Capturing the costs - increasing carbon capture uptake by reducing capex and opex

Francisco Alanis | Principal Consultant, Industrial Decarbonization | Aditya Thallam Thattai | Senior Consultant, Industrial Decarbonization | 20 April 2022

With a small window for industry to reach carbon capture targets, we explored configurations with Worley’s Comprimo and Alfa Laval that can help the industry reduce capital and operating costs. 

Carbon capture, utilization and storage (CCUS) is gathering momentum. In 2021 alone, energy operators announced over 100 new CCUS projects in an attempt to reach decarbonization targets. But was this enough?

Francisco Alanis, Principal Consultant for Industrial Decarbonization, says, “By 2030, we’ll need to have captured 1.7 billion tonnes of carbon dioxide (CO₂). So, the number of projects needs to increase. However, carbon capture is costly, which hinders uptake.”

With that in mind, Alanis and Dr. Aditya Thallam Thattai, Senior Consultant for Industrial Decarbonization, together with Leorelis Vasquez from Comprimo and Eva Andersson from Alfa Laval explored ways to reduce carbon capture costs. In a paper, titled Carbon capture with least opex and capex, they proposed optimization design alternatives for a basic chemical solvent-based carbon capture process.

“Solvent based absorption/stripping has been around for 30 years,” explains Alanis. “It’s currently a common and mature carbon capture process. But it consumes too much electricity, water, and steam. So, we wanted to optimize the process to use less of each.”

The team focused on four optimizations in total. They assessed options to reduce energy consumption using a refinery facility’s available waste heat and the full capacity of heat transfer equipment. This would help increase energy efficiency, water management, and lower investment costs.

Where optimization one looks at waste heat recovery from flue gas, optimization two looks at maximizing solvent cooling and heat recovery in the lean/rich interchanger. Optimization three attempts to maximize condenser and interstage cooling of a CO₂ compressor system. And optimization four explores reducing process and cooling water requirements.

Thallam Thattai says, “The paper stands out because the optimizations can work independently of each other or together.

“Let’s take optimization one as an example. If a post-combustion capture plant deploys it without the other optimizations, 90 percent of emitted CO₂ (equivalent to 375 ktpa CO₂) can be captured from a typical refinery furnace flue gas feed composing of 12 percent mass CO₂ with cost reductions by 16 €/tonCO₂.”

While a facility can reduce its capex and opex just by applying one optimization, the biggest cuts happen when it deploys all four. 

“Together, the optimizations can help a refinery capture up to 90 percent of CO₂ and reduce the cost significantly by more than 20 €/tonCO₂,” explains Thallam Thattai.

He concludes by saying, “These are significant gains, regardless of how many optimizations are applied. It’s our hope that they will encourage operators to implement carbon capture in their journeys to decarbonize.”

Digital Refining recently published the team’s findings in its 2021 Q4 issue. To read the full paper, please visit PTQ Magazine.