Carbon
SEQUESTERING IN PLACE
Pipeline aggregation of ethanol plant CO2 has captured industry attention, but stand-alone CCS projects might be uniquely positioned for early success. By Luke Geiver
Carbon capture and sequestration (CCS) projects are integrating into existing ethanol plants like never before. In the
past two years, numerous plants in the heart of ethanol-production country—spanning several Midwest states—have announced their intentions to implement CCS. A majority of the projects announced will rely on pipeline networks to take compressed CO2 from participating ethanol plants to alternative locations where the gas will be utilized for industrial purposes or, more likely, injected thousands of feet below the surface. In early May, Summit Carbon Solutions announced a successful $1 billion equity raise for its proposed CCS pipeline, which would link more than 30 ethanol plants into its system. But not every ethanol plant eyeing CCS is planning for pipelines. A handful of plants are taking the steps—or already have—to explore the feasibility of capturing and storing CO2 onsite, or very close to the confines of the ethanol plant’s geographic footprint. Reviewing why and how those plants are approaching and dealing with the variables related to the process shows what it takes to sequester on location, autonomously. 30 | ETHANOL PRODUCER MAGAZINE | JUNE 2022 30 | ETHANOL PRODUCER MAGAZINE | JULY 2022
Putting CO2 Under Your Plant Ethanol plants considering onsite CCS should remember that tried-and-true real estate mantra: it’s all about location, location, location. There’s a twist, however. It’s not so much about the surface location. The sequestration portion of CCS relies on the presence of a geologic formation capable of housing carbon gas molecules and trapping them. Every plant location is different in terms of the geologic formations below ground. In some areas, a suitable rock structure like sandstone or limestone may exist only 1,000 feet underground. In other cases, the target structure for CCS may be more than two miles down. The deeper the suitable formation, the costlier the upfront price. While CCS projects using pipelines must overcome the challenge of gaining public and government buy-in for rightof-ways and multi-month installation, inplace sequestration projects must start with the well permitting process. From there, a permitted well can be drilled by a reputable drilling company. The core samples from the drill-out will reveal the geologic formations below the surface. Although the geology is generally already understood for most areas in ethanol country, the process still has to be undertaken to ensure exactly what lies
beneath. If the test well shows favorable geology, it can be used as the injection well. Other injection points can be added, along with the compression equipment needed to take CO2 from its gas state into the liquid state needed for injection. A monitoring system must also be installed. In California, progressive renewable energy producer Aemetis has undergone the early test well phase. The company has completed a study, led by globally recognized drilling contractor Baker Hughes, to evaluate the drilling site, perform an underground formation review and ensure the feasibility of drilling technology for
