Based on the theory of industrial ecology and recycling economics,this paper described the structure of the bio-energy industrial chain of HB Corporation in Mongolia,which has the three characteristics of the ecological,recycling economics and network chain.On this basis,from the perspective of the longitudinal extension and circumferential process,this paper further put forward several suggestions on perfecting the network of the bio-energy industrial chain.

Tianjin,as one of national low-carbon city pilots,should take the lead in exploring an effective way.to achieve sustainable development and to develop low-carbon economy.This paper systematically describes 9 factors associated which prevent development of low-carbon economy in Tianjin,and shows the interactions of the factors by utilization of interpretive structural model.On this basis,the paper researches the path to low-carbon economy in Tianjin.Therefore,it is concluded that improving the planning system for low-carbon in Tianjin,increasing the proportion of modern service industry,establishing pilot regional low-carbon economy and raising resident's awareness of low carbon are important ways to build low-carbon city.

At present, China is already one of the largest countries in energy consumption and CO2 emissions. Therefore, it is of great strategic importance for China to enhance its oil security by utilizing its existing materials to produce alternative liquid fuel, that is, biodiesel on a large scale. In addition, the impact that desertification has had on China in general, is undeniable. It will become even severer and wider as the environment becomes increasingly worse. It is a feasible way to develop biodiesel in the desertification regions in China. This paper gives an analysis framework of biodiesel produced from microalgae and a systematic collection of all material and energy inputs and outputs throughout the life cycle of microalgae biodiesel production. To illustrate these, this study also evaluates the life cycle of the JJ company’s biodiesel production system with an annual output of 120 tons and places emphasis on studying its environmental impacts and resource consumption during various stages of the life cycle. Considering that microalgae are suitable for development of desert areas, this paper, through analyzing the technology roadmap of biodiesel produced by microalgae and evaluating the life circle of microalgae biodiesel, draws a conclusion that it is the optimal choice for China’s desert areas to develop biodiesel from microalgae. Results include that 1） compared with other general energy crops, the microalgae outweighs them due to the benefits of high oil content, small area requirement, and short growth cycle. In addition, microalgae seem to be suitable for the development of vast desertification areas in China. 2） According to the construction of microalgae biodiesel consumption CO2 analysis framework map and the systematic collection of the framework chart of material, energy input and output data, it is concluded that the technical difficulties are species selection and massive production of microalgae. The microalgae cultivation phase determines the amount of energy consumption. Besides, the method of microalgae biodiesel production by JJ Company can be meaningful for desertification areas in China to develop biodiesel. 3） Using the life cycle theory, it was calculated that 1t microalgae biodiesel oil consumes 1.77t standard coal approximately and discharges 4.92t CO2. The most energy consumption is in the microalgae production phase, where microalgae can absorb 0.72t CO2 approximately and have a good environment benefit. Therefore, developing microalgae biodiesel oil in the desertification area is one kind of effective way in relieving energy crisis and the environment pressure

The input-output model is a universal method to conceptualize the structure of an economic system.On the basis of data-mining the input-output table,the paper develops an evaluation system to analyze the bio-energy industry chains.The evaluation system realizes identification of the leading enterprises,and comprehensively evaluates the economic and technological relationships between enterprises in the chains and the overall quality of the function of the bio-energy industry chain.The paper ends with a case study of EF Corporation by analyzing the bio-energy industry chains of it.