阅读说明：本技术 一种糖汁复合清净剂及其用于清净糖汁的方法 (Sugar juice composite detergent and method for cleaning sugar juice by using same ) 是由 李利军 李慰霞 程昊 孔红星 黄文艺 李彦青 杨岚风 毛祥 于 2019-03-26 设计创作，主要内容包括：本发明涉及一种糖汁复合清净剂及其用于清净糖汁的方法,该糖汁复合清净剂是由硝酸镁、磷酸和水构成,该糖汁复合清净剂中镁离子质量分数为1.0-3.0%,磷酸质量分数为1.0-2.5%；其用于清净糖汁的方法是：向糖汁中加入糖汁复合清净剂,糖汁复合清净剂的加入量是糖汁体积的1-3%,再用石灰乳调pH值至10.5-11.5,在30-60℃温度下搅拌反应5-30min,加入聚丙烯酰胺,快速搅拌0.5-3 min,转为慢速搅拌1-10 min,静置,待絮凝沉降稳定后取上清液得到清净汁。本发明采用磷酸和硝酸镁作为清净剂,在高pH下混凝生成氢氧化镁能高效电中和吸附糖汁中的色素及非糖组分,提高了糖汁脱色率,且混凝产物羟基磷酸钙可加速沉降速度,辅助絮凝,缩短了沉降时间。(The invention relates to a sugar juice composite detergent and a method for cleaning sugar juice, wherein the sugar juice composite detergent is composed of magnesium nitrate, phosphoric acid and water, the mass fraction of magnesium ions in the sugar juice composite detergent is 1.0-3.0%, and the mass fraction of phosphoric acid is 1.0-2.5%; the method for purifying the sugar juice comprises the following steps: adding sugar juice composite detergent into sugar juice, wherein the adding amount of the sugar juice composite detergent is 1-3% of the volume of the sugar juice, adjusting the pH value to 10.5-11.5 by using lime milk, stirring and reacting for 5-30min at the temperature of 30-60 ℃, adding polyacrylamide, stirring quickly for 0.5-3min, stirring slowly for 1-10 min, standing, and taking supernatant after flocculation and sedimentation are stable to obtain clean juice. The invention adopts phosphoric acid and magnesium nitrate as the cleaning agent, the magnesium hydroxide is generated by coagulation under high pH, the pigment and the non-sugar components in the sugar juice can be efficiently electrically neutralized and adsorbed, the decolorization rate of the sugar juice is improved, and the coagulation product calcium hydroxy phosphate can accelerate the settling speed, assist flocculation and shorten the settling time.)

1. The sugar juice composite detergent is characterized in that: the sugar juice composite detergent consists of magnesium nitrate, phosphoric acid and water, wherein the mass fraction of magnesium ions in the sugar juice composite detergent is 1.0-3.0%, and the mass fraction of phosphoric acid is 1.0-2.5%.

2. A sugar juice complex detergent as claimed in claim 1, characterised in that: the mass fraction of magnesium ions in the sugar juice composite detergent is 2.0%, and the mass fraction of phosphoric acid is 1.7%.

3. A method of using the sugar juice complex detergent as claimed in claim 1 or 2 for cleaning sugar juice, characterized in that: adding sugar juice composite detergent into sugar juice, wherein the adding amount of the sugar juice composite detergent is 1-3% of the volume of the sugar juice, adjusting the pH value to 10.5-11.5 by using lime milk, stirring and reacting for 5-30min at the temperature of 30-60 ℃, adding polyacrylamide, stirring quickly for 0.5-3min, stirring slowly for 1-10 min, standing, and taking supernatant after flocculation and sedimentation are stable to obtain clean juice; the addition amount of polyacrylamide is calculated by adding 0.05-0.20mL of polyacrylamide with the concentration of 1-3 g/L into 100mL of sugar juice.

4. The method for cleaning sugar juice according to claim 3, which is characterized in that: the sugar juice is sugarcane mixed juice or brown granulated sugar redissolved syrup or raw sugar redissolved syrup.

5. The method for cleaning sugar juice according to claim 3, which is characterized in that: the rapid stirring speed is 250-350 r/min, and the slow stirring speed is 20-40 r/min.

6. The method for cleaning sugar juice according to claim 3, which is characterized in that: the stirring speed of the stirring reaction is 80-150 r/min.

Technical Field

The invention relates to a sugar juice composite detergent and a method for cleaning sugar juice by using the same, belonging to the field of sugar juice clarification and decoloration.

Background

Cane juice cleaning is an important process in a sugar making process, and the main purpose of the cane juice cleaning is to remove pigment molecules and non-sugar components, so that high-quality clear juice is provided for a sugar boiling process.

The traditional decoloring process comprises a phosphoric acid-sulfurous acid method, a carbonic acid method, a lime method and the like, the phosphoric acid-sulfurous acid method is generally adopted in Chinese sugar mills, sulfur dioxide is generated by burning sulfur for decoloring, the utilization rate is not high, and the environmental pollution is caused. In addition, the decolorization rate of the traditional cleaning process is less than 70 percent, the quality and the yield of sugar are influenced, and the sugar content in the waste honey is high. The honey production coefficients of different substances are researched by Maurandi and Ezekari abroad, and a magnesium-containing compound and calcium nitrate are found to have the honey production resistance. The chitosan is high in cost, and meanwhile, the coagulation product calcium sulfate can scale, so that heat transfer and mass transfer in the later period are influenced. For solving the problem that magnesium hydroxide is difficult to settle, the Yuquan adopts bagasse as a flocculating aid, can reduce the volume to a certain extent, but still needs pressure filtration, has low settling speed, and does not research a cleaning mechanism.

At present, no report about the use of phosphoric acid and magnesium nitrate as composite detergents for cleaning sugar juice is found.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: phosphoric acid and magnesium nitrate are used as the detergents, magnesium hydroxide is generated by coagulation under high pH, pigment and non-sugar components in the sugar juice can be efficiently electrically neutralized and adsorbed, the decolorization rate of the sugar juice is improved, and the coagulation product calcium hydroxy phosphate can accelerate the settling speed, assist flocculation and shorten the settling time.

The technical scheme for solving the technical problems is as follows: the sugar juice composite detergent consists of magnesium nitrate, phosphoric acid and water, wherein the mass fraction of magnesium ions in the sugar juice composite detergent is 1.0-3.0%, and the mass fraction of phosphoric acid is 1.0-2.5%.

The further technical scheme of the invention is as follows: the mass fraction of magnesium ions in the sugar juice composite detergent is 2.0%, and the mass fraction of phosphoric acid is 1.7%.

The other technical scheme of the invention is as follows: adding the sugar juice composite detergent into the sugar juice, wherein the adding amount of the sugar juice composite detergent is 1-3% of the volume of the sugar juice, adjusting the pH value to 10.5-11.5 by using lime milk, stirring and reacting for 5-30min at the temperature of 30-60 ℃, adding polyacrylamide, stirring quickly for 0.5-3min, stirring slowly for 1-10 min, standing, and taking the supernatant after flocculation and sedimentation are stable to obtain the clean juice; the addition amount of polyacrylamide is calculated by adding 0.05-0.20mL of polyacrylamide with the concentration of 1-3 g/L into 100mL of sugar juice.

The sugar juice is sugarcane mixed juice or brown granulated sugar redissolved syrup or raw sugar redissolved syrup.

The rapid stirring speed is 250-350 r/min, and the slow stirring speed is 20-40 r/min.

The stirring speed of the stirring reaction is 80-150 r/min.

The phosphoric acid-magnesium nitrate composite detergent of the invention carries out cleaning treatment on sugar juice, and under the optimal process conditions: the composite detergent (the mass fraction of magnesium ions is 2.0%, the mass fraction of phosphoric acid is 1.7%) is 2.0% (based on the volume of sugar juice), the pH value is 11.0, the dosage of a Polyacrylamide (PAM) aqueous solution (2.0 mg/L) is 0.1%, the temperature is 30 ℃, the decolorization rate is 88.2% under the condition, the sedimentation time is 69s, and the phosphoric acid is used as a green auxiliary agent, so that the sedimentation time can be obviously shortened, the decolorization rate is improved, the introduction decolorization rate of the phosphoric acid is improved by 3.1%, and the sedimentation time is shortened by 52 s. Therefore, the phosphoric acid-magnesium nitrate composite detergent belongs to a high-efficiency green detergent.

According to the invention, SEM, TEM and ZETA potential analysis and XRD representation are carried out on the aggregates of a sucrose system and a sugar juice system, and the calcium hydroxy phosphate and magnesium hydroxide generated by the coagulation reaction of the composite detergent are used for carrying out electric neutralization adsorption, embedding and net capture on non-sugar substances such as pigments and the like, so that the crystallinity of a coagulated product is reduced. The coagulation product calcium hydroxy phosphate can accelerate the sedimentation speed and assist flocculation, the coagulation by-product calcium nitrate has the honey-making resistance, and the filter mud containing calcium nitrate, magnesium salts and the like can be used as a fertilizer for plants, so that the problem of difficult treatment of the sugar filter mud can be solved.

The invention adopts the stirring speed from high to low after adding the polyacrylamide, and is very favorable for the decoloring effect of the sugar juice. The rapid stirring speed is 300-350 r/min, which is beneficial to forming fine alum floc in a very short time by polyacrylamide and sugar juice; the slow stirring speed is 20-40 r/min, so that small alum flocs continuously collide with each other and are greatly beneficial to floc sedimentation.

The technical characteristics of a sugar juice complex detergent and the application thereof of the present invention will be further described with reference to the accompanying drawings and examples.

Drawings

FIG. 1: graph showing the effect of complex detergents with different mass fractions of phosphoric acid on decolorization.

FIG. 2: graph of the effect of complex detergents of different mass fractions of phosphoric acid on settling time.

FIG. 3: and (3) a curve chart of the influence of the dosage of the composite detergent on the decolorization rate and the settling time.

FIG. 4: the influence of pH on decolorization rate and settling time is shown in the graph.

FIG. 5: and (3) a graph of the influence of the mass concentration of PAM on the decolorization rate and the sedimentation time of the sugar juice.

FIG. 6: the influence curve of temperature on the decolorization rate and the sedimentation time of the sugar juice.

FIG. 7: SEM images of the aggregates of detergent in different systems. Wherein, a-SEM of the aggregates in the single detergent sucrose system; b-SEM of aggregates in the brown granulated sugar redissolving syrup system with single detergent; c-SEM of the aggregate of the complex detergent in a sucrose system; d-SEM of the aggregate of complex detergents in brown granulated sugar remelt syrup system.

FIG. 8: TEM image of coagulation product of the composite detergent in different systems. TEM images of aggregates in the sucrose a and b; c. TEM image of a system of d-brown granulated sugar redissolved syrup.

FIG. 9: XRD patterns of aggregates of sucrose system and brown granulated sugar redissolution syrup system.

Detailed Description