超临界流体开始在农业中发挥作用。一般来说，植物根系只能吸收少量的肥料，但通过超临界流体的技术得到的纳米颗粒可以大大提高肥料的吸收率，减缓农药的过量施用和导致土壤污染，实现新的高效生态农业。

许多物质可以达到超临界状态。由于二氧化碳的临界温度为31°C，压力为74 bar，无毒、不易燃、化学惰性、成本低，因此二氧化碳常被选为绿色溶剂。换句话说，你可以使用超临界二氧化碳液在温和条件下提取物质，而不会产生有害物质。对于大多数溶质，超临界CO2的溶剂能力类似于轻烃，如己烷和戊烷。

除萃取外，超临界二氧化碳还可用于控制固态颗粒的尺寸。这可以通过在超临界相中溶解材料，然后通过降低压力快速膨胀内容物来实现，在这种情况下，溶解的材料迅速膨胀。这种快速膨胀防止了材料的聚集或晶体生长，导致在纳米尺度上形成精细分段固体。这种特殊的过程被称为CO2超临界发泡过程。

超临界CO2流体也容易与氮气或氢气等气体混合，溶解气体的浓度比使用溶剂时高得多。这对于合成变化如氢化是非常有用的。

Supercritical fluids are beginning to play a role in agriculture. Generally speaking, plant roots can only absorb a small amount of fertilizer, but the nanoparticles obtained through supercritical fluid technology can greatly improve the absorption rate of fertilizer, slow down excessive pesticide application and soil pollution, and achieve new and efficient ecological agriculture.

Many substances can reach supercritical states. Because of its critical temperature of 31°C and pressure of 74 bar, carbon dioxide is non-toxic, non-flammable, chemically inert, and low cost, carbon dioxide is often chosen as a green solvent. In other words, you can use supercritical carbon dioxide liquid to extract substances under mild conditions without producing harmful substances. For most solutes, the solvent capacity of supercritical CO2 is similar to that of light hydrocarbons such as hexane and pentane

In addition to extraction, supercritical carbon dioxide can also be used to control the size of solid particles. This can be achieved by dissolving the material in a supercritical phase and then rapidly expanding the contents by reducing the pressure, in which case the dissolved material rapidly expands. This rapid expansion prevents the aggregation or crystal growth of the material, resulting in the formation of finely segmented solids at the nanoscale. This particular process is called the CO2 supercritical foaming process.

Supercritical CO2 fluids also easily mix with gases such as nitrogen or hydrogen, and the concentration of dissolved gas is much higher than when using solvents. This is very useful for synthetic changes such as hydrogenation.

图1 超临界二氧化碳萃取装置A

FIG. 1 Supercritical carbon dioxide extraction device A

图2 超临界二氧化碳萃取装置B

FIG. 2 Supercritical carbon dioxide extraction device B

超临界CO2的应用包括提取（超临界CO2萃取比传统的有机溶液萃取更具扩散性和选择性，并且可以调整性质以提取不同组分）和浸渍（用超临界流体浸渍以将活性材料输送到惰性物质的表面）。

超临界干燥涉及从超临界溶液到气体的相变。该方法首先适用于气凝胶的干燥）。图3显示了间歇式氢气导入型超临界二氧化碳处理装置。图4为连续式氢气导入型超临界二氧化碳处理装置。

Applications of supercritical CO2 include extraction (supercritical CO2 extraction is more diffused and selective than conventional organic solution extraction, and properties can be adjusted to extract different components) and impregnation (impregnation with supercritical fluids to transport the active material to the surface of the inert material).

Supercritical drying involves a phase transition from supercritical solution to gas. The method is first applied to the drying of aerogel). Figure 3 shows a Intermittent hydrogen import type supercritical carbon dioxide treatment unit. Figure 4 shows a Continuous hydrogen import type supercritical carbon dioxide treatment unit..

图3 间歇式氢气导入型超临界二氧化碳处理装置

FIG. 3 Intermittent hydrogen import type supercritical carbon dioxide treatment unit

图4 连续式氢气导入型超临界二氧化碳处理装置

FIG. 4 Continuous hydrogen import type supercritical carbon dioxide treatment unit.

图5 超临界流体二氧化碳从气液态到超临界流体状态的对比图。

Fig. 5 The comparison of supercritical fluid carbon dioxide from gas-liquid state to supercritical fluid state

图5为超临界流体二氧化碳从气液态到超临界流体状态的对比图。可以看到从状态1到状态4，气液界面在逐渐消失。二氧化碳的临界点：临界温度约31°C，临界压力约7.4MPa，水的临界点：临界温度为374.1°C，临界压力为22.06MPa。

超临界二氧化碳萃取装置以二氧化碳作为介质来进行萃取。在室温左右即可达到超临界状态。其热损低，且无需使用有机溶剂即可实现萃取。可大幅度降低有机溶剂残留。因此，这一点在化妆品萃取领域可以说是革新点。

Figure 5 shows the comparison of supercritical fluid carbon dioxide from gas-liquid state to supercritical fluid state. You can see that from state 1 to state 4, the gas-liquid interface is gradually disappearing. The critical point of carbon dioxide: the critical temperature is about 31°C, the critical pressure is about 7.4MPa, the critical point of water: the critical temperature is 374.1°C, the critical pressure is 22.06MPa.

The supercritical carbon dioxide extraction device uses carbon dioxide as the medium for extraction. It reaches a supercritical state at around room temperature. It has low heat loss and can be extracted without the use of organic solvents. The residue of organic solvent can be greatly reduced. Therefore, this point can be said to be innovative in the field of cosmetic extraction.

应用于化妆品领域

Cosmetics field

超临界二氧化碳萃取装置用于提取鞘磷脂(SM)是一个出色的应用实例。此技术不仅优化了现有产品的提取效果，而且开启了未知的新工艺和产品的研发可能性，这是传统工艺所无法企及的。

在传统的提纯工艺中，油性溶液的提纯通常依赖于丙酮和乙醚等有机溶剂来提取有效成分。然而，利用超临界二氧化碳萃取装置，我们能够避免使用这些有机溶剂。例如，提取玫瑰的香味成分（精油）时，传统工艺需要经过多道溶剂萃取步骤。相比之下，超临界二氧化碳萃取装置不仅能显著简化这一过程，还能确保整个过程不涉及任何有机溶剂的使用。

The supercritical carbon dioxide extraction device for extracting sphingomyelin (SM) is an excellent application example. This technology not only optimizes the extraction effect of existing products, but also opens up the possibility of research and development of unknown new processes and products, which cannot be achieved by traditional processes.

In the traditional purification process, the purification of oil-based solutions usually relies on organic solvents such as acetone and ether to extract the active ingredients. However, with a supercritical carbon dioxide extraction unit, we are able to avoid the use of these organic solvents. For example, when extracting the fragrance component (essential oil) of roses, the traditional process requires multiple solvent extraction steps. In contrast, supercritical carbon dioxide extraction devices not only significantly simplify the process, but also ensure that the entire process does not involve the use of any organic solvents.

应用于食品领域：

Food field

提取咖啡因

Extract caffeine

超临界流体具有独特的溶解性能，能迅速地溶解物质，因此可以用于萃取和分离不同成分。在提取咖啡因的过程中，超临界二氧化碳发挥了重要作用。

首先，通过升高温度和施加压力，我们将二氧化碳转变为超临界状态，使其既具备气体的扩散性又具有液体的溶解性。

接着，我们将含有咖啡因的咖啡豆放入超临界二氧化碳萃取设备中。此时，二氧化碳渗透到咖啡豆中，溶解出咖啡因。

经过几小时的处理，我们能够从咖啡豆中提取出超过90%的咖啡因。最后，残留在咖啡豆中的二氧化碳会自然挥发，不会留下任何异味或有害物质。

值得一提的是，“超临界二氧化碳提取法”不仅提高了提取效率，而且重新利用了原本会排放到大气中的二氧化碳，从而降低了对环境的影响。  

Supercritical fluids have unique solubility properties and can quickly dissolve substances, so they can be used for extraction and separation of different components. In the process of extracting caffeine, supercritical carbon dioxide plays an important role.

First, by raising the temperature and applying pressure, we transform carbon dioxide into a supercritical state, giving it both the dispersive properties of a gas and the solubility of a liquid.

Next, we put the caffeinated coffee beans into a supercritical carbon dioxide extraction facility. At this point, the carbon dioxide seeps into the coffee beans and dissolves the caffeine.

After a few hours of processing, we were able to extract more than 90% of the caffeine from the coffee beans. Finally, the carbon dioxide remaining in the coffee beans will evaporate naturally, leaving no odor or harmful substances.

It is worth mentioning that the "supercritical carbon dioxide extraction method" not only improves the extraction efficiency, but also reuses the carbon dioxide that would otherwise be emitted into the atmosphere, thereby reducing the impact on the environment.

图：超临界二氧化碳萃取装置

图：超临界二氧化碳萃取装置

图：超高压处理装置

本公司研发的超临界二氧化碳设备，采用先进技术，实现高效、环保的二氧化碳处理。该设备性能稳定，操作简便，能广泛应用于化工、医药等领域，助力提升生产效率，降低能耗，为客户创造更多价值。选择我们，共创绿色未来！