Yourun Li

Evaluating waste treatment, recycle and reuse in industrial system: an application of the eMergy approach

This paper deals with the application of emergy analysis of industrial systems in considering wastes. Making process system engineering decisions that are ecologically conscious requires emergy analysis of both industrial and ecological processes. The traditional emergy analysis methods of a natural ecological system usually do not consider the impact of wastes. This paper considers the impact of wastes and improves existing emergy analysis methods for industrial system. A new index of sustainability for industrial processes is presented.

Modeling and optimization of herb leaching processes

Abstract The mathematical model of the herb leaching process is presented in this paper based on the mass transfer principle. At the same time, the process system engineering methodology is applied to study the herb leaching process in order to improve the operating conditions and the yields of effective compounds. The modification parameters in the model are predicted using parameter estimation technique to make the model calculated values agree with the experimental data. A case study for the angelica leaching process was presented. The simulation results show a perfect matching between the calculated values with the experimental data. The effects of different operating conditions on the yield of effective compounds in the herb leaching process are also investigated applying the simulation study. Furthermore, the optimal operating condition is obtained to maximize economic profit. The results also indicate the extended application prospects of simulation and optimization technology in the modernization of Chinese traditional herb leaching production.

Three-distribution-parameter general model for reactor network synthesis

Abstract Reactor network synthesis has attracted more and more attentions especially under the increasing stress on the environment problem. Recent advances have been made chiefly in approaches for superstructure optimization as well as reactor network targeting concept. In this paper, a three-distribution-parameter general model for reactor network synthesis is proposed. The three distribution parameters are side feeding, recycling and bypassing distribution parameters respectively. Because they can greatly influence the concentration and residence time profile within the reactors, which enable the proposed general model to be compact and efficient. Based on this general model, the reactor network synthesis problem can be formulated as an optimization problem. By orthogonal collocation on finite element discretization strategy, the original optimization model is transformed into a NLP problem. After optimization, the reactor type with varying maximum mixing to minimum mixing and configuration including series and parallel connection in the reactor network can be directly decided according to the optimal solution of distribution parameters. Three examples are studied and discussed. From the results, it can be concluded that the side feeding, recycling and bypassing strategy can give a comprehensive reflection of optimal characteristic of the reactor network under various reaction kinetics and the objective formulation, and easy to be used to gain practical network.

Reaction path synthesis for a mass closed-cycle system

Abstract With more and more severe problems of environmental pollution, the chemical industry entails the consideration of minimum environmental impact when synthesizing reaction path. In this paper, a systematic method for reaction path synthesis is described in which undesirable chemicals are cycled to realize zero avoidable pollution. A novel concept of simple stoichiometric reactions (SSRs) is introduced to determine simple stoichiometries between raw materials, probable intermediate chemicals and co-products and to form a reaction path network. Promising reactions are identified by an optimization program from this network. Case studies are discussed to illustrate the proposed method.

Delayed sampling approach to stochastic programming in chemical processes

Abstract In this paper, a new stochastic programming approach is presented to address chemical process optimization problems under uncertainty. The novel algorithm, named as delayed sampling approach, solves an equivalent deterministic optimization model transformed from the stochastic optimization problem between two stochastic simulations. The sampling numbers are reduced considerably and the computational burden is then alleviated remarkably. A complex crude distillation unit is modeled and optimized using the new stochastic approach. Savings of up to 80% in CPU time has been achieved without significant loss of solution precision compared to the conventional stochastic optimization method.

Development of a management information system for an eco-industrial park

Abstract With the development of Eco-Industry, Management Information System (MIS) comes to become an important part of Eco-industrial Parks. Based on the concept of Eco-industrial Park, a MIS is developed through the processes of database and function modules design, using the Browser/Server method. A mathematic model is addressed for analyzing pollution sources in a river. The quantitative evaluating index presented in this paper can be used to indicate which environments cause the pollution accident. A case study shows the effectiveness of the model.

Synthesis of eco-industrial system considering environmental value using adaptive simulated annealing genetic algorithms

Abstract This paper elaborates the establishment of the model of eco-industrial system including selection of members, environmental value and construction of eco-industrial chains. The model is formulated into a large-scale mixed integer non-linear programming (MINLP) problem. The hybrid adaptive simulated annealing genetic algorithm (ASAGA) is proposed to solve the problem of synthesis of eco-industrial system. A case study shows that the model is applicable and the ASAGA algorithm is effective.

The approach of multi-factor life cycle assessment and product structure optimization

Abstract Currently, the approach of Life Cycle Assessment (LCA) has been widely used for product and process environmental management. However, when an enterprise or an industrial park makes product decision, the economic and social performance should also be considered besides environmental impact. So an approach that can be applied for economic, environmental and social LCA is in need now. In order to meet this kind of need, one LCA index system considering product economic, environmental and social performance is established in this paper. Using the composite index method, product overall economic, environmental and social index can be calculated. When multiple products are to be compared, these indexes can be applied as the criterion. Also in this paper this assessment index system is combined with optimization technology of process system to optimize one organic silicone product structure. This approach can make compositive assessment of product and give an enterprise or industrial park proper product design, guaranteeing best economic, environmental and social overall performance.