Disclosed herein is 4-chamber microbial electrolysis process and apparatus that recovers lignin, NaOH, and H.sub.2 products while removing waste organics from deacetylation and mechanical refining black liquor.

Disclosed herein is 4-chamber microbial electrolysis process and apparatus that recovers lignin, NaOH, and H.sub.2 products while removing waste organics from deacetylation and mechanical refining black liquor.

There are provided methods for preparing lithium carbonate. For example, such methods can comprise reacting an aqueous composition comprising lithium hydroxide with CO.sub.2 by sparging the CO.sub.2 the said composition, thereby obtaining a precipitate comprising the lithium carbonate. The methods can also comprise inserting at least a portion of the precipitate into a clarifier and obtaining a supernatant comprising lithium bicarbonate and a solid comprising the lithium carbonate, separating the solid from the supernatant; and heating the supernatant at a desired temperature so as to at least partially convert the lithium bicarbonate into lithium carbonate.

There are provided methods for preparing lithium carbonate. For example, such methods can comprise reacting an aqueous composition comprising lithium hydroxide with CO.sub.2 by sparging the CO.sub.2 the said composition, thereby obtaining a precipitate comprising the lithium carbonate. The methods can also comprise inserting at least a portion of the precipitate into a clarifier and obtaining a supernatant comprising lithium bicarbonate and a solid comprising the lithium carbonate, separating the solid from the supernatant; and heating the supernatant at a desired temperature so as to at least partially convert the lithium bicarbonate into lithium carbonate.

In this disclosure, a process of recycling acid, base and the salt reagents required in the Li recovery process is introduced. A membrane electrolysis cell which incorporates an oxygen depolarized cathode is implemented to generate the required chemicals onsite. The system can utilize a portion of the salar brine or other lithium-containing brine or solid waste to generate hydrochloric or sulfuric acid, sodium hydroxide and carbonate salts. Simultaneous generation of acid and base allows for taking advantage of both chemicals during the conventional Li recovery from brines and mineral rocks. The desalinated water can also be used for the washing steps on the recovery process or returned into the evaporation ponds. The method also can be used for the direct conversion of lithium salts to the high value LiOH product. The method does not produce any solid effluent which makes it easy-to-adopt for use in existing industrial Li recovery plants.

In this disclosure, a process of recycling acid, base and the salt reagents required in the Li recovery process is introduced. A membrane electrolysis cell which incorporates an oxygen depolarized cathode is implemented to generate the required chemicals onsite. The system can utilize a portion of the salar brine or other lithium-containing brine or solid waste to generate hydrochloric or sulfuric acid, sodium hydroxide and carbonate salts. Simultaneous generation of acid and base allows for taking advantage of both chemicals during the conventional Li recovery from brines and mineral rocks. The desalinated water can also be used for the washing steps on the recovery process or returned into the evaporation ponds. The method also can be used for the direct conversion of lithium salts to the high value LiOH product. The method does not produce any solid effluent which makes it easy-to-adopt for use in existing industrial Li recovery plants.

An ion source and ion recycle module includes an electrolyte reservoir, an eluent recovery chamber, and an ion exchange connector. The electrolyte reservoir includes a chamber containing an aqueous electrolyte solution including an electrolyte having a chamber inlet and a chamber outlet, and a first electrode. The chamber inlet is fluidically connected to a source chamber of an electrolytic eluent generator and configured to receive depleted electrolyte solution from the source chamber of the electrolytic eluent generator. The chamber outlet is fluidically connected to the source chamber of the electrolytic eluent generator and configured to provide recycled electrolyte solution to the electrolytic eluent generator source chamber. The eluent recovery chamber including a second electrode and configured to receive an eluent solution including eluent counter ions from the eluent generator; and the ion exchange connector including an ion exchange membrane stack.

An ion source and ion recycle module includes an electrolyte reservoir, an eluent recovery chamber, and an ion exchange connector. The electrolyte reservoir includes a chamber containing an aqueous electrolyte solution including an electrolyte having a chamber inlet and a chamber outlet, and a first electrode. The chamber inlet is fluidically connected to a source chamber of an electrolytic eluent generator and configured to receive depleted electrolyte solution from the source chamber of the electrolytic eluent generator. The chamber outlet is fluidically connected to the source chamber of the electrolytic eluent generator and configured to provide recycled electrolyte solution to the electrolytic eluent generator source chamber. The eluent recovery chamber including a second electrode and configured to receive an eluent solution including eluent counter ions from the eluent generator; and the ion exchange connector including an ion exchange membrane stack.

Nanogas dispersions including an electrochemically activated (“ECA”) aqueous solution having an electrolyte and water; and a plurality of gas-filled cavities (i.e., nanobubbles) dispersed within the ECA aqueous solution. An enhanced oil recovery system including a reservoir containing an ECA aqueous solution; a nanogas dispersion generator configured to generate a nanogas dispersion within the ECA aqueous solution, the nanogas dispersion having the ECA aqueous solution and a plurality of nanobubbles dispersed therein; and an injection pump connected to the reservoir and configured to pump an effective amount of the nanogas dispersion into a subterranean formation. A method for treating a subterranean formation including: providing a nanogas dispersion made of an ECA aqueous solution and a plurality of nanobubbles; pumping an effective amount of the nanogas dispersion into the subterranean formation; and extracting a mixture of water from the subterranean formation to a surface-located device.

Nanogas dispersions including an electrochemically activated (“ECA”) aqueous solution having an electrolyte and water; and a plurality of gas-filled cavities (i.e., nanobubbles) dispersed within the ECA aqueous solution. An enhanced oil recovery system including a reservoir containing an ECA aqueous solution; a nanogas dispersion generator configured to generate a nanogas dispersion within the ECA aqueous solution, the nanogas dispersion having the ECA aqueous solution and a plurality of nanobubbles dispersed therein; and an injection pump connected to the reservoir and configured to pump an effective amount of the nanogas dispersion into a subterranean formation. A method for treating a subterranean formation including: providing a nanogas dispersion made of an ECA aqueous solution and a plurality of nanobubbles; pumping an effective amount of the nanogas dispersion into the subterranean formation; and extracting a mixture of water from the subterranean formation to a surface-located device.