The assignee ranking for this corpus covers 42 companies, and it is heavily front-loaded: the top-ranked assignee alone holds 98 of the 233 records in scope, while the top five combined hold 158 records, or 67.8% of the field. These are largely long-established refining technology licensors rather than recent entrants. Anyone doing competitive tracking here should watch the top handful closely, since the remaining 32 ranked assignees each hold comparatively few records.

No — filings peaked at 12 in 2018 and have declined since, falling from 3 in 2021 to 1 in 2024, a 67% drop over that span. That said, 2025 and 2026 counts in any dataset like this are understated because patent publication typically lags the filing date by around 18 months, so the most recent one to two years should not be read as the true current filing rate. The multi-year trend through 2024 is the more reliable read, and it points to a mature, slowing field.

US4440628A, filed by Exxon Research and Engineering in 1984, claims a reforming process using graded rhenium content across a series of reactors — high-rhenium platinum-rhenium catalyst in the rearward zones and lower-rhenium or plain platinum catalyst forward, with a specified share of rearward reactors carrying the high-rhenium load. It remains one of the most heavily cited records in this corpus, which signals that much of the field's later catalyst-loading practice built directly on this design. It is old enough that its own claims have likely expired, but the citation pattern shows its influence on how later, still-active patents frame their claims.

Classification data shows the corpus concentrated almost entirely in C10G (89.7% of 233 records) and B01J (54.1%), while control-systems class G05B and analytics class G01N sit at just 1.3% each. That gap suggests real-time chloride balance sensing, coke burn control algorithms and reactor pressure-drop diagnostics are comparatively under-claimed relative to the core catalyst and reactor chemistry. Anyone considering a digital-monitoring or control-loop angle on CCR reforming should verify this gap against their specific claim language before assuming it is open, since a thin IPC count does not guarantee an absence of blocking prior art.

By the figures in this dataset, ownership is quite concentrated: the top five assignees hold 67.8% of the 233 records in scope and the top ten hold 83.3%. That level of concentration is consistent with a technology area built around a small number of long-running catalyst and reforming process licensing businesses, rather than one with many independent innovators. For a new entrant, this means the practical FTO exercise is narrower than the total assignee count of 42 might suggest — most of the risk sits with a handful of portfolios.