阅读说明：本技术 一种从皂脚提取中性油的生产工艺 (Production process for extracting neutral oil from soapstock ) 是由 王月华 程芳园 成良玉 李桂芝 韩娜 宋秋月 于 2020-12-22 设计创作，主要内容包括：本发明提供了一种从皂脚提取中性油的生产工艺,包括一次破乳过程、二次破乳过程；在一次破乳过程中,添加钠盐,且控制皂脚液的温度在50-70℃之间,保温时间在3-7min之间,获得破乳液Ⅰ；在二次破乳过程中,添加助滤剂,且控制破乳液Ⅰ的温度为80-110℃,保温时间在2-10min之间,获得破乳液Ⅱ。该生产工艺中,严格控制搅拌速度、严格控制温度,充分发挥助滤剂的性能,使该生产过程自开始至中性油的提取率达78％以上,时间在40min之内。该生产工艺具有过程易于控制、对中性油的提取率高且生产过程时间短的优点；生产过程无废水、废气的排放,实现了清洁生产和资源的高效利用。(The invention provides a production process for extracting neutral oil from soapstock, which comprises a primary demulsification process and a secondary demulsification process; in the primary demulsification process, adding sodium salt, controlling the temperature of the soapstock solution to be between 50 and 70 ℃, and keeping the temperature for 3 to 7min to obtain a demulsification agent I; in the secondary demulsification process, a filter aid is added, the temperature of the demulsification agent I is controlled to be 80-110 ℃, and the heat preservation time is controlled to be 2-10min, so that a demulsification agent II is obtained. In the production process, the stirring speed and the temperature are strictly controlled, the performance of the filter aid is fully exerted, and the extraction rate of neutral oil from the beginning of the production process to the beginning reaches over 78 percent within 40 min. The production process has the advantages of easily controlled process, high extraction rate of neutral oil and short production process time; the production process has no discharge of waste water and waste gas, and realizes clean production and high-efficiency utilization of resources.)

1. A production process for extracting neutral oil from soapstock is characterized by comprising a primary demulsification process and a secondary demulsification process;

in the primary demulsification process, adding sodium salt, controlling the temperature of the soapstock solution to be between 50 and 70 ℃, and keeping the temperature for 3 to 7min to obtain a demulsification agent I;

in the secondary demulsification process, a filter aid is added, the temperature of the demulsification agent I is controlled to be 80-110 ℃, and the heat preservation time is controlled to be 2-10min, so that a demulsification agent II is obtained.

2. The process of claim 1, wherein the soapstock is diluted before the primary demulsification process, and the weight to volume (g/ml) ratio of soapstock to water is 100: 70-80.

3. The process for producing neutral oil extracted from soapstock as claimed in claim 2, wherein the stirring speed is controlled to be 50-80 rpm during the dilution of soapstock solution.

4. The process of claim 1, wherein the weight (g/g) ratio of salt to soapstock is 5-11:100 in one demulsification process; after adding salt, stirring at 30-80 rpm, and heating the soap stock solution at 8 deg.C/min.

5. The process for producing neutral oil from soapstock as claimed in claim 1, wherein in the second demulsification process, the temperature of the demulsification agent I is controlled between 50-80 ℃, then a filter aid is added, the mass (g/g) ratio of the filter aid to the soapstock is 0.4-0.9:1000, and the stirring speed is 20-50 r/min.

6. The process for producing neutral oil from soapstock according to any one of claims 1-5, wherein the filter aid is one or more selected from activated carbon, diatomaceous earth, acid clay, and silica.

7. The process for producing neutral oil from soapstock as claimed in claim 6, wherein a centrifugation step is provided after the secondary demulsification step, and the temperature of the emulsion breaking liquid II is controlled to be between 70-110 ℃ during the centrifugation step.

8. The process as claimed in claim 7, wherein the rotation speed of the centrifuge is 3500-5000 rpm and the centrifugation time is 2-3 min.

Technical Field

The invention relates to the technical field of neutral oil extraction, in particular to a production process for extracting neutral oil from soapstock.

Background

Vegetable oil is oil obtained from fruits, seeds, and germs of plants, such as peanut oil, soybean oil, corn germ oil, sunflower seed oil, etc., and soapstock is produced as a byproduct during the alkali refining extraction of vegetable oil.

Soapstock is a viscous substance, is not liquid or solid, cannot be treated according to conventional liquid or solid, and is difficult to treat. At present, the main purpose of soapstock is to produce acidified oil, and the most traditional method is to add concentrated sulfuric acid to prepare the acidified oil which is used as biodiesel. In the process, about 0.5 ton of acid water is generated from 1 ton of soapstock, the corn oil yield is calculated to be 120 ten thousand tons every year in China according to the statistical data of the national statistical bureau, about 6 ten thousand tons of acid water is generated every year, the environment is greatly polluted, the acid odor is rushed to the sky in a production field, almost every acidification oil factory is a pollution source, in addition, the treatment difficulty of acid-containing wastewater is high, the cost is high, and the production cost is greatly increased due to the treatment cost of the wastewater. Therefore, more economical means for disposing and utilizing soapstock must be sought to increase the utilization of soapstock.

The neutral oil in the soapstock is edible semi-finished corn oil discharged along with a centrifugal machine when the corn oil is subjected to soap removal in an alkali refining section, and the neutral oil in the soapstock is less and less left along with continuous optimization and innovation of a refining technology, so that the neutral oil is more and more difficult to extract. At present, neutral oil in the soapstock is poorly extracted, because the viscosity of the soapstock is high, and neutral oil and part of water are tightly wrapped by substances such as sodium fatty acid, colloid, partial phospholipid and the like in the soapstock, so that the extraction difficulty of the neutral oil is increased, which is a problem difficult to solve in the industry and influences the treatment of the soapstock and the extraction rate of vegetable oil.

Disclosure of Invention

In view of the above-mentioned deficiencies of the prior art, the present invention provides a process for extracting neutral oil from soapstock, and in particular, a process for controlling the temperature of soapstock during the process of adding filter aid. In the production process, the stirring speed and the temperature are strictly controlled, the performance of the filter aid is fully exerted, and the time from the beginning of the production process to the time when the extraction rate of the neutral oil reaches more than 78% is within 40 min. The production process has the advantages of easily controlled process, high extraction rate of neutral oil and short production process time; the production process has no discharge of waste water and waste gas, and realizes clean production and high-efficiency utilization of resources.

The technical scheme of the invention is as follows:

a production process for extracting neutral oil from soapstock comprises primary demulsification process and secondary demulsification process;

in the primary demulsification process, adding sodium salt, controlling the temperature of the soapstock solution to be between 50 and 70 ℃, and keeping the temperature for 3 to 7min to obtain a demulsification agent I;

in the secondary demulsification process, a filter aid is added, the temperature of the demulsification agent I is controlled to be 80-110 ℃, and the heat preservation time is controlled to be 2-10min, so that a demulsification agent II is obtained.

Further, before the primary demulsification process, diluting the nigre, wherein the weight-volume (g/ml) ratio of the nigre to the water is 100: 70-80; diluting the soapstock with water to obtain diluted soapstock solution.

Preferably, the stirring speed is controlled to be 50-80 r/min in the process of diluting the soapstock solution; the stirring speed is controlled to be uniform, so that the neutral oil wrapped in the soapstock solution is uniformly distributed in the water to prepare for subsequent treatment.

Further, in the primary demulsification process, the weight (g/g) ratio of the salt to the soapstock is 5-11: 100; after adding salt, stirring at 30-80 rpm, and heating the soap stock solution at 8 deg.C/min.

Further, in the secondary demulsification process, the temperature of the demulsification agent I is controlled to be between 50 and 80 ℃, then a filter aid is added, the mass (g/g) ratio of the filter aid to the soapstock is 0.4 to 0.9:1000, and the stirring speed is 20 to 50 r/min.

Preferably, the filter aid is one or a mixture of more of activated carbon, diatomite, acid clay and silicon dioxide.

Further, after the secondary demulsification process, a centrifugation process is also set, and in the centrifugation process, the temperature of the demulsification agent II is controlled to be between 70 and 110 ℃; controlling the temperature, preventing colloid and the like from further forming a wrapping layer on the surface of the neutral oil, and improving the extraction rate of the neutral oil.

Preferably, during the centrifugation, the rotation speed of the centrifuge is 3500-5000 rpm, and after 2-3min of centrifugation, neutral oil is obtained.

Compared with the prior art, the invention has the beneficial effects that:

1. the production process provided by the invention has the advantage of high extraction rate of neutral oil, and the extraction rate of the soapstock is up to 82.79%; in addition, no waste water and waste gas are discharged in the production process, and clean production and efficient utilization of resources are realized.

2. The production process provided by the invention has the advantage of short extraction time, and the time consumed by the whole production process is less than or equal to 40 min; in addition, the production process has mild conditions and easily controlled process.

3. The neutral oil obtained by the invention meets the quality acceptance requirements of the corn crude oil of GB19111 and GB2716, and the total vitamin E content and the total sterol content in the neutral oil are respectively between 110-120mg/100g and 1000-1200mg/kg, so that the neutral oil product is good, can be directly used as alkali refining oil, and improves the oil refining yield.

Detailed Description

In order to make those skilled in the art better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the following examples 1-5, the crude corn oil obtained from corn germ has a vitamin E content of about 128mg/100g and a total sterol content of 13880 mg/kg; the oil content of the soapstock used was: 17 percent.

Example 1 neutral oil extraction of corn germ soapstock 1

A production process for extracting neutral oil from soapstock comprises the following steps:

(1) diluting the soapstock, wherein the weight-volume (g/ml) ratio of the soapstock to water is 100: 75; controlling the stirring speed to be 70 r/min, and diluting the soapstock with water to obtain diluted soapstock liquid with uniformly distributed neutral oil;

(2) primary demulsification: adding sodium chloride into the soapstock solution, wherein the particle size of the sodium chloride is 30-50 mu m, the weight (g/g) ratio of the sodium chloride to the soapstock is 8:100, stirring at 60 r/min, simultaneously heating the soapstock solution to 65 ℃ at the heating rate of 8 ℃/min, and preserving heat for 5min to obtain emulsion I;

(3) secondary demulsification: controlling the temperature of the demulsifying agent I to be 70 ℃, then adding a filter aid, wherein the mass (g/g) ratio of the filter aid to the soapstock is 0.6:1000, the filter aid is silicon dioxide and diatomite, the weight (g/g) ratio of the silicon dioxide to the diatomite is 2:0.5, stirring for 2min under the condition of 35 revolutions per minute, then heating to 100 ℃, and preserving heat for 6min to obtain a demulsifying agent II;

(4) centrifuging: and (3) putting the demulsifying fluid II with the temperature of 100 ℃ into a centrifugal machine, controlling the rotating speed of the centrifugal machine to be 4300 r/min, and centrifuging for 2min to obtain neutral oil.

Example 2 neutral oil extraction of corn germ soapstock 2

A production process for extracting neutral oil from soapstock comprises the following steps:

(1) diluting the soapstock, wherein the weight-volume (g/ml) ratio of the soapstock to water is 100: 70; controlling the stirring speed to be 50 r/min, and diluting the soapstock with water to obtain diluted soapstock liquid with uniformly distributed neutral oil;

(2) primary demulsification: adding sodium sulfate into the soapstock solution, wherein the particle size of the sodium sulfate is 30-50 mu m, the weight (g/g) ratio of the sodium sulfate to the soapstock is 5:100, stirring at 30 r/min, simultaneously heating the soapstock solution to 50 ℃ at the heating rate of 8 ℃/min, and preserving heat for 7min to obtain emulsion I;

(3) secondary demulsification: controlling the temperature of the emulsion breaking I to be 50 ℃, adding a filter aid, wherein the mass (g/g) ratio of the filter aid to the nigre is 0.4:1000, the filter aid is silicon dioxide, acid clay and activated carbon, the weight (g/g) ratio of the silicon dioxide, the acid clay and the activated carbon is 1.8:0.2:0.4, stirring for 3min under the condition of 20 revolutions/min, then heating to 80 ℃, and preserving heat for 10min to obtain an emulsion breaking II;

(4) centrifuging: and (3) placing the demulsifying liquid II with the temperature of 80 ℃ into a centrifugal machine, controlling the rotating speed of the centrifugal machine to be 3500 rpm, and centrifuging for 3min to obtain neutral oil.

Example 3 neutral oil extraction of corn germ soapstock 3

A production process for extracting neutral oil from soapstock, which is different from the example 1 in that the weight (g/g) ratio of salt to soapstock in the primary demulsification process of the step (2) is 6: 100.

Example 4 neutral oil extraction of corn germ soapstock 4

A production process for extracting neutral oil from soapstock comprises the following steps:

(1) diluting the soapstock, wherein the weight-volume (g/ml) ratio of the soapstock to water is 100: 80; controlling the stirring speed to be 80 r/min, and diluting the soapstock with water to obtain diluted soapstock liquid with uniformly distributed neutral oil;

(2) primary demulsification: adding sodium carbonate into the soapstock solution, wherein the particle size of the sodium carbonate is 30-50 mu m, the weight (g/g) ratio of the sodium carbonate to the soapstock is 9:100, stirring at 60 r/min, simultaneously heating the soapstock solution to 60 ℃ at the heating rate of 8 ℃/min, and preserving heat for 7min to obtain emulsion I;

(3) secondary demulsification: controlling the temperature of the broken emulsion I to be 60 ℃, adding a filter aid, wherein the filter aid is acid clay, the mass (g/g) ratio of the acid clay to the nigre is 0.75:1000, stirring for 2min under the condition of 40 revolutions/min, then heating to 90 ℃, and preserving heat for 8min to obtain a broken emulsion II;

(4) centrifuging: and (3) placing the demulsifying liquid II with the temperature of 90 ℃ into a centrifugal machine, controlling the rotating speed of the centrifugal machine to be 4000 revolutions per minute, and centrifuging for 2.5 minutes to obtain neutral oil.

Example 5 neutral oil extraction of corn germ soapstock 5

A production process for extracting neutral oil from soapstock comprises the following steps:

(1) diluting the soapstock, wherein the weight-volume (g/ml) ratio of the soapstock to water is 100: 80; controlling the stirring speed to be 70 r/min, and diluting the soapstock with water to obtain diluted soapstock liquid with uniformly distributed neutral oil;

(2) primary demulsification: adding sodium nitrate into the soapstock solution, wherein the particle size of the sodium nitrate is 30-50 mu m, the weight (g/g) ratio of the sodium nitrate to the soapstock is 11:100, stirring at 80 r/min, simultaneously heating the soapstock solution to 70 ℃ at the heating rate of 8 ℃/min, and preserving heat for 7min to obtain emulsion breaking I;

(3) secondary demulsification: controlling the temperature of the demulsifying agent I to be 70 ℃, then adding a filter aid, wherein the mass (g/g) ratio of the filter aid to the soapstock is 0.75:1000, the filter aid comprises acid clay and diatomite, the weight (g/g) ratio of the acid clay to the diatomite is 1.8:2.2, stirring for 2min under the condition of 50 revolutions/min, then heating to 110 ℃, and preserving heat for 2min to obtain a demulsifying agent II;

(4) centrifuging: and (3) placing the demulsifying liquid II with the temperature of 110 ℃ into a centrifugal machine, controlling the rotating speed of the centrifugal machine to be 5000 revolutions per minute, and centrifuging for 2 minutes to obtain neutral oil.

The acid value of the neutral oil obtained in examples 1 to 5 is detected according to GB2009.229, peroxide value according to GB5009.227, water according to GB5009.236, insoluble impurities according to GB/T15688, density according to GB/T5526, VE according to GB 5009.82 and phytosterol according to GB/T25223, and the extraction rate of the neutral oil is calculated as follows:

table 1 neutral oil detection and extraction rates for examples 1-5

As can be seen from the table, in example 1, the extraction rate of the neutral oil is the highest, and the extraction rate fluctuates with the change of parameters in the extraction process, but the extraction rate of the neutral oil is more than 78%.

The total vitamin E and the total sterol are important indexes for measuring the oil product of the maize germ oil, and the table and the content of the maize germ oil and the crude oil are combined, so that the production process provided by the invention has little influence on the total vitamin E and the total sterol in the nigre, the loss rate of the nutrient components of the obtained neutral oil is low, and the nutrient components in the maize oil are retained to the maximum extent.

The data in the table show that the produced neutral oil has good quality and meets the quality acceptance requirements of the corn crude oil of GB19111 and GB2716, therefore, the neutral oil can be used as crude oil, the yield of the vegetable oil is indirectly improved, the quality of the obtained neutral oil can also reach the national standard requirements, and the nutrient content can be furthest reserved. The extraction rate of neutral oil in the soapstock reaches about 80 percent, the production yield is improved, and the economic benefit is obvious.

Comparative example 1

The comparative example 1 is different from example 1 in that the particle size of the sodium salt added in the primary demulsification process of the step (2) is between 500-800.

The extraction rate of the produced neutral oil is calculated to obtain the extraction rate of the neutral oil of 69.59%, and it can be seen that the particle size of the sodium salt plays a vital role in the extraction process of the neutral oil, particularly in the primary demulsification process.

Example 6 neutral oil extraction of sunflower seed soapstock

The difference from the example 1 is that the soapstock used is sunflower seed soapstock after the oil is extracted by alkalization, and the oil content in the soapstock is as follows: 21 percent;

the extraction rate is as follows: 82 percent, the acid value of the neutral oil obtained in the example 6 is detected according to GB2009.229, the peroxide value is detected according to GB5009.227, the water content is detected according to GB5009.236, insoluble impurities are detected according to GB/T15688, and the total vitamin E is detected according to GB 5009.82, and in addition, the extraction rate of the neutral oil is calculated, and the results are shown in the following table 2, wherein the quality acceptance requirements of the crude oil of GB2716 are met.

Table 2 neutral oil detection and extraction yield of example 6

Item	Example 6
		Acid value (mg/kg)	2.78
Moisture (%)	0.07
		Insoluble impurities (%)	0.08
Peroxide number (g/100g)	0.12
		Total vitamin E (mg/100g)	59
Extraction ratio (%)	82

Example 7 neutral oil extraction of peanut oil soapstock

The difference from example 1 is that the soapstock used is an alkalized oil-extracted peanut oil soapstock, the oil content of the soapstock is: 19 percent;

the extraction rate is as follows: 81% of the acid value of the neutral oil obtained in example 7 was measured in accordance with GB2009.229, peroxide value in accordance with GB5009.227, moisture in accordance with GB5009.236, and insoluble impurities in accordance with GB/T15688, and the extraction rate of the neutral oil was calculated as follows, and the results were shown in Table 3, which satisfy the quality acceptance requirements of the crude oil of GB 2716.

Table 3 neutral oil detection and extraction yield of example 7

Item	Example 7
		Acid value (mg/kg)	2.91
Moisture (%)	0.08
		Insoluble impurities (%)	0.07
Peroxide number (g/100g)	0.11
		Extraction ratio (%)	81

The above examples show that when the production process provided by the invention is applied to neutral oil extraction of soapstock produced by sunflower seeds, peanuts, corn germs and the like, the obtained neutral oil meets the national standard, and therefore, the neutral oil can be used as crude oil; in addition, the statistical extraction rate shows that the extraction rate is more than 80 percent, which further shows that the production process has the advantages of wide applicability and strong practicability and has high extraction rate of neutral oil.

By the production process provided by the invention, the obtained neutral oil is used as crude oil, the yield of vegetable oil is indirectly improved, no wastewater or waste gas is produced in the extraction process of the neutral oil, clean production is realized, efficient utilization of soapstock resources is improved, and energy conservation and environmental protection are realized.

Although the present invention has been described in detail by referring to the preferred embodiments, the present invention is not limited thereto. Various equivalent modifications or substitutions can be made on the embodiments of the present invention by those skilled in the art without departing from the spirit and scope of the present invention, and these modifications or substitutions are within the scope of the present invention/any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.