Method for high-yield preparation of bio-oil by using cow dung as raw material

Abstract

The invention provides a method for high-yield preparation of bio-oil by using cow dung as a raw material. The method comprises the following steps: a, drying, crushing and sieving of fresh cow dung;b, subcritical / supercritical liquefaction: adding the cow dung raw material and a liquefaction solvent in a solid-to-liquid ratio of 0.05-0.15 g / mL into a reaction kettle according to a solvent filling rate of 10-30%, adding calcium oxide accounting for 5-10% of the weight of the cow dung raw material as a catalyst, sealing the reaction kettle, setting the pressure of the reaction kettle to be 10-15 MPa and a liquefaction temperature to be 220-300 DEG C, heating the reaction kettle, keeping the temperature for 30-60 minutes when the temperature reaches the set liquefaction temperature, stopping heating after a reaction is finished, and carrying out cooling to room temperature; c, solid-liquid separation; and d, feeding of a liquefied product into a rotary evaporator for preparation of thebio-oil. According to the method disclosed by the invention, resourceful and harmless treatment of the cow dung can be realized; the method is wide in raw material source, low in energy consumption, and convenient for large-scale preparation of the bio-oil; the calcium oxide, used as the catalyst, is high in activity, and the method is mild in reaction conditions, low in cost, capable of being used on large scale and extremely high in industrial potential.

Description

technical field

[0001] The present invention relates to the technical field of energy-based treatment of livestock and poultry manure, in particular to a method for preparing bio-oil with cow dung as a raw material with a high yield, and in particular to a method for preparing bio-oil by sub / supercritical liquefaction of fresh cow dung and adding Calcium oxide as a catalyst to increase its bio-oil yield. Background technique

[0002] Cattle farming has always been a very important industry in animal husbandry, and beef has always been one of the favorite meats in China. In recent years, beef production accounts for about 8.5% of the national meat production. The scale of the cattle breeding industry has also continued to increase under the increasing demand. By 2000, there were about 105 million cattle in China. At the same time, the discharge of cow dung is also increasing. According to relevant statistical estimates, the annual excrement discharge (including urine) in 201...

Examples

Embodiment 1

[0052] A method for preparing bio-oil with high yield using cow dung as raw material, specifically comprising the following steps:

[0053] a, pretreatment: dry the fresh cow dung to a moisture content of 10%, then crush the cow dung through an 80-mesh sieve;

[0054] b. Sub- / supercritical liquefaction: the treated cow dung and absolute ethanol have a solid-to-liquid ratio of 0.1g / mL, the solvent absolute ethanol has a filling rate of 20%, and calcium oxide of 7% of the total amount of cow dung raw materials Mix the fragments evenly and pour them into the reaction kettle; seal the reaction kettle, the design pressure is 12.5MPa, the heating voltage is 250V, and the set liquefaction temperature is 220°C; the reaction kettle is heated up, and the temperature reaches the set liquefaction temperature. Stop heating after the reaction is over, and cool the reactor to room temperature with condensed water when the temperature of the reactor is about 100°C;

[0055] c. Solid-liquid s...

Embodiment 2

[0058] The difference between this example and Example 1 is that the liquefaction temperature is set at 260° C., and the prepared bio-oil sample is denoted as S2.

Embodiment 3

[0060] The difference between this example and Example 1 is that the liquefaction temperature is set at 300° C., and the prepared bio-oil sample is denoted as S3.

technical field

[0001] The present invention relates to the technical field of energy-based treatment of livestock and poultry manure, in particular to a method for preparing bio-oil with cow dung as a raw material with a high yield, and in particular to a method for preparing bio-oil by sub / supercritical liquefaction of fresh cow dung and adding Calcium oxide as a catalyst to increase its bio-oil yield. Background technique

[0002] Cattle farming has always been a very important industry in animal husbandry, and beef has always been one of the favorite meats in China. In recent years, beef production accounts for about 8.5% of the national meat production. The scale of the cattle breeding industry has also continued to increase under the increasing demand. By 2000, there were about 105 million cattle in China. At the same time, the discharge of cow dung is also increasing. According to relevant statistical estimates, the annual excrement discharge (including urine) in 201...

Examples

Embodiment 1

[0052] A method for preparing bio-oil with high yield using cow dung as raw material, specifically comprising the following steps:

[0053] a, pretreatment: dry the fresh cow dung to a moisture content of 10%, then crush the cow dung through an 80-mesh sieve;

[0054] b. Sub- / supercritical liquefaction: the treated cow dung and absolute ethanol have a solid-to-liquid ratio of 0.1g / mL, the solvent absolute ethanol has a filling rate of 20%, and calcium oxide of 7% of the total amount of cow dung raw materials Mix the fragments evenly and pour them into the reaction kettle; seal the reaction kettle, the design pressure is 12.5MPa, the heating voltage is 250V, and the set liquefaction temperature is 220°C; the reaction kettle is heated up, and the temperature reaches the set liquefaction temperature. Stop heating after the reaction is over, and cool the reactor to room temperature with condensed water when the temperature of the reactor is about 100°C;

[0055] c. Solid-liquid s...

Embodiment 2

[0058] The difference between this example and Example 1 is that the liquefaction temperature is set at 260° C., and the prepared bio-oil sample is denoted as S2.

Embodiment 3

[0060] The difference between this example and Example 1 is that the liquefaction temperature is set at 300° C., and the prepared bio-oil sample is denoted as S3.

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