PTQ Q3 2022 Issue

Role of FCC process and catalysts in the energy transition In the evolving circular economy, proper leveraging of FCC technology and operations can deliver value for refiners in the decades going forward

Maria Nieves Alvarez MERYT Catalysts & Innovation

R efinery fluid catalytic cracking (FCC) as a secondary chemical conversion process breaks down hydro - carbon fractions present in crude oil feedstocks into simpler fractions that can be commercially utilised, includ - ing olefinic gases, gasoline, and various other important petroleum-based products. Cracking catalysts have made a huge contribution towards FCC flexibility. They are, in fact, the heart of the process. After all, it is the catalyst that reacts with the feed - stock. The history of FCC catalyst development described in Figure 1 eventually led to sustained catalyst activity and product differentiation. Figure 1 shows the evolution of advanced FCC processing designed to obtain more specific products from higher activity fluidised bed catalysts. FCC process and catalyst innovations have enabled a continuous adaptation of the technology to meet the needs of refining for more than 80 years. While the FCC unit was initially designed to meet the rapid increase in gasoline demand that began in the 1940s, the last 30 years have seen the advent of significant new drivers expanding and reshaping the process (see Figure 2 ). Over the past few decades, economic and population growth have stirred a significant increase in oil demand, with a current consumption of 100 Mb/d and additional demand growth of 1 Mb/d per year expected for the next decade. 1 This is mostly due to the expanding automotive and aviation transportation sectors. No less important is the high products and energy con - sumption leading to expansion of the chemical sector. In parallel, efficiency improvements, important advances in clean energy generation, and environmental concerns accompanied by stricter policies are expected to result

in far slower growth in the use of oil-derived fuels in the second half of the decade and a likely demand decrease after 2030. In contrast, petrochemicals demand is not expected to stop growing in the foreseeable future. In the next two decades, oil-based feedstock demand for petrochemicals is expected to increase to 34% of the total oil market in 2040, in contrast to the current 15%. These petrochemi - cals include light olefins in the C₂−C₄ range and aromatics (mostly benzene, toluene and xylenes [BTXs]). Currently, these petrochemicals are primarily produced via steam cracking and as FCC byproducts. Industry’s con - cern over minimising operating costs of petroleum refining processes has made FCC the best alternative for cracking petroleum fractions, predicating increased demand for FCC catalysts, with an emphasis on increasing yields. A wide variety of relevant proprietary processes have been proposed, such as DCC (RIPP/SINOPEC), CPP (RIPP Kellog), MIP_GCP (RIPP), PetroFCC (UOP), and HPFCC (Grace Davison). These processes are conducted at an ele - vated reaction temperature with an increased catalyst/feed recycle ratio on the catalyst based on modified zeolite ZSM- 5. The yield of propylene can reach 20% or more. In the proprietary MAXOFIN (KBR) process, gasoline is recycled into a separate riser reactor, thereby making it possible to change the yields of cracking products flexibly. Although the cracking of light feedstocks proceeds under more severe conditions, it is characterised by a higher yield of propylene as compared with the cracking of a vacuum distillate. Thus, the yield of propylene in the cracking of par - affin base light gasoline can reach 50%. Using catalysts and processes that improve FCC

McAfee (1915)

Houdry (1936) - a commercial process Continuous ow /multiple xed-bed reactors

Thermafor catalytic cracking (TCC) (1942) Continuous ow with moving bed catalysts Catalyst: Synthetic alumina / silica particles

Fluid catalytic cracking (FCC) (1942)

Batch reactor catalytic cracking Catalyst: AlCl

Continuous ow with uidised- bed catalysts Synthetic catalyst: Silica/alumina + zeolite Y (1965) Additives ZSM-5 (1980)

Cracking/regeneration cycles Catalyst: clays, natural alumina/ silica particles

Figure 1 History of FCC catalyst development

PTQ Q3 2022