: Geochemical reaction path modeling is useful for rapidly assessing the extent of water-aqueous-gas interactions both in natural systems and in industrial processes. Modeling of some systems, such as those at low temperature with relatively high hydrologic flow rates, or those perturbed by the subsurface injection of industrial waste such as CO2 or H2S, must account for the relatively slow kinetics of mineral-gas-water interactions. We have therefore compiled parameters conforming to a general Arrhenius-type rate equation, for over 70 minerals, including phases from all the major classes of silicates, most carbonates, and many other non-silicates. These data have been added to a computer code that simulates an infinitely well-stirred batch reactor, allowing computation of mass transfer as a function of time. Actual equilibration rates are expected to be much slower than those predicted by the selected computer code, primarily because actual geochemical processes commonly involve flow through porous or fractured media, wherein the development of concentration gradients in the aqueous phase near mineral surfaces, which results in decreased absolute chemical affinity and slower reaction rates. Further differences between observed and computed reaction rates may occur because of variables beyond the scope of most geochemical simulators, such as variation in grain size, aquifer heterogeneity, preferred fluid flow paths, primary and secondary mineral coatings, and secondary minerals that may lead to decreased porosity and clogged pore throats.

/pdf/a-compilation-of-rate-parameters-of-water-mineral-1o9qltikkk.pdf

A Compilation of Rate Parameters of Water-Mineral Interaction Kinetics for Application to Geochemical Modeling

Numerical simulation of CO2 disposal by mineral trapping in deep aquifers

Accident tolerant fuel cladding development: Promise, status, and challenges

General kinetic description of multioxide silicate mineral and glass dissolution

https://escholarship.org/content/qt9jx243hn/qt9jx243hn.pdf

Mineral sequestration of carbon dioxide in a sandstone–shale system

https://pangea.stanford.edu/ERE/pdf/IGAstandard/SGW/1993/Tester.pdf

Correlating quartz dissolution kinetics in pure water from 25 to 625°C

Reaction rate constants for the hydrolysis of organic esters and amides were determined at temperatures of 100–240°C in aqueous solutions buffered at pH values between 5.5 and 7.3. Experiments are modeled assuming alkaline hydrolysis with a thermodynamic solution model included to account for the temperature dependence of hydroxide ion concentration. In most cases, the ester hydrolysis second order rate constants agree well with published values from experiments in strongly basic solutions at pH values from 11 to 14 and temperatures from 25–80°C, despite the large extrapolations required to compare the data sets. The amide hydrolysis rate constants are about one order of magnitude higher than the extrapolated results from other investigators, but the reaction rate increased proportionally with hydroxide ion concentration, suggesting that an alkaline hydrolysis mechanism is also appropriate. These data establish the validity of the alkaline hydrolysis mechanism and can be used to predict hydrolysis reaction rates in neutrally-buffered solutions such as many groundwater and geothermal fluids.

Kinetics of alkaline hydrolysis of organic esters and amides in neutrally‐buffered solution

Characterization of flow maldistribution using inlet-outlet tracer techniques: An application of internal residence time distributions

Non-reactive tracer tests in prototype hot dry rock (HDR) geothermal reservoirs indicate multiple fracture flow paths that show increases in volume due to energy extraction. Tracer modal volumes correlate roughly with estimated reservoir heat-transfer capacity. Chemically reactive tracers are proposed which will map the rate of advance of the cooled region of an HDR reservoir, providing advanced warning of thermal drawdown. Critical parameters are examined using a simplified reservoir model for screening purposes. Hydrolysis reactions are a promising class of reactions for this purpose.

/pdf/reservoir-sizing-using-inert-and-chemically-reacting-tracers-29ogdm8lfw.pdf

Reservoir sizing using inert and chemically reacting tracers

The theory behind how chemically reactive tracers are used to characterize the velocity and temperature distribution in steady flowing systems is reviewed. Ranges of kinetic parameters are established as a function of reservoir temperatures and fluid residence times for selecting appropriate reacting systems. Reactive tracer techniques are applied to characterize the temperature distribution in a laminar-flow heat exchanger. Models are developed to predict reactive tracer behavior in fractured geothermal reservoirs of fixed and increasing size. 5 figs., 11 refs.

/pdf/the-theory-and-selection-of-chemically-reactive-tracers-for-2b33nu7cqm.pdf

Bruce A. Robinson

Papers

Correlating quartz dissolution kinetics in pure water from 25 to 625°C

Kinetics of alkaline hydrolysis of organic esters and amides in neutrally‐buffered solution

Characterization of flow maldistribution using inlet-outlet tracer techniques: An application of internal residence time distributions

Reservoir sizing using inert and chemically reacting tracers

The Theory and Selection of Chemically Reactive Tracers for Reservoir Thermal Capacity Production