RFCCU Transition from Grey to Blue – Issue Definition and Options to Consider?

What emisson transition means? An existing or a planned conventional RFCCU or FCCU is a Grey Facility. This means, a process facility that adds CO2 to the environment. To change it into a Blue designated facility, that is Net Zero with respect to the CO2, first step is to investigate the process aspects that cause CO2 emissions and imbalances. Then, the second step is to examine the existing knowledge base. If elimination of CO2 Emission or Capture & Sequestration and use of power from renewable sources are practical and adequate options and make economic sense to deploy to transition to Net Zero. The third and final step belongs to the management on how to handle this future challenge to conform to the goals set for 2050. The two main choices are to either install the emissions reduction or removal processes, with likely additional capex and some O&M risk, or rely on buying emissions credits (e.g., EU ETA or similar) and/or making offsetting investments and paying a carbon tax, if required by local regulations. Considering that new refineries may be operable for 30–50 year, albeit the design is usually based on of 20-25 years, the time is now for the Owners' to make the long-term policy decision.

This article is only for educational sharing of my opinion and can have inaccuracies and omissions. This is not professional advice for any real situation of any kind. Readers assume all risks for any deduction or extrapolation. The Disclaimer at the end of this Article should be reviewed. It applies to the entire content and any comments or response

This is First Part of a three-part series. The First Part is to define the timeline and scope of the Net Zero challenge basis various elements of the process. The Second Part plans to outline where the potential opportunities may be and what these might be. The Third Part summarizes the current state of published knowledge of various strategies for carbon capture, storage and sequestration, other potential options that researchers mat be looking into and the extent and limitation of using renewable energy in high power consuming units where reliability is crucial.    

Before going further let us define the term Net Zero and Carbon Neutral. Although, for simplicity these are used here interchangeably, these are not the same. In my understanding, Carbon Neutral applies to companies who offsets the emission across all their facilities by funding projects elsewhere that can be considered as CO2 sink or investing in renewable energy that replace CO2 emission facilities. For example, wind power to replace a coal power plant.

The term Net Zero emissions, in my understanding, refer to balancing the greenhouse gases (CO2, CH4 NOX, O3, etc.,) produced within a facility with on-site measures to capture or neutralize so that no new addition of these gases can be added to the environment. 

So, what is the timeline and the main goals? The EU has proposed to raise the 2030 greenhouse gas emission reduction targets to at least 55%, from the existing 40%, compared to 1990. The other additional targets are increasing the share of renewable energy in the mix to one third and a similar improvement in energy efficiency. The goal is to reach a carbon neutral status by 2050 to limit the world temperature increase within 1.5 Deg by the end of this century. The Biden Administration has also adopted a similar goal to reach net-zero greenhouse emissions by 2050 and make a large public investment toward clean energy. 

Now, lets overview how much RFCCU/FCCU contributes? The approximate reported annual emission of CO2 in 2019 was ~ 40 GTPY. Out of this, the world refineries, not sure if Petrochem includes or not, contribute around 5%, meaning ~ 2 GTPY. The FCCU contribution is not exactly known to me, but understanding is that it is the largest contributor in a refinery. The reported estimates vary from 25-40%, if the latter number is assumed and averaged over around 400 FCCU/RFCCU facilities globally, it is ~ 2 MMTPY. The main contributor, as most who know FCCU can guess, is the Regenerator Flue Gas. The other major contribution is from the power plant, whether in-plot or outside power, that support the requirements for the air blower and the WGC compressor among other things. The minor contributors may be a feed heater, if fossil based, air heater, occasional torch oil, FCC off gas amine regenerator if CO2 is vented and the debutanizer reboiler, if for some reason an internal hot stream cannot be used. 

What is a paradox, in my opinion, is that one hand there is an increasing drive to use residue for fluid catalytic cracking and the feedstocks are getting heavier and heavier, while on the other hand objective of reducing CO2 emission is catapulting into high priority in the board rooms of major companies? As an example, ExxonMobil recently announced a new business group to focus on low carbon initiatives. Coming back to the paradox, as residue content of RFCCU feedstock increase, so does the carbon on coke and the CO2, NOX, and SOX emissions from the stack. Furthermore, this increase also cause the size of the air blower and wet gas compressor to increase as well consuming more and more power, mainly coming either from fossil power plants only or from a mix of fossil with hydro or nuclear power. Thus, a dilemma for owners’ who are constructing or planning a RFCCU facility.

Before closing this Part 1 of the Article, FCCU catalyst industry needs to be highlighted as well. The manufacturing of the catalyst and various exchanges, treatments, heating & calcination, etc., are all partners in this equation to achieve net zero emissions. If a RFCCU project goes to great lengths to make the unit as emissions friendly as possible, I think, it would be incumbent upon the catalyst supplier as well to show their facilities also following the same. 

Disclaimer: This is not professional advice, directly or indirectly, and can be edited or deleted at any time. Anyone accessing this Blog unconditionally agrees that the expressed views are only the personal opinions of the Author for educational sharing only, basis author’s knowledge only, and may contain omissions and inaccuracies. It must not be used for any actual new project or on an existing facility. Readers accept all risks and responsibility for any interpretation or extrapolation and any consequences stemming from such reliance