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Title: Modeling non-isothermal multiphase multi-species reactive chemical transport in geologic media

The assessment of mineral deposits, the analysis of hydrothermal convection systems, the performance of radioactive, urban and industrial waste disposal, the study of groundwater pollution, and the understanding of natural groundwater quality patterns all require modeling tools that can consider both the transport of dissolved species as well as their interactions with solid (or other) phases in geologic media and engineered barriers. Here, a general multi-species reactive transport formulation has been developed, which is applicable to homogeneous and/or heterogeneous reactions that can proceed either subject to local equilibrium conditions or kinetic rates under non-isothermal multiphase flow conditions. Two numerical solution methods, the direct substitution approach (DSA) and sequential iteration approach (SIA) for solving the coupled complex subsurface thermo-physical-chemical processes, are described. An efficient sequential iteration approach, which solves transport of solutes and chemical reactions sequentially and iteratively, is proposed for the current reactive chemical transport computer code development. The coupled flow (water, vapor, air and heat) and solute transport equations are also solved sequentially. The existing multiphase flow code TOUGH2 and geochemical code EQ3/6 are used to implement this SIA. The flow chart of the coupled code TOUGH2-EQ3/6, required modifications of the existing codes and additional subroutines needed are presented.
Authors:
; ; ;
Publication Date:
OSTI Identifier:
589221
Report Number(s):
LBNL--40504
ON: DE98052709; TRN: 98:001859
DOE Contract Number:
AC03-76SF00098
Resource Type:
Technical Report
Resource Relation:
Other Information: PBD: 1 Jul 1997
Research Org:
Lawrence Livermore National Lab., CA (United States)
Sponsoring Org:
USDOE Office of Energy Research, Washington, DC (United States)
Country of Publication:
United States
Language:
English
Subject:
54 ENVIRONMENTAL SCIENCES; 58 GEOSCIENCES; MULTIPHASE FLOW; POROUS MATERIALS; FLOW MODELS; E CODES; T CODES; COMPUTERIZED SIMULATION; ENVIRONMENTAL TRANSPORT; GROUND WATER; RADIONUCLIDE MIGRATION; LAWRENCE BERKELEY LABORATORY; RESEARCH PROGRAMS