scholarly journals One-Dimensional Heterogeneous Reaction Model of a Drop-Tube Carbonator Reactor for Thermochemical Energy Storage Applications

Energies ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5905
Author(s):  
Evgenios Karasavvas ◽  
Athanasios Scaltsoyiannes ◽  
Andy Antzaras ◽  
Kyriakos Fotiadis ◽  
Kyriakos Panopoulos ◽  
...  

Calcium looping systems constitute a promising candidate for thermochemical energy storage (TCES) applications, as evidenced by the constantly escalating scientific and industrial interest. However, the technologically feasible transition from the research scale towards industrial and highly competitive markets sets as a prerequisite the optimal design and operation of the process, especially corresponding reactors. The present study investigates for the first time the development of a detailed, one-dimensional mathematical model for the steady-state simulation of a novel drop-tube carbonator reactor as a core equipment unit in a concentrated solar power (CSP)-thermochemical energy storage integration plant. A validated kinetic mathematical model for a carbonation reaction (CaO(s) + CO2(g) → CaCO3(s)) focused on thermochemical energy storage conditions was developed and implemented for different material conditions. The fast gas–solid reaction kinetics conformed with the drop-tube reactor concept, as the latter is suitable for very fast reactions. Reaction kinetics were controlled by the reaction temperature. Varying state profiles were computed across the length of the reactor by using a mathematical model in which reactant conversions, the reaction rate, and the temperature and velocity of gas and solid phases provided crucial information on the carbonator’s performance, among other factors. Through process simulations, the model-based investigation approach revealed respective restrictions on a tailor-made reactor of 10 kWth, pointing out the necessity of detailed models as a provision for design and scale-up studies.

2019 ◽  
Author(s):  
Karolina Matuszek ◽  
R. Vijayaraghavan ◽  
Craig Forsyth ◽  
Surianarayanan Mahadevan ◽  
Mega Kar ◽  
...  

Renewable energy has the ultimate capacity to resolve the environmental and scarcity challenges of the world’s energy supplies. However, both the utility of these sources and the economics of their implementation are strongly limited by their intermittent nature; inexpensive means of energy storage therefore needs to be part of the design. Distributed thermal energy storage is surprisingly underdeveloped in this context, in part due to the lack of advanced storage materials. Here, we describe a novel family of thermal energy storage materials based on pyrazolium cation, that operate in the 100-220°C temperature range, offering safe, inexpensive capacity, opening new pathways for high efficiency collection and storage of both solar-thermal energy, as well as excess wind power. We probe the molecular origins of the high thermal energy storage capacity of these ionic materials and demonstrate extended cycling that provides a basis for further scale up and development.


Minerals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 482
Author(s):  
Fatiha Berroug ◽  
Yassir Bellaziz ◽  
Naaila Ouazzani ◽  
Fatima Ait Nouh ◽  
Abdessamad Hejjaj ◽  
...  

Morocco is the leading producer of phosphate and its derivatives in the world with a total production of 35 Mt. However, the extraction and the valorization of this mine generate huge quantities of phosphate washing waste clay (PHWWC) that constitute a main environmental and economic concern. To facilitate this waste clay storage and handling, it is necessary to decrease its moisture content that represents 80% of PHWWC. The present paper is devoted to studying the conductive drying of PHWWC. Drying experiments were conducted in a laboratory pilot. Afterwards, the experiment results were implemented in a one-dimensional numerical model of heat and mass transfer in a porous media to identify the drying parameters and performances. It was found that most of the water contained in PHWWC is free water that is removed with a constant drying rate. The volume reduction with a marked cracks phenomenon attained 65% without any significant effect of drying temperature and sample thickness. The effective moisture diffusivity of the PHWWC for a conductive drying process is ranged between 10−9 and 1.1 × 10−8 m2·s−1. The thermal efficiency of the drying system is up to 86%. The results could be used for the purpose of design and scale-up of the industrial dryer based on laboratory-scale experiments.


2007 ◽  
Vol 7 (4) ◽  
pp. 347-359 ◽  
Author(s):  
Gaurav Ameta ◽  
Joseph K. Davidson ◽  
Jami J. Shah

A new mathematical model for representing the geometric variations of lines is extended to include probabilistic representations of one-dimensional (1D) clearance, which arise from positional variations of the axis of a hole, the size of the hole, and a pin-hole assembly. The model is compatible with the ASME/ ANSI/ISO Standards for geometric tolerances. Central to the new model is a Tolerance-Map (T-Map) (Patent No. 69638242), a hypothetical volume of points that models the 3D variations in location and orientation for a segment of a line (the axis), which can arise from tolerances on size, position, orientation, and form. Here, it is extended to model the increases in yield that occur when maximum material condition (MMC) is specified and when tolerances are assigned statistically rather than on a worst-case basis; the statistical method includes the specification of both size and position tolerances on a feature. The frequency distribution of 1D clearance is decomposed into manufacturing bias, i.e., toward certain regions of a Tolerance-Map, and into a geometric bias that can be computed from the geometry of multidimensional T-Maps. Although the probabilistic representation in this paper is built from geometric bias, and it is presumed that manufacturing bias is uniform, the method is robust enough to include manufacturing bias in the future. Geometric bias alone shows a greater likelihood of small clearances than large clearances between an assembled pin and hole. A comparison is made between the effects of choosing the optional material condition MMC and not choosing it with the tolerances that determine the allowable variations in position.


1984 ◽  
Vol 15 (4-5) ◽  
pp. 243-252 ◽  
Author(s):  
Helén Engelmark

A one-dimensional mathematical model is used to simulate the process of snow-melt infiltration in unsaturated frozen silt. Hydraulic and thermal parameters are mainly based on data given in the literature. Field observations in a watershed (of area 1.8 km2) are compared with simulated data and consequences on snow melt run-off are discussed.


2008 ◽  
Vol 74 (737) ◽  
pp. 142-148 ◽  
Author(s):  
Kentaro NARUMI ◽  
Tsutomu NAKANISHI ◽  
Atsushi SHIRAI ◽  
Toshiyuki HAYASE

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