1. A pretreatment method before biomass combustion is characterized by comprising the following steps:

1) collecting and collecting biomass raw materials, and recording and measuring to obtain an initial sample;

2) cleaning, drying and crushing the initial sample obtained in the step to obtain a sample to be processed;

3) placing the sample to be treated obtained in the step under a negative pressure condition, adding fatty alcohol-polyoxyethylene ether and an acid solution, vibrating and mixing, and carrying out a heat treatment reaction to obtain a pretreated biomass;

the biomass raw material comprises one or more of peanut shells, rice hulls, wheat straws and wood particles;

the specific steps of collecting and collecting are as follows:

firstly, selecting a sampling point, then collecting at the diagonal of the sampling point, and then shearing and collecting the biomass raw material.

2. The pretreatment method according to claim 1, wherein the collected fraction is 3 to 10;

the size of the sampling points is (0.5-2) m;

the shearing is realized by adopting ceramic scissors.

3. The pre-processing method of claim 1, wherein the recorded content comprises one or more of time, latitude and longitude, climate conditions, and ambient environment;

the determination comprises a physicochemical property determination;

the physical and chemical properties include one or more of moisture content, volatiles, and calorific value.

4. The pretreatment method according to claim 1, wherein the washing comprises washing with distilled water;

the cleaning is to clean the surface of the initial sample;

the drying comprises natural drying;

the drying time is 1-3 weeks.

5. The pretreatment method according to claim 1, wherein the fineness of the crushing is 80 to 200 mesh;

the step of drying is also included after the crushing;

the drying temperature is 105-120 ℃;

the drying time is 2-5 hours.

6. The pretreatment method according to claim 1, wherein the negative pressure is 0.02 to 0.06 MPa;

the vibration mixing mode comprises ultrasonic or oscillation;

the frequency of the ultrasonic wave or the oscillation is 0.5-20 KHz;

the fatty alcohol-polyoxyethylene ether accounts for 0.01-1% of the mass ratio of the sample to be treated;

the mass concentration of the acid solution is 0.1-5%.

7. The pretreatment method of claim 1, wherein the acid comprises one or more of hydrochloric acid, nitric acid, and sulfuric acid;

the mass ratio of the sample to be treated to the acid solution is 1: (100-200);

the heat treatment reaction is carried out in a constant-temperature water bath;

the time of the heat treatment reaction is 2-4 hours;

the temperature of the heat treatment reaction is 60-80 ℃.

8. The pretreatment method according to claim 1, wherein the acid does not use sulfuric acid;

the post-treatment step is also included after the heat treatment reaction;

the post-treatment step comprises a washing step and a drying step again;

the pretreatment method before biomass combustion is specifically a pretreatment method before biomass combustion for biomass recycling.

9. The pretreatment method according to claim 8, wherein the washing step is in particular washing to neutrality;

the drying time is 1-2 hours;

and the temperature for drying again is 105-120 ℃.

Background

With the increasing exhaustion of fossil resources and the strong support of the whole society for energy capable of being circularly developed, in recent years, the technology of biomass energy has received wide attention of various scholars. The biomass energy recycling technology is an effective means for converting biomass into liquid, solid and gas products and realizing efficient utilization of the biomass, and is also one of the most applied biomass. The biomass fuel is fuel produced by burning biomass material, mainly agricultural and forestry waste (such as straw, sawdust, bagasse and rice chaff), and is mainly different from fossil fuel. In the current national policy and environmental standard, direct combustion of biomass is a highly polluting fuel and is therefore to be avoided as much as possible. In the application of biomass fuel, Biomass Molded Fuel (BMF) is a novel clean fuel which is prepared by using agricultural and forestry wastes as raw materials and performing processes such as crushing, mixing, extruding, drying and the like to form various shapes (such as blocks, particles and the like) and can be directly combusted.

The biomass will release PM in the combustion process_2.5Air pollutants such as CO and VOCs have certain influence on regional environment quality, atmospheric visibility, human health and climate change. In recent years, different scholars conduct research of different scales aiming at open-air combustion of biomass, China is used as a global agricultural kingdom, a large amount of straws, peanut shells, rice husks and the like are generated in the process of planting grains, the biomass energy is renewable clean energy, and the biomass energy has the advantages of low ash content, high volatility, high activity and the like, and the content of N and S is very low. However, with the related research and demonstration of biomass energy, the production plant is put into operation, and a plurality of defects are found, such as low heat value and low utilization efficiency of biomass, and a series of problems of corrosion and slag bonding are presented.

At present, the problem of biomass combustion slagging is rarely studied, and biomass slagging control is generally considered from fuel equipment. For boilers mainly using biomass as fuel, slagging is inhibited by adjusting parameters such as pressure, temperature and time of boiler operation. But has the practical problems of complicated process control, high control cost and the like.

Therefore, how to find a suitable way to facilitate the utilization of biomass combustion and reduce the above problems of biomass combustion has become one of the focuses of great attention of many researchers in the field.

Disclosure of Invention

In view of the above, the technical problem to be solved by the present invention is to provide a pretreatment method before biomass combustion, the pretreatment method provided by the present invention can greatly reduce the alkali metal content and heavy metal content in the biomass raw material, thereby reducing the slagging problem in the later biomass combustion process, and the method is simple and easy to implement, mild in condition, good in controllability, and more beneficial to industrial popularization and application.

The invention provides a pretreatment method before biomass combustion, which comprises the following steps:

1) collecting and collecting biomass raw materials, and recording and measuring to obtain an initial sample;

2) cleaning, drying and crushing the initial sample obtained in the step to obtain a sample to be processed;

3) and (3) placing the sample to be treated obtained in the step under a negative pressure condition, adding fatty alcohol-polyoxyethylene ether and an acid solution, vibrating and mixing, and carrying out a heat treatment reaction to obtain the pretreated biomass.

Preferably, the biomass raw material comprises one or more of peanut shells, rice hulls, wheat straws and wood particles;

the specific steps of collecting and collecting are as follows:

firstly, selecting a sampling point, then collecting at the diagonal of the sampling point, and then shearing and collecting the biomass raw material.

Preferably, the collection part is 3-10 parts;

the size of the sampling points is (0.5-2) m;

the shearing is realized by adopting ceramic scissors.

Preferably, the recorded content comprises one or more of time, latitude and longitude, climate conditions and surrounding environment;

the determination comprises a physicochemical property determination;

the physical and chemical properties include one or more of moisture content, volatiles, and calorific value.

Preferably, the washing comprises washing with distilled water;

the cleaning is to clean the surface of the initial sample;

the drying comprises natural drying;

the drying time is 1-3 weeks.

Preferably, the fineness of the crushing is 80-200 meshes;

the step of drying is also included after the crushing;

the drying temperature is 105-120 ℃;

the drying time is 2-5 hours.

Preferably, the negative pressure is 0.02-0.06 MPa;

the vibration mixing mode comprises ultrasonic or oscillation;

the frequency of the ultrasonic wave or the oscillation is 0.5-20 KHz;

the fatty alcohol-polyoxyethylene ether accounts for 0.01-1% of the mass ratio of the sample to be treated;

the mass concentration of the acid solution is 0.1-5%.

Preferably, the acid comprises one or more of hydrochloric acid, nitric acid and sulfuric acid;

the mass ratio of the sample to be treated to the acid solution is 1: (100-200);

the heat treatment reaction is carried out in a constant-temperature water bath;

the time of the heat treatment reaction is 2-4 hours;

the temperature of the heat treatment reaction is 60-80 ℃.

Preferably, the acid does not employ sulfuric acid;

the post-treatment step is also included after the heat treatment reaction;

the post-treatment step comprises a washing step and a drying step again;

the pretreatment method before biomass combustion is specifically a pretreatment method before biomass combustion for biomass recycling.

Preferably, the washing step is specifically washing to neutrality;

the drying time is 1-2 hours;

and the temperature for drying again is 105-120 ℃.

The invention provides a pretreatment method before biomass combustion, which comprises the following steps of firstly collecting and collecting biomass raw materials, and then recording and measuring to obtain an initial sample; then cleaning, drying and crushing the initial sample obtained in the step to obtain a sample to be processed; and finally, placing the sample to be treated obtained in the step under a negative pressure condition, adding fatty alcohol-polyoxyethylene ether and an acid solution, vibrating and mixing, and carrying out a heat treatment reaction to obtain the pretreated biomass. Compared with the prior art, the biomass combustion device aims at the problems of corrosion, slag bonding and the like of the combustion device in the existing biomass combustion process. The existing method for controlling biomass slagging by improving from the perspective of fuel equipment has the practical problems of complex process control, high control cost and the like.

The invention particularly considers from the fuel perspective, and abandons the prior complex and tedious improvement modes which are unfavorable for application, such as adding additives into raw materials, mixing and burning biomass and coal, and the like, and provides a pretreatment method before biomass burning. The pretreatment method provided by the invention is mainly used for improving the slagging phenomenon in the biomass combustion process and the catalyst poisoning condition in the tail gas treatment after combustion by pretreating the raw materials. According to the invention, through specific front and back steps and integration of details, particularly the matching application of negative pressure, vibration (ultrasound), fatty alcohol-polyoxyethylene ether and acid, the heat treatment is carried out under specific conditions, so that the alkali metal content and the heavy metal content in the biomass raw material can be greatly reduced, the slagging problem in the later biomass combustion process is reduced, more importantly, the heavy metals (As, Pb and the like) are removed, the poisoning condition of the denitration catalyst during flue gas treatment is reduced after the biomass is combusted, the use efficiency of the denitration catalyst is improved, and the use cost is reduced. And the method is simple and easy to implement, mild in condition and good in controllability, and is more beneficial to industrial popularization and application.

Experimental results show that the ash content of the straws is reduced after the pretreatment provided by the invention, but the C, O content is not changed greatly, the content of most elements is reduced after acid washing, wherein the Na, Cl and K elements are reduced most obviously, and heavy metal elements are also reduced obviously.

Detailed Description

For a further understanding of the invention, preferred embodiments of the invention are described below in conjunction with the examples, but it should be understood that these descriptions are included merely to further illustrate the features and advantages of the invention and are not intended to limit the invention to the claims.

All of the starting materials of the present invention, without particular limitation as to their source, may be purchased commercially or prepared according to conventional methods well known to those skilled in the art.

All the raw materials of the present invention are not particularly limited in purity, and the present invention preferably employs analytical purification or purity which is conventional in the field of biomass combustion.

The invention provides a pretreatment method before biomass combustion, which comprises the following steps:

1) collecting and collecting biomass raw materials, and recording and measuring to obtain an initial sample;

2) cleaning, drying and crushing the initial sample obtained in the step to obtain a sample to be processed;

3) and (3) placing the sample to be treated obtained in the step under a negative pressure condition, adding fatty alcohol-polyoxyethylene ether and an acid solution, vibrating and mixing, and carrying out a heat treatment reaction to obtain the pretreated biomass.

According to the invention, firstly, the biomass raw material is collected and measured to obtain an initial sample.

The invention is not particularly limited in principle to the type of the biological raw material, and a person skilled in the art can select and adjust the type according to the actual production condition, the combustion requirement and the energy supply requirement, in order to better facilitate the subsequent combustion treatment, reduce the content of alkali metal and heavy metal in the biomass raw material and reduce the slagging condition in the biomass combustion equipment, the biomass raw material preferably comprises one or more of peanut shells, rice hulls, wheat straws and wood particles, and more preferably comprises the peanut shells, the rice hulls, the wheat straws or the wood particles.

The invention is a complete and refined integral preparation process, better facilitates subsequent combustion treatment, reduces the content of alkali metals and heavy metals in biomass raw materials, and reduces the slagging condition in biomass combustion equipment, and the concrete steps of collecting and collecting are preferably as follows:

firstly, selecting a sampling point, then collecting at the diagonal of the sampling point, and then shearing and collecting the biomass raw material.

The collected parts are preferably 3-10 parts, more preferably 4-9 parts, more preferably 5-8 parts, and more preferably 6-7 parts, so that the biomass combustion equipment can be better and conveniently subjected to subsequent combustion treatment, the alkali metal content and the heavy metal content in the biomass raw material can be reduced, and the slagging condition in the biomass combustion equipment can be reduced.

The size of the sampling points is not particularly limited in principle, and can be selected and adjusted by a person skilled in the art according to actual production conditions, combustion requirements and energy supply requirements, the size of the sampling points is preferably (0.5-2) m, more preferably (1.0-1.5) m (0.5-2) m, and even more preferably (0.5-5) m (1.0-1.5) m, in order to better facilitate subsequent combustion treatment, reduce the content of alkali metals and heavy metals in the biomass raw material and reduce the slagging condition in biomass combustion equipment.

The specific mode of the shearing is not particularly limited in principle, and can be selected and adjusted by a person skilled in the art according to the actual production condition, the combustion requirement and the energy supply requirement.

The content requirements of the records are not particularly limited in principle, and can be selected and adjusted by a person skilled in the art according to actual production conditions, combustion requirements and energy supply requirements, the records preferably comprise one or more of time, longitude and latitude, climate conditions and surrounding environments, and more preferably time, longitude and latitude, climate conditions or surrounding environments, so that the subsequent combustion treatment is better facilitated, the alkali metal content and heavy metal content in the biomass raw material are reduced, and the slagging condition in biomass combustion equipment is reduced.

The requirements of the measurement are not particularly limited in principle, and can be selected and adjusted by a person skilled in the art according to actual production conditions, combustion requirements and energy supply requirements.

The content of the physicochemical properties is not particularly limited in principle, and can be selected and adjusted by a person skilled in the art according to the actual production condition, the combustion requirement and the energy supply requirement.

The initial sample obtained in the step is washed, dried and crushed to obtain the sample to be processed.

The specific choice of the cleaning is not particularly limited in principle, and can be selected and adjusted by a person skilled in the art according to actual production conditions, combustion requirements and energy supply requirements.

The specific manner of cleaning is not particularly limited in principle, and can be selected and adjusted by a person skilled in the art according to actual production conditions, combustion requirements and energy supply requirements.

The specific manner of drying is not particularly limited in principle, and can be selected and adjusted by a person skilled in the art according to actual production conditions, combustion requirements and energy supply requirements.

The drying time is not particularly limited in principle, and can be selected and adjusted by a person skilled in the art according to actual production conditions, combustion requirements and energy supply requirements, so that the subsequent combustion treatment is more convenient, the alkali metal content and the heavy metal content in the biomass raw material are reduced, the slagging condition in biomass combustion equipment is reduced, and the drying time is preferably 1-3 weeks, and more preferably 1.5-2.5 weeks.

The fineness of the crushing is not particularly limited in principle, and can be selected and adjusted by a person skilled in the art according to actual production conditions, combustion requirements and energy supply requirements, the fineness of the crushing is preferably 80-200 meshes, more preferably 100-180 meshes, and more preferably 120-160 meshes, so that the subsequent combustion treatment is better facilitated, the alkali metal content and the heavy metal content in the biomass raw material are reduced, and the slag formation condition in biomass combustion equipment is reduced.

The invention is a complete and refined integral preparation process, is better convenient for subsequent combustion treatment, reduces the content of alkali metal and heavy metal in biomass raw materials, reduces the slagging condition in biomass combustion equipment, and preferably comprises a drying step after crushing.

The drying temperature is not particularly limited in principle, and can be selected and adjusted by a person skilled in the art according to actual production conditions, combustion requirements and energy supply requirements, the subsequent combustion treatment is better facilitated, the alkali metal content and the heavy metal content in the biomass raw material are reduced, the slagging condition in biomass combustion equipment is reduced, and the drying temperature is preferably 105-120 ℃, more preferably 108-117 ℃, more preferably 110-115 ℃, and particularly 105 ℃.

The drying time is not particularly limited in principle, and can be selected and adjusted by a person skilled in the art according to actual production conditions, combustion requirements and energy supply requirements, the drying time is preferably 2-5 hours, more preferably 2.5-4.5 hours, more preferably 3-4 hours, and particularly 2 hours, so as to better facilitate subsequent combustion treatment, reduce the content of alkali metals and heavy metals in the biomass raw material, and reduce the slagging condition in biomass combustion equipment.

Finally, placing the sample to be treated obtained in the step under a negative pressure condition, adding fatty alcohol-polyoxyethylene ether and an acid solution, vibrating and mixing, and carrying out a heat treatment reaction to obtain the pretreated biomass.

The specific pressure of the negative pressure is not particularly limited in principle, and can be selected and adjusted by a person skilled in the art according to the actual production condition, the combustion requirement and the energy supply requirement, the negative pressure is preferably 0.02-0.06 MPa, more preferably 0.03-0.05 MPa, and more preferably 0.04-0.05 MPa, so that the subsequent combustion treatment is better facilitated, the alkali metal content and the heavy metal content in the biomass raw material are reduced, and the slagging condition in the biomass combustion equipment is reduced.

The specific time for the standing is not particularly limited in principle, and can be selected and adjusted by a person skilled in the art according to the actual production condition, the combustion requirement and the energy supply requirement, so that the subsequent combustion treatment is more convenient, the alkali metal content and the heavy metal content in the biomass raw material are reduced, and the slagging condition in the biomass combustion equipment is reduced, wherein the standing time is preferably 20-60 min, and more preferably 30-50 min.

The concrete mode of the vibration mixing mode is not particularly limited in principle, and can be selected and adjusted by a person skilled in the art according to the actual production condition, the combustion requirement and the energy supply requirement.

The specific frequency of the ultrasonic or oscillation is not particularly limited in principle, and can be selected and adjusted by a person skilled in the art according to actual production conditions, combustion requirements and energy supply requirements, the subsequent combustion treatment is better facilitated, the alkali metal content and the heavy metal content in the biomass raw material are reduced, the slagging condition in biomass combustion equipment is reduced, and the oscillation frequency is preferably 0.5-20 KHz, more preferably 1-15 KHz, and more preferably 5-10 KHz.

The specific addition amount of the fatty alcohol-polyoxyethylene ether is not particularly limited in principle, and a person skilled in the art can select and adjust the addition amount according to actual production conditions, combustion requirements and energy supply requirements, in order to better facilitate subsequent combustion treatment, reduce the alkali metal content and heavy metal content in biomass raw materials and reduce the slagging condition in biomass combustion equipment, the mass ratio of the fatty alcohol-polyoxyethylene ether to the sample to be treated is preferably 0.01-1%, more preferably 0.05-0.5%, and even more preferably 0.1-0.3%.

The specific selection of the acid is not particularly limited in principle, and can be selected and adjusted by a person skilled in the art according to actual production conditions, combustion requirements and energy supply requirements, and the acid preferably comprises one or more of hydrochloric acid, nitric acid and sulfuric acid, and more preferably hydrochloric acid, nitric acid or sulfuric acid, so as to better facilitate subsequent combustion treatment, reduce the content of alkali metals and heavy metals in the biomass raw material and reduce the slagging condition in biomass combustion equipment.

The mass concentration of the acid solution is not particularly limited in principle, and can be selected and adjusted by a person skilled in the art according to actual production conditions, combustion requirements and energy supply requirements, and the mass concentration of the acid solution is preferably 0.1-0.5%, more preferably 0.15-0.45%, more preferably 0.2-0.4%, and more preferably 0.25-0.35%, in order to better facilitate subsequent combustion treatment, reduce the alkali metal content and heavy metal content in the biomass raw material, and reduce the slagging condition in biomass combustion equipment.

The mass ratio of the sample to be treated and the acid solution is not particularly limited in principle, and can be selected and adjusted by a person skilled in the art according to actual production conditions, combustion requirements and energy supply requirements, so that the subsequent combustion treatment is better facilitated, the alkali metal content and the heavy metal content in the biomass raw material are reduced, and the slagging condition in biomass combustion equipment is reduced, wherein the mass ratio of the sample to be treated and the acid solution is preferably 1: (100-200), more preferably 1: (120-180), more preferably 1: (140 to 160)

The specific selection of the heat treatment reaction is not particularly limited in principle, and can be selected and adjusted by a person skilled in the art according to the actual production condition, the combustion requirement and the energy supply requirement.

The time of the heat treatment reaction is not particularly limited in principle, and can be selected and adjusted by a person skilled in the art according to actual production conditions, combustion requirements and energy supply requirements, the time of the heat treatment reaction is preferably 2-4 hours, more preferably 2.2-3.8 hours, more preferably 2.5-3.5 hours, more preferably 2.7-3.3 hours, and particularly 2 hours, so as to better facilitate subsequent combustion treatment, reduce the content of alkali metals and heavy metals in biomass raw materials and reduce the slagging condition in biomass combustion equipment.

The temperature of the heat treatment reaction is not particularly limited in principle, and can be selected and adjusted by a person skilled in the art according to actual production conditions, combustion requirements and energy supply requirements, the subsequent combustion treatment is better facilitated, the alkali metal content and the heavy metal content in the biomass raw material are reduced, and the slagging condition in biomass combustion equipment is reduced, wherein the temperature of the heat treatment reaction is preferably 60-80 ℃, more preferably 62-78 ℃, more preferably 65-75 ℃, and more preferably 68-72 ℃.

The invention is a complete and refined integral preparation process, better facilitates subsequent combustion treatment, reduces the content of alkali metal and heavy metal in biomass raw materials, and reduces the slagging condition in biomass combustion equipment.

The pretreatment method before biomass combustion is not particularly limited in principle, and can be selected and adjusted by a person skilled in the art according to actual production conditions, combustion requirements and energy supply requirements.

The specific washing step is not particularly limited in principle, and can be selected and adjusted by a person skilled in the art according to actual production conditions, combustion requirements and energy supply requirements.

The secondary drying time is not particularly limited in principle, and can be selected and adjusted by a person skilled in the art according to actual production conditions, combustion requirements and energy supply requirements, the secondary drying time is preferably 1-2 hours, more preferably 1.2-1.8 hours, and even more preferably 1.4-1.6 hours, so that the subsequent combustion treatment is better facilitated, the alkali metal content and the heavy metal content in the biomass raw material are reduced, and the slagging condition in biomass combustion equipment is reduced.

The temperature for secondary drying is not particularly limited in principle, and can be selected and adjusted by a person skilled in the art according to actual production conditions, combustion requirements and energy supply requirements, the secondary drying temperature is preferably 105-120 ℃, more preferably 107-118 ℃, more preferably 105-115 ℃, more preferably 108-112 ℃, and particularly 105 ℃ in order to better facilitate subsequent combustion treatment, reduce the content of alkali metals and heavy metals in the biomass raw material and reduce the slagging condition in biomass combustion equipment.

The invention is a complete and refined integral preparation process, is better convenient for subsequent combustion treatment, reduces the content of alkali metal and heavy metal in biomass raw materials, and reduces the slagging condition in biomass combustion equipment, and the pretreatment method specifically comprises the following steps:

a sampling stage: in the collection process, selecting a sampling point, collecting at a diagonal line, shearing and collecting samples by using ceramic scissors in the collection process, uniformly collecting a plurality of samples, filling the samples into a sealed bag, recording data such as sampling time, sampling place and the like, and taking the samples to a laboratory for basic physicochemical property determination.

An initial treatment stage: washing the surface of the straw with distilled water, placing the straw in the air for natural drying, crushing the straw by a crusher, sieving the crushed straw, drying the sieved straw by an oven, and sealing the dried straw for later use.

And (3) an experimental stage: placing the raw materials in a closed container (vibration can be started at the moment), pumping negative pressure, adding fatty alcohol-polyoxyethylene ether after a certain time, respectively adding hydrochloric acid, sulfuric acid and nitric acid in different proportions, vibrating and mixing, finally placing in a constant-temperature water bath for heating (vibration can be continued at the same time), collecting and filtering samples in different times during heating, repeatedly washing with deionized water until the samples are neutral, placing in an oven for drying, and sealing for later use.

And (4) carrying out anion and cation measurement on the sealed sample by using an ion chromatograph and carrying out inorganic element measurement by using ICP-OES.

The invention provides a pretreatment method before biomass combustion for biomass recycling. The invention particularly considers from the fuel perspective, and abandons the prior complex and tedious improvement modes which are unfavorable for application, such as adding additives into raw materials, mixing and burning biomass and coal, and the like, and provides a pretreatment method before biomass burning. The pretreatment method provided by the invention is mainly used for improving the slagging phenomenon in the biomass combustion process and the catalyst poisoning condition in the tail gas treatment after combustion by pretreating the raw materials. According to the invention, through specific front and back steps and integration of details, particularly the matching application of negative pressure, vibration (ultrasound), fatty alcohol-polyoxyethylene ether and acid, the heat treatment is carried out under specific conditions, so that the alkali metal content and the heavy metal content in the biomass raw material can be greatly reduced, the slagging problem in the later biomass combustion process is reduced, more importantly, the heavy metals (As, Pb and the like) are removed, the poisoning condition of the denitration catalyst during flue gas treatment is reduced after the biomass is combusted, the use efficiency of the denitration catalyst is improved, and the use cost is reduced. And the method is simple and easy to implement, mild in condition and good in controllability, and is more beneficial to industrial popularization and application.

Experimental results show that the ash content of the straws is reduced after the pretreatment provided by the invention, but the C, O content is not changed greatly, the content of most elements is reduced after acid washing, wherein the Na, Cl and K elements are reduced most obviously, and heavy metal elements are also reduced obviously.

For further illustration of the present invention, a pretreatment method for biomass before combustion according to the present invention will be described in detail with reference to the following examples, but it should be understood that these examples are carried out on the premise of the technical solution of the present invention, and the detailed embodiments and specific procedures are given only for further illustration of the features and advantages of the present invention, not for limitation of the claims of the present invention, and the scope of protection of the present invention is not limited to the following examples.

The reagents used in the following examples of the present invention are all commercially available.

Example 1

A sampling stage: in the collection process, 1m multiplied by 1m sampling points are selected, collection is carried out at diagonal lines, in the collection process, sample shearing and collection are carried out by using ceramic scissors, three parts of samples are uniformly collected and are filled into a sealed bag, data such as sampling time, sampling place and the like are recorded, and the data are brought to a laboratory for basic physicochemical property determination.

4 biomass types of peanut shells, rice hulls, wheat straws and wood particles are collected respectively, and the water content, the volatile components and the heat value of the biomass types are tested.

Referring to table 1, table 1 shows the basic physicochemical properties of different biomass fuel feedstocks provided by the present invention.

TABLE 1

	Peanut shell	Rice husk	Wheat straw	Wood particles
					Water content (%)	10.3	8	15.5	9
Volatile matter (%)	66.4	64	64.38	75.7
					Calorific value (kcal/kg)	3453.822	3762.19	2867.92	3855.89

An initial treatment stage: washing the surface of the straw with distilled water, placing the straw in the air for natural drying, crushing the straw by a crusher, sieving the crushed straw by a 100-mesh sieve, drying the crushed straw by an oven at 105 ℃ and sealing the dried straw for later use.

And (3) an experimental stage: all reagents in the experimental process are analytically pure, the raw materials are placed in a closed vibration container, the frequency is adjusted to be 20KHz, negative pressure is extracted, the absolute pressure is 0.04MPa, after 20min, fatty alcohol-polyoxyethylene ether accounting for 0.1% of the raw materials is added, hydrochloric acid, nitric acid and sulfuric acid are respectively prepared into an acid solution with the mass fraction of 0.1%, and the biomass raw materials and the acid solution are mixed according to the proportion of 1: putting the mixture in the proportion of 200 into a constant-temperature water bath for heating, filtering after 4h, repeatedly washing with deionized water until the mixture is neutral, putting the mixture into an oven for drying for 24h, and sealing for later use. And (4) carrying out anion and cation measurement on the sealed sample by using an ion chromatograph and carrying out inorganic element measurement by using ICP-OES.

Referring to table 2, table 2 shows the inorganic element content analysis of the pretreated biomass according to the embodiment of the present invention.

TABLE 2

Referring to table 3, table 3 shows the water-soluble ion content analysis after the pretreatment provided in the examples of the present invention.

TABLE 3

The foregoing detailed description of the pre-treatment process for biomass combustion for biomass recycling provided by the present invention, and the specific examples used herein to illustrate the principles and embodiments of the present invention, are provided solely to facilitate an understanding of the process and its core concepts, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated processes. It should be noted that, for those skilled in the art, it is possible to make various improvements and modifications to the present invention without departing from the principle of the present invention, and those improvements and modifications also fall within the scope of the claims of the present invention. The scope of the invention is defined by the claims and may include other embodiments that occur to those skilled in the art. Such other embodiments are intended to be within the scope of the claims if they have structural elements that approximate the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.