Preparation method of high-base-number calcium sulfonate

Abstract

The invention relates to the technical field of high-base-number calcium sulfonate, in particular to a preparation method of high-base-number calcium sulfonate. The invention provides a preparation method of high-base-number calcium sulfonate, which comprises the following steps: mixing a solvent, methanol, part of calcium hydroxide, neutral oil and alkyl benzene sulfonic acid, carrying out reflux reaction, adding the rest of calcium hydroxide and carbon dioxide, carrying out carbonation reaction, and sequentially carrying out methanol recovery, sedimentation, desolvation and filtration to obtain the high-base-number calcium sulfonate, the residual calcium hydroxide and carbon dioxide are continuously added at a constant speed. The calcium sulfonate prepared by the preparation method has the advantages of high base number, small particle size, low precipitation value, small turbidity and no chlorine element.

Description

Technical Field

[0001] This invention relates to the field of high-alkalinity calcium sulfonate technology, and more particularly to a method for preparing high-alkalinity calcium sulfonate. Background Technology

[0002] High-alkalinity sulfonates are one of the sulfonate metal detergent series. Compared with medium-high and ultra-high-alkalinity sulfonates, high-alkalinity sulfonates, while lacking alkali storage properties, excel in the solubilizing, dispersing, and rust-preventing functions of sulfonate metal detergents. They exhibit excellent piston cleaning properties, especially under the high-temperature operating conditions of turbocharged diesel engines. Furthermore, they have advantages over other types of high-alkalinity metal detergents in terms of additive compatibility and cost. Therefore, high-alkalinity sulfonates play an important role in internal combustion engine oil formulations. Currently, the most widely used high-alkalinity sulfonate in oil products is high-alkalinity calcium sulfonate. Since the mid-1990s, the development of high-alkalinity calcium sulfonate has primarily focused on low-chlorine or chlorine-free production. Domestic production of high-alkalinity calcium sulfonate began in the early 1990s, but domestic production uses methanol and calcium oxide as accelerators or synthetic raw materials, which generally suffers from low production efficiency and the presence of chlorine in the final product. The presence of chloride ions in internal combustion engine oils produces hydrochloric acid, which not only corrodes steel parts but also lowers the oil's base value and increases its acid value, affecting its performance, accelerating aging, and leading to oil loss and a shortened service life. Summary of the Invention

[0003] In view of this, the purpose of the present invention is to provide a method for preparing high-alkalinity calcium sulfonate, wherein the calcium sulfonate prepared by the method has the advantages of high alkalinity, small particle size, low precipitation value, low turbidity and no chlorine.

[0004] To achieve the above-mentioned objectives, the present invention provides the following technical solution: This invention provides a method for preparing high-alkalinity calcium sulfonate, comprising the following steps: mixing solvent, methanol, a portion of calcium hydroxide, neutral oil and alkylbenzene sulfonic acid and subjecting the mixture to a reflux reaction; then adding the remaining calcium hydroxide and carbon dioxide to carry out a carbonation reaction; and sequentially performing methanol recovery, sedimentation, solvent removal and filtration to obtain the high-alkalinity calcium sulfonate; wherein the remaining calcium hydroxide and carbon dioxide are added continuously and at a uniform rate.

[0005] Preferably, the solvent includes one or more of toluene, butanol, and gasoline.

[0006] Preferably, the mass ratio of the solvent to methanol is (250~300):(80~100); the mass ratio of the solvent to a portion of calcium hydroxide is (250~300):30.

[0007] Preferably, the neutral oil is a lubricating oil base oil; the alkylbenzene sulfonic acid includes long-chain alkylbenzene sulfonic acid or heavy alkylbenzene sulfonic acid.

[0008] Preferably, the number of carbon atoms in the long-chain alkylbenzene sulfonic acid is 20-24; the number of carbon atoms in the heavy alkylbenzene sulfonic acid is 20-24.

[0009] Preferably, the mass ratio of the solvent to the neutral oil is (250~300):200; and the mass ratio of the solvent to the alkylbenzene sulfonic acid is (250~300):140.

[0010] Preferably, the reflux reaction is carried out at a temperature of 60-70°C for 1 hour.

[0011] Preferably, the mass ratio of the solvent to the remaining calcium hydroxide is (250~300):148.

[0012] Preferably, the ratio of solvent to carbon dioxide is (250~300) g: 40 L; the addition time of carbon dioxide is greater than or equal to the addition time of the remaining calcium hydroxide.

[0013] Preferably, the methanol recovery method is distillation; the sedimentation agent used is toluene; the desolvation method is heating; and the filter aid used for filtration is diatomaceous earth.

[0014] This invention provides a method for preparing high-alkalinity calcium sulfonate, comprising the following steps: mixing solvent, methanol, a portion of calcium hydroxide, neutral oil, and alkylbenzene sulfonic acid and subjecting the mixture to a reflux reaction; then adding the remaining calcium hydroxide and carbon dioxide to initiate a carbonation reaction; followed by methanol recovery, sedimentation, solvent removal, and filtration to obtain the high-alkalinity calcium sulfonate; wherein the remaining calcium hydroxide and carbon dioxide are added continuously and at a uniform rate. The preparation method of this invention uses the continuous and uninterrupted addition of the remaining calcium hydroxide and carbon dioxide to control the carbonation reaction, enabling calcium carbonate to be continuously and in-situ generated within the micelles, resulting in calcium sulfonate with small particle size, low precipitation value and turbidity, and excellent performance due to the calcium component being predominantly distributed within the micelles (structural formula as shown). Figure 2 (As shown). Attached Figure Description

[0015] Figure 1 The BET curves are for the calcium sulfonate described in Example 1 (corresponding to the high-alkalinity calcium sulfonate in the figure) and the calcium sulfonate described in Comparative Example 1 (corresponding to C in the figure); Figure 2 The structural formula of calcium sulfonate prepared by the preparation method described in this invention is shown below. Detailed Implementation

[0016] This invention provides a method for preparing high-alkalinity calcium sulfonate, comprising the following steps: mixing solvent, methanol, a portion of calcium hydroxide, neutral oil and alkylbenzene sulfonic acid and subjecting the mixture to a reflux reaction; then adding the remaining calcium hydroxide and carbon dioxide to carry out a carbonation reaction; and sequentially performing methanol recovery, sedimentation, solvent removal and filtration to obtain the high-alkalinity calcium sulfonate; wherein the remaining calcium hydroxide and carbon dioxide are added continuously and at a uniform rate.

[0017] In this invention, unless otherwise specified, all raw materials used in the preparation are commercially available products well known to those skilled in the art.

[0018] In this invention, the solvent preferably includes one or more of toluene, butanol, and gasoline. When the solvent is two or more of the above-mentioned specific selections, this invention does not impose any special limitation on the ratio of the above-mentioned specific substances, and they can be mixed in any ratio. In the embodiments of this invention, the solvent is specifically toluene, butanol, or gasoline.

[0019] In this invention, the preferred mass ratio of the solvent to methanol is (250~300):(80~100), more preferably 250:80, 250:90, 250:100, 300:80, 300:90, or 300:100. In an embodiment of this invention, the mass ratio of the solvent to methanol can be 250:100.

[0020] In this invention, the neutral oil preferably comprises a lubricating oil base oil, which is preferably a mineral base oil, and more preferably comprises one of paraffinic base oil, intermediate base oil, and naphthenic base oil. In an embodiment of this invention, the lubricating oil base oil is specifically a lubricating oil base oil of type 150SN.

[0021] In this invention, the alkylbenzene sulfonic acid preferably includes long-chain alkylbenzene sulfonic acid or heavy alkylbenzene sulfonic acid. The long-chain alkylbenzene sulfonic acid preferably has 20-24 carbon atoms in its alkyl group, i.e., it preferably includes one or more of C20, C21, C22, C23, and C24 alkylbenzene sulfonic acids. The heavy alkylbenzene sulfonic acid preferably has 20-24 carbon atoms in its alkyl group. In embodiments of this invention, the alkylbenzene sulfonic acid is specifically a long-chain alkylbenzene sulfonic acid and heavy alkylbenzene sulfonic acid in a mass ratio of 2.5:1, a long-chain alkylbenzene sulfonic acid and heavy alkylbenzene sulfonic acid in a mass ratio of 1:1, or a long-chain alkylbenzene sulfonic acid and heavy alkylbenzene sulfonic acid in a mass ratio of 1:2.5.

[0022] In this invention, the preferred mass ratio of the solvent to a portion of the calcium hydroxide is (250~300):30, more preferably 250:30, 260:30, 270:30, 280:30, 290:30, or 300:30. In an embodiment of this invention, the specific mass ratio of the solvent to a portion of the calcium hydroxide is 250:30.

[0023] In this invention, the preferred mass ratio of the solvent to the neutral oil is (250~300):200, more preferably 250:200, 260:200, 270:200, 280:200, 290:200, or 300:200. In an embodiment of this invention, the specific mass ratio of the solvent to the neutral oil is 250:200.

[0024] In this invention, the preferred mass ratio of the solvent to alkylbenzenesulfonic acid is (250~300):140, more preferably 250:140, 260:140, 270:140, 280:140, 290:140, or 300:140. In an embodiment of this invention, the specific mass ratio of the solvent to alkylbenzenesulfonic acid is 250:140.

[0025] The present invention does not impose any special limitations on the mixing process; any process known to those skilled in the art can be used.

[0026] In this invention, the reflux reaction is preferably carried out under stirring conditions. The stirring speed is not particularly limited and can be any speed well-known to those skilled in the art. The reflux reaction temperature is preferably 60-70°C, more preferably 60°C, 62°C, 64°C, 66°C, 68°C, or 70°C; the reflux reaction time is preferably 1 hour. In an embodiment of this invention, the reflux reaction temperature can be 65°C and the time can be 1 hour. In this invention, the reflux reaction process is a neutralization reaction.

[0027] In this invention, the preferred mass ratio of the solvent to the remaining calcium hydroxide is (250~300):148, more preferably 250:148, 260:148, 270:148, 280:148, 290:148, or 300:148. In an embodiment of this invention, the specific mass ratio of the solvent to the remaining calcium hydroxide is 250:148.

[0028] In this invention, the preferred ratio of solvent to carbon dioxide is (250~300) g:40 L, more preferably 250 g:40 L, 260 g:40 L, 270 g:40 L, 280 g:40 L, 290 g:40 L, or 300 g:40 L. In an embodiment of this invention, the ratio of solvent to carbon dioxide can be 250 g:40 L.

[0029] In this invention, the remaining calcium hydroxide is added continuously and at a constant rate. The carbon dioxide is added continuously and at a constant rate. The addition time of the carbon dioxide is longer than the addition time of the calcium hydroxide.

[0030] In an embodiment of the present invention, the addition rate of the remaining calcium hydroxide is specifically 1 g / min, and the addition rate of the carbon dioxide is preferably 0.26 L / min.

[0031] In this invention, a carbonation reaction occurs during the addition of the remaining calcium hydroxide and carbon dioxide, and the preferred temperature for the carbonation reaction is 50°C.

[0032] In this invention, the methanol recovery method is preferably distillation, and the distillation temperature is preferably 70°C and the distillation time is preferably 20 min.

[0033] In this invention, the settling agent used for settling is preferably toluene, and the mass ratio of toluene to solvent is preferably 1500:(250~300), more preferably 1500:250, 1500:260, 1500:270, 1500:280, 1500:290 or 1500:300.

[0034] In this invention, the settling temperature is preferably 60°C and the settling time is preferably 24 hours.

[0035] In this invention, the solvent removal process preferably involves heating the supernatant obtained from sedimentation, with the heating temperature preferably being 150°C. The standard for completing the solvent removal process is preferably that the flash point temperature of the material reaches 180°C and the moisture content is less than 0.4%.

[0036] In this invention, the filter aid used for filtration is preferably diatomaceous earth, more preferably diatomaceous earth 40#; the mass ratio of the solvent to the filter aid is preferably (250~300):40, more preferably 250:40, 260:40, 270:40, 280:40, 290:40 or 300:40.

[0037] In this invention, the filtration temperature is preferably 100~140℃, more preferably 100℃, 110℃, 120℃, 130℃ or 140℃. In an embodiment of this invention, the filtration temperature can be 100℃.

[0038] In this invention, the high-alkalinity calcium sulfonate prepared by the preparation method is preferably used to adjust marine cylinder oil or low-to-medium grade engine oil; the amount of high-alkalinity calcium sulfonate added to the marine cylinder oil or low-to-medium grade engine oil is preferably 1.5 to 20 wt%, more preferably 1.5 wt%, 5 wt%, 10 wt%, 15 wt%, or 20 wt%.

[0039] The technical solutions of this invention will be clearly and completely described below with reference to the embodiments thereof. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0040] Example 1 In a three-necked flask at room temperature, add 250g of toluene (purity ≥99.5wt%, moisture ≤0.10%), 100g of long-chain alkylbenzene sulfonic acid (specifically, carbon number 20-24), 40g of heavy alkylbenzene sulfonic acid (specifically, carbon number 20-24), 100g of methanol, 30g of calcium hydroxide, and 200g of neutral oil (model 150SN). Stir and heat to 65℃ for reflux (install a fork tube on the left side of the three-necked flask, with a temperature measuring point on one fork tube and a pre-installed port for adding carbon dioxide on the other fork tube, a stirrer on the middle port, and a fork tube on the right side, with a condenser on one fork tube and a pre-installed port for adding ash). The neutralization reaction is carried out for 1 hour to obtain the first product system. After cooling the first product system to 50°C, carbon dioxide (purity ≥99.0 vol%, free of free water, odor, and oil) and calcium hydroxide (purity ≥95 wt%, white powder, moisture ≤1 wt%) were continuously added to the left and right forked tube openings of the three-necked flask while stirring at 200 rpm. The calcium hydroxide was added at a rate of 1 g / min, with an amount of 148 g and an addition time of 148 min; the carbon dioxide was added at a rate of 0.26 L / min, with an amount of 40 L and an addition time of 154 min, to carry out a carbonation reaction and obtain the second product system. The second product system was heated to 70°C to remove methanol (the condenser was kept constant, and a receiving bottle was added later) for 20 minutes. After cooling to below 60°C, the obtained material was poured into a 3000mL beaker, and 1500g of toluene was added and stirred until it settled for 24 hours. The supernatant was taken and heated to 150°C. A negative pressure (-0.08MPa) was applied to remove toluene and water (flash point greater than 180°C, water content less than 0.4%). Filter aid No. 40 (diatomaceous earth 40#) was added and filtered at 100°C to obtain calcium sulfonate.

[0041] Example 2 Referring to Example 1, the difference is that the amount of long-chain alkylbenzene sulfonic acid added is 70g, and the amount of heavy alkylbenzene sulfonic acid added is 70g, to obtain calcium sulfonate.

[0042] Example 3 Referring to Example 1, the difference is that the amount of long-chain alkylbenzene sulfonic acid added is 40g, and the amount of heavy alkylbenzene sulfonic acid added is 100g, to obtain calcium sulfonate.

[0043] Example 4 Referring to Example 1, the difference is that toluene is replaced with butanol to obtain calcium sulfonate.

[0044] Example 5 Referring to Example 1, the difference is that toluene is replaced with gasoline to obtain calcium sulfonate.

[0045] Comparative Example 1 Referring to Example 1, the difference is that, in addition to adding carbon dioxide and calcium hydroxide during the carbonation reaction, 3g of calcium chloride, an auxiliary agent, is also added; calcium hydroxide is added in three batches, with 50g of calcium hydroxide added all at once, followed by 13.5L of carbon dioxide, then the carbon dioxide flow is stopped, another 50g of calcium hydroxide is added, followed by 13.5L of carbon dioxide, then the carbon dioxide flow is stopped; then 48g of carbon dioxide is added, followed by 13L of carbon dioxide, and after the carbonation reaction, the temperature is directly raised to 150°C, and then negative pressure is applied until the flash point is greater than 180°C, the moisture content is less than 0.4%, and the final product is filtered using diatomaceous earth 40# to obtain calcium sulfonate (turbidity 43.8 ntu).

[0046] Test case Test items and test standards: Molecular particle size: Laser particle size analyzer GB / T 41949-2022; Color code (dilution) (number): GB / T 6540; Density (20℃) (kg / m³) 3 GB / T 1884; Flash point (open cup, °C): GB / T 3536; Kinematic viscosity (100℃, mm) 2 / s): GB / T 265; Total alkalinity (mg KOH / g): SH / T 0251; Precipitation value (mL): SH / T 0024-90; Turbidity (ntu): SH / T 0028-90; Calcium content (wt%): SH / T 0297; Moisture content (wt%): GB / T 260; The performance parameters of the calcium sulfonate prepared in Examples 1-5 and Comparative Example 1 are shown in Table 1: Table 1 Performance parameters of calcium sulfonate prepared in Examples 1-5 and Comparative Example 1

[0047] As shown in Table 1, the calcium sulfonate prepared by the method of the present invention has a high total base value, a low precipitation value, a small molecular particle size, and does not contain chlorine, and is non-corrosive.

[0048] Figure 1 The BET curves of calcium sulfonate described in Example 1 (corresponding to high-base-value calcium sulfonate in the figure) and calcium sulfonate described in Comparative Example 1 (corresponding to C in the figure) are obtained from... Figure 1 It is known that the molecular particle size of calcium sulfonate prepared by the preparation method of the present invention is less than 50 nm, which is much smaller than the particle size of calcium sulfonate described in Comparative Example 1.

[0049] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing high-alkalinity calcium sulfonate, characterized in that, Includes the following steps: After mixing solvent, methanol, a portion of calcium hydroxide, neutral oil, and alkylbenzene sulfonic acid and refluxing, the remaining calcium hydroxide and carbon dioxide are added to carry out a carbonation reaction. Methanol recovery, sedimentation, solvent removal, and filtration are performed sequentially to obtain the high-alkalinity calcium sulfonate. The remaining calcium hydroxide and carbon dioxide are added continuously and at a uniform rate.

2. The preparation method according to claim 1, characterized in that, The solvent includes one or more of toluene, butanol, and gasoline.

3. The preparation method according to claim 1, characterized in that, The mass ratio of the solvent to methanol is (250~300):(80~100); the mass ratio of the solvent to a portion of calcium hydroxide is (250~300):

30.

4. The preparation method according to claim 1, characterized in that, The neutral oil is a lubricating oil base oil; the alkylbenzene sulfonic acid includes long-chain alkylbenzene sulfonic acid or heavy alkylbenzene sulfonic acid.

5. The preparation method according to claim 4, characterized in that, The long-chain alkylbenzene sulfonic acid has 20-24 carbon atoms in its long-chain alkyl group; the heavy alkylbenzene sulfonic acid has 20-24 carbon atoms in its heavy alkyl group.

6. The preparation method according to claim 1, characterized in that, The mass ratio of the solvent to the neutral oil is (250~300):200; the mass ratio of the solvent to the alkylbenzene sulfonic acid is (250~300):

140.

7. The preparation method according to claim 1, characterized in that, The reflux reaction is carried out at a temperature of 60-70°C for 1 hour.

8. The preparation method according to claim 1, characterized in that, The mass ratio of the solvent to the remaining calcium hydroxide is (250~300):

148.

9. The preparation method according to claim 8, characterized in that, The ratio of solvent to carbon dioxide is (250~300) g: 40 L; the addition time of carbon dioxide is greater than or equal to the addition time of the remaining calcium hydroxide.

10. The preparation method according to claim 1, characterized in that, The methanol recovery method is distillation; the sedimentation agent used is toluene; the solvent removal method is heating; and the filter aid used for filtration is diatomaceous earth.

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