A method for treating organic solid waste distiller's grains using supercritical CO2

Abstract

The present application relates to a kind of methods for treating organic solid waste distiller's grains with supercritical CO2, relate to the technical field of distiller's grains processing.White liquor distiller's grains is removed impurities, dried, pulverized, neutralized, and pretreated distiller's grains is obtained;The pretreated distiller's grains is sent into supercritical extraction kettle, CO2 is introduced after being closed, extraction is carried out, and supercritical CO2 fluid loaded with effective components and residue after extraction are obtained;The supercritical CO2 fluid loaded with effective components is sent into separation device, and effective component is separated out, and distiller's grains extract is collected and obtained;The present application can efficiently extract various effective components such as aroma and flavor substances, lipids, polyphenols etc.in distiller's grains, realizes the full component of distiller's grains, high-value resource utilization, and greatly improves the economic benefit of distiller's grains processing.

Description

Technical Field

[0001] This invention relates to the field of distiller's grains treatment technology, and in particular to a method for treating organic solid waste distiller's grains using supercritical CO2. Background Technology

[0002] Distillers' grains are a major source of organic solid waste generated by the brewing industry, and are typically characterized by high yield, high moisture content, and high organic matter content. Currently, the main methods for treating distillers' grains are landfill, incineration, and composting. However, these treatment technologies have many drawbacks: landfilling consumes a large amount of land resources, and the soluble organic matter in the grains can seep into the soil and groundwater, causing soil and groundwater pollution; incineration of distillers' grains has a low calorific value, requires the addition of auxiliary fuel during the incineration process, resulting in high energy consumption, and also produces harmful gases; composting has a long treatment cycle, requires a large area, and is prone to producing foul odor pollution.

[0003] Chinese patent with publication number CN111280308A discloses a method for harmless treatment of rice wine lees, including the following steps: (1) pretreatment of rice wine lees; (2) grinding with a colloid mill; (3) spray drying; (4) packaging. This patent utilizes colloid mill technology combined with spray drying technology, so that after the fermented mash is steamed, it can be discharged for continuous grinding, drying and powdering.

[0004] Chinese patent CN113603520A discloses a method for treating fermented distiller's grains, a fermented distiller's grains organic fertilizer and its application. The method involves soaking the distiller's grains in water to remove easily soluble acids and alcohols, resulting in a residue containing nutrients such as cellulose and protein. To address the issue of high moisture content after soaking, a desiccant is mixed into the residue to adjust its moisture content to between 50-60%. After this adjustment, the residue is inoculated with a composting agent and stacked for fermentation.

[0005] The CO2 released from the CO2 recovery and recycling separation unit after the effective components are extracted carries small-molecule organic impurities from the distiller's grains (including lower esters, alcohols, aldehydes, small polyphenol molecules, trace lipids, etc.). These impurities enter the recovery unit with the CO2, and after cooling and pressurization, are directly recycled back to the extraction vessel, which will cause three major technical problems: Deterioration of extraction efficiency: Impurities compete with supercritical CO2 in the extraction vessel to bind with the effective components of the distiller's grains, reducing the extraction rate of aroma and flavor substances, lipids, and polyphenols. Long-term circulation will cause the extraction rate to gradually decrease by 5%-15%. Reduced purity of extract: Impurities in recycled CO2 will mix into the new distillers' grains extract, resulting in a complex composition of the extract, increasing the cost of subsequent separation and purification, and affecting its application in the food and pharmaceutical fields. Decreased equipment and process stability: Small molecule impurities can be adsorbed and accumulated in CO2 delivery pipelines, extraction vessel valves, and heat exchange surfaces of separation devices, causing pipeline blockage, reduced heat exchange efficiency, increased equipment maintenance frequency, and affecting continuous industrial production.

[0006] Existing technologies have shortcomings: they fail to simultaneously extract multiple recyclable components from distiller's grains, resulting in low resource utilization; the extraction rate is low, and CO2 is not recycled, leading to high processing costs and making industrial-scale promotion difficult. Summary of the Invention

[0007] To address the aforementioned problems, this invention provides a method for treating organic solid waste, distiller's grains, using supercritical CO2. The operation steps are as follows: S1: Take the lees of baijiu (Chinese liquor), remove impurities such as stones and mud, dry them, crush them, and neutralize the pH to 7 to obtain pretreated lees; S2: The pretreated lees are fed into a supercritical extraction vessel, sealed, and CO2 is introduced for extraction to obtain a supercritical CO2 fluid loaded with effective components and the residue after extraction; the supercritical CO2 fluid loaded with effective components is sent into a separation device to separate the effective components and collect the lees extract. S3: The residue after extraction of S2 is sent to the activation vessel, an activator is added, and activation is carried out. After activation, it is cooled and crushed to obtain modified distiller's grains residue. S4: The CO2 after the effective components are precipitated in the S2 separation device is sent to the recovery device. After cooling and pressurization, liquid CO2 is obtained and recycled back to the supercritical extraction vessel of S2 for reuse. S5: The CO2 containing impurities discharged from the separation device in S2 is pretreated by a pretreatment unit to remove water and impurities before entering the adsorption tower. Organic impurities are selectively adsorbed and removed by a modified TS-1 titanium-silicon molecular sieve. The purified CO2 flows out from the top of the adsorption tower into a buffer tank. After the modified TS-1 titanium-silicon molecular sieve in the adsorption tower reaches adsorption saturation, the supply of CO2 containing impurities to the adsorption tower is stopped. The adsorption tower is first depressurized in the forward direction to send the high-purity CO2 remaining in the tower into the buffer tank. Then, the adsorption tower is vacuum depressurized to desorb the organic impurities adsorbed on the molecular sieve. Subsequently, the adsorption tower is hot-purged with low-temperature hot purging gas to remove residual impurities in the molecular sieve channels. After regeneration, the adsorption tower is equalized and pressurized to restore it to the adsorption pressure and continues the CO2 purification operation. S6: The purified CO2 in the buffer tank of S5 is sent to the recovery device. After cooling and pressurization, liquid CO2 is obtained. The liquid CO2 is then recycled back to the supercritical extraction vessel of S2 for reuse.

[0008] As a preferred embodiment, the drying temperature of S1 is 60-100℃, the drying time is 2-8h, the particle size of the pulverized lees is 0.3-0.6mm, and the amount of neutralizing agent added is 0.5-2% of the mass of the lees.

[0009] As a preferred embodiment, the neutralizing agent during the neutralization of S1 is one of calcium oxide and sodium bicarbonate.

[0010] As a preferred embodiment, the supercritical extraction vessel of S2 has an extraction pressure of 20-30 MPa, an extraction temperature of 45-65℃, a CO2 flow rate of 80-150 g / min, and an extraction time of 2-4 h.

[0011] As a preferred embodiment, the separation device of S2 adopts a two-stage separation, with a first-stage separation pressure of 8-10MPa and a temperature of 50-60℃; and a second-stage separation pressure of 5-7MPa and a temperature of 40-50℃.

[0012] As a preferred embodiment, the activator of S3 is an aqueous ethanol solution with a volume fraction of 70-95%, and the mass ratio of the activator to the residue after extraction is 0.1-0.5:1.

[0013] As a preferred embodiment, the activation temperature of S3 is 100-130℃, and the activation time is 1-2h.

[0014] As a preferred embodiment, the cooling temperature of the recovery device of S4 is 4-8℃ and the pressurization pressure is 15-25MPa.

[0015] As a preferred embodiment, the preparation method of the modified TS-1 titanium-silicon molecular sieve of S5 is as follows: H1: Take 100-150 parts of TS-1 titanium silicon molecular sieve, add 3-6 parts of aminosilane coupling agent KH-550, 1100-1400 parts of ethanol, and 120-140 parts of water, stir and react at 30-50℃ for 40-80 minutes, filter, and dry. H2: Mix the molecular sieve treated with H1 with 3-7 parts of 4-propenylthiourea and 1500-2000 parts of ethanol, then add 2-5 parts of sodium hydroxide, and heat the mixture under a nitrogen atmosphere. After the reaction is complete, filter, wash and dry to obtain the modified TS-1 titanium silicon molecular sieve.

[0016] As a preferred embodiment, the reaction temperature of H2 is 65-75℃ and the reaction time is 50-100 minutes.

[0017] Reaction Mechanism: Supercritical CO2, with its unique solubility and mass transfer properties, can quickly penetrate into the interior of the distiller's grains matrix and react with the aroma and flavor substances, lipids, polyphenols and other effective components in the distiller's grains, achieving efficient dissolution and extraction of the target components. Modified TS-1 titanium-silicon molecular sieve constructs specific adsorption sites through the addition reaction of amino and propylene groups, which can accurately identify and adsorb small molecule organic impurities entrained in CO2, achieving efficient purification of CO2 and ensuring the stability of the circulating extraction system. At the same time, the residue after extraction undergoes pore structure modification under the action of activator, improving the resource utilization value of the residue.

[0018] This invention provides a method for treating organic solid waste, distiller's grains, using supercritical CO2. Compared with existing technologies, this invention has the following significant advantages: 1. This invention uses supercritical CO2 as the extractant and a modified TS-1 titanium-silicon molecular sieve for CO2 purification, achieving closed-loop recovery and efficient recycling of CO2. The entire process does not use any toxic or harmful organic solvents and has no waste discharge, meeting the requirements of green and environmentally friendly industrial production.

[0019] 2. This invention achieves simultaneous and efficient extraction of various effective components such as aroma and flavor substances, lipids, and polyphenols from distiller's grains through parameter optimization of supercritical extraction process. Furthermore, the residue after extraction can be activated and modified to achieve secondary resource utilization, thus realizing high-value utilization of all components of distiller's grains and improving the overall economic benefits of distiller's grains treatment.

[0020] 3. This invention effectively removes organic impurities from circulating CO2 through the specific adsorption of modified TS-1 titanium-silicon molecular sieve, avoiding interference from impurities in the extraction process, ensuring the stability of extraction efficiency and extract purity, and reducing the accumulation of impurities in equipment pipelines, thereby improving the continuous operation capability of the process and equipment. Detailed Implementation

[0021] To further illustrate the technical means and effects adopted by the present invention to achieve the intended purpose, the following detailed description is provided in conjunction with embodiments and comparative examples: 1. Extraction rate of aroma and flavor substances: The content of aroma and flavor substances in the distillers' grains extract was detected by gas chromatography-mass spectrometry, and the extraction rate was calculated; Extraction rate = (mass of aroma and flavor substances in the extract / mass of aroma and flavor substances in the raw distillers' grains) × 100%.

[0022] 2. Lipid extraction rate: The lipid content in the distillers' grains extract was determined by Soxhlet extraction, and the extraction rate was calculated; Extraction rate = (mass of lipids in the extract / mass of lipids in the raw distillers' grains) × 100%.

[0023] 3. Polyphenol extraction rate: The content of polyphenols in the distillers' grains extract was determined by the Folin-Ciocalteu method, and the extraction rate was calculated; Extraction rate = (mass of polyphenols in the extract / mass of polyphenols in the raw distillers' grains) × 100%.

[0024] Example 1: A method for treating organic solid waste distiller's grains using supercritical CO2, the operation steps of which are as follows: S1: Take the lees of baijiu (Chinese liquor), remove impurities such as stones and mud, dry them, crush them, and neutralize the pH to 7 to obtain pretreated lees; S2: The pretreated lees are fed into a supercritical extraction vessel, sealed, and CO2 is introduced for extraction to obtain a supercritical CO2 fluid loaded with effective components and the residue after extraction; the supercritical CO2 fluid loaded with effective components is sent into a separation device to separate the effective components and collect the lees extract. S3: The residue after extraction of S2 is sent to the activation vessel, an activator is added, and activation is carried out. After activation, it is cooled and crushed to obtain modified distiller's grains residue. S4: The CO2 after the effective components are precipitated in the S2 separation device is sent to the recovery device. After cooling and pressurization, liquid CO2 is obtained and recycled back to the supercritical extraction vessel of S2 for reuse. S5: The CO2 containing impurities discharged from the separation device in S2 is pretreated by a pretreatment unit to remove water and impurities before entering the adsorption tower. Organic impurities are selectively adsorbed and removed by a modified TS-1 titanium-silicon molecular sieve. The purified CO2 flows out from the top of the adsorption tower into a buffer tank. After the modified TS-1 titanium-silicon molecular sieve in the adsorption tower reaches adsorption saturation, the supply of CO2 containing impurities to the adsorption tower is stopped. The adsorption tower is first depressurized in the forward direction to send the high-purity CO2 remaining in the tower into the buffer tank. Then, the adsorption tower is vacuum depressurized to desorb the organic impurities adsorbed on the molecular sieve. Subsequently, the adsorption tower is hot-purged with low-temperature hot purging gas to remove residual impurities in the molecular sieve channels. After regeneration, the adsorption tower is equalized and pressurized to restore it to the adsorption pressure and continues the CO2 purification operation. S6: The purified CO2 in the buffer tank of S5 is sent to the recovery device. After cooling and pressurization, liquid CO2 is obtained. The liquid CO2 is then recycled back to the supercritical extraction vessel of S2 for reuse.

[0025] The drying temperature of S1 is 60℃ and the drying time is 2h; the particle size of the pulverized lees is 0.3mm; the amount of neutralizing agent added is 0.5% of the mass of the lees.

[0026] The neutralizing agent during the neutralization of S1 is calcium oxide.

[0027] The supercritical extraction vessel of S2 has an extraction pressure of 20 MPa, an extraction temperature of 45 °C, a CO2 flow rate of 80 g / min, and an extraction time of 2 h.

[0028] The separation device of S2 adopts two-stage separation: the first stage separation pressure is 8MPa and the temperature is 50℃; the second stage separation pressure is 5MPa and the temperature is 40℃.

[0029] The activator of S3 is a 70% (v / v) aqueous solution of ethanol, and the mass ratio of the activator to the residue after extraction is 0.1:1.

[0030] The activation temperature of S3 is 100℃, and the activation time is 1 hour.

[0031] The cooling temperature of the S4 recovery device is 4°C, and the pressurization pressure is 15MPa.

[0032] The preparation method of the modified TS-1 titanium-silicon molecular sieve of S5 is as follows: H1: Take 100kg of TS-1 titanium silicon molecular sieve, add 3kg of aminosilane coupling agent KH-550, 1100kg of ethanol and 120kg of water, stir and react at 30℃ for 40 minutes, filter and dry. H2: The molecular sieve treated with H1 was mixed with 3 kg of 4-propenylthiourea (CAS: 3766-55-0) and 1500 kg of ethanol, and then 2 kg of sodium hydroxide was added. The mixture was heated under a nitrogen atmosphere and reacted. After the reaction was completed, the mixture was filtered, washed and dried to obtain the modified TS-1 titanium-silicon molecular sieve.

[0033] The reaction temperature of H2 is 65℃, and the reaction time is 50 minutes.

[0034] Example 2: A method for treating organic solid waste distiller's grains using supercritical CO2, the operation steps of which are as follows: S1: Take the lees of baijiu (Chinese liquor), remove impurities such as stones and mud, dry them, crush them, and neutralize the pH to 7 to obtain pretreated lees; S2: The pretreated lees are fed into a supercritical extraction vessel, sealed, and CO2 is introduced for extraction to obtain a supercritical CO2 fluid loaded with effective components and the residue after extraction; the supercritical CO2 fluid loaded with effective components is sent into a separation device to separate the effective components and collect the lees extract. S3: The residue after extraction of S2 is sent to the activation vessel, an activator is added, and activation is carried out. After activation, it is cooled and crushed to obtain modified distiller's grains residue. S4: The CO2 after the effective components are precipitated in the S2 separation device is sent to the recovery device. After cooling and pressurization, liquid CO2 is obtained and recycled back to the supercritical extraction vessel of S2 for reuse. S5: The CO2 containing impurities discharged from the separation device in S2 is pretreated by a pretreatment unit to remove water and impurities before entering the adsorption tower. Organic impurities are selectively adsorbed and removed by a modified TS-1 titanium-silicon molecular sieve. The purified CO2 flows out from the top of the adsorption tower into a buffer tank. After the modified TS-1 titanium-silicon molecular sieve in the adsorption tower reaches adsorption saturation, the supply of CO2 containing impurities to the adsorption tower is stopped. The adsorption tower is first depressurized in the forward direction to send the high-purity CO2 remaining in the tower into the buffer tank. Then, the adsorption tower is vacuum depressurized to desorb the organic impurities adsorbed on the molecular sieve. Subsequently, the adsorption tower is hot-purged with low-temperature hot purging gas to remove residual impurities in the molecular sieve channels. After regeneration, the adsorption tower is equalized and pressurized to restore it to the adsorption pressure and continues the CO2 purification operation. S6: The purified CO2 in the buffer tank of S5 is sent to the recovery device. After cooling and pressurization, liquid CO2 is obtained. The liquid CO2 is then recycled back to the supercritical extraction vessel of S2 for reuse.

[0035] The drying temperature of S1 is 70℃ and the drying time is 4h; the particle size of the pulverized lees is 0.4mm; the amount of neutralizing agent added is 1% of the mass of the lees.

[0036] The neutralizing agent during the neutralization of S1 is calcium oxide.

[0037] The supercritical extraction vessel of S2 has an extraction pressure of 25 MPa, an extraction temperature of 50 °C, a CO2 flow rate of 100 g / min, and an extraction time of 3 h.

[0038] The separation device of S2 adopts two-stage separation: the first stage separation pressure is 9MPa and the temperature is 55℃; the second stage separation pressure is 6MPa and the temperature is 45℃.

[0039] The activator of S3 is an 80% (v / v) aqueous solution of ethanol, and the mass ratio of the activator to the residue after extraction is 0.2:1.

[0040] The activation temperature of S3 is 110℃ and the activation time is 1.5h.

[0041] The cooling temperature of the S4 recovery device is 5°C, and the pressurization pressure is 18MPa.

[0042] The preparation method of the modified TS-1 titanium-silicon molecular sieve of S5 is as follows: H1: Take 110kg of TS-1 titanium silicon molecular sieve, add 4kg of aminosilane coupling agent KH-550, 1200kg of ethanol and 125kg of water, stir and react at 35℃ for 50 minutes, filter and dry. H2: The molecular sieve treated with H1 was mixed with 4 kg of 4-propenylthiourea (CAS: 3766-55-0) and 1600 kg of ethanol, and then 3 kg of sodium hydroxide was added. The mixture was heated under a nitrogen atmosphere and reacted. After the reaction was completed, the mixture was filtered, washed and dried to obtain the modified TS-1 titanium-silicon molecular sieve.

[0043] The reaction temperature of H2 is 70℃, and the reaction time is 60 minutes.

[0044] Example 3: A method for treating organic solid waste distiller's grains using supercritical CO2, the operation steps of which are as follows: S1: Take the lees of baijiu (Chinese liquor), remove impurities such as stones and mud, dry them, crush them, and neutralize the pH to 7 to obtain pretreated lees; S2: The pretreated lees are fed into a supercritical extraction vessel, sealed, and CO2 is introduced for extraction to obtain a supercritical CO2 fluid loaded with effective components and the residue after extraction; the supercritical CO2 fluid loaded with effective components is sent into a separation device to separate the effective components and collect the lees extract. S3: The residue after extraction of S2 is sent to the activation vessel, an activator is added, and activation is carried out. After activation, it is cooled and crushed to obtain modified distiller's grains residue. S4: The CO2 after the effective components are precipitated in the S2 separation device is sent to the recovery device. After cooling and pressurization, liquid CO2 is obtained and recycled back to the supercritical extraction vessel of S2 for reuse. S5: The CO2 containing impurities discharged from the separation device in S2 is pretreated by a pretreatment unit to remove water and impurities before entering the adsorption tower. Organic impurities are selectively adsorbed and removed by a modified TS-1 titanium-silicon molecular sieve. The purified CO2 flows out from the top of the adsorption tower into a buffer tank. After the modified TS-1 titanium-silicon molecular sieve in the adsorption tower reaches adsorption saturation, the supply of CO2 containing impurities to the adsorption tower is stopped. The adsorption tower is first depressurized in the forward direction to send the high-purity CO2 remaining in the tower into the buffer tank. Then, the adsorption tower is vacuum depressurized to desorb the organic impurities adsorbed on the molecular sieve. Subsequently, the adsorption tower is hot-purged with low-temperature hot purging gas to remove residual impurities in the molecular sieve channels. After regeneration, the adsorption tower is equalized and pressurized to restore it to the adsorption pressure and continues the CO2 purification operation. S6: The purified CO2 in the buffer tank of S5 is sent to the recovery device. After cooling and pressurization, liquid CO2 is obtained. The liquid CO2 is then recycled back to the supercritical extraction vessel of S2 for reuse.

[0045] The drying temperature of S1 is 90℃ and the drying time is 6h; the particle size of the pulverized lees is 0.5mm; the amount of neutralizing agent added is 1.5% of the mass of the lees.

[0046] The neutralizing agent during the neutralization of S1 is sodium bicarbonate.

[0047] The supercritical extraction vessel of S2 has an extraction pressure of 25 MPa, an extraction temperature of 60 °C, a CO2 flow rate of 130 g / min, and an extraction time of 3 h.

[0048] The separation device of S2 adopts two-stage separation: the first stage separation pressure is 9MPa and the temperature is 55℃; the second stage separation pressure is 6MPa and the temperature is 45℃.

[0049] The activator of S3 is a 90% (v / v) aqueous solution of ethanol, and the mass ratio of the activator to the residue after extraction is 0.4:1.

[0050] The activation temperature of S3 is 120℃ and the activation time is 1.5h.

[0051] The cooling temperature of the S4 recovery device is 7°C, and the pressurization pressure is 23 MPa.

[0052] The preparation method of the modified TS-1 titanium-silicon molecular sieve of S5 is as follows: H1: Take 140kg of TS-1 titanium silicon molecular sieve, add 5kg of aminosilane coupling agent KH-550, 1300kg of ethanol and 135kg of water, stir and react at 45℃ for 60 minutes, filter and dry. H2: The molecular sieve treated with H1 was mixed with 6 kg of 4-propenylthiourea (CAS: 3766-55-0) and 1900 kg of ethanol, and then 4 kg of sodium hydroxide was added. The mixture was heated and reacted under a nitrogen atmosphere. After the reaction was completed, the mixture was filtered, washed and dried to obtain the modified TS-1 titanium-silicon molecular sieve.

[0053] The reaction temperature of H2 is 70℃ and the reaction time is 90 minutes.

[0054] Example 4: A method for treating organic solid waste distiller's grains using supercritical CO2, the operation steps of which are as follows: S1: Take the lees of baijiu (Chinese liquor), remove impurities such as stones and mud, dry them, crush them, and neutralize the pH to 7 to obtain pretreated lees; S2: The pretreated lees are fed into a supercritical extraction vessel, sealed, and CO2 is introduced for extraction to obtain a supercritical CO2 fluid loaded with effective components and the residue after extraction; the supercritical CO2 fluid loaded with effective components is sent into a separation device to separate the effective components and collect the lees extract. S3: The residue after extraction of S2 is sent to the activation vessel, an activator is added, and activation is carried out. After activation, it is cooled and crushed to obtain modified distiller's grains residue. S4: The CO2 after the effective components are precipitated in the S2 separation device is sent to the recovery device. After cooling and pressurization, liquid CO2 is obtained and recycled back to the supercritical extraction vessel of S2 for reuse. S5: The CO2 containing impurities discharged from the separation device in S2 is pretreated by a pretreatment unit to remove water and impurities before entering the adsorption tower. Organic impurities are selectively adsorbed and removed by a modified TS-1 titanium-silicon molecular sieve. The purified CO2 flows out from the top of the adsorption tower into a buffer tank. After the modified TS-1 titanium-silicon molecular sieve in the adsorption tower reaches adsorption saturation, the supply of CO2 containing impurities to the adsorption tower is stopped. The adsorption tower is first depressurized in the forward direction to send the high-purity CO2 remaining in the tower into the buffer tank. Then, the adsorption tower is vacuum depressurized to desorb the organic impurities adsorbed on the molecular sieve. Subsequently, the adsorption tower is hot-purged with low-temperature hot purging gas to remove residual impurities in the molecular sieve channels. After regeneration, the adsorption tower is equalized and pressurized to restore it to the adsorption pressure and continues the CO2 purification operation. S6: The purified CO2 in the buffer tank of S5 is sent to the recovery device. After cooling and pressurization, liquid CO2 is obtained. The liquid CO2 is then recycled back to the supercritical extraction vessel of S2 for reuse.

[0055] The drying temperature of S1 is 100℃ and the drying time is 8h; the particle size of the pulverized lees is 0.6mm; the amount of neutralizing agent added is 2% of the mass of the lees.

[0056] The neutralizing agent during the neutralization of S1 is sodium bicarbonate.

[0057] The supercritical extraction vessel of S2 has an extraction pressure of 30 MPa, an extraction temperature of 65 °C, a CO2 flow rate of 150 g / min, and an extraction time of 4 h.

[0058] The separation device of S2 adopts two-stage separation: the first stage separation pressure is 10MPa and the temperature is 60℃; the second stage separation pressure is 7MPa and the temperature is 50℃.

[0059] The activator of S3 is a 95% (v / v) aqueous solution of ethanol, and the mass ratio of the activator to the residue after extraction is 0.5:1.

[0060] The activation temperature of S3 is 130℃, and the activation time is 2h.

[0061] The cooling temperature of the S4 recovery device is 8°C, and the pressurization pressure is 25 MPa.

[0062] The preparation method of the modified TS-1 titanium-silicon molecular sieve of S5 is as follows: H1: Take 150kg of TS-1 titanium silicon molecular sieve, add 6kg of aminosilane coupling agent KH-550, 1400kg of ethanol and 140kg of water, stir and react at 50℃ for 80 minutes, filter and dry. H2: The molecular sieve treated with H1 was mixed with 7 kg of 4-propenylthiourea (CAS: 3766-55-0) and 2000 kg of ethanol, and then 5 kg of sodium hydroxide was added. The mixture was heated under a nitrogen atmosphere and reacted. After the reaction was completed, the mixture was filtered, washed and dried to obtain the modified TS-1 titanium silicon molecular sieve.

[0063] The reaction temperature of H2 is 75℃, and the reaction time is 100 minutes.

[0064] Comparative Example 1: A method for treating organic solid waste distillers' grains using supercritical CO2, the operation steps of which are as follows: S1: Take the lees of baijiu (Chinese liquor), remove impurities such as stones and mud, dry them, crush them, and neutralize the pH to 7 to obtain pretreated lees; S2: The pretreated lees are fed into a supercritical extraction vessel, sealed, and CO2 is introduced for extraction to obtain a supercritical CO2 fluid loaded with effective components and the residue after extraction; the supercritical CO2 fluid loaded with effective components is sent into a separation device to separate the effective components and collect the lees extract. S3: The residue after extraction of S2 is sent to the activation vessel, an activator is added, and activation is carried out. After activation, it is cooled and crushed to obtain modified distiller's grains residue. S4: The CO2 after the effective components are precipitated in the S2 separation device is sent to the recovery device. After cooling and pressurization, liquid CO2 is obtained and recycled back to the supercritical extraction vessel of S2 for reuse. S5: The CO2 containing impurities discharged from the separation device in S2 is pretreated by a pretreatment unit to remove water and impurities before entering the adsorption tower. Organic impurities are selectively adsorbed and removed by the TS-1 titanium-silicon molecular sieve. The purified CO2 flows out from the top of the adsorption tower into a buffer tank. After the TS-1 titanium-silicon molecular sieve in the adsorption tower reaches adsorption saturation, the supply of CO2 containing impurities to the adsorption tower is stopped. The adsorption tower is first depressurized in the forward direction to send the high-purity CO2 remaining in the tower into the buffer tank. Then, the adsorption tower is vacuum depressurized to desorb the organic impurities adsorbed on the molecular sieve. Subsequently, the adsorption tower is hot-purged with low-temperature hot purging gas to remove the residual impurities in the molecular sieve channels. After regeneration, the adsorption tower is equalized and pressurized to restore it to the adsorption pressure and continues the CO2 purification operation. S6: The purified CO2 in the buffer tank of S5 is sent to the recovery device. After cooling and pressurization, liquid CO2 is obtained. The liquid CO2 is then recycled back to the supercritical extraction vessel of S2 for reuse.

[0065] The drying temperature of S1 is 60℃ and the drying time is 2h; the particle size of the pulverized lees is 0.3mm; the amount of neutralizing agent added is 0.5% of the mass of the lees.

[0066] The neutralizing agent during the neutralization of S1 is calcium oxide.

[0067] The supercritical extraction vessel of S2 has an extraction pressure of 20 MPa, an extraction temperature of 45 °C, a CO2 flow rate of 80 g / min, and an extraction time of 2 h.

[0068] The separation device of S2 adopts two-stage separation: the first stage separation pressure is 8MPa and the temperature is 50℃; the second stage separation pressure is 5MPa and the temperature is 40℃.

[0069] The activator of S3 is a 70% (v / v) aqueous solution of ethanol, and the mass ratio of the activator to the residue after extraction is 0.1:1.

[0070] The activation temperature of S3 is 100℃, and the activation time is 1 hour.

[0071] The cooling temperature of the S4 recovery device is 4°C, and the pressurization pressure is 15MPa.

[0072] Comparative Example 2: A method for treating organic solid waste distiller's grains using supercritical CO2, the operation steps of which are as follows: S1: Take the lees of baijiu (Chinese liquor), remove impurities such as stones and mud, dry them, crush them, and neutralize the pH to 7 to obtain pretreated lees; S2: The pretreated lees are fed into a supercritical extraction vessel, sealed, and CO2 is introduced for extraction to obtain a supercritical CO2 fluid loaded with effective components and the residue after extraction; the supercritical CO2 fluid loaded with effective components is sent into a separation device to separate the effective components and collect the lees extract. S3: The residue after extraction of S2 is sent to the activation vessel, an activator is added, and activation is carried out. After activation, it is cooled and crushed to obtain modified distiller's grains residue. S4: The CO2 after the effective components are precipitated in the S2 separation device is sent to the recovery device. After cooling and pressurization, liquid CO2 is obtained and recycled back to the supercritical extraction vessel of S2 for reuse. S5: The CO2 containing impurities discharged from the separation device in S2 is pretreated by a pretreatment unit to remove water and impurities before entering the adsorption tower. Organic impurities are selectively adsorbed and removed by a modified TS-1 titanium-silicon molecular sieve. The purified CO2 flows out from the top of the adsorption tower into a buffer tank. After the modified TS-1 titanium-silicon molecular sieve in the adsorption tower reaches adsorption saturation, the supply of CO2 containing impurities to the adsorption tower is stopped. The adsorption tower is first depressurized in the forward direction to send the high-purity CO2 remaining in the tower into the buffer tank. Then, the adsorption tower is vacuum depressurized to desorb the organic impurities adsorbed on the molecular sieve. Subsequently, the adsorption tower is hot-purged with low-temperature hot purging gas to remove residual impurities in the molecular sieve channels. After regeneration, the adsorption tower is equalized and pressurized to restore it to the adsorption pressure and continues the CO2 purification operation. S6: The purified CO2 in the buffer tank of S5 is sent to the recovery device. After cooling and pressurization, liquid CO2 is obtained. The liquid CO2 is then recycled back to the supercritical extraction vessel of S2 for reuse.

[0073] The drying temperature of S1 is 60℃ and the drying time is 2h; the particle size of the pulverized lees is 0.3mm; the amount of neutralizing agent added is 0.5% of the mass of the lees.

[0074] The neutralizing agent during the neutralization of S1 is calcium oxide.

[0075] The supercritical extraction vessel of S2 has an extraction pressure of 20 MPa, an extraction temperature of 45 °C, a CO2 flow rate of 80 g / min, and an extraction time of 2 h.

[0076] The separation device of S2 adopts two-stage separation: the first stage separation pressure is 8MPa and the temperature is 50℃; the second stage separation pressure is 5MPa and the temperature is 40℃.

[0077] The activator of S3 is a 70% (v / v) aqueous solution of ethanol, and the mass ratio of the activator to the residue after extraction is 0.1:1.

[0078] The activation temperature of S3 is 100℃, and the activation time is 1 hour.

[0079] The cooling temperature of the S4 recovery device is 4°C, and the pressurization pressure is 15MPa.

[0080] The preparation method of the modified TS-1 titanium-silicon molecular sieve of S5 is as follows: H1: Take 100kg of TS-1 titanium silicon molecular sieve, add 1100kg of ethanol and 120kg of water, stir and react at 30℃ for 40 minutes, filter, and dry. H2: The molecular sieve treated with H1 was mixed with 3 kg of 4-propenylthiourea (CAS: 3766-55-0) and 1500 kg of ethanol, and then 2 kg of sodium hydroxide was added. The mixture was heated under a nitrogen atmosphere and reacted. After the reaction was completed, the mixture was filtered, washed and dried to obtain the modified TS-1 titanium-silicon molecular sieve.

[0081] The reaction temperature of H2 is 65℃, and the reaction time is 50 minutes.

[0082] Comparative Example 3: A method for treating organic solid waste distiller's grains using supercritical CO2, the operation steps of which are as follows: S1: Take the lees of baijiu (Chinese liquor), remove impurities such as stones and mud, dry them, crush them, and neutralize the pH to 7 to obtain pretreated lees; S2: The pretreated lees are fed into a supercritical extraction vessel, sealed, and CO2 is introduced for extraction to obtain a supercritical CO2 fluid loaded with effective components and the residue after extraction; the supercritical CO2 fluid loaded with effective components is sent into a separation device to separate the effective components and collect the lees extract. S3: The residue after extraction of S2 is sent to the activation vessel, an activator is added, and activation is carried out. After activation, it is cooled and crushed to obtain modified distiller's grains residue. S4: The CO2 after the effective components are precipitated in the S2 separation device is sent to the recovery device. After cooling and pressurization, liquid CO2 is obtained and recycled back to the supercritical extraction vessel of S2 for reuse. S5: The CO2 containing impurities discharged from the separation device in S2 is pretreated by a pretreatment unit to remove water and impurities before entering the adsorption tower. Organic impurities are selectively adsorbed and removed by a modified TS-1 titanium-silicon molecular sieve. The purified CO2 flows out from the top of the adsorption tower into a buffer tank. After the modified TS-1 titanium-silicon molecular sieve in the adsorption tower reaches adsorption saturation, the supply of CO2 containing impurities to the adsorption tower is stopped. The adsorption tower is first depressurized in the forward direction to send the high-purity CO2 remaining in the tower into the buffer tank. Then, the adsorption tower is vacuum depressurized to desorb the organic impurities adsorbed on the molecular sieve. Subsequently, the adsorption tower is hot-purged with low-temperature hot purging gas to remove residual impurities in the molecular sieve channels. After regeneration, the adsorption tower is equalized and pressurized to restore it to the adsorption pressure and continues the CO2 purification operation. S6: The purified CO2 in the buffer tank of S5 is sent to the recovery device. After cooling and pressurization, liquid CO2 is obtained. The liquid CO2 is then recycled back to the supercritical extraction vessel of S2 for reuse.

[0083] The drying temperature of S1 is 60℃ and the drying time is 2h; the particle size of the pulverized lees is 0.3mm; the amount of neutralizing agent added is 0.5% of the mass of the lees.

[0084] The neutralizing agent during the neutralization of S1 is calcium oxide.

[0085] The supercritical extraction vessel of S2 has an extraction pressure of 20 MPa, an extraction temperature of 45 °C, a CO2 flow rate of 80 g / min, and an extraction time of 2 h.

[0086] The separation device of S2 adopts two-stage separation: the first stage separation pressure is 8MPa and the temperature is 50℃; the second stage separation pressure is 5MPa and the temperature is 40℃.

[0087] The activator of S3 is a 70% (v / v) aqueous solution of ethanol, and the mass ratio of the activator to the residue after extraction is 0.1:1.

[0088] The activation temperature of S3 is 100℃, and the activation time is 1 hour.

[0089] The cooling temperature of the S4 recovery device is 4°C, and the pressurization pressure is 15MPa.

[0090] The preparation method of the modified TS-1 titanium-silicon molecular sieve of S5 is as follows: H1: Take 100kg of TS-1 titanium silicon molecular sieve, add 3kg of aminosilane coupling agent KH-550, 1100kg of ethanol and 120kg of water, stir and react at 30℃ for 40 minutes, filter and dry. H2: Mix the molecular sieve treated with H1 with 1500 kg of ethanol, then add 2 kg of sodium hydroxide, and heat the mixture under a nitrogen atmosphere. After the reaction is complete, filter, wash, and dry to obtain the modified TS-1 titanium-silicon molecular sieve.

[0091] The reaction temperature of H2 is 65℃, and the reaction time is 50 minutes.

[0092] Table 1: Results of extraction rates of aroma and flavor compounds, lipids, and polyphenols from distiller's grains in each example and comparative example.

[0093] The test data show that the extraction rates of aroma and flavor substances, lipids, and polyphenols from the lees in this embodiment of the invention are significantly higher than those in the comparative example, fully demonstrating that the treatment method can efficiently extract various effective components from the lees. Among them, the TS-1 titanium-silicon molecular sieve modified by the amino-propylene addition reaction achieves precise removal of organic impurities from the circulating CO2, effectively avoiding problems such as impurities competing for extraction and mixing into the extract, which is a key innovation point for improving the extraction rate of various effective components. At the same time, the comparative data also shows that the process parameter optimization and whole-process design of this invention are significantly better than traditional treatment methods, providing an efficient and feasible technical solution for the high-value resource utilization of lees.

[0094] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A method for treating organic solid waste distiller's grains using supercritical CO2, characterized in that: The operating steps are as follows: S1: Take the lees of baijiu (Chinese liquor), remove stones, mud and sand impurities, dry, crush, and neutralize the pH to 7 to obtain pretreated lees; S2: The pretreated lees are fed into a supercritical extraction vessel, sealed, and CO2 is introduced for extraction to obtain a supercritical CO2 fluid loaded with effective components and the residue after extraction. A supercritical CO2 fluid loaded with active ingredients is fed into a separation device to separate the active ingredients and collect the distillers' grains extract. S3: The residue after extraction of S2 is sent to the activation vessel, an activator is added, and activation is carried out. After activation, it is cooled and crushed to obtain modified distiller's grains residue. S4: The CO2 after the effective components are precipitated in the S2 separation device is sent to the recovery device. After cooling and pressurization, liquid CO2 is obtained and recycled back to the supercritical extraction vessel of S2 for reuse. S5: The CO2 containing impurities discharged from the separation device in S2 is pretreated by a pretreatment unit to remove water and impurities before entering the adsorption tower. Organic impurities are selectively adsorbed and removed by a modified TS-1 titanium-silicon molecular sieve. The purified CO2 flows out from the top of the adsorption tower into a buffer tank. After the modified TS-1 titanium-silicon molecular sieve in the adsorption tower reaches adsorption saturation, the supply of CO2 containing impurities to the adsorption tower is stopped. The adsorption tower is first depressurized in the forward direction to send the high-purity CO2 remaining in the tower into the buffer tank. Then, the adsorption tower is vacuum depressurized to desorb the organic impurities adsorbed on the molecular sieve. Subsequently, the adsorption tower is hot-purged with low-temperature hot purging gas to remove residual impurities in the molecular sieve channels. After regeneration, the adsorption tower is equalized and pressurized to restore it to the adsorption pressure and continues the CO2 purification operation. S6: The purified CO2 in the buffer tank of S5 is sent to the recovery device. After cooling and pressurization, liquid CO2 is obtained. The liquid CO2 is then recycled back to the supercritical extraction vessel of S2 for reuse. The modified TS-1 titanium-silicon molecular sieve of S5 is prepared by reacting TS-1 titanium-silicon molecular sieve, aminosilane coupling agent KH-550, 4-propenylthioaminourea, and sodium hydroxide.

2. The method for treating organic solid waste distiller's grains using supercritical CO2 according to claim 1, characterized in that: The drying temperature of S1 is 60-100℃, and the drying time is 2-8h; the particle size of the pulverized lees is 0.3-0.6mm; the amount of neutralizing agent added is 0.5-2% of the mass of the lees.

3. The method for treating organic solid waste distiller's grains using supercritical CO2 according to claim 1, characterized in that: The neutralizing agent during the neutralization of S1 is one of calcium oxide and sodium bicarbonate.

4. The method for treating organic solid waste distiller's grains using supercritical CO2 according to claim 1, characterized in that: The supercritical extraction vessel of S2 has an extraction pressure of 20-30 MPa, an extraction temperature of 45-65℃, a CO2 flow rate of 80-150 g / min, and an extraction time of 2-4 h.

5. The method for treating organic solid waste distiller's grains using supercritical CO2 according to claim 1, characterized in that: The separation device of S2 adopts two-stage separation: the first stage separation pressure is 8-10MPa and the temperature is 50-60℃; the second stage separation pressure is 5-7MPa and the temperature is 40-50℃.

6. The method for treating organic solid waste distiller's grains using supercritical CO2 according to claim 1, characterized in that: The activator of S3 is an aqueous ethanol solution with a volume fraction of 70-95%, and the mass ratio of the activator to the residue after extraction is 0.1-0.5:

1.

7. The method for treating organic solid waste distiller's grains using supercritical CO2 according to claim 1, characterized in that: The activation temperature of S3 is 100-130℃, and the activation time is 1-2h.

8. The method for treating organic solid waste distiller's grains using supercritical CO2 according to claim 1, characterized in that: The cooling temperature of the S4 recovery device is 4-8℃, and the pressurization pressure is 15-25MPa.

9. A method for treating organic solid waste distiller's grains using supercritical CO2 according to claim 1, characterized in that: The preparation method of the modified TS-1 titanium-silicon molecular sieve of S5 is as follows: H1: Take 100-150 parts of TS-1 titanium silicon molecular sieve, add 3-6 parts of aminosilane coupling agent KH-550, 1100-1400 parts of ethanol, and 120-140 parts of water, stir and react at 30-50℃ for 40-80 minutes, filter, and dry. H2: Mix the molecular sieve treated with H1 with 3-7 parts of 4-propenylthiourea and 1500-2000 parts of ethanol, then add 2-5 parts of sodium hydroxide, and heat the mixture under a nitrogen atmosphere. After the reaction is complete, filter, wash and dry to obtain the modified TS-1 titanium silicon molecular sieve.

10. A method for treating organic solid waste distiller's grains using supercritical CO2 according to claim 9, characterized in that: The reaction temperature of H2 is 65-75℃, and the reaction time is 50-100 minutes.

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