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A nonlinear programming (NLP) model has been established to describe the process of low rank coal pyrolysis, and the model was validated through comparison with pilot or semi-industry technologies. Results showed good agreement with actual production values, suggesting that the model can be regarded as a general one for simulating low rank coal pyrolysis. On the basis of this model, the products’ distributions and energy penalties can be obtained from the coal pyrolysis process. In this study, the NLP model was used to simulate typical five pyrolysis processes such as the Toscoal process, Lurgi–Ruhrgas process, Char Oil Energy Development technology, Dalian University of Technology process, and Multistage Rotary Furnace technology from China Coal Research Institute, and Hulunbuir lignite was taken as a coal sample. Combined with the simulation results from the NLP model, effects of the key parameters on the performance of the pyrolysis technologies are investigated and a comprehensive evaluation in terms ...
70A non-linear model for farm optimization with adequate and limited water supplies: Application to the South-east Anatolian Project (GAP) Region
A non-linear model for farm optimization with adequate and limited water supplies: Application to the South-east Anatolian Project (GAP) Region
Read more76Dynamic profiles of tar products during Naomaohu coal pyrolysis revealed by large-scale reactive molecular dynamic simulation
Dynamic profiles of tar products during Naomaohu coal pyrolysis revealed by large-scale reactive molecular dynamic simulation
Read more17Pyrolysis behaviors and product distributions of coal flotation sample separated by float and sink test
Pyrolysis behaviors and product distributions of coal flotation sample separated by float and sink test
78Research on logistics management layout optimization and real-time application based on nonlinear programming
To solve the problem of long logistics delivery time in supply chain, a Mixed Integer Non-linear Program (MINLP) model is built by using Mixed Integer nonlinear programming theory. Firstly, the General algebraic modeling system (GAMS) is used to build the model to fully integrate each parameter of logistics transportation, the total distribution time of the supply chain network, the coverage radius of the logistics base, the number of users, the total capacity of the logistics base, the mode of railway and road transportation, the nonlinear programming model is built and solved by DICOPT solver in GAMS. The cost of logistics can be decreased, transportation time can be reduced, and the logistics system's operating efficiency can be increased in the long term with the help of this algorithm. The proper operation of the logistics system is critical in encouraging the supply chain circulation of various industries and has a direct impact on the society's economic development. The optimal logistics distribution plan with 5 logistics bases covered users of 18 and railway capacity of 2. With the same railway capacity and the same total budget, the larger the number of covered users, the greater the total distribution time increases, but the larger the total budget, the growth of the total distribution time slows down significantly. Experiments show that MINLP model can solve the problem of logistics-based layout optimization in nonlinear logistics management.
Read more10A master–slave solving method with adaptive model reformulation technique for water network synthesis using MINLP
A master–slave solving method with adaptive model reformulation technique for water network synthesis using MINLP
10A linear approximation model for the parameter design problem
A linear approximation model for the parameter design problem
38Fuzzy non-linear programming: Theory and application in manufacturing
Due to the complexity of the manufacturing environment, problems that can be solved by mathematical programming techniques are usually represented with non-linear programming (NP) models instead of linear programming (LP) models. When non-stochastic vagueness exists between the problem description and its corresponding NP model, fuzzy set theory can be applied to the mathematical model for the purpose of vividly representing the problem. This paper discusses the idea of the fuzzy NP model. Fuzzy set concepts are adapted to the NP objective function and constraints. An identical crisp NP model is derived from the fuzzy NP model for solving the problem numerically. Kuhn-Tucker conditions are addressed to determine the existence of a global optimal solution. A fuzzy machining economics model, which attempts to find optimal manufacturing parameters under vague elements of influence, is used to demonstrate the theory of the fuzzy NP model.
Read more11Tar Emission during Pyrolysis of Low Rank Coal in a Circulating Fluidized Bed Reactor
A circulating fluidized bed (CFB) reactor composed of a pyrolyzer and combustor was developed to observe tar emission during pyrolysis of low rank coal. Tar emission in the CFB pyrolyzer was examined under a wide range of operating conditions. Emissions of light tar substances (e.g., benzene, toluene, naphthalene, etc.) could be suppressed at 973 K by enhancement of contact between tar and resultant char in the pyrolyzer (i.e., enhancement of the volatile–char interaction (VCI)). It was also confirmed that about 50% of the heavy tar fraction emissions could be suppressed by the enhancement of VCI at 973 K. These trends were also observed at higher temperature (1173 K). A certain amount of heavy tar was emitted even after enhancement of VCI, so the mechanism of tar elimination was qualitatively determined using Spiral-type TOF-MS. The heavy tar was homogeneously deposited on the char and then was cracked to form lighter fractions by enhanced contact between tar and resultant char during pyrolysis.
Read more6Pyrolysis of shenmu coal to prepare blue-coke used as reductant
Pyrolysis of shenmu coal to prepare blue-coke used as reductant
22Analysis and distribution of volatile gases from catalytic pyrolysis of Sulcis low-rank coal
Analysis and distribution of volatile gases from catalytic pyrolysis of Sulcis low-rank coal
17Prediction of volatile composition of coal pyrolysis under various swelling and catalytic conditions based on recurrent neural network
Prediction of volatile composition of coal pyrolysis under various swelling and catalytic conditions based on recurrent neural network
Read more37Methane-rich syngas production in an integrated fluidized bed by coupling pyrolysis and gasification of low-rank coal
Methane-rich syngas production in an integrated fluidized bed by coupling pyrolysis and gasification of low-rank coal
11Time control point strategy coupled with transfer coordination in bus schedule design
SummaryA schedule consisting of an appropriate arrival time at each time control point can ensure reliable transport services. This paper develops a novel time control point strategy coupled with transfer coordination for solving a multi‐objective schedule design problem to improve schedule adherence and reduce intermodal transfer disutility. The problem is formulated using a robust mixed‐integer nonlinear programming model. The mixed‐integer nonlinear programming model is equivalently transformed into a robust mixed‐integer linear programming model, which is then approximated by a deterministic mixed‐integer linear programming model through Monte Carlo simulation. Thus, the optimal scheduled arrival time at each time control point can be precisely obtained using cplex. Numerical experiments based on three bus lines and the mass rapid transit system in Singapore are presented, and the results show that the schedule determined using the developed model is able to provide not only reliable bus service but also a smooth transfer experience for passengers. Copyright © 2016 John Wiley & Sons, Ltd.
Read more13Incentives and yield management in improving productivity of manufacturing facilities
Financial incentives are used to improve productivity and quality in manufacturing and service facilities. This improvement in productivity would normally release part of the facility's productive capacity. Without stimulating additional demand to consume this released capacity, the facility would Be unable to tap the full benefits of the improvements in productivity. Hence, yield management is introduced in an attempt to entice more demand and increase revenues. In this paper, we develop a Non Linear Programming (NLP) model to jointly determine the optimum financial incentives and price discount levels for each rate class. The model aims at maximizing net revenues. It includes nonlinear relationships representing the impact of incentives on productivity and quality improvements as well as the effect of price discounts on customer demand in each market segment. The generic nature of our NLP model makes it applicable to all multi-product manufacturing facilities covering sales, production and delivery. The model is applied to determine the optimum incentive and price discount levels for perishable products in a multi-product ready-mix concrete plant. It is demonstrated that the model is useful in maximizing net revenues through productivity improvements and an increase in customer demand.
Read more66Effect of low-temperature pyrolysis on surface properties of sub-bituminous coal sample and its relationship to flotation response
Effect of low-temperature pyrolysis on surface properties of sub-bituminous coal sample and its relationship to flotation response
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