CN110437864A - A kind of wood vinegar efficiently separates technique - Google Patents

Abstract

A high-efficiency separation process of wood vinegar, which relates to a wood vinegar separation process. The top of the wood vinegar crude distillation tower undergoes primary condensation and secondary condensation to obtain light components, and the lower part of the primary condensation is provided with a return pipe to remove heavy components. Reflux back to the crude distillation tower; the multi-component distillate from the middle part of the wood vinegar crude distillation tower enters the acetic acid delightening tower, distills the light components from the top of the tower, and the heavy components at the bottom of the tower enter the acetic acid deweighting tower for further separation of each group Divide; The present invention adopts a crude fractionation rectification tower with a plurality of side line extraction outlets to cut and separate wood vinegar stock solution into several liquids with completely different characteristics with the lowest energy. Then through the solvent regeneration tower to realize the regeneration of the solvent and obtain the target product with higher purity, the present invention can obtain the wood vinegar distillate with rich variety and higher quality.

Description

A kind of high-efficiency separation process of wood vinegar

technical field

The invention relates to a process for separating wood vinegar, in particular to a process for efficiently separating wood vinegar.

Background technique

Carbonizing crop stalks, fruit core shells, and some branches to produce organic fertilizers is a work of national strategic importance. But this work is also difficult to carry out smoothly at present, and its topmost reason is exactly must spray a large amount of water to carbonization process in this process, therefore produced a large amount of wood vinegar. And there is no practical means to utilize and process wood vinegar to realize its high-efficiency resource utilization.

Wood vinegar contains organic matter with a very wide molecular weight distribution, and the number of carbon atoms of these organic matter can vary from one to dozens. This results in a wide range of physical and chemical properties of these organics. At the same time, except for a few organic substances with a slightly higher concentration, such as methanol up to 2% to 5%, and acetic acid up to 10% to 15%, the concentration of most other organic substances is very low, often less than 1%. The total organic matter content in wood vinegar can vary in a large range, such as from about 15% to 30%, and the others are water. It is very difficult to separate such a low-concentration aqueous solution containing very widely distributed organic matter using conventional low-cost technical methods.

Wood vinegar has been developed for many purposes, such as insecticides for crops, herbicides, sterilization and deodorization for poultry farming, and so on. Yet because the contained organic matter concentration of wood vinegar is too low, water content is too high, causes its economic value to be lower, popularization and application is difficult. If the place where the wood vinegar is used is a little far from the place where it is produced, the shipping cost of the wood vinegar can easily exceed the value of the wood vinegar itself.

Wood vinegar contains many extremely valuable organic substances, which are often difficult to obtain through normal chemical processes. And when these extremely valuable organic matter exists in wood vinegar with very low concentration, also make them can't be utilized at all.

To sum up, if we want to carbonize crop stalks, fruit core shells, and some branches to produce organic fertilizers, we must effectively process and utilize a large amount of wood vinegar produced in this process. To efficiently process and utilize a large amount of wood vinegar that this process produces, it is necessary to concentrate the wood vinegar in a very economical way and extract the organic compound components that people need. And a large amount of water obtained in the concentrated process of wood vinegar must be effectively purified so that it can be recycled.

So far, people have developed many technologies to process wood vinegar. However, most of them simply distill or rectify wood vinegar to remove wood glue and other dirty substances in wood vinegar, so as to achieve the purpose of purifying wood vinegar (a kind of wood vinegar refining equipment, application publication number CN 104650939 A; a wood vinegar distillation device, application number 201910128153.7; wood vinegar refining and separation device, application publication number CN 106811225 A; wood vinegar distillation device and distillation method, application publication number CN 106823436 A). Only a small number of pretreated wood vinegars are used for other purposes. For example, there is a patent (a method for efficiently extracting phenolic extracts from wood vinegar, application number: application number 201710543474.4) to extract organic phenols from wood vinegar by extraction . There is also a patent (an application of wood vinegar in the preparation of fuel oil, authorized announcement number CN 101962562 B) intending to use wood vinegar to produce biofuels. The patent (a combination of enzymolysis-distillation-adsorption for refining wood vinegar, application publication number CN 105441101 A) uses enzymolysis-distillation-adsorption combined method to refine wood vinegar to obtain some special liquids for special occasions . These processes are all based on the wood vinegar with very low organic matter concentration after simple distillation or rectification purification, and the efficiency is very low, so it is difficult to popularize and apply.

Contents of the invention

The object of the present invention is to provide a kind of high-efficiency separation process of wood vinegar. The present invention adopts a crude fractionation rectification tower with a plurality of side-line extraction outlets to cut and separate the stock solution of wood vinegar into several strands with the lowest energy. Liquids with different characteristics. The light component from the top of the crude fractionation tower is collected through primary condensation and secondary condensation, and the heavy component stream at the bottom of the tower enters the extraction tower to separate the effective components in the wood vinegar, and then passes through the solvent regeneration tower to realize solvent recovery. By regenerating and obtaining the target product with higher purity, the present invention can obtain wood vinegar distillate with rich variety and high quality.

The purpose of the present invention is achieved through the following technical solutions:

A high-efficiency separation process for wood vinegar, the device of the process includes a crude distillation tower for wood vinegar, an acetic acid delightening tower, an acetic acid deweighting tower, an extraction tower, a solvent regeneration tower, and a crude distillation tower condensing device;

Including the following process:

The top of the wood vinegar crude distillation tower undergoes primary condensation and secondary condensation to obtain light components, and the lower part of the primary condensation is provided with a reflux pipe to return the heavy components to the crude distillation tower; The fractional distillate enters the acetic acid de-lightening tower, distills light components from the top of the tower, and the heavy components at the bottom of the tower enter the acetic acid de-weighting tower to further separate components; the upper part of the acetic acid de-weighting tower is purified acetic acid, and the lower part is Heavy components; the heavy components in the crude distillation tower of wood vinegar go from the bottom of the tower to the extraction tower, and the crude distillation tower of wood vinegar cuts and separates the raw liquid of wood vinegar into several liquids with completely different characteristics with low energy consumption, containing effective The rich solvent of the components comes out from the top of the tower; the heavy components in the wood vinegar crude distillation tower go to the bottom of the tower, the heaviest components are obtained at the bottom of the tower, and the lightest components are obtained at the top of the tower, while the middle side line, the number of side lines If it is greater than or equal to 1, fractions with different boiling point ranges are obtained; the components from the top of the extraction tower enter the solvent regeneration tower for separation of useful components and solvents, thereby obtaining fresh solvents and target products.

In the high-efficiency separation process of wood vinegar, the upper and lower sides of the feed port of the wood vinegar crude distillation tower are provided with side-line extraction outlets, and there are one or more side-line extraction outlets.

According to the high-efficiency separation process of wood vinegar, the crude distillation column of wood vinegar is operated under negative pressure, or under normal pressure and slightly positive pressure.

In the high-efficiency separation process of wood vinegar, the operating temperature of the wood vinegar crude distillation tower, that is, the tower top/bottom temperature, and the operating pressure of the tower, the tower top/bottom products are in a state of thermodynamic equilibrium.

In the high-efficiency separation process of wood vinegar, the temperature of the crude distillation tower for wood vinegar is between 120°C and 280°C, depending on the operating pressure of the tower and the composition of the bottom product.

Advantage and effect of the present invention are:

The invention provides a high-efficiency separation process for obtaining useful components of wood vinegar. The most critical of the present invention is exactly that the first step adopts a crude fractionation rectification tower with a plurality of side line extraction outlets to cut and separate the stock solution of wood vinegar into several liquids with completely different characteristics with the lowest energy. The upper and lower sides of the feed inlet of the tower are provided with side-line extraction outlets, and these side-line extraction outlets may be one or multiple. After the wood vinegar stock solution is sent into this tower, the heavy components go to the bottom of the tower, the heaviest components are obtained at the bottom of the tower, the lightest components are obtained at the top of the tower, and fractions of different boiling point ranges are obtained from the middle side line. The light component from the top of the crude fractionation tower is collected through primary condensation and secondary condensation, and the heavy component stream at the bottom of the tower enters the extraction tower to separate the effective components in the wood vinegar, and then passes through the solvent regeneration tower to realize solvent recovery. By regenerating and obtaining the target product with higher purity, the present invention can obtain wood vinegar distillate with rich variety and high quality.

Description of drawings

Figure 1 is a schematic diagram of the overall process route of the present invention.

Detailed ways

The present invention will be described in detail below in conjunction with the embodiments shown in the accompanying drawings.

In order to achieve large-scale, low-cost processing of wood vinegar, the present invention adopts a set of continuously operated rectification-adsorption-extraction process, including wood vinegar crude distillation tower, acetic acid light removal tower, acetic acid weight removal tower, extraction Tower, solvent regeneration tower, five main towers and the condensation process at the top of the crude distillation tower. Wherein the most critical is that the first step adopts a rectifying tower with multiple side draws to cut and separate the stock solution of wood vinegar into several liquids with completely different characteristics with the lowest energy. Here we call it the crude fractionator.

Figure 1 of the present invention is a schematic process flow diagram. Side line extraction outlets are arranged above and below the feed port of wood vinegar crude distillation tower C1, and these side line extraction outlets may be one or multiple. After the wood vinegar stock solution is sent into this tower, the heavy components go to the bottom of the tower, the heaviest components are obtained at the bottom of the tower, the lightest components are obtained at the top of the tower, and fractions of different boiling point ranges are obtained from the middle side line.

Now take a process of extracting acetic acid and removing water to illustrate.

Contain about 10% acetic acid in wood vinegar, about 80% water, and others are various organic compounds with extremely wide molecular weight distribution and extremely wide boiling point distribution. After the wood vinegar is sent to the crude fractionation tower C1, by properly controlling the operating pressure and the bottom temperature of the crude fractionation tower, most of the acetic acid (more than 95%) can be distilled out from the bottom of the tower. In the stripping section of the crude fractionation tower (between the feed port and the bottom of the tower), a side line extraction outlet can be set up to obtain a stream mainly composed of acetic acid, and then send this stream to the refining device for acetic acid, such as this By inventing the acetic acid delightening tower C2 and the acetic acid delightening tower C3 in Fig. 1, high-purity refined acetic acid can be obtained.

The boiling point of acetic acid is 117.9 degrees. A side collection port is set between the inlet of the crude fractionation tower and the bottom of the tower (called the stripping section) to obtain materials mainly composed of acetic acid, and the remaining materials at the bottom of the tower must be heavy components with a higher boiling point than acetic acid. Most of the water and the organic matter with a lower boiling point than water must move above the feed inlet. Some organic substances, such as phenol, have a high boiling point (182 degrees for phenol), but they can form azeotropes with a lower boiling point (less than 100 degrees) with water. These azeotropes are also distilled above the feed inlet of the crude fractionation column.

Since the heavy components at the bottom of the tower may coke when the temperature is too high, some may even decompose. At the same time, in this heavy component stream, the concentration of solid impurities is relatively high. Therefore, if the heavy component stream at the bottom of the tower is to be further processed and separated to extract the required organic compounds, the liquid/liquid extraction process should be given priority, as shown in C4 and C5 towers in Figure 1.

Most of the water above the feed inlet is water, and a small part is light components and organic matter that form low-boiling azeotropes with water. A component stream mainly composed of water (water content up to 90%) can be obtained by setting a sideline collection outlet from the feed inlet to the top of the crude fractionation tower (referred to as the rectification section). Since the relatively large amount of acetic acid has been completely extracted from the stripping section, this water is close to neutral (pH value is around 7), so it can be recycled back to the system for use.

After passing through the side extraction port of the rectification section of the crude fractionation tower, what can go on to the top of the tower is mainly light components with a lower boiling point than water and a part of water. This part of the material is evaporated out of the top of the tower in the vapor phase and then condensed into a liquid phase, part of it is sent back to the crude fractionation tower to form a reflux, and the other part is extracted as a product. In order to obtain the most concentrated stream of light components, a two-stage or multi-stage condenser should be installed at the top of the tower. The first-stage condenser (A1) naturally cools the water-based stream. Part of this stream is sent back to the crude fractionation tower to form a reflux, and part of it is withdrawn as a product. The liquid cooled in the secondary condenser (or the condenser after the secondary stage, A2) is an aqueous solution with a high concentration of light components.

To sum up, multiple side extraction outlets can be set up and down the feed inlet of the crude fractionation tower (rectification section and stripping section). The side extraction outlets of the rectification section mainly extract fractions with more light components except water, and extract The side extraction port of the distillation section mainly extracts the fraction with more heavy components. These different fractions can be mixed in different proportions to obtain concentrated wood vinegar with different functions to meet the needs of different applications.

The above is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Anyone familiar with the technical field within the technical scope disclosed in the present invention, according to the technical solution of the present invention Any equivalent replacement or change of the inventive concepts thereof shall fall within the protection scope of the present invention.

Claims (5)

1. a kind of wood vinegar efficient separation process, it is characterized in that, the device of described technology comprises wood vinegar crude distillation tower, acetic acid delightening tower, acetic acid deweighting tower, extraction tower, solvent regeneration tower and crude distillation tower condensing device; Including the following process: The top of the wood vinegar crude distillation tower undergoes primary condensation and secondary condensation to obtain light components, and the lower part of the primary condensation is provided with a reflux pipe to return the heavy components to the crude distillation tower; The fractional distillate enters the acetic acid de-lightening tower, distills light components from the top of the tower, and the heavy components at the bottom of the tower enter the acetic acid de-weighting tower to further separate components; the upper part of the acetic acid de-weighting tower is purified acetic acid, and the lower part is Heavy components; the heavy components in the crude distillation tower of wood vinegar go from the bottom of the tower to the extraction tower, and the crude distillation tower of wood vinegar cuts and separates the raw liquid of wood vinegar into several liquids with completely different characteristics with low energy consumption, containing effective The rich solvent of the components comes out from the top of the tower; the heavy components in the wood vinegar crude distillation tower go to the bottom of the tower, the heaviest components are obtained at the bottom of the tower, and the lightest components are obtained at the top of the tower, while the middle side line, the number of side lines If it is greater than or equal to 1, fractions with different boiling point ranges are obtained; the components from the top of the extraction tower enter the solvent regeneration tower for separation of useful components and solvents, thereby obtaining fresh solvents and target products. 2. a kind of wood vinegar efficient separation process according to claim 1, is characterized in that, the upper and lower sides of the feed port of the wood vinegar crude distillation tower are provided with side line extraction outlets, and these side line extraction outlets are one or more . 3. a kind of wood vinegar efficient separation process according to claim 1, is characterized in that, described wood vinegar crude distillation column operates under negative pressure, or operates under normal pressure and slight positive pressure. 4. a kind of wood vinegar efficient separation process according to claim 1, is characterized in that, described wood vinegar crude distillation tower operating temperature, i.e. tower top/bottom temperature, and under the operating pressure of tower, tower top / The bottom product is in thermodynamic equilibrium. 5. a kind of wood vinegar efficient separation process according to claim 4, is characterized in that, described wood vinegar crude distillation column still temperature is between 120 degree to 280 degree, depending on the operating pressure of tower and the bottom product Composition depends.