Jingzhu Shen

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.

Multidimensional non-orthogonal wavelet-sigmoid basis function neural network for dynamic process fault diagnosis

Abstract Dealing with multidimensional problems has been the “bottle-neck” for implementing wavenets to process systems engineering. To tackle this problem, a novel multidimensional wavelet (MW) is presented with its rigorously proven approximation theorems. Taking the new wavelet function as the activation function in its hidden units, a new type of wavenet called multidimensional non-orthogonal non-product wavelet-sigmoid basis function neural network (WSBFN) model is proposed for dynamic fault diagnosis. Based on the heuristic learning rules presented by authors, a new set of heuristic learning rules is presented for determining the topology of WSBFN s . The application of the proposed WSBFN is illustrated in detail with a dynamic hydrocracking process.

A hybrid ANN-ES system for dynamic fault diagnosis of hydrocracking process

Abstract In this paper, the wavelet-sigmoid basis neural network(WSBN) proposed by authors earlier is integrated with expert system(ES) for dynamic fault diagnosis(DFD). Meanwhile, a two-level integration strategy(TLIS) for DFD is also presented. At the first level of TLIS, a WSBN detects the fault sources through data from the dynamic processes, and outputs the corresponding fault degrees. At the second level, ES interprets the results from the WSBN and predicts the time period for fully developing the faults and the product qualities as well as the reactor states at the moment when the fault is fully developed by using a dynamic simulation package. If the predicted values exceed their acceptable ranges, then ES gives some related proposals for removing the fault causes or canceling their effects by using the reasoning context consisted of production rules. DFD is applied to a hydrocracking process showing the efficiency of the TLIS.

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.

Development of an expert system for synthesis of heat exchanger networks

Abstract A knowledge-based system for aiding in the construction of practical heat exchanger networks called SPHEN is presented in this article. The created network configurations feature low utility cost, low capital investment, rather stable heat recovery during operation and rational distribution of pressure drops among the network branches. SPHEN consists of four component parts: network construction, simulator, flowsheet diagram generation and users feedback subsystem. So SPHEN is characterized by its hybridity, reflected in knowledge representation and abstraction,solving methods and implementation languages. The hybrid system is implemented through disk files and data files connecting different parts into one working space. An example of redesigning an energy recovery network of a large-scale crude oil unit is illustrated and the results obtained are successful.

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.

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.