Shallow Anatomy of the San Ramon Fault (Chile) Constrained by Geophysical Methods: Implications for its Role in the Andean Deformation
TECTONICS
Authors: Yanez, G.; Perez-Estay, N.; Araya-Vargas, J.; Sanhueza, J.; Figueroa, R.; Maringue, J.; Rojas, T.
Abstract
The San Ramon Fault (SRF) runs for 30 km along the western flank of the Andes in front of the city of Santiago, Chile (33.5 degrees S). Geological studies have highlighted the SRF role in the Neogene uplift of the Andes at this latitude, but the fault geometry at depth is not well constrained. Here we infer the structure of the sedimentary cover and bedrock up to a depth of 500 m along the SRF by integrating gravimetric, electrical resistivity, seismic, and magnetic methods. In a section crossing the central segment of the SRF, lateral variations inPwave velocity models indicate that the sedimentary cover is more deformed close to SRF scarps, while coincident low-density and low-resistivity zones suggest that the presence of two depocenters in the sedimentary cover below the SRF scarps. Gravimetric profiles distributed along the entire trace of the SRF show the same configuration of two depocenters, but the geometry of these depocenters is complex and varies along strike. Our findings suggest that the bedrock and sediments deformation along the SRF exhibit a complex geometry, which can be explained by the interplay of reverse and strike-slip movements during the late Cenozoic. Based on our results, the distribution of crustal seismicity and shortening rates interpreted across the Andes, we estimated that SRF deformation represents 5-20% of the whole Andean shortening for the last 4 Ma. Using empirical length scales for crustal seismicity, this deformation pattern is consistent with a maximum earthquake magnitude in the range of 6.0-6.5 Mw.
CPFD simulation of petcoke and SRF co-firing in a full-scale cement calciner
FUEL PROCESSING TECHNOLOGY
Authors: Nakhaeia, Mohammadhadi; Wu, Hao; Grevain, Damien; Jensen, Lars Skaarup; Glarborg, Peter; Dam-Johansen, Kim
Abstract
Computational particle fluid dynamics (CPFD) simulation is carried out to study the effect of petcoke and solid recovered fuel (SRF) co-firing in a full-scale cement calciner. The simulations are conducted using the Multi-Phase Particle-In-Cell (MP-PIC) approach with the Barracuda Virtual Reactor (R) 17.3.1 solver. The results from the CPFD simulation are compared with extensive field measurements of gas temperature and composition at several points in different calciner cross-sections. In the simulation, the SRF particles are divided into three components of plastic, biomass, and inert. The plastic particles go through drying, melting and decomposition while the conversion of biomass particles involves drying, devolatilization, and char oxidation. The predicted concentrations of O-2 and CO2 are in good agreement with the measurements, while the gas temperature is overpredicted, especially in the lower calciner vessel. However, the trends of changes in the gas temperature are well-captured. The converted fuel fraction and calcination factor are predicted with an acceptable degree of accuracy. The simulation results show that large biomass particles in SRF tend to leave the calciner without complete conversion. Furthermore, a recirculation pattern for SRF particles is observed in the lower calciner vessel and the conical section, leading to high conversion degree of this fuel.