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Energy markets
Published in Kornelis Blok, Evert Nieuwlaar, Introduction to Energy Analysis, 2020
Kornelis Blok, Evert Nieuwlaar
The global markets for biofuels are in an early stage of development and these markets are still very small compared to the international oil and coal markets. For the currently most important application of bio-energy, cooking in rural areas in developing countries, no markets, or at best local markets exist. Many biomass streams, especially waste, are used close to the area of generation; sometimes even in the same factory as where the streams are generated, e.g. in the pulp and paper industry. Prices depend very much on the composition of the waste streams, and the local situation of supply and demand.
Robust asynchronous switching predictive control for multi-phase batch processes with time-varying tracking trajectory and delay
Published in International Journal of Control, 2023
Bo Peng, Huiyuan Shi, Chengli Su, Xin Wen, Ping Li
A robust asynchronous switching predictive controller was designed for a kind of multi-phase asynchronous switching process with uncertainties, interval time-varying delay, external disturbances and time-varying tracking trajectory. In order to improve the free degree of the controller, the output tracking error was introduced into the traditional state space model. By using mode-dependent average dwell time method, this paper proves the exponential stability conditions of the asynchronous system and obtains the minimum running time in the stable subsystems and the longest running time in the unstable subsystems. In order to verify the effectiveness of the designed controller, taking the injection moulding process as an example, the proposed controller was used to simulate the injection phase and the pressure holding phase. According to the simulation results, the proposed method can calculate the minimum running time in the stable subsystems and the longest running time in the unstable subsystems at each phase. Based on the calculated times, the controller can be switched in advance before the system is switched. The switching signal can effectively avoid the emergence of asynchronous case and make the system stable, fast and accurate operation. It can not only improve production efficiency and product quality, but also effectively reduce energy loss and enhance the economic benefits of the factory. Furthermore, the current researches mainly focus on linear systems. The fuzzy control methods for the nonlinear multi-phase systems may be our future work.
An analysis of cleaner production planning by applying analytic hierarchy process: a wood industry case study
Published in International Journal of Sustainable Engineering, 2021
Fatemeh Hasani Khorshidi, Majid Azizi, Charles Ray, Mohammad Mahdi Faezipour, Hamid Zarea Hosseinabadi
4.2.6. Overall, cleaner production alternatives in this factory showed that its implementation had the greatest effect on reducing energy consumption, increasing occupational health and safety, reducing emissions and environmental pollution, reducing effluent generation, reducing raw materials consumption, reducing water consumption, and reducing waste generation.