Abstract:Challenges to the attainment of sustainable development in China include: the efficient use of an abundance of labor, the growing population and growing pollution in cities, a gross national production that is relatively high but that on a per capita basis is low, and a big market and a situation where the rate of primary goods production is high with large depletion of energy and materials for which there is much room for improvement. The main problems are: energy and materials resources per capita are lower than the world level, the level of technology is low with a need for more advanced techniques for higher added value, and the environmental pollution and ecological degradation problems are severe. The only way to respond is by building a cycle economy and metabolic society. This requires the development of an ecological industry and technologies for clean production. The development needs to follow the 3R principles of reduce, recycle and reuse of resources. The cycle economy is comprised of three levels and three supports, in which the three levels are the metabolic society, the establishment of ecological industrial parks, and the realization of clean production, and the three supports are growth by hi-tech R&D, the rules of ecological systems, and ecology education and upholding of moral standards.
    A distinction is made between two possible modes of economic expansion. Mode 1 is a true and intrinsic development that is driven by progress in science and technology, which would achieve GDP growth while decreasing resource depletion and pollution. Mode 2 is a market based development, in which there is duplication of construction at a low technological level with increased resources depletion and pollution. Process engineering in the industries of petroleum products, metallurgy, chemicals, building materials, pharmaceuticals and others is very important in the national economy. They are also the largest users of energy and resources, and cause the heaviest pollutions. The optimal use, reuse and recycle of resources are discussed by a classification into three categories: category 1 in which the reuse of a product is considered on the basis of functionality recovery by mechanical means, category 2 in which metabolic processes are developed for several important elements in industry, and category 3 in which carbon and hydrogen cycles function as energy carriers. The concept of “clean production” is considered at five levels: pollution treatment of standard discharges, recycled utilization to minimize discharge, green chemical engineering processes in which pollution sources are replaced by clean alternative processes, ecological chemical engineering and full life-cycle clean product design, and the establishment of eco-industrial parks (EIP).
    In summary, sustainable development is an urgent and international task. New technological developments are the corner stone of a cycle economy. Ecological process engineering can make significant contributions.

Key words: cycle economy; ecological process engineering; sustainable development