Abstract
This paper presents the results of a program of computational modeling focused on elucidating the physics and chemical processes associated with the extraction of volatile materials from asteroid feedstocks with an eye toward use of the extracted materials for propulsion, radiation shielding, and replenishment of mission consumables. We present a math model of conductive heat transport, chemical processes, and gas escape by Darcian diffusion. Chemical processes in the model include pyrolysis of organic chemical constituents and thermal dehydration and decarbonization of hydrates and carbonates. The model is implemented in a spherical finite difference computational engine that predicts time histories of gas release and flow rates, interstitial gas pressure, and material temperature profiles as a function of the time history of the outer surface of the sample being modeled. Samples of materials modeled include solid and granular forms of terrestrial clays, engineered stimulants, asteroid material based on canonical CI and CM type meteorites, and one particular CM type meteorite which was tested in a related experimental effort. Modeling results show good agreement with experimental results suggesting that the model is largely complete and descriptive demonstrating a practical understanding of the process as needed for engineering applications. Particular unknowns associated with certain chemical processes, for example vacuum pyrolysis of bitumen and kerogen, as well as vacuum TGA analysis of certain phyllosilicate materials are identified as needs for future basic supporting research. After presenting direct comparisons of model outputs with recently completed experimental results, in effect validating the model, the model is applied to hypothetical meter, decameter, and hectometer scale asteroids in a hypothetical solar oven. This analysis motivates an extension of the model to address Optical Mining technology which has certain advantages over bulk heating as specified in the paper. An outline of our plan for a finite difference model of the Optical Mining process is presented. The importance and the value of terrestrial macroscopic thermal oven experiments for fundamental research supporting Optical Mining is clarified.
Recommended Citation
J. C. Sercel et al., "Computational Modeling of Heat Transport and Volatile Extraction from Asteroid Materials," Earth and Space 2018: Engineering for Extreme Environments - Proceedings of the 16th Biennial International Conference on Engineering, Science, Construction, and Operations in Challenging Environments, pp. 414 - 428, American Society of Civil Engineers, Jan 2018.
The definitive version is available at https://doi.org/10.1061/9780784481899.041
Department(s)
Geosciences and Geological and Petroleum Engineering
Second Department
Mining Engineering
International Standard Book Number (ISBN)
978-078448189-9
Document Type
Article - Conference proceedings
Document Version
Citation
File Type
text
Language(s)
English
Rights
© 2024 American Society of Civil Engineers, All rights reserved.
Publication Date
01 Jan 2018
