JP4545432B2 - Method for efficiently producing sea salt and bitter juice with stable quality - Google Patents

Description

  The present invention relates to a method for producing sea salt and bitter juice using seawater, and more particularly to a method for efficiently producing sea salt and bitter juice with stable quality.

  Regarding the production method of natural salt using seawater, the ion exchange membrane method and the heating method are generally carried out as the concentration method, and productivity, low energy, and contamination of harmful substances such as PCB and heavy metals can be prevented. Especially when mass production is intended, the ion exchange membrane method is usually used. Originally, Japanese used to take natural salt, which was originally condensed with minerals from the sea, but in 1905, the salt monopolization system was enforced, and since the 1960s the “ion-exchange membrane salt production method” was recommended. Since artificial salt of 99% or more sodium chloride lacking minerals was regarded as table salt used in general households, we fell into a chronic mineral deficiency. It is said that this mineral deficiency contributes to the causes of various current diseases.

  Sea salt contains many mineral components such as magnesium, zinc, potassium, iron, calcium, etc. in sea water, so it is generally permeated that it has a mellow taste and good health compared to artificial salt. Demand has been increasing for several years.

  In addition, natural bitter juice obtained as a by-product during the production of sea salt is a condensed product of minerals in sea water. Therefore, it is increasingly used for external preparations.

  In this way, the importance of sea salt and natural bitter juice is increasing, and a production method that can obtain these at the same time efficiently and with high quality is desired.

  As a method for efficiently producing high-quality sea salt and natural bitter juice at the same time, since there is no idea that both sea salt and natural bitter juice are the target products, there are few reports. In other words, the reason is that the presence of bitter juice was treated only as a by-product.

  As a method for obtaining seawater salt and natural bitter juice, there is a method for obtaining high-concentration brine using a seawater concentration plant that employs a reverse osmosis membrane made of a polyamide-based composite membrane. A method for obtaining a versatile salt and a versatile bitter juice having an arbitrary ionic composition by manipulating the heating and concentration temperature using a rotary evaporator (see Patent Document 1) has been filed by the same applicant. In addition, at least one selected from inorganic ammonium salt, seafood extract, livestock meat extract, yeast extract, and soy milk is dissolved in seawater, and inorganic nitrate and nitrite are enhanced by nitrifying bacteria under aerobic conditions. An application has also been filed for salt and bitter juice, a method for producing the salt (see Patent Document 2), and the like, wherein the salt is obtained by concentrating fresh seawater and separating the salt. The other is a method of efficiently producing an aggregated salt of salt that has high solubility and moisture retention and retains bitter ingredients and has high mechanical strength. The mother liquor is cooled to a supersaturated state, and the supersaturated mother liquor is obtained. To produce a flocculated salt of a salt to which a large number of microcrystals are attached by supplying the slag to a fluidized bed type crystallizer (see Patent Document 3). and so on. In addition, as for a salt making apparatus using only the heating method, by providing a preliminary kettle that preheats the raw material seawater supplied to the concentration kettle at a temperature lower than the boiling point, the mineral component is burned at a high rate by suppressing the burning of the mineral ingredient A salt making apparatus (see Patent Document 4) that can produce a natural salt containing, has been filed.

JP 2002-114512 A Japanese Patent Laid-Open No. 2002-360218 JP 2002-169139 A JP 2002-179425 A

  The ion exchange membrane method is a method for producing natural salt using natural seawater, which realizes low-cost mass production and has the advantage of removing some of the seawater that may contain pollutants. On the other hand, some mineral components in seawater are also removed. In contrast, the heating method is low cost, low energy, and is not good at mass production, but has the advantage of less loss of mineral components in seawater. The conventional salt production method is based on the ion exchange membrane method, and the heating method is rarely noticed. Moreover, attention has not been paid to a method for producing sea salt and natural bitter juice simultaneously and efficiently with high quality as in the present invention.

  In the heating method, the presence of calcium often becomes a hindrance to productivity, and it is easy to cause a situation where production is forced to stop because it adheres to the pipe wall of the pipe and becomes clogged. There are drawbacks. In addition, when seawater salt and natural bitter juice are produced by a series of production flows that are simply heated and concentrated using an evaporating kettle, it has been difficult to achieve high quality with respect to their mineral composition and purity. High quality as used herein means that seawater is distributed without loss to seawater salt with a high mineral content and a high sodium content and a natural bitter juice with a stable mineral composition and a high mineral content.

  Therefore, an object of the present invention is to efficiently produce sea salt and natural bitter juice with stable quality simultaneously from sea water by a heating method.

  As means for solving these problems, the present inventors first used three types of heating, evaporating kettles of primary, secondary, and tertiary as production equipment. The primary evaporating kettle mainly removes calcium salts such as calcium sulfate and calcium carbonate, which cause clogging of pipe walls. In the secondary evaporating kettle, the primary brine obtained in the primary evaporating kettle is further heated and concentrated and distributed to seawater salt and secondary brine. In the tertiary evaporating kettle, the secondary brine obtained in the secondary evaporating kettle is further heated and concentrated and filtered to obtain bitter juice. By continuously performing these three steps, the target quality of stable sea salt and natural bitter juice are simultaneously produced efficiently.

  Until now, the salt production method by the heating method is generally regarded as a primitive and inefficient production method. However, as shown in the following embodiment, we use a heating method seawater concentration plant to simultaneously produce sea salt showing an ideal ionic composition and natural bitter juice showing an ideal ionic composition. Could get the way. Since only one manufacturing condition is set and both can be obtained with an ideal composition at the same time, it can be said that the method is very efficient as a result. Only the seawater salt produced in the first and second times of the secondary concentration step and the inorganic salt filtered and separated in the tertiary concentration step are the amount of loss, which is also efficient.

  Seawater concentration plant sampling process (seawater storage, seawater pressure pump, filtration, etc.) and rice cake process (primary brine storage tank, concentrated liquid pressure pump, evaporation concentrator, agitator, condenser, vacuum pump, filtration, salt All dehydrators, etc. can be automated, and by concentrating seawater through a continuous production process, high-quality seawater salt and natural bitter juice can be produced efficiently and continuously in a simple process. .

  Further, the embodiment will be described in detail. First, since seawater is manufactured only by the heating method, there is a need to select seawater from which no harmful substances are confirmed from the sea area that may not be contaminated. In the waters near Japan, the Nansei Islands and the Daito Islands are known as extremely low pollution areas in the world. Recently, deep ocean water is sometimes used.

  In the primary evaporation kettle, first, seawater is concentrated to 1/8 to 1/11 volume. The heating temperature at this time is not particularly affected by the final product, but is preferably set to around 100 to 115 ° C. The flake-like crystals of calcium salt begin to precipitate around when the seawater is concentrated to 1/4 volume. This is completely filtered to obtain primary brine.

  Next, the primary brine obtained in the primary evaporator is concentrated using a secondary evaporator under temperature control of 100 to 115 ° C. The heating temperature at this time is preferably set in the vicinity of 109 ° C., which is a temperature range in which the proportion of magnesium concentration in the obtained sea salt tends to increase from the proportion of sodium concentration. As the concentration progresses, seawater salt begins to precipitate at once when the primary brine is concentrated to around 4/5 volume. When it is concentrated to 6/10 to 9/10 volume and precipitation of sea salt is completed, heating is stopped and the sea salt is separated into secondary brine. This secondary brine is almost saturated at this concentration, but still contains sodium chloride. An amount corresponding to 10 to 15% by volume of the secondary brine is stored separately and used for bitter juice production in a tertiary evaporating kettle. The sea salt obtained by the first secondary evaporation kettle treatment is not yet the target sea salt. An amount of 40 to 60% by volume of primary brine is added to the remaining first secondary brine, and the second concentration is performed under the same conditions. Furthermore, the third concentration is performed under the same conditions for the second secondary brine. Such a concentration step is repeatedly performed. The mineral composition and mineral salt concentration in the sea salt obtained after the third time are constant, and the target sea salt is obtained from this stage.

  Further, a part of the secondary brine obtained in the secondary evaporation kettle is used to obtain the desired natural bitter juice using the tertiary evaporation kettle. The heating temperature at this time is preferably set in the vicinity of 114 ° C., which is a temperature range in which the proportion of magnesium concentration in the bitter juice tends to increase from the proportion of sodium concentration. When the secondary brine is concentrated to 3/5 to 4/5 volume, it is filtered, and this becomes the intended natural bitter juice. At this time, sodium chloride is mainly removed from the secondary brine, so that the bitter juice having the highest purity and stable mineral composition is obtained in this method.

  By carrying out this series of steps continuously, it has become possible to efficiently produce high-quality and stable seawater salt and natural bitter juice simultaneously.

  Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited thereto.

Example:
(Primary concentration process)
Primary concentration of 2000 liters of seawater is performed at a heating temperature of 105 ° C. The primary evaporation tank with a capacity of 2550 liters is charged with seawater in an amount that does not exceed the heat transfer volume that corresponds to the double jacket structure filled with steam in the evaporation tank. Continue and finally concentrate to 1/9 volume. At this time, calcium salts such as calcium sulfate and calcium carbonate are deposited. This is filtered to obtain primary brine.
(Secondary concentration process)
Next, this primary brine is subjected to secondary concentration at a heating temperature of 110 ° C. 750 liters of primary brine is charged into the secondary evaporation kettle and concentrated by heating. Here, about 50 kg of sea salt and about 580 liters of secondary brine are obtained. Of this, 80 liters of secondary brine is once stored in the filtrate storage tank. Add 750 liters of 250 liters of primary brine to the remaining 500 liters of secondary brine to the secondary evaporation kettle and perform the same concentration to obtain about 50 kg of sea salt for the second time and about 580 liters of secondary brine. . Further, the same operation is performed. Such a concentration step is repeatedly performed. Here, about 50 kg of sea salt obtained at the third concentration and sea salt obtained thereafter are the target sea salt.
(Tertiary concentration process)
Next, 100 kg of the secondary brine stored in the filtrate storage tank is put into a tertiary evaporating kettle and subjected to tertiary concentration at a heating temperature of 113 ° C. When concentrated to 7/10 volume, it is filtered to obtain the desired natural bitter juice with high bitter juice purity.

  Table 1 shows the weight (g) of each ion contained in 100 g of sea salt obtained in the examples. Here, the data for six treatments in the secondary evaporation kettle are shown.

  In addition, Table 2 shows each ion weight (g) contained in 100 g of natural bitter juice obtained in the examples. Here, data for four treatments in the tertiary evaporating pot are shown.

  Mineral components to be analyzed were only three components of sodium, magnesium and potassium.

  As shown in Table 1, in sea salt, it was confirmed that the mineral composition was stabilized every time the treatment was performed. Almost stable after the third treatment.

  As shown in Table 2, in bitter juice, it was confirmed that the mineral composition was always stable as long as the results of four treatments were observed.

Claims (3)

In a method of efficiently producing sea salt and bitter juice without using an ion exchange membrane by continuously using a primary evaporating kettle, a secondary evaporating kettle, and a tertiary evaporating kettle in the step of heating and concentrating seawater, The primary brine obtained in the evaporating kettle is concentrated in the secondary evaporating kettle under a temperature control of 100 to 115 ° C., and when concentrated to 6/10 to 9/10 volume, sea salt and secondary brine are After adding 40-60% by volume primary brine to the secondary brine and concentrating under the same conditions, and performing this operation for 3 cycles or more, obtain secondary brine. Features.   The method for efficiently producing sea salt and bitter juice according to claim 1, wherein in the primary evaporation kettle, first, sea water is concentrated to 1/8 to 1/11 volume and filtered.   The secondary brine obtained in the secondary evaporating kettle is concentrated under a temperature control of 100 to 115 ° C. in the tertiary evaporating kettle and filtered when it is concentrated to 3/5 to 4/5 volume. A method for efficiently producing sea salt and bitter juice according to claim 1.