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Spatiallydistributed first-principles process models provide anaccurate physical description of chemical processes, but lead to large-scalemodels whose numerical solution can be challenging and computationallyexpensive. Therefore, fast reduced order models are required for model-basedreal-time applications, such as advanced process control and dynamicreal-time optimization. In this paper, we focus on the model reductionof a bubbling fluidized bed (BFB) adsorber, which is a key componentof a postcombustion carbon capture system. From a temporal aspect,dynamic reduced models are generated using the nullspace projectionand eigenvalue analysis method, with the basic idea of quasi-steadystate approximation for the states with fast dynamics. From a spatialaspect, dynamic reduced models are developed using orthogonal collocationand proper orthogonal decomposition to reduce the size of the rigorousmodel. Finally, a computationally efficient and accurate dynamic reducedmodel is developed for the BFB adsorber by combining temporal andspatial model reduction techniques, which is suitable for an onlineoptimization-based control strategy. [ABSTRACT FROM AUTHOR]

Concentrating photovoltaic (CPV) technology has recently gained interest based on its scalability and expected low levelized cost of electricity. The reliability of encapsulation materials used in CPV systems, however, is not well established. For example, the present qualification test for CPV modules includes only real-time ultraviolet (UV) exposure, i.e., methods for accelerated UV testing have not yet been developed. To better define the stress inherent to CPV systems, the UV and infrared spectra transmitted through representative optical systems were evaluated. Measurements of optical components are used to assess expected optical performance and quantify damaging optical exposure. Optical properties (transmittance, refractive index, reflectance, and absorptance) of candidate materials (including PMMA, soda-lime glass, borosilicate glass, and quartz refractors), components (including Ag- and Al-enabled reflectors), and encapsulants (including EVA, ionomer, PDMS, PPMS, polyolefin, and PVB) were identified. The activation spectrum was calculated for the representative optical systems using an assumed action spectrum to compare the expected damaging dose of UV radiation delivered to the cell encapsulation. The dose and flux analysis identifies the significance of IR relative to UV exposure for CPV systems. Because UV light is typically more highly attenuated, the UV dose within the encapsulation may not greatly exceed the unconcentrated global solar condition, but the thermal load scales nearly directly with the geometric concentration. Relative to a previous analysis for crystalline silicon cell technology, the analysis here is performed for III-V multijunction technology. Novel aspects here also include additional materials (such as TPU encapsulation) and additional components (transmission through silicone on glass lenses, antireflective coatings, and the front glass used with reflective systems, as well as reflection off of the cell). [ABSTRACT FROM AUTHOR]