阅读说明：本技术 一种提高水热炭强化厌氧消化产甲烷效率的方法 (Method for improving efficiency of methane production through hydrothermal carbon enhanced anaerobic digestion ) 是由 罗刚 任爽 张士成 于 2021-07-12 设计创作，主要内容包括：本发明提供了一种提高水热炭强化厌氧消化产甲烷效率的方法。通过对水热炭进行球磨改性处理,可提高水热炭强化厌氧消化产甲烷的效率,添加球磨改性水热炭的实验组比添加未改性水热炭实验组的产甲烷速率高出12.5%,达到了未添加水热炭对照组的3.44倍。本方法具体步骤即将生物质通过水热转化制备水热炭,进一步将水热炭采用球磨改性,然后投加有机废弃物/废水厌氧消化产甲烷反应器中即可显著提升产甲烷速率。本方法可有效提高厌氧消化反应器产甲烷速率,提高厌氧消化反应器的稳定性,有利于更有效地将有机废弃物减量和资源化利用。(The invention provides a method for improving the efficiency of methane production by hydrothermal carbon enhanced anaerobic digestion. The ball milling modification treatment is carried out on the hydrothermal carbon, so that the efficiency of methane production by hydrothermal carbon enhanced anaerobic digestion can be improved, and the methane production rate of an experimental group added with the ball milling modified hydrothermal carbon is 12.5% higher than that of an experimental group added with unmodified hydrothermal carbon, and reaches 3.44 times of that of a control group without the hydrothermal carbon. The method specifically comprises the steps of preparing hydrothermal carbon from biomass through hydrothermal conversion, further performing ball milling modification on the hydrothermal carbon, and then adding the hydrothermal carbon into an organic waste/wastewater anaerobic digestion methane production reactor to remarkably improve the methane production rate. The method can effectively improve the methane production rate of the anaerobic digestion reactor, improve the stability of the anaerobic digestion reactor, and is beneficial to more effectively reducing and recycling organic wastes.)

1. A method for improving hydrothermal carbon reinforced anaerobic digestion efficiency is characterized by comprising the following specific steps:

(1) biomass waste is converted into hydrothermal carbon through hydrothermal reaction; washing away biological oil on the surface of the biomass waste by using an organic solvent, drying, and further performing ball milling treatment;

(2) and (2) adding the ball-milling modified hydrothermal carbon obtained in the step (1) into a reactor for producing methane by utilizing anaerobic digestion of organic wastes/wastewater and the like, wherein the methane production rate is increased by over 12.5 percent compared with an experimental group added with non-ball-milling hydrothermal carbon.

2. The method for improving hydrothermal char-enhanced anaerobic digestion efficiency as claimed in claim 1, wherein the biomass waste in step (1) is any one of corn stover, sludge or algae.

3. The method for improving hydrothermal carbon enhanced anaerobic digestion efficiency as claimed in claim 1, wherein the hydrothermal reaction temperature in step (1) is 260 ℃ to 320 ℃, and the reaction time is 1-6 h.

4. The method for improving hydrothermal char-enhanced anaerobic digestion efficiency according to claim 1, wherein the organic solvent in step (1) is any one of alcohol, tetrahydrofuran or dichloromethane.

5. The method for improving hydrothermal carbon enhanced anaerobic digestion efficiency as claimed in claim 1, wherein the ball milling treatment time in step (1) is 4-8 hours, and the rotation speed is 300-.

Technical Field

The invention belongs to the technical field of organic waste resource utilization, and particularly relates to a method for improving the efficiency of methane production by anaerobic digestion of organic wastes.

Background

With the acceleration of the urbanization process in China, the production amount of urban waste is rapidly increased, wherein the organic waste comprises kitchen waste, excrement, excess sludge generated in the sewage treatment process and the like. Anaerobic Digestion (AD) is an ideal organic waste treatment method that can not only reduce the amount of organic waste but also generate methane. However, the anaerobic reactor cannot achieve stable operation due to accumulation of volatile organic acids (VFA) caused by instability of the feeding amount and feeding property. The improvement of the anaerobic digestion rate and the stability has important significance for the effective treatment of organic wastes.

Hydrothermal char (hydrochar) is a solid product produced by the hydrothermal reaction of biomass waste (document Soil Research, 2010, 48: 618-. The hydrothermal conversion Process is generally a Process for obtaining bio-oil, chemicals and hydrothermal char by liquefying organic matter with water as a reaction solvent under subcritical conditions (temperature: 220-. It has been reported that hydrothermal carbon can promote direct electron transfer (DIET) in anaerobic digestion systems to enhance anaerobic digestion and increase methane production rate (Environmental science & technology, 2020: 5755-. The ball milling can increase the specific surface area of the hydrothermal carbon and increase the contact surface of the oxygen-containing functional groups of the hydrothermal carbon (the document ACS Sustainable Chemistry & Engineering, 2017: 9568-. However, no studies have been made on the ball milling of hydrothermal carbon to improve its ability to promote anaerobic digestion.

According to the invention, the hydrothermal carbon to be added into the anaerobic digestion reactor is subjected to ball milling treatment, so that the performance of enhancing anaerobic digestion is improved, the methane production speed is further accelerated, and the anaerobic digestion methane production system can run more stably.

Disclosure of Invention

The invention aims to provide a method for improving hydrothermal carbon reinforced anaerobic digestion efficiency, which increases the abundance of oxygen-containing functional groups exposed on the surface of hydrothermal carbon by ball milling the hydrothermal carbon, improves the capability of mediating direct electron transfer in an anaerobic digestion system, improves the methane production rate, and further improves the treatment efficiency of organic wastes.

The invention provides a method for improving hydrothermal carbon reinforced anaerobic digestion efficiency, which comprises the following specific steps:

(1) biomass waste is converted into hydrothermal carbon through hydrothermal reaction; washing away biological oil on the surface of the biomass waste by using an organic solvent, drying, and further performing ball milling treatment without other pretreatment steps;

(2) and (2) adding the ball-milling modified hydrothermal carbon obtained in the step (1) into a reactor for producing methane by utilizing anaerobic digestion of organic wastes/wastewater and the like, wherein the methane production rate is increased by over 12.5 percent compared with an experimental group added with non-ball-milling hydrothermal carbon.

In the invention, the biomass waste in the step (1) is any one of corn straw, sludge, algae and the like.

In the invention, the hydrothermal reaction temperature in the step (1) is 260 ℃ and 320 ℃, and the reaction time is 1-8 h.

In the present invention, the organic solvent in the step (1) is any one of alcohol, tetrahydrofuran, dichloromethane, or the like.

In the invention, the ball milling treatment time in the step (1) is 4-8 hours, and the rotating speed is 300-.

The invention has the beneficial effects that: according to the invention, the hydrothermal carbon is prepared by taking the biomass waste as the raw material, the hydrothermal carbon is subjected to ball milling, the ball-milled hydrothermal carbon has stronger capability of enhancing anaerobic digestion than the non-ball-milled hydrothermal carbon, and the reduction and the recycling of organic waste can be effectively realized.

Drawings

FIG. 1 illustrates the effect of hydrothermal carbon on anaerobic digestion to produce methane before and after ball milling;

figure 2 example 2 the cumulative methane production in the three reactors.

Detailed Description

The invention is described in more detail below with reference to examples and figures, but the scope of the invention is not limited to these.

Example 1:

(1) adding 300 g of corn straw powder and 2L of water into a 3L high-temperature high-pressure reaction kettle, reacting for 1 hour at 260 ℃ to prepare hydrothermal charcoal, washing soluble organic matters on the surface of the hydrothermal charcoal with alcohol, and drying;

(2) and putting the dried hydrothermal carbon into a planetary ball mill to perform ball milling for 8 hours at the rotating speed of 300 rpm.

(3) Three groups of anaerobic reactors are arranged, the volume of each reactor is 108 mL, 60 mL of glucose solution with the concentration of 4 g/L is filled, the same amount of microorganisms (F/M = 2) are inoculated, the initial pH value in the reactors is adjusted to be 7.5, no water heating carbon is added, 10 g/L of non-ball-milled water heating carbon is added, 10 g/L of ball-milled water heating carbon is added, after nitrogen is blown off to manufacture an anaerobic environment, the three groups of reactors are placed in a reactor at 37 ℃ for anaerobic fermentation, a sampling needle is used for taking a trace gas sample at regular time in the fermentation process, and a gas chromatograph is used for measuring the content of gas components. The cumulative methane production in the three reactors is shown in FIG. 1.

As can be seen from fig. 1, the ball-milled hydrothermal carbon promotes anaerobic digestion to produce methane more efficiently than the untreated hydrothermal carbon.

Example 2:

(1) adding 300 g of corn straw powder and 2L of water into a 3L high-temperature high-pressure reaction kettle, reacting for 8 hours at 260 ℃ to prepare hydrothermal charcoal, washing soluble organic matters on the surface of the hydrothermal charcoal with alcohol, and drying;

(2) and putting the dried hydrothermal carbon into a planetary ball mill to perform ball milling for 8 hours at the rotating speed of 300 rpm.

(3) Three groups of anaerobic reactors are arranged, the volume of each reactor is 108 mL, 60 mL of glucose solution with the concentration of 4 g/L is filled, the same amount of microorganisms (F/M = 2) are inoculated, the initial pH value in the reactors is adjusted to be 7.5, no water heating carbon is added, 10 g/L of non-ball-milled water heating carbon is added, 10 g/L of ball-milled water heating carbon is added, after nitrogen is blown off to manufacture an anaerobic environment, the three groups of reactors are placed in a reactor at 37 ℃ for anaerobic fermentation, a sampling needle is used for taking a trace gas sample at regular time in the fermentation process, and a gas chromatograph is used for measuring the content of gas components. The cumulative methane production in the three reactors is shown in FIG. 2.

As can be seen from fig. 2, the ball-milled hydrothermal carbon promoted the anaerobic digestion to produce methane more efficiently than the untreated hydrothermal carbon.

The embodiments described above are intended to facilitate the understanding and appreciation of the invention by those skilled in the art. It will be readily apparent to those skilled in the art that various modifications to these embodiments may be made, and the generic principles described herein may be applied to other embodiments without the use of the inventive faculty. Therefore, the present invention is not limited to the embodiments described herein, and those skilled in the art should make improvements and modifications to the present invention based on the disclosure of the present invention within the protection scope of the present invention.