash composition and the fusion characteristic are integrated, preferably, the mass ratio of V ₂ O ₅ to NiO is (0.25-1): 1, the optimal mass ratio of V ₂ O ₅ to NiO is finally determined to be 0.25, the mass of V ₂ O ₅ is reduced, the mass of NiO is increased, the method is favorable for the large-scale formation of liquid metal oxide molten mass in ash, and is more favorable for liquid-state slag discharge.

drawings

FIG. 1 is a schematic view of a fixed-bed gasification reaction apparatus of a high-temperature horizontal furnace.

Figure 2 is an XRD spectrum of petroleum coke synthesis ash at different gasification temperatures.

FIG. 3 is a simulation of the change of minerals in petroleum coke ash with temperature during gasification.

FIG. 4 is an XRD spectrum of petroleum coke synthesis ash at different silica to alumina ratios (1300 ℃ C.).

Fig. 5 is a thermodynamic equilibrium simulation of the effect of silica-alumina ratio on mineral changes in ash during petroleum coke gasification.

FIG. 6 is an XRD spectrum of petroleum coke synthetic ash at different iron to calcium ratios (1300 ℃ C.).

fig. 7 is a thermodynamic equilibrium simulation of the effect of iron calcium ratio on mineral changes in ash during petroleum coke gasification.

FIG. 8 is an XRD spectrum of petroleum coke synthesized ash at different vanadium-nickel ratios (1300 ℃ C.).

Fig. 9 is a thermodynamic equilibrium simulation of the effect of vanadium nickel ratio on mineral changes in ash during petroleum coke gasification.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. In addition, the technical features involved in the embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.