阅读说明：本技术 脱除微量乙烯的方法及适用的果蔬保鲜箱和保鲜方法 (Method for removing trace ethylene, and applicable fruit and vegetable fresh-keeping box and fresh-keeping method ) 是由 何涛 谢晓清 管仁贵 于 2020-06-10 设计创作，主要内容包括：本发明公开了脱除微量乙烯的方法及适用的果蔬保鲜箱和保鲜方法。所述方法将混杂臭氧与乙烯的空气先通过臭氧催化剂,然后经过光催化剂解析脱除乙烯。本发明在0~4℃利用臭氧活化后光催化氧化乙烯,使乙烯浓度降低到0.1 ppm以下,果蔬保鲜箱体具有除乙烯效率高、体积小、能耗低、安全环保的特点。本发明的除乙烯装置也适用于冰箱、冷链物流箱车等领域的果蔬保鲜、杀菌和去除异味。(The invention discloses a method for removing trace ethylene, and a fruit and vegetable fresh-keeping box and a fresh-keeping method which are suitable for the method. The method comprises the steps of enabling air mixed with ozone and ethylene to pass through an ozone catalyst, and then desorbing and removing ethylene through a photocatalyst. The method utilizes photocatalysis to oxidize ethylene after ozone activation at 0-4 ℃ so as to reduce the ethylene concentration to be below 0.1 ppm, and the fruit and vegetable fresh-keeping box body has the characteristics of high ethylene removal efficiency, small volume, low energy consumption, safety and environmental protection. The ethylene removing device is also suitable for fruit and vegetable fresh-keeping, sterilization and peculiar smell removal in the fields of refrigerators, cold-chain logistics box vehicles and the like.)

1. The method for removing the trace ethylene is characterized by comprising the following steps:

air mixed with ozone and ethylene passes through an ozone catalyst, then is desorbed and removed with ethylene through a photocatalyst,

wherein the ozone catalyst is a single or composite oxide containing silicon, aluminum, boron, iron, cerium, manganese, copper, zinc, titanium, zirconium, vanadium, nickel, calcium, magnesium, sodium and potassium elements and active carbon as a carrier, single metal nanoparticles or alloy nanoparticles of silver, gold, palladium and platinum as active components,

the photocatalyst is TiO with one of glass, titanium sheet and carbon fiber paper as a carrier and growing in situ on the surface₂A single crystal nanorod array.

2. The fruit and vegetable fresh-keeping box for removing trace ethylene is characterized by comprising a fresh-keeping box body, a circulating fan and an ethylene removing device,

the ethylene removing device comprises an air inlet, an ozone generator, an internal circulation fan, a first gas filter screen, an ozone catalyst, a second gas filter screen, a first LED light source, a photocatalyst, a second LED light source and an air outlet,

the bottom of the ethylene removing device is provided with an air inlet, the top of the ethylene removing device is provided with an air outlet, and the ozone generator, the internal circulation fan, the first gas filter screen, the ozone catalyst, the second gas filter screen, the first LED light source, the photocatalyst and the second LED light source are sequentially arranged inside the ethylene removing device from bottom to top.

3. The fresh-keeping box for fruits and vegetables with trace ethylene removed according to claim 2, wherein the fresh-keeping box body is a fresh-keeping storage chamber for fruits and vegetables.

4. The fruit and vegetable fresh-keeping box for removing trace ethylene according to claim 2, wherein the ozone catalyst is a catalyst containing single or composite oxides of silicon, aluminum, boron, iron, cerium, manganese, copper, zinc, titanium, zirconium, vanadium, nickel, calcium, magnesium, sodium and potassium elements and activated carbon as a carrier, and single metal nanoparticles or alloy nanoparticles of silver, gold, palladium and platinum as active components.

5. The fruit and vegetable fresh-keeping box for removing trace ethylene according to claim 2, wherein the photocatalyst is TiO grown in situ on the surface of one of glass, titanium sheet and carbon fiber paper as a carrier₂A single crystal nanorod array.

6. The fruit and vegetable fresh-keeping box for removing trace ethylene according to claim 2, wherein the wavelengths of the first LED light source and the second LED light source are 200-365 nm.

7. The method for removing trace ethylene in the fruit and vegetable fresh-keeping box for removing trace ethylene in any one of claims 2 to 6, which is characterized by comprising the following steps of:

1) starting a circulating fan to circulate the air in the fresh-keeping box body;

2) starting an ozone generator to release ozone at the temperature of 0-4 ℃, starting an internal circulation fan, fully mixing the ozone produced by the bottom ozone generator with air, making the ozone pass through a first gas filter screen, an ozone catalyst, a second gas filter screen, a first LED light source, a photocatalyst and a second LED light source upwards, and discharging the ozone through an air outlet;

3) after circulating for 4-6 hours, the ethylene concentration in the fresh-keeping box body is reduced to be less than 0.1 ppm.

Technical Field

The invention relates to ethylene removal of fruits and vegetables in storage and cold chain transportation, in particular to a method for removing trace ethylene, and a fruit and vegetable fresh-keeping box and a fresh-keeping method suitable for the method.

Background

Ethylene is ripening hormone of fruits and vegetables, and when the concentration of ethylene is 0.1 ppm, the fruits and vegetables can be induced to ripen more quickly. The fruits and vegetables can spontaneously generate ethylene, and if the ethylene is not timely and effectively removed in the storage and transportation processes, the fruits and vegetables can be quickly rotten. According to statistics, the economic loss caused by fruit and vegetable rot in China is up to 750 billions of yuan per year.

At present, ethylene generated by fruits and vegetables during storage and transportation of the fruits and vegetables is mainly removed by an ethylene adsorbent. However, commercially available products (e.g., porous materials loaded with KMnO₄Noble metals, etc.) on ethyleneThe rate is still to be improved, the dosage of the remover is usually large, and the remover needs to be replaced frequently. Recently, a research on ethylene removal by ozone oxidation was reported, with Skog at 10.5 m³The two ozone generators are arranged in the refrigerating chamber, although the ethylene concentration in the apple and pear storage chambers can be reduced, the ethylene concentration in the storage chambers is still 2.14 ppm/m³While 0.1 ppm of ethylene is present, it affects fruits and vegetables. In recent years, photocatalytic degradation of ethylene is also applied to the field of fruit and vegetable preservation. Wangyi et al reported the use of nano TiO₂The powder is used as an ethylene removal device of the photocatalyst. A photocatalysis ethylene removing device with the patent number of CN 110053881A. However, at present, TiO is used₂The efficiency of the photocatalyst represented by the nanoparticles in the photodegradation of ethylene is yet to be improved. In general, it is difficult to achieve the goal of high efficiency, low cost removal of ethylene using ozone or photocatalysis alone. In addition, the current ethylene removal equipment is usually large, and cannot meet the requirements of miniaturization of the ethylene removal equipment such as a portable fresh-keeping box body, a refrigerator, a fruit and vegetable logistics box vehicle and the like.

Disclosure of Invention

In order to solve the technical problems, the invention provides a method for removing trace ethylene, and a fruit and vegetable fresh-keeping box and a fresh-keeping method which are suitable for the method. The invention can reduce the ethylene concentration to below 0.1 ppm by combining the ozone catalytic oxidation modification with the photocatalysis degradation of ethylene.

The method for removing trace ethylene comprises the following steps:

air mixed with ozone and ethylene passes through an ozone catalyst, then is desorbed and removed with ethylene through a photocatalyst,

the ozone catalyst is a single or composite oxide containing metal elements such as silicon, aluminum, boron, iron, cerium, manganese, copper, zinc, titanium, zirconium, vanadium, nickel, calcium, magnesium, sodium, potassium and the like and active carbon as a carrier, and single metal nanoparticles or alloy nanoparticles of silver, gold, palladium and platinum as active components;

wherein the photocatalyst is TiO grown in situ on the surfaces of glass, titanium sheets, carbon fiber paper and the like₂A single crystal nanorod array.

The fruit and vegetable fresh-keeping box for removing trace ethylene comprises a fresh-keeping box body 100, a circulating fan 101 and an ethylene removing device 200,

the ethylene removing device 200 comprises an air inlet 201, an ozone generator 202, an internal circulation fan 203, a first gas filter 204, an ozone catalyst 205, a second gas filter 206, a first LED light source 207, a photocatalyst 208, a second LED light source 209 and an air outlet 210,

the bottom of the ethylene removing device 200 is provided with an air inlet 201, the top is provided with an air outlet 210, and the ozone generator 202, the internal circulation fan 203, the first gas filter 204, the ozone catalyst 205, the second gas filter 206, the first LED light source 207, the photocatalyst 208 and the second LED light source 209 are sequentially arranged in the ethylene removing device 200 from bottom to top.

Preferably, the fresh-keeping box body 100 is a fruit and vegetable fresh-keeping storage room.

Preferably, the ozone catalyst 205 is a catalyst containing a single or composite oxide of a metal element such as silicon, aluminum, boron, iron, cerium, manganese, copper, zinc, titanium, zirconium, vanadium, nickel, calcium, magnesium, sodium, potassium, or the like, and activated carbon as a carrier, and a single metal nanoparticle or alloy nanoparticle of silver, gold, palladium, platinum as an active component.

Preferably, the photocatalyst 208 is TiO grown in situ on the surface of glass, titanium sheet, carbon fiber paper and the like₂A single crystal nanorod array.

Preferably, the wavelengths of the first LED light source 207 and the second LED light source 209 are 200-365 nm.

The method for removing the trace ethylene in the fruit and vegetable fresh-keeping box for removing the trace ethylene comprises the following steps of:

1) starting a circulating fan 101 to circulate air in the preservation box body 100;

2) under the condition of 0-4 ℃, starting the ozone generator 202 to release ozone, starting the internal circulation fan 203, fully mixing the ozone produced by the bottom ozone generator 202 with air, upwards passing through the first gas filter screen 204, the ozone catalyst 205, the second gas filter screen 206, the first LED light source 207, the photocatalyst 208 and the second LED light source 209, and discharging through the air outlet 210;

3) after circulating for 4-6 hours, the ethylene concentration in the preservation box body 100 is reduced to be below 0.1 ppm.

Advantageous effects

1) The method utilizes photocatalysis to oxidize ethylene after ozone activation at 0-4 ℃ so as to reduce the ethylene concentration to be below 0.1 ppm.

2) The fruit and vegetable fresh-keeping box body has the characteristics of high ethylene removal efficiency, small volume, low energy consumption, safety and environmental protection.

3) The ethylene removal device 200 of the invention is also suitable for fruit and vegetable fresh-keeping, sterilization and odor removal in the fields of refrigerators, cold-chain logistics box trucks and the like.

Drawings

FIG. 1 is a schematic view of the fruit and vegetable fresh-keeping box for removing trace ethylene.

FIG. 2 is a diagram of a fruit and vegetable fresh-keeping box device for removing trace ethylene according to the present invention.

Fig. 3 is the alumina pellet supported gold catalyst of example 1.

FIG. 4 shows TiO of example 1₂XRD and SEM images of the nanoarrays.

Fig. 5 is an activated carbon catalyst supporting a gold-silver alloy of example 1.

FIG. 6 is a graph comparing the ethylene removal of example 1 with comparative examples 1-2.

FIG. 7 is a graph comparing the ethylene removal of example 2 with comparative examples 3-4.

Detailed Description

In order to make the objects and advantages of the invention more comprehensible, specific embodiments of the invention are described in detail below.

As shown in fig. 1 and 2, the fruit and vegetable fresh-keeping box for removing trace ethylene comprises a fresh-keeping box body 100, a circulating fan 101 and an ethylene removing device 200, wherein the ethylene removing device 200 comprises an air inlet 201, an ozone generator 202, an internal circulating fan 203, a first gas filter screen 204, an ozone catalyst 205, a second gas filter screen 206, a first LED light source 207, a photocatalyst 208, a second LED light source 209 and an air outlet 210.

The bottom of the ethylene removal device 200 is provided with an air inlet 201, the top of the ethylene removal device is provided with an air outlet 210, an ozone generator 202, an internal circulation fan 203, a first gas filter screen 204, an ozone catalyst 205, a second gas filter screen 206, a first LED light source 207, a photocatalyst 208 and a second LED light source 209 are sequentially installed inside the ethylene removal device 200 from bottom to top, the ozone generator 202 is a commercially available household ozone generator, the ozone output is 500 mg/h, and the wavelengths of the first LED light source 207 and the second LED light source 209 are 200-365 nm.

The method for removing the trace ethylene in the fruit and vegetable fresh-keeping box for removing the trace ethylene comprises the following steps of:

1) starting a circulating fan 101 to circulate air in the preservation box body 100;

2) under the condition of 0-4 ℃, starting the ozone generator 202 to release ozone, starting the internal circulation fan 203, fully mixing the ozone produced by the ozone generator 202 at the bottom with the gas in the preservation box body 100, upwards passing through the first gas filter screen 204, the ozone catalyst 205, the second gas filter screen 206, the first LED light source 207, the photocatalyst 208 and the second LED light source 209, and discharging through the air outlet 210;

3) after circulating for 4-6 hours, the ethylene concentration in the preservation box body 100 is reduced from 50 ppm to below 0.1 ppm.

The following examples all adopt the above fruit and vegetable fresh-keeping box test for removing trace ethylene.