阅读说明：本技术 一种复分解生产小苏打的工艺方法 (Process for producing sodium bicarbonate by double decomposition ) 是由 滕隆 廖义军 王昱帅 于 2021-11-18 设计创作，主要内容包括：一种复分解生产小苏打的工艺方法,涉及小苏打生产技术领域,其(一)将卤水溶液和碳酸氢铵加入反应塔的上部,充分混合,搅拌,并过滤,得到过滤物；(二)所述过滤物在反应塔中往下落,与反应塔下部通入的二氧化碳气体逆流进行反应,并由反应塔底部生成小苏打晶浆；(三)将步骤(二)得到的小苏打晶浆进行固液分离；(四)步骤(二)中的一部分二氧化碳气体混合氨气并从反应塔(1)的塔顶排出后,通过管道回收至洗涤塔进行冷却、脱氨；(五)将步骤(四)中经过洗涤塔处理后的二氧化碳通入二氧化碳压缩机中,升压后返回到步骤(二)。本发明可回收利用反应塔排放出去的CO-(2)气体,节约资源。(A process method for producing baking soda by double decomposition relates to the technical field of baking soda production, and comprises the steps of (I) adding brine solution and ammonium bicarbonate into the upper part of a reaction tower, fully mixing, stirring and filtering to obtain a filtrate; (II) the filtrate falls down in the reaction tower, and reacts with the carbon dioxide gas introduced from the lower part of the reaction tower in a countercurrent manner, and baking soda crystal slurry is generated from the bottom of the reaction tower; thirdly, carrying out solid-liquid separation on the baking soda crystal slurry obtained in the second step; fourthly, mixing a part of carbon dioxide gas in the step II with ammonia gas, discharging the mixture from the top of the reaction tower (1), and recovering the mixture to a washing tower through a pipeline for cooling and deamination; and (V) introducing the carbon dioxide treated by the washing tower in the step (IV) into a carbon dioxide compressor, and returning to the step (II) after boosting. The invention can recycle CO discharged from the reaction tower 2 Gas and resource saving.)

1. A process for producing baking soda by double decomposition is characterized by comprising the following steps:

adding brine solution and ammonium bicarbonate into the upper part of a reaction tower (1), fully mixing, stirring and filtering to obtain a filtrate;

(II) the filtrate falls down in the reaction tower (1), and reacts with the carbon dioxide gas introduced from the lower part of the reaction tower (1) in a countercurrent way, and baking soda crystal slurry is generated from the bottom of the reaction tower (1);

thirdly, carrying out solid-liquid separation on the baking soda crystal slurry obtained in the second step;

fourthly, mixing a part of carbon dioxide gas in the second step with ammonia gas, discharging the mixture from the top of the reaction tower (1), and recycling the mixture to a washing tower (2) through a pipeline for cooling and deamination;

and (V) introducing the carbon dioxide treated by the washing tower (2) in the step (IV) into a carbon dioxide compressor (3), boosting the pressure and returning to the step (II).

2. A process for the production of baking soda from metathesis as claimed in claim 1, characterized in that: in the fourth step, the washing liquid is drawn from the bottom of the washing tower by the washing liquid circulation pump (4) and sent to the top of the washing tower (2).

3. A process for the production of baking soda from metathesis as claimed in claim 2, characterized in that: in the third step, the baking soda crystal slurry is conveyed from the bottom of the reaction tower (1) to a thickener by a material pumping pump (5) for solid-liquid separation.

Technical Field

The invention relates to the technical field, in particular to a technical method for producing baking soda by double decomposition.

Background

Baking soda is the commercial name for refined sodium bicarbonate and is an important alkali product. Baking soda is widely used in the food industry as a bulking or expanding agent for the production of various biscuit, bread and confectionery products; a generating agent for carbon dioxide in carbonated drinks and a preservative for butter; the cleaning agent is used for cleaning surfaces of airplanes, circuit boards, teeth and the like; are used in medicine for the manufacture of various drugs and medicaments. It is also widely used in the industries of ore dressing, smelting, metal heat treatment, tanning, dye, fiber, rubber, foamed plastic, metal sodium manufacture, detergent, personal care products, foam extinguishing agent, dry powder extinguishing agent and the like.

The production methods of baking soda are mainly divided into two methods: one is to prepare sodium bicarbonate by double decomposition of natural bittern and ammonium bicarbonate, and the other is to prepare sodium bicarbonate by carbonation of sodium carbonate solution. The process of preparing baking soda by the double decomposition method comprises the working procedures of brine refining, double decomposition reaction, filtering and washing of baking soda, drying and packaging of baking soda, deamination of baking soda filtrate, salt preparation by evaporation, ammonium chloride preparation by cooling and the like. During the metathesis reaction, CO₂The gas is needed for reaction, one part of the gas is absorbed, the other part of the gas is mixed with ammonia gas and is discharged from the top of the reaction tower as tail gas, certain waste is caused, and certain cost is consumed for tail gas treatment.

Disclosure of Invention

The invention aims to provide a process method for producing baking soda by double decomposition so as to recycle CO discharged by a reaction tower₂Gas and resource saving.

In order to solve the technical problems, the invention adopts the following technical scheme: a process for the production of baking soda by metathesis, which comprises the following steps:

adding brine solution and ammonium bicarbonate into the upper part of a reaction tower, fully mixing, stirring and filtering to obtain a filtrate.

And (II) the filtrate falls down in the reaction tower, and reacts with the carbon dioxide gas introduced from the lower part of the reaction tower in a countercurrent manner, and baking soda crystal slurry is generated from the bottom of the reaction tower.

And (III) carrying out solid-liquid separation on the baking soda crystal slurry obtained in the step (II).

And (IV) mixing a part of the carbon dioxide gas in the step (II) with ammonia gas, discharging the mixture from the top of the reaction tower (1), and then recovering the mixture to a washing tower through a pipeline for cooling and deamination.

And (V) introducing the carbon dioxide treated by the washing tower in the step (IV) into a carbon dioxide compressor, and returning to the step (II) after boosting.

Preferably, in step (iv), the washing liquid is withdrawn from the bottom of the washing column by a washing liquid circulation pump and transferred to the top of the washing column.

More preferably, in the step (three), the baking soda crystal slurry is conveyed to a thickener from the bottom of the reaction tower through a material pumping pump for solid-liquid separation.

The invention has the beneficial effects that: the carbon dioxide discharged from the reaction tower is recycled and deaminated, and then the pressure of the carbon dioxide compressor is increased to return the carbon dioxide to the lower part of the reaction tower for continuous reaction, so that the recycling of the carbon dioxide is realized, and the resources are saved to a great extent.

Drawings

Fig. 1 is a schematic view of a flow structure in an embodiment of the present invention.

The reference signs are:

1-reaction tower 2-washing tower 3-carbon dioxide compressor

4-washing liquid circulating pump 5-material-beating pump.

Detailed Description

In order to facilitate understanding of those skilled in the art, the present invention will be further described with reference to the following examples and drawings, which are not intended to limit the present invention.

It should be noted that, unless otherwise explicitly stated or limited, the terms "mounted," "connected," "fixed," and the like are used broadly in the present invention, and may be, for example, fixedly connected, detachably connected, or integrally connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

Further, in the present invention, unless otherwise expressly specified or limited, the first feature "on" or "under" the second feature may comprise the first and second features being in direct contact, or may comprise the first and second features being in contact, not in direct contact, but via another feature in between. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature. The terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like, indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience in describing and simplifying the description, but do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the invention.

As shown in fig. 1, a process for producing baking soda by metathesis comprises the following steps:

adding brine solution and ammonium bicarbonate into the upper part of the reaction tower 1, fully mixing, stirring and filtering to obtain filtrate.

And (II) enabling the filtrate to fall down in the reaction tower 1, carrying out counter-current reaction with carbon dioxide gas introduced from the lower part of the reaction tower 1, and generating baking soda crystal slurry from the bottom of the reaction tower 1.

And (III) carrying out solid-liquid separation on the baking soda crystal slurry obtained in the step (II).

And (IV) mixing a part of the carbon dioxide gas in the step (II) with ammonia gas, discharging the mixture from the top of the reaction tower 1, and then recovering the mixture to a washing tower 2 through a pipeline for cooling and deamination.

And (V) introducing the carbon dioxide treated by the washing tower 2 in the step (IV) into a carbon dioxide compressor 3, boosting the pressure and returning to the step (II).

In the process of producing baking soda by double decomposition provided by the embodiment, in the practical application process, the brine solution and the ammonium bicarbonate are fully mixed and stirred at the upper part of the reaction tower 1, a motor arranged at the top of the reaction tower 1 can be used for connecting a rotating shaft, the rotating shaft extends into the upper part of the reaction tower 1 to drive stirring blades to rotate so as to realize mixing and stirring, the filtering realized after stirring can be realized by arranging a mesh filter plate in the reaction tower 1, fine particle filtered substances passing through the mesh filter plate fall downwards in the reaction tower 1 and can react with carbon dioxide gas introduced at the lower part of the reaction tower 1 in a countercurrent manner, so that baking soda crystal slurry is produced at the bottom of the reaction tower 1, and finally, the obtained baking soda crystal slurry material is subjected to solid-liquid separation so as to obtain the baking soda required by the invention. In the process of producing baking soda by double decomposition, carbon dioxide discharged from the reaction tower 1 is recovered and deaminated, and then the pressure of the carbon dioxide is increased by the carbon dioxide compressor 3 to return to the lower part of the reaction tower 1 for continuous reaction, so that the carbon dioxide is recycled, and resources are saved to a great extent.

Preferably, in the step (four), the washing liquid is extracted from the bottom of the washing tower by the washing liquid circulating pump 4 and is conveyed to the top of the washing tower 2, so that the washing liquid is fully utilized, and the cost is saved.

In the step (one) of this embodiment, a recycled brine inlet may be further provided at the upper part of the reaction tower 1 for allowing the recycled brine to enter the reaction tower 1 for reaction.

In addition, in the step (three), the baking soda crystal slurry can be conveyed to a thickener from the bottom of the reaction tower (1) through a material pumping pump 5 for solid-liquid separation.

The above embodiments are preferred implementations of the present invention, and the present invention can be implemented in other ways without departing from the spirit of the present invention.

Some of the drawings and descriptions of the present invention have been simplified to facilitate the understanding of the improvements over the prior art by those skilled in the art, and some other elements have been omitted from this document for the sake of clarity, and it should be appreciated by those skilled in the art that such omitted elements may also constitute the subject matter of the present invention.