阅读说明：本技术 一种新型生物质固体燃料及其制备方法及应用 (Novel biomass solid fuel and preparation method and application thereof ) 是由 卫俊涛 高雯然 李辉 张书 黄勇 石磊 于 2021-09-13 设计创作，主要内容包括：本发明提供了一种新型生物质固体燃料,包括以下组分：质量百分比为2-11%的重质生物油和89-98%的生物质。本发明以生物质和生物质经慢速热解或者水热液化产生重质生物油为原料,经造粒机制备成圆柱状,既能方便固体燃料的运输,其高位热值也得到较大提升,燃烧性能更优。(The invention provides a novel biomass solid fuel which comprises the following components: 2-11% of heavy bio-oil and 89-98% of biomass. According to the invention, the biomass and the heavy bio-oil generated by slow pyrolysis or hydrothermal liquefaction of the biomass are used as raw materials, and the raw materials are prepared into a cylindrical shape by the granulator, so that the transportation of solid fuel is facilitated, the high calorific value of the solid fuel is greatly improved, and the combustion performance is better.)

1. The novel biomass solid fuel is characterized by comprising the following components: 2-11% of heavy bio-oil and 89-98% of biomass.

2. The novel biomass solid fuel according to claim 1, wherein the heavy bio-oil is produced by slow pyrolysis or hydrothermal liquefaction of biomass.

3. The novel biomass solid fuel as claimed in claim 2, wherein the conditions of slow pyrolysis are heating from room temperature to 110 ℃ at a heating rate of 10 ℃/min, keeping the temperature at 110 ℃ for 30min, continuing heating to 500 ℃ at a heating rate of 10 ℃/min, keeping the temperature for 60min, and stopping heating and naturally cooling to room temperature.

4. The novel biomass solid fuel as claimed in claim 2, wherein the hydrothermal liquefaction condition is autoclave internal use of N₂The air was evacuated and pressurized to 1MPa, then the heating was stopped immediately after heating to 280 ℃ at a rate of 5 ℃/min, and the reactor was then cooled by immersion in a water/ice bath during which the stirring speed was constant at 175 rpm.

5. The novel biomass solid fuel as claimed in claim 1, wherein the moisture content of the biomass is 5-10% by mass.

6. The novel biomass solid fuel as claimed in claim 1, wherein the biomass is rice husk with particle size of 0.2-1.0 mm.

7. A method for preparing a novel biomass solid fuel as claimed in any one of claims 1 to 6, characterized in that the heavy bio-oil and the biomass are put into a stirrer to be stirred uniformly and pressed into cylindrical granules by a granulator under the pressure of 50 to 200MPa and the temperature of 40 to 130 ℃, and the diameter of the obtained cylindrical granules is 12.3 to 12.6mm, and the height is 6.92 to 8.86 mm.

8. The application of the novel biomass solid fuel as claimed in claim 1.

Technical Field

The invention belongs to the technical field of preparation of environment application type materials, and particularly relates to a novel biomass solid fuel and a preparation method and application thereof.

Background

For a long time, people use fossil fuels such as coal, petroleum, natural gas and the like as main energy consumption. However, since fossil resources such as coal, oil, and natural gas are non-renewable resources, they are subject to a problem of gradual depletion.

The biomass fuel replaces fossil energy as fuel, and generally takes agricultural and forestry wastes as main materials. However, the use of biomass for biomass fuel production is limited by low energy density, unstable combustion performance, and storage and transportation problems. Densification molding is an economical, efficient and simple processing technique that is widely used to increase the energy density of biomass feedstock and reduce transportation costs and the resulting biomass particles are relatively easy to integrate into existing coal-fired supply chains for power generation and heat supply. Densification of biomass presents problems such as the particles produced are prone to attrition and breakage during transport, moisture during storage, etc. Not only can the durability of the particles be enhanced, but some added value can be provided by the addition of suitable binders (e.g., thermoplastics, molasses, lignin). However, the currently used additives have the disadvantages of difficult collection and high price.

Disclosure of Invention

The invention mainly aims to overcome the defects in the prior art and provide a novel biomass solid fuel and a preparation method and application thereof.

The invention provides a novel biomass solid fuel which comprises the following components: 2-11% of heavy bio-oil and 89-98% of biomass.

Preferably, the heavy bio-oil is produced by slow pyrolysis or hydrothermal liquefaction of biomass.

Preferably, the slow pyrolysis is carried out under the conditions that the temperature is increased from room temperature to 110 ℃ at the temperature increasing rate of 10 ℃/min, the temperature is kept at 110 ℃ for 30min, then the temperature is continuously increased to 500 ℃ at the temperature increasing rate of 10 ℃/min, the temperature is kept for 60min, and then the heating is stopped and the temperature is naturally reduced to the room temperature.

Preferably, the hydrothermal liquefaction is carried out under the condition that the autoclave is filled with N₂The air was evacuated and pressurized to 1MPa, then the heating was stopped immediately after heating to 280 ℃ at a rate of 5 ℃/min, and the reactor was then cooled by immersion in a water/ice bath during which the stirring speed was constant at 175 rpm.

Preferably, the water content of the biomass is 5-10% by mass.

Preferably, the biomass is rice hulls with the grain diameter of 0.2-1.0 mm.

The invention also provides a preparation method of the novel biomass solid fuel, which comprises the steps of uniformly stirring the heavy bio-oil and the biomass in a stirrer, and pressing the heavy bio-oil and the biomass into cylindrical particles by a granulator at the pressure of 50-200MPa and the temperature of 40-130 ℃, wherein the diameter of the obtained cylindrical particles is 12.3-12.6mm, and the height of the obtained cylindrical particles is 6.92-8.86 mm.

The invention also provides application of the novel biomass solid fuel

Compared with the prior art, the invention has the beneficial effects that:

according to the invention, the biomass and the heavy bio-oil produced by the biomass through slow pyrolysis or hydrothermal liquefaction are used as raw materials, and the raw materials are prepared into a cylindrical shape through the granulator, so that the transportation of solid fuel is facilitated, the high calorific value of the solid fuel is greatly improved, the combustion performance is better, and the heavy bio-oil waste produced in the biomass thermochemical conversion process can be recycled.

The foregoing is only an overview of the technical solutions of the present invention, and in order to more clearly understand the technical solutions of the present invention, the present invention is further described below with reference to the accompanying drawings.

Drawings

FIG. 1 is a graph showing a comparison of the drop strengths of solid fuels prepared in examples of the present invention and comparative examples;

fig. 2 is a graph of the main effect of granulation parameters on drop strength of a granular fuel.

Detailed Description

In order to understand the present invention, the following examples are given to further illustrate the present invention.

Example 1

The invention provides a novel biomass solid fuel which comprises the following components: 2 percent of heavy bio-oil and 98 percent of biomass.

Example 2

The invention provides a novel biomass solid fuel which comprises the following components: 5 percent of heavy bio-oil and 95 percent of biomass.

Example 3

The invention provides a novel biomass solid fuel which comprises the following components: 8 percent of heavy bio-oil and 92 percent of biomass.

Example 4

The invention provides a novel biomass solid fuel which comprises the following components: the mass percent is 11% of heavy bio-oil and 89% of biomass.

Example 5

A preparation method of a novel biomass solid fuel comprises the steps of placing 2mg of heavy bio-oil and 98mg of rice hulls in a stirrer, uniformly stirring, and pressing into cylindrical particles through a granulator at the pressure of 50MPa and the temperature of 40 ℃, wherein the diameter of the obtained cylindrical particles is 12.3mm, and the height of the obtained cylindrical particles is 6.92 mm.

Example 6

A preparation method of a novel biomass solid fuel comprises the steps of placing 2mg of heavy bio-oil and 98mg of rice hulls in a stirrer, uniformly stirring, and pressing into cylindrical particles through a granulator under the pressure of 100MPa and at the temperature of 70 ℃, wherein the diameter of the obtained cylindrical particles is 12.6mm, and the height of the obtained cylindrical particles is 8.86 mm.

Example 7

A preparation method of a novel biomass solid fuel comprises the steps of placing 2mg of heavy bio-oil and 98mg of rice hulls in a stirrer, uniformly stirring, and pressing into cylindrical particles through a granulator at the pressure of 150MPa and the temperature of 100 ℃, wherein the diameter of the obtained cylindrical particles is 12.4mm, and the height of the obtained cylindrical particles is 8.00 mm.

Example 8

A preparation method of a novel biomass solid fuel comprises the steps of placing 2mg of heavy bio-oil and 98mg of rice hulls in a stirrer, uniformly stirring, and pressing into cylindrical particles through a granulator under the pressure of 200MPa and at the temperature of 130 ℃, wherein the diameter of the obtained cylindrical particles is 12.3mm, and the height of the obtained cylindrical particles is 6.92 mm.

Example 9

A preparation method of a novel biomass solid fuel comprises the steps of placing 5mg of heavy bio-oil and 95mg of rice hulls in a stirrer, uniformly stirring, and pressing into cylindrical particles through a granulator at the pressure of 50MPa and the temperature of 70 ℃, wherein the diameter of the obtained cylindrical particles is 12.4mm, and the height of the obtained cylindrical particles is 8.00 mm.

Example 10

A preparation method of a novel biomass solid fuel comprises the steps of placing 5mg of heavy bio-oil and 95mg of rice hulls in a stirrer, uniformly stirring, and pressing into cylindrical particles through a granulator under the pressure of 100MPa and at the temperature of 40 ℃, wherein the diameter of the obtained cylindrical particles is 12.4mm, and the height of the obtained cylindrical particles is 8.00 mm.

Example 11

A preparation method of a novel biomass solid fuel comprises the steps of placing 5mg of heavy bio-oil and 95mg of rice hulls in a stirrer, uniformly stirring, and pressing into cylindrical particles through a granulator under the pressure of 150MPa and at the temperature of 130 ℃, wherein the diameter of the obtained cylindrical particles is 12.4mm, and the height of the obtained cylindrical particles is 8.00 mm.

Example 12

A preparation method of a novel biomass solid fuel comprises the steps of placing 5mg of heavy bio-oil and 95mg of rice hulls in a stirrer, uniformly stirring, pressing into cylindrical particles through a granulator at the pressure of 200MPa and the temperature of 100 ℃, wherein the diameter of the obtained cylindrical particles is 12.4mm, and the height of the obtained cylindrical particles is 8.00 mm.

Example 13

A preparation method of a novel biomass solid fuel comprises the steps of placing 8mg of heavy bio-oil and 92mg of rice hulls in a stirrer, uniformly stirring, and pressing into cylindrical particles through a granulator at the pressure of 50MPa and the temperature of 100 ℃, wherein the diameter of the obtained cylindrical particles is 12.4mm, and the height of the obtained cylindrical particles is 8.00 mm.

Example 14

A preparation method of a novel biomass solid fuel comprises the steps of placing 8mg of heavy bio-oil and 92mg of rice hulls in a stirrer, uniformly stirring, pressing into cylindrical particles through a granulator under the pressure of 100MPa and at the temperature of 130 ℃, wherein the diameter of the obtained cylindrical particles is 12.4mm, and the height of the obtained cylindrical particles is 8.00 mm.

Example 15

A preparation method of a novel biomass solid fuel comprises the steps of placing 8mg of heavy bio-oil and 92mg of rice hulls in a stirrer, uniformly stirring, and pressing into cylindrical particles through a granulator at the pressure of 150MPa and the temperature of 40 ℃, wherein the diameter of the obtained cylindrical particles is 12.4mm, and the height of the obtained cylindrical particles is 8.00 mm.

Example 16

A preparation method of a novel biomass solid fuel comprises the steps of placing 8mg of heavy bio-oil and 92mg of rice hulls in a stirrer, uniformly stirring, pressing into cylindrical particles through a granulator at the pressure of 200MPa and the temperature of 70 ℃, wherein the diameter of the obtained cylindrical particles is 12.4mm, and the height of the obtained cylindrical particles is 8.00 mm.

Example 17

A preparation method of a novel biomass solid fuel comprises the steps of putting 11mg of heavy bio-oil and 89mg of rice hulls into a stirrer, uniformly stirring, and pressing into cylindrical particles through a granulator at the pressure of 50MPa and the temperature of 130 ℃, wherein the diameter of the obtained cylindrical particles is 12.4mm, and the height of the obtained cylindrical particles is 8.00 mm.

Example 18

A preparation method of a novel biomass solid fuel comprises the steps of putting 11mg of heavy bio-oil and 89mg of rice hulls into a stirrer, uniformly stirring, and pressing into cylindrical particles through a granulator under the pressure of 100MPa and at the temperature of 100 ℃, wherein the diameter of the obtained cylindrical particles is 12.4mm, and the height of the obtained cylindrical particles is 8.00 mm.

Example 19

A preparation method of a novel biomass solid fuel comprises the steps of putting 11mg of heavy bio-oil and 89mg of rice hulls into a stirrer, uniformly stirring, and pressing into cylindrical particles through a granulator at the pressure of 150MPa and the temperature of 70 ℃, wherein the diameter of the obtained cylindrical particles is 12.4mm, and the height of the obtained cylindrical particles is 8.00 mm.

Example 20

A preparation method of a novel biomass solid fuel comprises the steps of putting 11mg of heavy bio-oil and 89mg of rice hulls into a stirrer, uniformly stirring, and pressing into cylindrical particles through a granulator at the pressure of 200MPa and the temperature of 40 ℃, wherein the diameter of the obtained cylindrical particles is 12.4mm, and the height of the obtained cylindrical particles is 8.00 mm.

Examples 5-20 were granulated under different pressures and different temperatures to produce cylindrical granules, the results of which are shown in table 1.

TABLE 1

In order to test the effect of the heavy bio-oil in the granulation process, the present invention also provides a control example without the heavy bio-oil, and the rice hulls are granulated under different pressures and different temperatures to obtain cylindrical particles, and the results are shown in table 2.

TABLE 2

The novel biomass solid fuel was prepared according to the conditions prepared in the above examples and comparative examples, and the obtained cylindrical sample was subjected to drop strength test. The mass of the pellet sample was recorded before each test, then it was dropped freely from a height of 1.85m onto a steel plate, and the weight of the larger part of the pellet after dropping was recorded after 4 drops. The ratio of the weight of the pellet after dropping to the weight before dropping is the drop strength of the pellet. All data are shown as mean ± sd for 10 replicates of each condition in the examples and comparative examples, and the results are shown in figure 1.

As can be seen from the data in FIG. 1, the novel biomass solid fuel provided by the invention has greatly improved drop strength under the conditions of example 9 and example 15, meets the requirements of biomass granular fuel, and has wide application prospects.

The invention uses five variables of heavy bio-oil content, granulation pressure, granulation temperature, rice hull grain size and heavy bio-oil source to discuss the influence on the novel biomass fuel falling strength, wherein the heavy bio-oil content is set at four levels of 2%, 5%, 8% and 11%, the granulation pressure is set at four levels of 50MPa, 100MPa, 150MPa and 200MPa, the granulation temperature is set at four levels of 40 ℃, 70 ℃, 100 ℃ and 130 ℃, the rice hull grain size is set at four levels of 0.8-1.0mm, 0.6-0.8mm, 0.4-0.6mm and 0.2-0.4mm, the heavy bio-oil source is provided with slow pyrolysis and hydrothermal liquefaction, the response of each factor to the falling resistance of the granular fuel is obtained by analyzing through statistical analysis software Minitab 19, and the result is shown in figure 2.

As can be seen from fig. 2-1, a sharp increase in drop strength from 84.1% to 96.3% was observed as the pelletization temperature was increased from 40 ℃ to 70 ℃. This value further increases to nearly 100% when the granulation temperature is increased to 100 ℃ and 130 ℃. Generally, higher densification temperatures ≧ 100 ℃ are preferred to obtain a particulate fuel with acceptable durability. This is because higher temperatures can cause the amorphous polymer contained in the biomass to better soften and melt and thereby increase the particle bonding strength.

As can be seen from fig. 2-2, as the pelletizing pressure increases (from 50 to 100MPa), the drop strength of the pellet fuel increases from 82.3% to 96.7%, and then approaches 100% at pelletizing pressures of 150MPa and higher. This is because the lower pelletizing pressure does not ensure the bond between the rice hull pellet fuel-pellet fuel and the rice hull pellet fuel-binder. Moreover, under extremely high pressure (namely 100-200 MPa), the rice hull particle fuel can generate elastic and plastic deformation, so that more gaps are generated among particles, and the bonding strength of the rice hull particle fuel is reduced.

As can be seen from the figures 2-3, the maximum drop strength reaches 99.1% when the grain diameter of the rice hull granular fuel is 0.4-0.6 mm. When the size of the rice hull is increased to 0.8-1.0mm, the drop strength is obviously reduced to 84.3%. This is because larger particles can cause the particulate fuel to form voids and an uneven surface after densification.

As can be seen from fig. 2-4 and 2-5, the drop strength of the particulate fuel increased from 82.5% to 98.0% when the heavy bio-oil content increased from 2% to 5%, and then slightly increased to 99.2% when the heavy bio-oil content was 8%. Further increasing the heavy bio-oil content to 11% found a slight drop strength reduction. Comparing two heavy bio-oil sources, the hydrothermal liquefaction is more improved than the slow pyrolysis on the falling resistance strength of the rice hull granular fuel, and the hydrothermal liquefaction rate is 98.8 percent and is more than 90.3 percent of that of the slow pyrolysis.

Example 21

A preparation method of a novel biomass solid fuel comprises the steps of placing 8mg of heavy bio-oil and 92mg of rice hulls in a stirrer, uniformly stirring, pressing into cylindrical particles through a granulator under the pressure of 200MPa and at the temperature of 130 ℃, wherein the diameter of the obtained cylindrical particles is 12.4mm, and the height of the obtained cylindrical particles is 8.00 mm.

Comparative example 21

A preparation method of biomass solid fuel comprises the steps of placing 100mg rice hulls in a stirrer to be uniformly stirred, pressing the rice hulls into cylindrical particles through a granulator under the pressure of 200MPa and at the temperature of 130 ℃, wherein the diameter of the obtained cylindrical particles is 12.4mm, and the height of the obtained cylindrical particles is 8.00 mm.

The solid fuels prepared in example 21 and comparative example 21 were measured for the mass percentages of moisture, volatiles, fixed carbon and ash according to the national standard GB/T28731-2012, and the solid fuels prepared in example 21 and comparative example 21 were measured for the mass percentages of hydrogen, oxygen, carbon, nitrogen and sulfur by an elemental analyzer, and the test results are shown in Table 3.

TABLE 3

The drop strength of the solid fuels prepared in example 21 and comparative example 21 was examined, and the higher calorific value thereof was calculated using the higher calorific value formula, which is the higher calorific value (HHV) calculation formula:

HHV 0.3491 XC 1.1783 XH 0.1005 XS-0.1034 XO-0.0211 XAsh

The results are shown in Table 4.

TABLE 4

As is apparent from Table 4, example 21 (99.79%) and comparative example 21 (99.74%) had similar drop resistance, and the densities thereof were all 1.17g/cm³But the high calorific value is greatly improved from 15.42MJ/kg to 19.06MJ/kg, and the combustion performance is better.

Although the present invention has been described with reference to a preferred embodiment, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims.