阅读说明：本技术 硝酸铜热化学预处理地沟油脱硫的方法 (Method for desulfurizing illegal cooking oil through thermochemical pretreatment of copper nitrate ) 是由 徐俊明 蒋霞 龙锋 蒋剑春 刘朋 翟巧龙 于 2021-06-24 设计创作，主要内容包括：本发明公开了硝酸铜热化学预处理地沟油脱硫的方法,属于生物质能源预处理技术领域。该方法为对地沟油进行热化学预处理时加入催化剂,所述催化剂为硝酸铜与碱性催化剂的混合催化剂或硝酸铜。本发明有效脱除生物油品中的硫元素,使其含量小于10ppm,并且脱硫方法简单,耗能少,可适性强。(The invention discloses a method for desulfurizing illegal cooking oil by thermochemical pretreatment of copper nitrate, belonging to the technical field of pretreatment of biomass energy sources. The method comprises the step of adding a catalyst during thermochemical pretreatment of the illegal cooking oil, wherein the catalyst is a mixed catalyst of copper nitrate and an alkaline catalyst or copper nitrate. The method effectively removes the sulfur element in the biological oil product, so that the content of the sulfur element is less than 10ppm, and the method is simple, low in energy consumption and strong in adaptability.)

1. The method for desulfurizing the illegal cooking oil by thermochemically pretreating the copper nitrate is characterized in that a catalyst is added when the illegal cooking oil is thermochemically pretreated, and the catalyst is a mixed catalyst of the copper nitrate and a basic catalyst or the copper nitrate.

2. The method for desulfurizing illegal cooking oil by thermochemical pretreatment of copper nitrate according to claim 1, wherein the catalyst is a mixed catalyst of an alkaline catalyst and copper nitrate, the amount of the alkaline catalyst is 1% to 10% by mass of the biological oil, and the amount of the copper nitrate is 1% to 3% by mass of the biological oil.

3. The method for desulfurizing illegal cooking oil by thermochemical pretreatment of copper nitrate according to claim 1, wherein the catalyst is copper nitrate and the amount of the catalyst is 3 to 10 percent of the mass of the biological oil.

4. The method for desulfurizing illegal cooking oil by thermochemical pretreatment of copper nitrate according to claim 1 or 2, wherein the basic catalyst in the mixed catalyst is any one or more of calcium oxide, magnesium oxide, sodium carbonate, potassium carbonate or zinc oxide.

5. The method for desulfurizing illegal cooking oil by thermochemical pretreatment of copper nitrate according to claim 1, wherein the thermochemical pretreatment temperature is 350 to 450 ℃.

6. The method for desulfurizing the illegal cooking oil subjected to thermochemical pretreatment of copper nitrate according to claim 1 or 2, wherein the catalyst is a mixed catalyst of potassium carbonate and copper nitrate, the amount of the potassium carbonate is 7.5-10% of the mass of the illegal cooking oil, and the amount of the copper nitrate is 1-2.5% of the mass of the illegal cooking oil.

7. The method for desulfurizing illegal cooking oil subjected to thermochemical pretreatment of copper nitrate according to claim 1 or 2, wherein the catalyst is a mixed catalyst of potassium carbonate, zinc oxide and copper nitrate, the amount of potassium carbonate is 5% by mass of the illegal cooking oil, the amount of zinc oxide is 5% by mass of the illegal cooking oil, and the amount of copper nitrate is 1% by mass of the illegal cooking oil.

8. The method for desulfurizing the illegal cooking oil chemically pretreated by the copper nitrate according to claim 1 or 2, wherein the catalyst is a mixed catalyst of zinc oxide and copper nitrate, the amount of the zinc oxide is 6.6-8% of the mass of the illegal cooking oil, and the amount of the copper nitrate is 2-3% of the mass of the illegal cooking oil.

9. The method for desulfurizing illegal cooking oil by thermochemical pretreatment of copper nitrate according to claim 1 or 3, characterized in that the catalyst is copper nitrate and the amount of the catalyst is 3% -4% of the mass of the biological oil.

Technical Field

The invention belongs to the technical field of biomass energy pretreatment, and particularly relates to a method for desulfurizing illegal cooking oil through thermochemical pretreatment of copper nitrate.

Background

At present, under the severe situation of the gradual depletion of fossil fuels, the search for a renewable energy source is a focus of attention in various countries around the world. The illegal cooking oil has the characteristics of low price, wide source, greenness and the like, is an ideal raw material for preparing the biodiesel, and is concerned by many researchers. The alternative fuel for converting the illegal cooking oil into the diesel has the advantages of being renewable, biodegradable and the like, and has important significance for reducing the concentration of atmospheric greenhouse gases, improving the living environment of human beings and realizing the sustainable development of economy. However, the illegal cooking oil contains a large amount of sulfur compounds from restaurants, factories and the like, so that the sulfur content in the illegal cooking oil is higher, and the sulfur content in the produced biodiesel is high. The sulfur in diesel will be converted to harmful sulfur dioxide and released to the atmosphere during the combustion of biodiesel, causing significant environmental and health problems, and in view of the sulfur hazard, strict biodiesel sulfur content standards are established, which must be lower than 15ppm in the united states (ASTM D6751,2015) and 10ppm in europe (EN14214,2008), and two standards are established in china, namely S50 (< 50ppm) and S10 (< 10ppm) (GB 25199-. Most of the prior art adopts an ester exchange method to produce biodiesel, while the illegal cooking oil generally contains a large amount of impurities and water and has high acid value, in order to improve the productivity and the quality of the biodiesel, the subsequent reaction can be carried out only by changing the waste edible oil into refined oil through pretreatment procedures such as impurity removal, deacidification, decoloration, dehydration and the like, which undoubtedly increases the production cost, and the ester exchange method is not feasible for the waste edible oil with many impurities and poor quality. There is another method for producing biodiesel by hydrocracking, however, the hydrocracking needs to be processed before hydrogenation to improve the purity of the raw material, and the hydrocracking safety requirement and the cost requirement are high.

The first generation of biodiesel only reduces the acid value, the second generation of biodiesel not only needs to reduce the acid value, but also needs to reduce the content of sulfur and the like in the biodiesel, the export is influenced by over high sulfur element, the sulfur element content is generally required to be less than 10ppm internationally, and the sulfur element content of the biodiesel produced at home is generally higher. The common biodiesel desulfurization at present adopts a two-step method, namely, the crude biodiesel is prepared by the transesterification of illegal cooking oil, and the crude biodiesel is distilled and desulfurized to reduce the sulfur content. The two-step method for preparing the low-sulfur biodiesel has low yield, the raw material is lost in the first step of ester exchange, the middle fraction sulfur content is low in the distillation of the crude biodiesel, and the two-step method for preparing the low-sulfur biodiesel has high energy consumption, complicated working procedures and more raw material loss.

Disclosure of Invention

Aiming at the problems in the prior art, the invention aims to solve the technical problem of providing a method for desulfurizing the illegal cooking oil subjected to copper nitrate thermochemical pretreatment, which effectively removes sulfur in the biological oil product to ensure that the content of the sulfur in the biological oil product is less than 10ppm, and has the advantages of simple desulfurization method, low energy consumption and strong adaptability.

In order to solve the problems, the technical scheme adopted by the invention is as follows:

the method for desulfurizing the illegal cooking oil subjected to thermochemical pretreatment of copper nitrate comprises the step of adding a catalyst in the thermochemical pretreatment process of the illegal cooking oil, wherein the catalyst is a mixed catalyst of copper nitrate and an alkaline catalyst or copper nitrate.

According to the method for desulfurizing the illegal cooking oil by thermochemical pretreatment of the copper nitrate, the catalyst is a mixed catalyst of an alkaline catalyst and the copper nitrate, the dosage of the alkaline catalyst is 1% -10% of the mass of the biological oil, and the dosage of the copper nitrate is 1% -3% of the mass of the biological oil.

According to the method for desulfurizing the illegal cooking oil by thermochemical pretreatment of the copper nitrate, the catalyst is the copper nitrate, and the using amount of the copper nitrate is 3-10% of the mass of the biological grease.

According to the method for desulfurizing the illegal cooking oil subjected to thermochemical pretreatment by using the copper nitrate, the alkaline catalyst in the mixed catalyst is any one or a mixture of more of calcium oxide, magnesium oxide, sodium carbonate, potassium carbonate or zinc oxide.

The method for desulfurizing the illegal cooking oil by thermochemical pretreatment of the copper nitrate is characterized in that the thermochemical pretreatment temperature is 350-450 ℃.

According to the method for desulfurizing the illegal cooking oil by thermochemical pretreatment of the copper nitrate, the catalyst is a mixed catalyst of potassium carbonate and the copper nitrate, the amount of the potassium carbonate is 7.5-10% of the mass of the illegal cooking oil, and the amount of the copper nitrate is 1-2.5% of the mass of the illegal cooking oil.

The method for desulfurizing the illegal cooking oil by thermochemically pretreating the copper nitrate comprises the steps of using a mixed catalyst of potassium carbonate, zinc oxide and copper nitrate, wherein the use amount of the potassium carbonate is 5% of the mass of the illegal cooking oil, the use amount of the zinc oxide is 5% of the mass of the illegal cooking oil, and the use amount of the copper nitrate is 1% of the mass of the illegal cooking oil.

According to the method for desulfurizing the illegal cooking oil by thermochemical pretreatment of the copper nitrate, the catalyst is a mixed catalyst of zinc oxide and the copper nitrate, the dosage of the zinc oxide is 6.6-8% of the mass of the illegal cooking oil, and the dosage of the copper nitrate is 2-3% of the mass of the illegal cooking oil.

According to the method for desulfurizing the illegal cooking oil by thermochemical pretreatment of the copper nitrate, the catalyst is the copper nitrate, and the using amount of the copper nitrate is 3-4% of the mass of the biological grease.

Has the advantages that: compared with the prior art, the invention has the advantages that: e-mail

The invention has simple operation, can effectively reduce the sulfur content in the biological oil product by adding a small amount of copper nitrate, can achieve better desulfurization effect by adding a small amount of copper nitrate catalyst or only adding copper nitrate into the alkaline catalyst, achieves the sulfur content requirement of the biodiesel by adding the sulfur content in the oil product after thermal cracking to be less than 10ppm, and can not achieve the technical effects by using other copper-containing compounds or nitric acid compounds,

Detailed Description

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with examples are described in detail below.

Example 1

The catalytic cracking desulfurization method for the illegal cooking oil comprises the following specific operations:

adding 20g of illegal cooking oil into a pyrolysis reaction device, adding 2g of potassium carbonate and 0.2g of copper nitrate catalyst, starting a thermal cracking heating device and a condensing device, heating to 350 ℃, starting generation of pyrolysis oil steam, liquefying and leading out through the condensing device to obtain thermal cracking oil, collecting the pyrolysis oil, continuously heating to 450 ℃, stopping heating when no liquid flows out, and detecting that the content of sulfur ions is 9.07ppm by using a sulfur-chlorine analyzer after the reaction is finished.

Example 2

The method for thermally cracking and desulfurizing the illegal cooking oil comprises the following specific operations:

adding 1kg of illegal cooking oil into a pyrolysis reaction device, adding 100g of potassium carbonate and 10g of copper nitrate catalyst, starting a thermal cracking heating device and a condensing device, heating to 350 ℃, starting generation of pyrolysis oil steam, liquefying and leading out through the condensing device to obtain thermal cracking oil, collecting the pyrolysis oil, continuously heating to 450 ℃, stopping heating when no liquid flows out, and detecting the obtained pyrolysis oil with a sulfur-chlorine analyzer to ensure that the sulfur ion content is 8.16 ppm.

Compared with the embodiment 1, the embodiment 2 has the advantages that the consumption of raw materials and the consumption of the catalyst are both enlarged by 50 times, and still has good desulfurization effect, which shows that the technical scheme has good stability.

Example 3

The method for thermally cracking and desulfurizing the illegal cooking oil comprises the following specific operations:

adding 2kg of illegal cooking oil into a pyrolysis reaction device, adding 150g of potassium carbonate and 50g of copper nitrate catalyst, starting a thermal cracking heating device and a condensing device, heating to 350 ℃, starting generation of pyrolysis oil steam, liquefying and leading out through the condensing device to obtain thermal cracking oil, collecting the pyrolysis oil, continuously heating to 450 ℃, stopping heating when no liquid flows out, and detecting the sulfur content of the obtained pyrolysis oil to be 7.94ppm by using a sulfur-chlorine analyzer.

Example 4

The catalytic cracking desulfurization method for the illegal cooking oil comprises the following specific operations:

adding 100g of illegal cooking oil into a pyrolysis reaction device, adding 5g of potassium carbonate, 5g of zinc oxide and 1g of copper nitrate catalyst, starting a thermal cracking heating device and a condensing device, heating to 350 ℃, starting generation of pyrolysis oil steam, liquefying and leading out through the condensing device to obtain thermal cracking oil, collecting the pyrolysis oil, continuously heating to 450 ℃, stopping heating when no liquid flows out, and detecting the sulfur content of the obtained pyrolysis oil to be 9.94ppm by using a sulfur-chlorine analyzer.

Example 5

The method for thermally cracking and desulfurizing the illegal cooking oil comprises the following specific operations:

adding 150g of illegal cooking oil into a pyrolysis reaction device, adding 10g of zinc oxide and 4.5g of copper nitrate catalyst, starting a thermal cracking heating device and a condensing device, heating to 350 ℃, starting generation of pyrolysis oil steam, liquefying and leading out through the condensing device to obtain thermal cracking oil, collecting the pyrolysis oil, continuously heating to 450 ℃, stopping heating when no liquid flows out, and detecting the sulfur content of the obtained pyrolysis oil to be 8.56ppm by using a sulfur-chlorine analyzer.

Example 6

The method for thermally cracking and desulfurizing the illegal cooking oil comprises the following specific operations:

adding 50g of illegal cooking oil into a pyrolysis reaction device, adding 4g of zinc oxide and 1g of copper nitrate catalyst, starting a thermal cracking heating device and a condensing device, heating to 350 ℃, starting generation of pyrolysis oil steam, liquefying and leading out through the condensing device to obtain thermal cracking oil, collecting the pyrolysis oil, continuously heating to 450 ℃, stopping heating when no liquid flows out, and detecting the sulfur content of the obtained pyrolysis oil to be 9.56ppm by using a sulfur-chlorine analyzer.

Example 7

The method for thermally cracking and desulfurizing the illegal cooking oil comprises the following specific operations:

adding 70g of illegal cooking oil into a pyrolysis reaction device, adding 2.8g of copper nitrate catalyst, starting a thermal cracking heating device and a condensing device, heating to 350 ℃, starting generation of pyrolysis oil steam, liquefying and leading out through the condensing device to obtain thermal cracking oil, collecting the pyrolysis oil, continuously heating to 450 ℃, stopping heating when no liquid flows out, and detecting the sulfur content of the obtained pyrolysis oil to be 6.29ppm by using a sulfur-chlorine analyzer.

Example 8

The method for thermally cracking and desulfurizing the illegal cooking oil comprises the following specific operations:

adding 70g of illegal cooking oil into a pyrolysis reaction device, adding 0.7g of copper nitrate catalyst, starting a thermal cracking heating device and a condensing device, heating to 350 ℃, starting generation of pyrolysis oil steam, liquefying and leading out through the condensing device to obtain thermal cracking oil, collecting the pyrolysis oil, continuously heating to 450 ℃, stopping heating when no liquid flows out, and detecting the sulfur content of the obtained pyrolysis oil to be 58.88ppm by using a sulfur-chlorine analyzer.

Example 9

The method for thermally cracking and desulfurizing the illegal cooking oil comprises the following specific operations:

adding 20g of illegal cooking oil into a pyrolysis reaction device, adding 0.4g of copper nitrate catalyst, starting a thermal cracking heating device and a condensing device, heating to 350 ℃, starting generation of pyrolysis oil steam, liquefying and leading out through the condensing device to obtain thermal cracking oil, collecting the pyrolysis oil, continuously heating to 450 ℃, stopping heating when no liquid flows out, and detecting the sulfur content of the obtained pyrolysis oil to be 22.77ppm by using a sulfur-chlorine analyzer.

Example 10

The method for thermally cracking and desulfurizing the illegal cooking oil comprises the following specific operations:

adding 20g of illegal cooking oil into a pyrolysis reaction device, adding 0.6g of copper nitrate catalyst, starting a thermal cracking heating device and a condensing device, heating to 350 ℃, starting generation of pyrolysis oil steam, liquefying and leading out through the condensing device to obtain thermal cracking oil, collecting the pyrolysis oil, continuously heating to 450 ℃, stopping heating when no liquid flows out, and detecting the sulfur content of the obtained pyrolysis oil to be 7.03ppm by using a sulfur-chlorine analyzer.

Examples 7-10 are copper nitrate alone catalysts with sulfur levels still high at less than 3% and 58.88ppm and 22.77ppm, respectively, but with sulfur levels significantly reduced at 3% or greater at 7.03ppm and 6.29ppm, respectively.

Comparative example 1

The catalytic cracking method of the illegal cooking oil comprises the following specific operations:

adding 20g of illegal cooking oil into a pyrolysis reaction device, adding the type and the amount of a catalyst according to the result shown in table 1, starting a pyrolysis heating device and a condensing device, liquefying and leading out the generated pyrolysis oil vapor through the condensing device to obtain pyrolysis oil, collecting the pyrolysis oil, stopping heating when no liquid flows out, and detecting the content of sulfur ions by using a sulfur-chlorine analyzer after the reaction is finished, wherein the result is shown in table 1. As can be seen from Table 1, the pyrolysis oil obtained by the catalytic pyrolysis reaction of the basic catalyst or the basic catalyst in combination with other copper salts has a high sulfur content.

TABLE 1 measurement results of comparative example 1

Group of	Catalyst and process for preparing same	Catalyst addition	Sulfur content (ppm)
				1	K2CO3/CuO	10％/1％	50.34
2	K2CO3/Cu(PO4)2	10％/1％	52.29
				3	K2CO3/Cu(CH3COO)2	10％/1％	44.12
4	K2CO3/Cu(OH)2	10％/1％	55.27
				6	K2CO3/ZnO	5％/5％	71.63
8	K2CO3/ZnO/Fe(NO3)3	5％/5％/1％	77.75