Fluidized Bed Scale-Up for Sustainability Challenges. 1. Tomorrow’s Tools

Abstract

The scaling up of fluidized beds has been purposefully pursued for more than 100 years. Yet, over that time, scale-up tools have not significantly changed. Data analysis is typically a standard analysis of variances statistical exercise, perhaps reinforced with a design of experimental procedure. Flowsheeting and equipment design are based on institutional knowledge, albeit graphical user interface-based process flow models make that job more manageable. Advanced models such as computational fluid dynamics are used but often as a supplement and not a primary driver. As a result, the scale-up process for a fluidized bed can take more than 10 years. Fluidized beds remain at the forefront of the present time-critical sustainability challenges, e.g., carbon capture by particulate sorbents, methane-to-hydrogen, plastic-to-chemicals, etc. In view of the exigency toward net zero, today's scale-up efforts need to be accelerated, leveraging the advanced new tools that have become readily available. The problem is that such tools are often neglected, inadequately implemented, ineffectively resourced, and/or poorly understood. This motivated the current effort, which is targeted at reviewing how scale-up tools have evolved over the years and the promising new tools, addressing some of the barriers of these tools in the design and scale-up of fluidized beds, as well as contemplating what can be done to circumvent these barriers. As a follow up, a companion part 2 (Cocco, R. A.; Chew, J. W. Ind. Eng. Chem. Res., submitted for publication) proposes a new scale-up path leveraging the advanced tools to achieve timely implementation of the new green fluidized bed processes.

Fluidized Bed Scale-Up for Sustainability Challenges. 2. New Pathway

“…A process risk analysis or a risk assessment process (RAP) is often considered in Stage 4. A RAP uses the team, expertise, and a cold-eye reviewer to evaluate the probability of failure and the corresponding ramifications for each piece of equipment in the proposed design . This assessment includes evaluation of circularity with regard to energy usage, CO x emissions, particle emissions, recyclability, and reliability.…”

“…As with Phase 2, a flowsheet synthesis tool can reduce the resource load and perhaps deliver an optimized configuration . Our earlier study discussed the algorithm and commercial application of such tools. With an optimized flowsheet design in place, the P&IDs are needed to complete the design of the commercial unit and the MDU.…”

“…The scaling up of fluidized bed reactors from concept to commercial scale is more uncertain than with more traditional chemical reactors, resulting in a time scale that is unconscionable for the urgent sustainability challenges . Fortunately, commercialization of fluidization units can be significantly expedited, as evident in catalyst cracking units (FCCUs) commercially producing abundant high-octane aviation fuel within a few years, which was driven by the then time-critical challenge posed by World War II. , This was instrumental in helping the Allied Forces win the war and is a testament to the scientific and engineering community that scale-up can be performed expeditiously with the right tools.…”

“…Fortunately, commercialization of fluidization units can be significantly expedited, as evident in catalyst cracking units (FCCUs) commercially producing abundant high-octane aviation fuel within a few years, which was driven by the then time-critical challenge posed by World War II. , This was instrumental in helping the Allied Forces win the war and is a testament to the scientific and engineering community that scale-up can be performed expeditiously with the right tools. There were other breakthrough technologies based on the fluidized bed that had similar speedy successes, with SOHIO taking four years for their acrylonitrile process and Union Carbide taking eight years for their UNIPOL process…”

“…The extensive time frame for scale-up is an issue. With the pressing need for climate-neutrality, accelerating the commercial implementation of the advanced concepts and tools is essential. Carbon-zero visions have been set for 2025, so the engineering marvel that drove the expedited commercialization of the FCCU during World War II has to be invoked.…”