Details are scarce on Exxon Mobil Corp.’s search for lithium resources in Arkansas’ Smackover Formation and its chosen direct lithium extraction (DLE) technology, but what’s clear is the company positioning itself to capture some of the region’s bromine-rich  riches.

Exxon Mobil, where the research of M. Stanley Whittingham led to the world’s first rechargeable lithium-ion battery in the 1970s and the 2019 Nobel Prize in chemistry with scientists John B. Goodenough and Akira Yoshino, is making a return to the battery materials business. The push by Exxon comes as as the U.S. aims to boost domestic supplies of critical materials needed for batteries.

The supermajor will join companies that include Standard Lithium Ltd., which is developing the area’s first commercial lithium extraction plant working with chemical company LANXESS Corp, and Albemarle Corp. The North Carolina-headquartered company, focused on extracting resources from hard rock and brine, is testing DLE technology in Magnolia, Arkansas.

Exxon Mobil is drilling about 10,000 ft deep to tap into the market with a target of first lithium production in 2027.

The process involves drilling a well to extract lithium-rich brine. The brine is then pumped to a processing unit where lithium is extracted by adsorption, resin or a membrane. The extracted lithium will be converted onsite into battery-grade material, the company said.

“We’ve got over 2,000 Ph.D.s within the company, experts in that field and across many different process steps, and we’ll pull on them to really get the best process design that we can for the opportunity,” Patrick Howarth, lithium global business manager for ExxonMobil Low Carbon Solutions, told Hart Energy.

While entering the lithium sector opens another revenue stream for Exxon, the move also gives the company an opportunity to help lower emissions. Lithium is a key component of batteries for electric vehicles.

Howarth spoke to Hart Energy following the company’s lithium drilling announcement this week.

Velda Addison: What will that first phase include and about how many wells will be drilled? Where are you planning to drill in the Smackover region?

Patrick Howarth: Earlier this year, we acquired 120,000 acres, and the wells will cover … that acreage in different locations. We’re currently working on the total number of wells that we plan to drill, but we will start [the] first well this coming week. That will then start a drilling campaign that will go into next year.

VA: Are you targeting specific zones when looking for a lithium? What conditions are you looking for in terms of porosity and permeability to find like the highest lithium concentrations and flow rates?

PH: What these wells will be targeting is really resource delineation approach or an appraisal approach that you might imagine. So, we will drill vertical wells that will penetrate all of intervals within Smackover. We’ll then test each of those intervals. We’re looking for lithium concentration and the ability of the reservoir to flow. … We’re hoping this drilling campaign that we’re about to embark on gives us a lot more specifics about that for the acreage that we’ve got.

VA: Why did Exxon decide to go with the direct lithium extraction method? Have you decided which type of technology will be used for this process—whether it’s ion exchange, lithium bonding or solvent extraction?

PH: The world has two different sources of lithium today. It’s either hard rock or from brine. Most of the brine is shallow brine within Latin America, and they use evaporation as the main mechanism to concentrate up the lithium and remove impurities. Within Arkansas, we don’t feel that there’s an opportunity for evaporation there. And frankly, we see DLE as being very advantageous from an environmental footprint perspective. So, significant benefits from a land use or water use perspective but then also substantially lower carbon intensity versus hard rock mining.

VA: Who are your major partners on this drilling project?

PH: We’re not announcing partners on the drilling project right now. We’re obviously working with drilling contractors to complete the campaign, but this is an Exxon Mobil-led endeavor.

VA: Generally, about how much lithium carbonate do you need to produce an EV battery? Exxon has set a goal to produce enough lithium for 1 million EVs per year by 2030. What’s the capital requirement for such a large number of vehicles?

PH: So, there are varying battery chemistries out there. The vast majority of them for EV applications contain lithium, but each of them have different compositions that need it. So, it’s a pretty tough question to say in an EV how much lithium there is. It really depends on the battery size, pack size of the vehicle, and the specific chemistry there. In terms of capital allocation, an individual project that we’re looking at could easily run into hundreds of millions of dollars. But really that final number will be determined by the results of the drilling campaign and engineering studies that are underway.

VA: Are you considering drilling for lithium in any other areas in the United States?

PH: Right now, our focus is on Arkansas. We see that as a great place to start. Some of the reasons are the really strong support we’ve seen from the local regulator, the government there. The existing regulator is well used to regulating brine operations. So, we see great regulatory response there. They’re very proactive. They know where the risks are. They permit on a timely basis. That’s one of the reasons why we picked Arkansas along with, obviously, the resource potential that we see there. If we’re successful in this endeavor, I certainly see that we would expand our ambitions within the U.S. and more globally. But right now, we’re really focused on Arkansas.

VA: Is there anything else you wanted to add on the topic?

PH: We’re really just excited about this opportunity. I think coming out with the announcement [Nov. 13] that we aim to be a leading supplier of lithium by 2030 is a really big step for us. We’re excited about the opportunity and really excited to deploy our skills and capabilities in this new area. We think we’ve got a pretty unique set of capabilities across this value chain, and so looking forward to more announcements as we get out to the future.

Patrick Howarth
Patrick Howarth (Source: LinkedIn Exxon)