3D Quantification of Pore Networks and Anthropogenic Carbon Mineralization in Stacked Basalt Reservoirs.

Basalt formations are promising candidates for the geologic storage of anthropogenic CO due to their storage capacity, porosity, permeability, and reactive geochemical trapping ability. The Wallula Basalt Carbon Storage Pilot Project demonstrated that supercritical CO injected into >800 m deep Columbia River Basalt Group stacked reservoir flow tops mineralizes to ankerite-siderite-aragonite on month-year time scales, with 60% of the 977 metric tons of CO converted within 2 years. The potential impacts of mineral precipitation and consequent changes in the rock porosity, pore structure, pore size, and pore size distributions have likely been underestimated hitherto.

Exotic Carbonate Mineralization Recovered from a Deep Basalt Carbon Storage Demonstration.

Mitigating climate change requires transformational advances for carbon dioxide removal, including geologic carbon sequestration in reactive subsurface environments. The Wallula Basalt Carbon Storage Pilot Project demonstrated that CO injected into >800 m deep Columbia River Basalt Group flow top reservoirs mineralizes on month-year timescales. Herein, we present new optical petrography, micro-computed X-ray tomography, and electron microscopy results obtained from sidewall cores collected two years after CO injection.

Mineralization of basalts in the CO2-H2O-SO2-O2 system.

Sequestering carbon dioxide (CO2) containing minor amounts of co-contaminants in geologic formations was investigated in the laboratory through the use of high pressure static experiments. Five different basalt samples were immersed in water equilibrated with supercritical CO2 containing 1 wt % sulfur dioxide (SO2) and 1 wt % oxygen (O2) at reservoir conditions (∼ 100 bar, 90 °C) for 48 and 98 days. Gypsum (CaSO4) was a common precipitate, occurred early as elongated blades with striations, and served as substrates for other mineral products.

Following 18O uptake in scCO2-H2O mixtures with Raman spectroscopy.

The uptake of (18)O by scC(16)O(2) in mixtures containing liquid H(2)(18)O was followed with Raman spectroscopy using a specially designed high-pressure optical cell. Characteristic bands from the C(16)O(18)O and C(18)O(2) molecules were identified in the supercritical phase and measured in the spectra as a function of time after introducing the liquid H(2)(18)O into the scC(16)O(2). Temporal dependence indicated the process was diffusion-limited in our cell for both C(16)O(18)O and C(18)O(2).

Enhanced radionuclide immobilization and flow path modifications by dissolution and secondary precipitates.

Caustic radioactive wastes that have leaked at Hanford Site (Richland, WA) induce mineral dissolution and subsequent secondary precipitation that influence the fate and transport of contaminants present in the waste solutions. The effects of secondary mineral precipitates, formed after contacting solids with simulated caustic wastes, on the flow path changes and radionuclide immobilization were investigated by reacting quartz, a mixture of quartz and biotite, and a Hanford sediment (Warden soil: coarse-silty, mixed, superactive, mesic Xeric Haplocambids) with simulated caustic tank waste solution. Continuous Si dissolution and concomitant secondary mineral precipitation were the principal reactions observed in both batch and flow-through tests.