Recovery of Lithium and Desalted Water From Oilfield Brine

Abstract

Oilfield brine extracted with hydrocarbons is often considered as a problematic waste. The typical management option for this produced water is reinjection into the formation to maintain the reservoir pressure (or just for disposal). High salinity of produced water is on the one hand a drawback, but on the other hand an advantage because it can be used as a raw material for the production of valuable chemicals. In this paper a freezing-thawing desalination method was tested to obtain partially desalted water and concentrated brine from produced water. The obtained desalted water with conductivity lower than 10 mS/cm could be beneficially reuse for non-potable applications (crop irrigation, livestock watering). The concentrate with conductivity above 80 mS/cm is a suitable feed for salt/chemicals production. As the lithium content in the obtained concentrate was high, up to 20 mg/L, so the Mn-based sorbent was applied to recover it. The lithium-selective sorbent was prepared via solid state reaction and its morphological and textural parameters confirm its good chemical stability and high affinity towards lithium ions. The lithium recovery ration in static conditions was above 95 %. The obtained results prove that produced water may be beneficially reuse outside the energy sector.