CN111495192A

CN111495192A - Concentration method for extracting nicotine condensate by steam distillation

Info

Publication number: CN111495192A
Application number: CN202010519812.2A
Authority: CN
Inventors: 孙旭海; 于开平; 张朋
Original assignee: China Tobacco Yunnan Reconstituted Tobacco Co Ltd
Current assignee: China Tobacco Yunnan Reconstituted Tobacco Co Ltd
Priority date: 2020-06-09
Filing date: 2020-06-09
Publication date: 2020-08-07

Abstract

The invention relates to a concentration method for extracting nicotine condensate by a steam distillation method, belonging to the technical field of nicotine extraction and concentration and comprising the following steps: naturally cooling the nicotine condensate to below 35 ℃, carrying out microfiltration firstly, removing part of substances with larger particle sizes, then filtering by adopting a nanofiltration membrane, taking the permeate as a distillation section extraction solvent for recycling, and taking the target substance contained in the retentate as an extraction stock solution of the next section. The process is simple to operate and convenient to clean; the temperature rise is small, the phase change of water does not exist, and energy is saved; the concentration of the target product is improved by 8-10 times after concentration.

Description

Concentration method for extracting nicotine condensate by steam distillation

Technical Field

The invention belongs to the technical field of nicotine concentration in a tobacco processing process, and particularly relates to a concentration process for extracting nicotine condensate by a steam distillation method.

Background

The nicotine is mainly from tobacco plants, accounts for 1-3% of the tobacco plants, has wider use value, and is mainly used for disinsection, medicine and cigarette essence and spice. The nicotine extraction technology is more, and mainly comprises a steam distillation method, a solvent extraction method, a carbonization and decarboxylation (dry distillation) sulfuric acid absorption method, a supercritical fluid extraction method and the like, wherein the steam distillation method is simple in process flow and convenient to operate, and low in efficiency due to the fact that a large amount of dehydration work exists.

In the distilled nicotine condensate, the nicotine content is low, generally between 0.2 and 0.5, the conventional evaporation and concentration are adopted, the water evaporation capacity is large, the time is long, higher energy is consumed, the production cost is high, and the process is gradually eliminated in industrial production.

Disclosure of Invention

The invention aims to solve the technical problem of providing a concentration method for extracting nicotine condensate by a steam distillation method, which has the advantages of simple process flow, low cost and high efficiency.

In order to achieve the purpose, the invention adopts the technical scheme that: a method for concentrating nicotine condensate by steam distillation comprises the following steps (as shown in figure 1):

(1) pretreatment: primarily cooling the nicotine condensate extracted by the steam distillation method to below 35 ℃ to obtain stock solution;

(2) and (3) microfiltration: pumping the stock solution into a microfiltration membrane connected in parallel, removing large-particle-size impurities carried by steam distillation, and allowing the microfiltered stock solution to enter a buffer pool to obtain a purified solution;

(3) nanofiltration and concentration: the liquid level of the buffer pool is always higher than that of the circulating pool, purified liquid flows into the circulating pool by utilizing potential energy difference, then the liquid in the circulating pool is pumped into the nanofiltration membranes connected in parallel, the liquid positively penetrates through the nanofiltration membranes under the action of pressure as driving force, such as water molecules with small molecular weight penetrate through the nanofiltration membranes under the action of pressure to form penetrating liquid, and molecules with large relative molecular weight, such as nicotine molecules, cannot pass through the membranes to be intercepted, so as to form trapped liquid; opening a trapped liquid switch to enable the trapped liquid switch to flow back to the circulating pool to be mixed with newly inflowing purified liquid, adjusting the outflow speed of the buffer pool to ensure that the liquid is at a required liquid level, circularly concentrating, increasing the liquid concentration of the circulating pool along with the lapse of time, correspondingly increasing the temperature, reducing the aperture due to membrane thermal expansion, adjusting the increased pressure difference, increasing the flux of the permeation liquid, and enabling the pressure difference of an inlet and an outlet not to be more than 1.0 Mpa; when the inlet pressure reaches 1.5-1.6Mpa and the outlet pressure reaches 2.3Mpa, closing the liquid inlet valve (buffer tank valve and trapped liquid valve) of the circulation tank, turning the trapped liquid valve to the outlet direction of the concentrated solution, and discharging the trapped liquid to obtain the concentrated solution; closing membrane equipment when the liquid in the circulating pool reaches a low liquid level, cleaning the membrane, flushing the membrane by using tap water, circularly cleaning the membrane by using organic acid, and finally cleaning the membrane by using the tap water until the pH value of outlet water is the same as that of the tap water, and finishing cleaning;

as a preferable mode of the present invention, in the step (2), the pore diameter of the microfiltration membrane is 1000nm, and the filtration temperature is 0 to 100 ℃.

In the preferred mode of the invention, in the step (3), the pore diameter of the nanofiltration membrane is 0.5-2nm, and the concentration temperature during filtration is 15-40 ℃.

In the invention, the permeate can be directly returned to the previous working section to be used as leaching liquor, and the whole process generates less sewage for cleaning membrane equipment.

The beneficial technical effects of the invention are as follows: according to the technical scheme, the nicotine condensate is naturally cooled to 35 ℃, microfiltration is firstly carried out, a part of substances with larger particle sizes are removed, a nanofiltration membrane is adopted for filtering, the permeation solution is used as the distillation section extraction solvent for recycling, and the trapped solution contains target substances and is used as the next section extraction stock solution. The process is simple to operate and convenient to clean; the temperature rise is small, the phase change of water does not exist, and energy is saved; the concentration of the target product is improved by 8-10 times after concentration. .

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

FIG. 1 is a process flow diagram of the concentration process of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in 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.

Example 1

(1) Naturally cooling the nicotine condensate to 35 ℃, and measuring the nicotine content to be 0.30%;

(2) microfiltering the raw liquid obtained in the step (2.1) in the step (1) to obtain raw liquid, and feeding the raw liquid into a circulating pool, wherein the aperture is 1000 nm;

(3) nano-filtering and concentrating, adjusting the size of an outlet valve, keeping the pressure difference at 1.0Mpa, stopping filtering when the outlet pressure is 2.3Mpa to obtain concentrated solution, detecting the nicotine content at 3.08%, permeating the solution, detecting the nicotine content at 0.02%, and returning to the previous working section to be used as leaching liquor;

(4) cleaning the membrane, namely cleaning membrane equipment by adopting citric acid with the concentration of 1.5%; the concentration ratio of the concentrated solution obtained in the process is 10.27 times.

Example 2

(1) Naturally cooling the nicotine condensate to 30 ℃, and measuring the nicotine content to be 0.23%;

(3) nano-filtering and concentrating, adjusting the size of an outlet valve, keeping the pressure difference at 0.8Mpa, stopping filtering when the outlet pressure is 2.3Mpa to obtain concentrated solution, detecting the nicotine content at 2.04%, permeating the solution, detecting the nicotine content at 0.03%, and returning to the previous working section to be used as leaching liquor;

(4) cleaning the membrane, namely cleaning membrane equipment by adopting citric acid with the concentration of 2.0 percent; the concentration ratio of the concentrated solution obtained in the process is 8.87 times.

Example 3

(1) Naturally cooling the nicotine condensate to 25 ℃, and measuring the nicotine content to be 0.42%;

(3) nano-filtering and concentrating, adjusting the size of an outlet valve, keeping the pressure difference at 0.6Mpa, stopping filtering when the outlet pressure is 2.3Mpa to obtain a concentrated solution, detecting the nicotine content at 3.94%, permeating the solution, detecting the nicotine content at 0.03%, and returning to the previous working section to be used as a leaching solution;

(4) cleaning the membrane, namely cleaning membrane equipment by adopting citric acid with the concentration of 2.5 percent; the concentration ratio of the concentrated solution obtained in the process is 9.38 times.

It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the prior art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

Those of ordinary skill in the art will understand that: the components in the devices in the embodiments may be distributed in the devices in the embodiments according to the description of the embodiments, or may be correspondingly changed in one or more devices different from the embodiments. The components of the above embodiments may be combined into one component, or may be further divided into a plurality of sub-components.

Finally, it should be noted that: although the present invention has been described in detail with reference to the above embodiments, it should be understood by those skilled in the art that: modifications and equivalents may be made thereto without departing from the spirit and scope of the invention and it is intended to cover in the claims the invention as defined in the appended claims.

Claims

1. A concentration method for extracting nicotine condensate by a steam distillation method is characterized by comprising the following steps:

(1) pretreatment: preliminarily cooling the nicotine condensate to below 35 ℃ to obtain stock solution;

(2) and (3) microfiltration: pumping the stock solution into a microfiltration membrane, removing large-particle-size impurities carried by steam distillation, and allowing the microfiltered stock solution to enter a buffer pool to obtain a purified solution;

(3) nanofiltration and concentration: the purified liquid flows into a circulating pool at a potential energy difference, then liquid in the circulating pool is pumped into a nanofiltration membrane, a pressure valve at an outlet of the concentrated liquid is adjusted to ensure that the pressure difference at the inlet and the outlet is not more than 1.0Mpa, and when the pressure at the outlet reaches 2.3Mpa, the filtration is stopped to obtain the concentrated liquid and the permeate liquid;

(4) cleaning the membrane: and (3) cleaning the membrane once by using tap water, circularly cleaning the membrane by using organic acid, and finally cleaning the membrane by using the tap water until the pH value of outlet water is the same as that of the tap water, and finishing cleaning.

2. The concentration method according to claim 1, wherein in the step (2), the pore size of the microfiltration membrane is 1000 nm.

3. The concentration method according to claim 1, wherein in the step (3), the nanofiltration membrane has a pore size of 0.5 to 2 nm.