Green Chemistry Ensures the Bright Prospects of the Chemical Industry

By Xu Danyang,  Chen Jun,  Zhou Gang, Jiangsu Polytechnic College   

While promoting the progress of mankind, the development of the chemical industry, we must admit, has also brought with it negative impacts such as environmental damage and the greenhouse effect. Some well known environmental events including the hole in the ozone, white pollution, acid rain and eutrophication of bodies of water (such as blue algae taking over Taihu Lake in May 2007, CCR2007 No.23) are closely related to waste released by the chemical industry. To cope with challenges facing the chemical industry and to reduce public misgivings about the chemical industry, it has become imperative to make the industry greener (cleaner).

Green chemistry is related to all links of the chemical industry

Green chemistry is also called environmentally friendly chemistry. The core of green chemistry is to use chemical mechanisms to fundamentally eliminate the chemical industry's pollution of the environment. It means minimal or even no generation of wastes and zero emissions.
   In terms of waste water treatment, cyclic utilization should be achieved through constructing sewage treatment plants to treat industrial and domestic waste water. The sewage treatment capacity in the sewage treatment plant constructed by Jiangsu Yabang Chemical Co., Ltd. has reached 100 000 t/d and has greatly improved the environmental quality and the investment environment in the industry park.
   In chemical production processes, green production should be achieved through strengthening research on production technologies, actively using clean production processes, introducing environment-friendly technologies and equipment and developing chemical products that are of high quality, have low environmental protection costs and are in conformity with international environmental protection requirements.
   In terms of product packaging, white pollution should be reduced through using biodegradable plastics.

Green chemistry helps energy
conservation and pollutant reduction in other sectors

Green chemistry can not only enable the chemical industry to attain the target of energy conservation and pollutant reduction, but also can achieve green production in other sectors through using green chemicals and green chemical processes. For example, raw materials with no toxicity and no hazards are used to replace intermediates with acute toxicity such as phosgene and hydrocyanuric acid and solvents with no toxicity and no hazards are used to replace volatile organic solvents. Dyestuffs and dyestuff intermediates make up a very high proportion of the fine chemicals exported from China. The country produces more than 1.0 million tons of nitroaromatic intermediates each year. Major production processes such as nitrification and reduction used in the production of such products all have heavy pollution. The research and development of clean nitrification and reduction technologies is therefore the key to the solution of heavy pollution in these traditional processes. In the pesticide sector, the development of green varieties with high potency, low toxicity, good degradability, great safety and good environmental compatibility to replace traditional varieties with low potency, high toxicity and high residue has already become an orientation in new pesticide formulations.

The development of the green chemical industry should start from the source

The chemical industry has made a brisk capacity expansion in recent years, but the overall development level is still quite low. There are 2 401 chemical enterprises in Changzhou of Jiangsu province. Some 575 of them have a considerable scale with an annual production of more than RMB5 million. The profits of chemical enterprises with considerable scale account for around 15% of the total profits of all enterprises with considerable scale in the city. Four out of five chemical enterprises are small-medium scale. These have outdated process technologies and their products are mainly varieties with low added value, high energy consumption and high pollution, and they are wasteful of natural resources. The brisk capacity expansion for such products has already added great difficulties to environmental control. Maintaining a balance between development and environmental protection has become an urgent problem. In addition, the incompleteness of methods for calculating energy consumption and pollutant emission in many enterprises also constrains the development of the chemical industry.
   Since the outbreak of blue algae in the Taihu Lake, Changzhou Municipal Government has adopted a series of new measures and actively launched environmental protection control activities. Pollutant emissions and flows in water drainage industrial enterprises, centralized sewage treatment plants and large-scale livestock/poultry breeding yards have been comprehensively surveyed, the approval and construction of new projects are more cautiously controlled and the three "simultaneous constructions" are being implemented. Enterprises in the chemical industry park must strictly observe environmental impact assessment requirements. Enterprises with good economic performance, bright development prospects, standardized management and little pollution are encouraged to merge with or acquire weaker firms, upgrade the industrial level in the park and solve the pollution problem at its source.