The so-called green chemistry is defined as applying the concept of environmental protection from the source in the production process of chemical products, promoting source reduction, optimizing and integrating the production process, reusing and recycling wastes, thus reducing costs and consumption, reducing waste emissions and toxicity, and reducing the adverse impact on the environment throughout the product life cycle. With the rise of green chemical industry, the environmental pollution control of chemical industry has changed from pollution first to source control.
This topic should be discussed in two parts. First of all, we should know what green chemistry is. It is understood that green chemistry is also called environment-friendly chemistry, and the technology developed from it is called environment-friendly technology or clean technology: that is, using chemical principles, in the design, production and application of chemicals, the use and production of toxic and harmful substances on human health, community safety and ecological environment are eliminated or reduced, and products and chemical processes that have no or little negative environmental impact as much as possible and are technically and economically feasible are designed and studied. As a liberal arts student, it is really difficult to understand these principles and other knowledge. However, no matter which discipline you belong to, you should establish a correct attitude and concept in the face of a new theory that is conducive to the development of human society. Therefore, it is necessary to clarify the theoretical sources, causes and effects, benefits, development direction, positive significance, development prospects and development methods of these technologies or scientific ideas.
First of all, we should explain the background of green chemistry, which can also be understood as specific reasons. There is one respectively, environmental crisis; Second, the energy crisis. Among them, the environmental crisis specifically includes: global warming, ozone layer destruction, biodiversity reduction, forest area reduction, acid rain disaster, air pollution, land desertification, marine pollution, fresh water pollution, urban garbage disposal and other issues. It is for these reasons that the homes we live in are becoming less and less suitable for human habitation, so it will also sound an alarm for human beings. While constantly promoting scientific development, we should also look back at the road we have traveled. You can't just focus on the present and ignore the behind, which may cause great hidden dangers. Therefore, people are constantly exploring superior science and technology to reduce the damage to the living environment and human health. Therefore, the core of the concept of green chemistry put forward now is to reduce and eliminate the environmental pollution caused by industrial production from the source by using chemical principles. The ideal production mode of green chemical industry is: first, make full use of resources and energy, and adopt non-toxic and harmless raw materials; Second, the reaction is carried out under non-toxic and harmless conditions to reduce the discharge of waste to the environment; Third, improve the utilization rate of atoms, and try to make all atoms as raw materials be absorbed by products to achieve "zero emission"; Four, the production of environmental protection products conducive to environmental protection, community safety and human health. If we put this series of theoretical knowledge into practice, it will greatly improve our quality of life and make great contributions to human survival and happiness index.
The concept of green chemistry should be widely used, not only in industrial production, but also in industrial production. Nowadays, the concept of sustainable development has been universally recognized by the world. It emphasizes the coordinated development of population, economy, society, environment and resources, which means not only developing economy, but also protecting natural resources and environment so that future generations can develop sustainably. Green chemistry is a sustainable development theory based on the harmonious development between man and nature. First of all, the slogan of green chemistry originated in the United States, where the chemical industry is very developed. 1990, the United States passed the "Pollution Prevention Action" Act. 199 1 year later, "green chemistry" was put forward by the American Chemical Society (ACS) and became the central slogan of the US Environmental Protection Agency (EPA). After more than ten years of research and exploration, researchers of green chemistry have summed up the principle of 12 green chemistry, which can be used as a guide and standard for experimental chemists to formulate and evaluate whether a synthetic route, a production process or a compound is green. According to the principle of green chemistry, the ideal chemical production mode is that all atoms of reactants are transformed into the expected final product.
Then, the twelve principles of green chemistry are introduced: 1. Prevention-it is much better to prevent waste from being produced than to treat and purify it after it is produced.
Second, talk about atomic economy-such a synthetic scheme should be designed so that the materials used in the reaction process can enter the final product to the maximum extent.
Third, less harmful synthesis reaction occurs-in any case, feasible methods should be adopted to make only substances with less toxicity to human body or environment be selected or produced in the design of synthesis program.
Fourth, the design should make the generated chemical products safe-the products of chemical reaction should not only have the required performance, but also have the minimum toxicity.
5. Solvents and auxiliary materials are relatively safe-try not to use auxiliary materials (such as solvents or precipitants) and be as harmless as possible when you have to use them.
Six, the use of energy in the design should pay attention to efficiency-as far as possible to reduce the energy needed in the chemical process, but also to consider environmental benefits and economic benefits. The synthesis process is carried out at atmospheric temperature and pressure as much as possible.
7. Use recyclable raw materials-as long as it is technically and economically feasible, raw materials should be recyclable, not spoiled.
Eight, try to reduce derivatives-should try to avoid or reduce redundant derivative reactions (to protect groups or remove protection and temporarily change the physical and chemical process), because these steps need to add some reactants, but also produce waste.
9. Catalysis-Catalysts (as selective as possible) are more important than stoichiometric reactants.
Ten, to design degradation-products produced according to the design, when its effective function is completed, can be decomposed into harmless degradation products, do not continue to exist in the environment.
XI。 The pollution prevention process can be analyzed in real time-analytical methods must be continuously developed to monitor the analysis and process in real time, especially to control the formation of harmful substances.
Twelve, especially from the safety of chemical reactions to prevent accidents-in the chemical process, the selection of reactants (including their specific forms) should focus on minimizing the possibility of chemical accidents including release, explosion, fire and so on.
The second core of green chemistry is five "R's", namely: the first is reduction, that is, reducing the discharge of "three wastes"; Second, reuse-"reuse", such as catalysts and carriers in the chemical process, is the need to reduce costs and waste; Third, recycling-"recycling" can effectively achieve the requirements of "saving resources, reducing pollution and reducing costs"; Fourth, regeneration-"regeneration" is an effective way to turn waste into treasure, save resources and energy and reduce pollution; The fifth is rejection-"rejection", which means that some raw materials that are irreplaceable, unrecoverable, non-renewable and non-reusable and have obvious toxic and side effects and pollution effects are refused to be used in the chemical process. This is the most fundamental way to eliminate pollution.
According to these twelve basic principles and their core contents, we can get the meaning of green chemistry. As its definition says, the use of natural energy, with the purpose of using solar energy, avoids the burden on the environment and the discharge of harmful substances, develops photocatalyst and hydrogen energy manufacturing and storage technologies, and considers energy conservation, resource conservation and waste emission reduction. Therefore, it shows its greenness in industrial production. For example, in the production process of chemical products, the concept of environmental protection is applied from the source of the process, source reduction is carried out, and the production process is optimized and integrated, so as to reduce the cost and consumption, waste emission and toxicity, and reduce the adverse impact on the environment during the whole life cycle of products. The rise of green chemical industry makes the environmental pollution control of chemical industry from pollution first to source control. Its advantages are also obvious. Green chemistry and chemical engineering are a way to solve the global pollution problem. Different from traditional pollution control, green chemistry and chemical engineering can reduce or eliminate the generation and use of harmful substances by changing the structure and properties of chemical products or production processes. By designing or redesigning the molecular structure of chemical substances, green chemistry can make them have the required characteristics and avoid or reduce the generation and use of toxic groups. At the same time, green chemistry pursues highly selective chemical reactions with few by-products, even achieving atomic economy and zero emission.
Therefore, green chemistry and chemical industry can not only prevent environmental pollution, but also improve the utilization rate of resources and energy, improve the economic benefits of chemical processes, and greatly promote the sustainable development of chemical processes.
Taking the application of various countries as an example, we can see the importance of this problem, and this green concept is also consistent with the idea of sustainable development advocated by China. Therefore, in order to better develop, we should vigorously and actively promote it, so that more producers can adapt to this trend of green development. Therefore, no matter scientists, entrepreneurs, producers or ordinary residents, they should establish the concept of green environmental protection, and use green environmental protection to evaluate green environmental protection at any time in the process of product production, sales and use, which is not only conducive to the healthy life of individuals, but also has a good guarantee for the living environment, survival and development. So as to promote the development of green industry and the growth of circular economy. Therefore, relevant experts and government workers should strengthen publicity to make the concept of green chemistry and chemical engineering deeply rooted in people's hearts.