阅读说明：本技术 一种生物质改性的方法 (Biomass modification method ) 是由 张宗超 颜佩芳 于 2019-02-27 设计创作，主要内容包括：本发明提供一种生物质改性的方法,涉及农林生物质资源利用和处理技术领域。该方法以低价态含磷无机酸为改性剂,在一定温度下对生物质处理一段时间,经过滤分离,即可得到改性后的生物质。本发明相对传统的生物质改性方法,处理条件温和、操作简单、对设备的要求低,且改性后的生物质降解温度大幅降低,为生物质的后续高值化应用提供了有利的条件。(The invention provides a biomass modification method, and relates to the technical field of utilization and treatment of agriculture and forestry biomass resources. The method takes low-valence inorganic acid containing phosphorus as a modifier, treats biomass for a period of time at a certain temperature, and obtains modified biomass after filtration and separation. Compared with the traditional biomass modification method, the method has the advantages of mild treatment conditions, simple operation and low requirement on equipment, greatly reduces the degradation temperature of the modified biomass, and provides favorable conditions for subsequent high-value application of the biomass.)

1. A method of biomass modification characterized by: the modification method specifically comprises the following steps: primarily crushing biomass, adding a solvent and a modifier, stirring at a controlled temperature, filtering, performing solid-liquid separation, collecting a solid part, cleaning and drying to obtain the modified biomass.

2. A method of biomass modification as claimed in claim 1, wherein: the modifier is low-valence phosphorus-containing inorganic acid with the P valence less than + 5.

3. A method of biomass modification as claimed in claim 1, wherein: the biomass raw material comprises one or a mixture of more of trees, crop straws, agricultural product processing industry byproducts, livestock and poultry manure and energy crops.

4. A method of biomass modification as claimed in claim 1, wherein: the biomass raw material comprises one or a mixture of more of cellulose, hemicellulose, lignin and related modified materials thereof.

5. A method of biomass modification as claimed in claim 1, wherein: the solvent is an oxygen-containing or non-oxygen-containing solvent.

6. A method of biomass modification according to claim 5, characterised in that: the oxygen-containing solvent is one or a mixture of more of water, methanol, ethanol, n-propanol, isopropanol, n-butanol, n-hexanol, cyclohexanol, benzyl alcohol, ethylene glycol, 1, 4-dioxane, ethyl acetate, ethyl formate, methyl acetate, gamma-valerolactone, n-propyl acetate, acetone, formaldehyde, acetaldehyde, propionaldehyde and n-butyraldehyde.

7. A method of biomass modification according to claim 5, characterised in that: the oxygen-free solvent is one or a mixture of acetonitrile, benzene, toluene, ethylbenzene, dichloromethane, trichloromethane and bromoethane.

8. A method of biomass modification as claimed in claim 1, wherein: the crushing method is one or a combination of a plurality of hammer type crushing, disc milling crushing, ball milling crushing or cutting crushing.

9. A method of biomass modification as claimed in claim 1, wherein: the low price

The phosphorus-containing inorganic acid is phosphorous acid or hypophosphorous acid.

10. A method of biomass modification as claimed in claim 1, wherein: the mass volume ratio of the biomass to the solvent is 0.01-80%.

11. A method of biomass modification according to claim 2, characterised in that: the concentration of the phosphorus-containing inorganic acid is 0.01-80%.

12. A method of biomass modification according to claim 2, characterised in that: the concentration of the inorganic acid containing phosphorus is 1-50%.

13. A method of biomass modification as claimed in claim 1, wherein: the modification temperature is 20-200 ℃; the modification time is 0.01 to 96 hours.

14. A method of biomass modification as claimed in claim 1, wherein: the modification temperature is 50-140 ℃; the modification time is 0.1-24 hours.

15. A method of biomass modification as claimed in claim 1, wherein: the solid-liquid separation method is one or a mixture of several methods of decantation, common filtration, reduced pressure filtration and centrifugation.

16. A method of biomass modification as claimed in claim 1, wherein: the biomass drying method is natural air drying, freeze drying or heating drying.

17. A method of biomass modification as claimed in claim 1, wherein: the thermal decomposition temperature of the modified biomass is obviously reduced relative to the biomass raw material, and the reduction range is 20-200 ℃.

Technical Field

The invention relates to the technical field of agriculture and forestry biomass resource utilization and treatment, in particular to an effective biomass modification method.

Background

With the shortage of non-renewable resources such as petroleum and coal, the rise of price, and the concern of people on environmental pollution, the research on the conversion and utilization of natural polymer materials is highly regarded. Due to the characteristics of being renewable, large in resource quantity, clean and pollution-free and the like, biomass becomes one of the hot areas of research in recent years. The rapid development of pyrolysis technology in recent years has made it one of the more efficient and mature technologies in biomass utilization technology. However, the basic composition and microstructure of biomass have a major impact on its efficient conversion process, and pretreatment or modification of biomass raw materials is often required [ J.anal.appl.pyrol.,2002, 68-69, 197-. Rational pretreatment techniques can modify some of the physicochemical properties of biomass, thereby changing the process and product distribution of biomass Pyrolysis [ Journal of Analytical and applied Pyrolysis,2014, 110, 44-54 ]. The method is suitable and effective, and especially has important significance in exploring a pretreatment technology capable of changing the inherent structure of the biomass, improving the pyrolysis efficiency and improving the quality and yield of pyrolysis products.

At present, biomass pretreatment technologies based on pyrolysis utilization are mainly classified into physical methods, chemical methods, biological methods, and the like. The commonly used physical pretreatment techniques mainly include mechanical pulverization treatment, microwave treatment [ Ind. Eng. chem. Res.,2013,52, 3563-3580. Energy Conversion and Management,2016, 110, 287-295 ], baking treatment [ EnergyFuels,2016,30,10627-10634], and the like, and the physical method is simple in operation, but low in efficiency and high in cost. The biological treatment method is a method of treating a biomass with microorganisms in the natural world. The biological treatment method has simple equipment, low energy consumption, no pollution and mild conditions, but the biological treatment method has the biggest problem of long treatment period and few types of lignin-degrading microorganisms known at present [ Bioresource. Technol.,2013,134,198-203. J.Microbiol.,2007,45(6), 485. 491 ]. Common chemical methods are acid wash [ J.Appl.Sci.1982, 27, 4577-4585 ], acid hydrolysis [ J.anal.appl.pyrolysis,1989,16, 127-142 ], hydrothermal treatment [ Bioresource.Technol, 2013,138,321-328, Energy environ.Sci.,2010,3, 358-365, Bioresource.Technol, 2013,129,676-679, Biomass and Bioenergy,2017,107, 299-304 ], gas explosion [ Energy Fuels,2011, 25, 3758-3764 ], alkali treatment [ Biofuel. Biorefiring 2008,2(1), 24-40, RSC adv, 2015,5, 244-24989, Bioreso.10ol, 2009, 2811 ], and organic solvent decomposition methods. The chemical methods have the problems that the treatment conditions are high temperature and high pressure, and although some components such as ash and the like harmful to pyrolysis are removed in the treatment process, the solid recovery rate of biomass is low, so that the resource waste phenomenon is caused to a certain extent.

The biomass modification method provided by the invention takes the low-valence inorganic acid containing P as the modifier, has mild treatment conditions, low requirements on equipment and simple operation, and the modified biomass has high recovery rate, less resource waste and greatly reduced thermal decomposition temperature, thereby providing favorable conditions for the pyrolysis conversion of lignocellulose into high-value chemicals.

Disclosure of Invention

The object of the present invention is to provide an efficient biomass modification process, resulting in a biomass with a low decomposition temperature, providing advantageous conditions for its catalytic conversion to high-value chemicals. Compared with the traditional modification method, the method has the advantages of mild treatment conditions, simple operation and low requirement on equipment.

In order to achieve the purpose, the invention adopts the following technical scheme:

a method for modifying biomass comprises the following steps: primarily crushing biomass, adding a solvent and a modifier, stirring at a controlled temperature, filtering, performing solid-liquid separation, collecting a solid part, cleaning and drying to obtain the modified biomass.

The modifier is low-valence phosphorus-containing inorganic acid with the P valence less than + 5.

The biomass raw material comprises one or a mixture of more of various trees, crop straws, agricultural product processing industry byproducts, livestock and poultry manure, energy crops and the like, and the trees are softwood and/or hardwood.

The biomass raw material comprises one or a mixture of more of cellulose, hemicellulose, lignin and related modified materials thereof.

The solvent is an oxygen-containing or non-oxygen-containing solvent.

Wherein the oxygen-containing solvent is one or a mixture of more of water, methanol, ethanol, n-propanol, isopropanol, n-butanol, n-hexanol, cyclohexanol, benzyl alcohol, ethylene glycol, 1, 4-dioxane, ethyl acetate, ethyl formate, methyl acetate, gamma-valerolactone, n-propyl acetate, acetone, formaldehyde, acetaldehyde, propionaldehyde and n-butyraldehyde.

The oxygen-free solvent is one or more of acetonitrile, benzene, toluene, ethylbenzene, dichloromethane, chloroform and bromoethane.

The crushing method is one or a combination of a plurality of hammer type crushing, disc milling crushing, ball milling crushing or cutting crushing.

The mass volume ratio of the biomass to the solvent is 0.01-80%.

The low-valence phosphorus-containing inorganic acid is preferably phosphorous acid or hypophosphorous acid. The concentration of the inorganic acid containing phosphorus is 0.01-80% (the concentration of the acid in the solvent), and preferably 1-50%.

The modification temperature is 20-200 ℃, and preferably 50-140 ℃; the modification time is 0.01 to 96 hours, preferably 0.1 to 24 hours.

The solid-liquid separation method is one or a mixture of several methods of decantation, common filtration, reduced pressure filtration and centrifugation.

The biomass drying method is natural air drying, freeze drying or heating drying.

The thermal decomposition temperature of the modified biomass is obviously reduced relative to the biomass raw material, and the reduction range is 20-200 ℃.

The invention has the advantages that:

(1) the thermal decomposition temperature of the modified biomass is greatly reduced, and favorable conditions are provided for catalytic conversion of the biomass into high-value chemicals such as pyrolysis.

(2) The method has the advantages of mild conditions, simple operation and low requirements on reaction equipment.

(3) The modified biomass has high recovery rate and less resource waste.

(4) The modified biomass has very low P content and meets the requirement of environmental protection.

Drawings

FIG. 1: DTG comparison (solvent: 1, 4-dioxane) before and after the rice hull is modified by hypophosphorous acid;

FIG. 2: DTG comparison (solvent: gamma-valerolactone) before and after the rice hull is modified by hypophosphorous acid;

FIG. 3: DTG comparison (solvent: ethyl acetate) of rice hulls before and after hypophosphorous acid modification;

FIG. 4: DTG comparison (solvent: 1, 4-dioxane) before and after the rice hull is modified by hypophosphorous acid;

FIG. 5: DTG comparison (solvent: 1, 4-dioxane) of rice hulls before and after modification with hypophosphorous acid (30 mmol);

FIG. 6: DTG comparison before and after the pine is modified by hypophosphorous acid (solvent: 1, 4-dioxane);

FIG. 7: DTG comparison before and after hypophosphorous acid modification of fast-growing poplars (solvent: 1, 4-dioxane);

FIG. 8: DTG comparison before and after the hemicellulose is modified by hypophosphorous acid (solvent: 1, 4-dioxane);

FIG. 9: DTG comparison before and after lignin modification by hypophosphorous acid (solvent: 1, 4-dioxane);

FIG. 10: DTG comparison before and after the pine is modified by phosphorous acid (solvent: 1.4-dioxane);

FIG. 11: DTG comparison before and after the pine is modified by hypophosphorous acid (solvent: 1, 4-dioxane, temperature 140 ℃);

FIG. 12: DTG comparison before and after the pine is modified by hypophosphorous acid (solvent: 1, 4-dioxane, temperature 50 ℃);

FIG. 13: DTG spectrogram (solvent: 1, 4-dioxane) of rice hull after phosphoric acid treatment.

Detailed Description

The present invention is further described with reference to the following specific examples, but the scope of the present invention is not limited by the examples, and if one skilled in the art makes some insubstantial modifications and adaptations to the present invention based on the above disclosure, the present invention still falls within the scope of the present invention.