System and process for geological sequestration of carbon-containing materials
This disclosure relates to methods and systems for injecting and/or sequestering carbon-containing materials in underground wells, and, in some examples, for using the carbon-containing materials for enhanced oil recovery and well abandonment. An example method includes: obtaining a mixture including biochar particles and a liquid; and providing the mixture for injection into an underground well.
1 . A method of sequestering carbon-containing materials, the method comprising:
obtaining biochar;
compressing the biochar to increase a density of the biochar;
combining the biochar with a liquid to obtain (i) a mixture comprising a first portion of the biochar dispersed in the liquid and (ii) a second portion of the biochar floating on the mixture;
separating the second portion of the biochar from the mixture; and
providing the mixture for injection into an underground well.
2 . The method of claim 1 , wherein the biochar comprises particles having a particle size less than about 100 microns.
3 . The method of claim 1 , wherein the mixture has a kinematic viscosity less than about 200 cSt and a density greater than about 1.25 kg/L.
4 . The method of claim 1 , wherein the liquid comprises bio-oil.
5 . The method of claim 1 , wherein the liquid comprises brine or water.
6 . The method of claim 1 , wherein the liquid comprises a mixture of bio-oil and at least one of brine or water.
7 . The method of claim 1 , wherein the liquid comprises at least one of bio-oil, biodiesel, ethanol, cooking oil, vegetable oil, plant-based oil, a solution containing microbes or algae, biocrude, a biocrude byproduct, petroleum, crude oil, gasoline, or diesel.
8 . The method of claim 1 , further comprising milling the biochar in a mill to form biochar particles, and wherein combining the biochar with the liquid comprises mixing the biochar particles with the liquid.
9 . The method of claim 1 , wherein separating the second portion of the biochar comprises separating biochar particles from the mixture according to density.
10 . The method of claim 1 , wherein combining the biochar with the liquid comprises adding a surfactant to the mixture.
11 . The method of claim 1 , wherein combining the biochar with the liquid comprises adding biomass particles to the mixture, and wherein the biomass particles comprise at least one of agricultural waste, forestry waste, soil, processed waste, algae, microbes, kelp, human waste, or animal waste.
12 . The method of claim 1 , wherein the underground well comprises at least one of a commercial disposal well, a salt cavern, a Class II cavern, a depleted mine, an abandoned mine, a purpose-constructed mine, or a natural cavern.
13 . The method of claim 1 , wherein providing the mixture for injection comprises subjecting the mixture to a test for compatibility with the underground well using a core sample for the underground well, and wherein the test for compatibility determines a tendency for at least one of premature polymerization, auto-polymerization, phase separation, gas generation, or precipitation of solids.
14 . The method of claim 1 , wherein providing the mixture for injection comprises adjusting a property of the mixture to improve compatibility with the underground well.
15 . The method of claim 14 , wherein the property comprises at least one of pH, viscosity, specific gravity, microbial growth potential, solids loading, tendency to auto-polymerize, or flash point.
16 . The method of claim 1 , further comprising:
obtaining a modified biochar by at least one of:
milling the second portion of the biochar; or
compressing the second portion of the biochar; and
adding the modified biochar to the mixture.
17 . The method of claim 1 , wherein the first portion of the biochar has a density greater than or equal to a density of the liquid, and the second portion of the biochar has a density less than the density of the liquid.
18 . The method of claim 1 , wherein compressing the biochar comprises using a pellet mill or a roller compactor.
19 . A system for sequestering carbon-containing materials, the system comprising:
a source of biochar;
a compression device for compressing the biochar to increase a density of the biochar;
a mixing device for combining the biochar with a liquid to obtain (i) a mixture comprising a first portion of the biochar dispersed in the liquid and (ii) a second portion of the biochar floating on the mixture;
a separation device for separating the second portion of the biochar from the mixture; and
at least one of a container, a pump, or a pipe for injecting the mixture into an underground well.
20 . The system of claim 19 , wherein the biochar comprises particles having a particle size less than about 100 microns.
21 . The system of claim 19 , wherein the mixture has a kinematic viscosity less than about 200 cSt and a density greater than about 1.25 kg/L.
22 . The system of claim 19 , wherein the liquid comprises bio-oil.
23 . The system of claim 19 , wherein the liquid comprises a mixture of bio-oil and at least one of brine or water.
24 . The system of claim 19 , wherein the system is configured to:
produce a modified biochar using at least one of:
a mill to mill the second portion of the biochar; or
the compression device to compress the second portion of the biochar; and
use the mixing device to combine the modified biochar with the mixture.