Humans are facing the unprecedented environmental crises nowadays, which are caused by the increased population, the higher consumption of source, the reduction of per capita amount of land, water and mineral products. The contradiction between population and resource become shaper and sharper. The environmental protection turns out to be one of the most important issues of economy and social development.

The developing of industrialization provides people many new materials, and improves their substantial lives, however, it also brings so many wastes that degenerate the environment. In order to keep the level of people's lives and to protect the environment, the new material which is nonpoisonous and harmless must be found.

Chemical industry and other related industry, being one of the pillar cornerstone industries in national economy, contribute much to the creation of human's material civilization, meanwhile, discharging large numbers of harmful substances. Chemical industry also brings certain detriment to human health and environment. The environmental renovation in developed country has been changed from the symptoms to the roots, namely, from the terminal renovation to the development of clean industrial technology, cutting down the pollution source and the production of environmental friendly products. "Green chemistry" is become the hot spot and essential technology frontier of 21st century's chemical research.

"Green chemistry" is also named green technology, environmental friendly technology and clean chemistry. Green chemistry is to reduce or cut down the harmful raw material that affect the human health, community safety and ecological environment through chemical way and other technology. The harmful raw material can be divided into catalyst, solvent, reagent, products and by-product.

Chemistry can be roughly described as a science that converts one substance to another.  Although the traditional chemistry can get some new materials those human needs, it has not fully utilized the resources in many occasions, and discharges large numbers of wastes, causing the serious environmental pollution. "Green chemistry" is the chemistry with higher level. Atom economy is the main characteristics of "Green chemistry", that is to make full use of every atom to achieve no mission , therefore, "Green chemistry" can fully utilize the sources and make pollution free. The convert from traditional chemistry to "Green chemistry" can be defined the transformation from extensive mode to intensive mode. "Green chemistry" is able to make the wastes useful, increasing the economic benefits greatly. "Green chemistry" has been raised all around the world, which means a rare chance to the developing country like China. The related chemical products is degreasing agent