--- title: "Chemical Engineering Expert’s Testimony on Catalyst Damage Excluded" meta: "og:description": "The chemical engineering expert was not allowed to opine on the carryover theory of catalyst damage because he erred in reading the graph" "og:title": "Chemical Engineering Expert’s Testimony on Catalyst Damage Excluded" author: "Expert Witness Profiler" description: "The chemical engineering expert was not allowed to opine on the carryover theory of catalyst damage because he erred in reading the graph" --- # Chemical Engineering Expert’s Testimony on Catalyst Damage Excluded Posted on April 10, 2026 by Expert Witness Profiler Plaintiff, a manufacturer of materials (e.g., nylon), contracted with Defendant to provide railcar switching services at Plaintiff’s Pensacola plant. On November 24, 2023, Defendant misidentified a railcar containing resin and delivered it to the phenol unloading area at Plaintiff’s plant. The resin railcar was unloaded into Plaintiff’s phenol holding tank, and Plaintiff alleged that the resin then contaminated the reactor unit that normally draws phenol from the tank. Plaintiff further claimed that contamination permanently damaged the reactor’s catalyst and resulted in an extended shutdown of certain plant operations. Defendant designated expert [Bruce Williams](https://expertwitnessprofiler.com/expert-witness/Bruce-Williams/1573611) to opine on the procedures that resulted in the phenol contamination and the subsequent damage to the reactor’s catalyst. As to the contamination, Williams concluded it was caused by Plaintiff’s employees falsely claiming the resin railcar contained phenol and that it was on the approved unloading list. He also noted that Plaintiff should have been aware that resin had been unloaded into the tank based on the tank’s level data. Williams concluded that the damage to the catalyst was caused by Plaintiff overfeeding liquid into the reactor, not the resin contamination. Plaintiff sought to exclude portions of Williams’ testimony as premised on unsupported statements and unreliable inputs. ## **Chemical Engineering Expert Witness** [Bruce C. Williams](https://expertwitnessprofiler.com/expert-witness/Bruce-Williams/1573611) has over 46 years of experience working for Dow Chemical, Novus International, and Covestro AG where he has designed, constructed, and operated chemical plants across a variety of technologies and countries. [Get the full story on challenges to Bruce Williams’ expert opinions and testimony with an in-depth Challenge Study](https://expertwitnessprofiler.com/order/add?eId=1573611&pId=3). ## **Discussion by the Court** #### **A. Williams’ opinion on the length of time the pump operated should not be excluded** A key part of the Parties’ dispute involves whether Plaintiff should have been aware that resin had been unloaded into the phenol tank. Plaintiff contended that its operators “experienced unloading issues,” and required additional confirmation that resin was unloaded. Williams opined that the Plaintiff should have realized resin had been unloaded from the railcar into the phenol tank because, he claimed, the unloading pump ran for over an hour, moving at least some resin into the phenol tank. As demonstrated in his report and discussed during his deposition, Williams arrived at the conclusion that the pump operated for this amount of time by considering the operators’ statements in light of the pump’s technical features. He explained that although the meter indicating whether material was flowing through the pump may have shown there was no flow, the fact the pump continued to operate without triggering the automatic shutoff—which occurs when there is no flow, low flow, or high flow—demonstrated flow and that resin was being unloaded from the railcar. He further argued that no indicators of no flow, low flow, or high flow were present, and a reasonable operator would have recognized that material was flowing. ### _**Analysis**_ Plaintiff made two arguments for exclusion of Williams’ opinion that the pump ran for over an hour. First, Plaintiff argued that the expert opinion should be excluded as not helpful to the jury because the jury can apply common sense and simple logic to determine whether the pump ran for an hour. Second, Plaintiff contended that any opinions based on the pump running for an hour must be excluded as not based on sufficient facts or data or as otherwise unreliable. The Court found that the opinion is helpful to the jury because the Parties dispute how long the pump ran and Williams, who has technical knowledge of the pumps and unloading process, bases his opinion on statements by the witnesses. Technical knowledge of the pumps and how they operate is outside the realm of experience of a common juror and Williams’ technical explanation regarding the pump operation could assist the jury in determining whose version of events is correct. Application of his technical knowledge to the operators’ statements is a reliable approach, particularly considering Plaintiff did not challenge Williams’ knowledge itself. #### **B. Williams’ opinion on the phenol tank levels should not be excluded** Williams also opined that Plaintiff should have been aware resin had been unloaded into the phenol tank based on the tank’s level data. The phenol tank is an active tank, meaning phenol is often being simultaneously added to the tank from railcars and removed from it into the reactor. Using the level data itself, as well as the rates of change in the data occurring during the unloading of the railcar, Williams purports to have calculated accurate estimates of the amount of unloaded resin. According to Williams, if the Plaintiff had done the same, it would have noticed that during the unloading attempts, the rate at which the tank level dropped decreased, indicating that material was being pumped into the tank from the railcar, rather than solely being pulled from the tank into the reactor. Williams based his calculations on historical data provided by the Plaintiff and the one hour unloading period he previously determined. ### _**Analysis**_ Plaintiff made three arguments for why Williams’ calculations are unreliable. First, the calculations assumed pump ran for one hour, as discussed above. Second, Williams used an estimated phenol flow rate (that is, how fast the phenol is being pumped into or out of the tank). Third, Williams did not account for the range of error, which Plaintiff claims is between plus/minus 0.5 to 1.0 percent, of the instrument that measures the level of the tank. The Court will allow Williams to opine on how long the pump ran. Plaintiff has not explained why Williams’ use of an estimated flow rate, based on the historical data provided by Plaintiff, is unreliable. Similarly, Williams’ claims failed to account for the tank level instrument’s tolerance because he did not know “the manufacturer and the model number.” Plaintiff failed to explain how this lack of information would make the calculations unreliable as opposed to inaccurate, particularly because the point of Williams’ opinion is not that he has precisely calculated the amount of resin, but that Ascend failed to “use readily available phenol storage tank level data to evaluate whether material had been off-load.” #### **C. Williams’ opinion on the cause of the catalyst damage based on his misreading of Plaintiff’s chart should be excluded** Williams offered the opinion that the damage to the catalyst was not caused by contamination from the resin, but rather from overfeeding phenol from the saturator into the reactor. His opinion was based on his reading of a graph displaying the saturator levels. Plaintiff argued that Williams’ interpretation of the graph was facially incorrect. Specifically, Plaintiff claimed that Williams confused the “saturator level” and “output for feed control valve” trend lines, when forming the opinion that the saturator level was over 100 percent at certain times. In short, Williams was looking at and commenting on the wrong line in the graph. Williams admitted his mistake during his deposition. Defendant did not deny that Williams erred in reading the graph but argued that corroborating evidence supported the causation opinion regarding the carryover theory of catalyst damage. The Court can confirm Williams’ mistake by examining his report. Any opinion based on his reading of the graph must be excluded as unreliable and potentially confusing to the jury. Williams’ opinion derived from the incorrect reading of the graph are excluded, but those opinions that have some other basis of support are not. #### **D. Williams’ opinion on how the resin would have reacted in the phenol tank should not be excluded** Williams opined that the resin would have been soluble in the phenol which was already inside Plaintiff’s storage tank, and that it would have reacted in the storage tank rather than causing the damage to the catalyst. He bases his opinion on an email from the resin manufacturer discussing the resin’s reactivity. The email purports to contain an opinion from the resin manufacturer’s Quality Manager, that based on the tank temperature, the resin would have reacted with the phenol in the tank and produced water. There is no evidence that a statement from a chemical’s manufacturer about its properties is not the sort of information on which a chemical engineer would rely in these circumstances. Williams, an experienced chemical engineer, incorporated the information from the resin manufacture in his discussion. ## **Held** The Court granted in part and denied in part Plaintiff’s motion to exclude certain testimony of Bruce C. Williams. ## **Key Takeaways**: - Reliable expert testimony often involves estimation and reasonable inferences from a sometimes incomplete record. Further, a few scattered errors in an expert report are not necessarily grounds for exclusion. - A lack of particularization or reliance on estimates goes to weight of the conclusion, not reliability of the methodology. Please refer to the blog previously published about this case: [https://expertwitnessprofiler.com/chemical-engineering-expert-allowed-to-opine-on-railcar-switching](https://expertwitnessprofiler.com/chemical-engineering-expert-allowed-to-opine-on-railcar-switching) ## **Case Details:** --- ## **You Might Also Like** ![Chemical Engineering Expert's Testimony on Catalyst Damage Excluded](https://ewp-blog.expertwitnessprofiler.org/wp-content/uploads/2026/04/blog-pic-640X480-2026-04-10T190614.043.jpg) [**Chemical Engineering Expert’s Testimony on Catalyst Damage Excluded**](https://expertwitnessprofiler.com/chemical-engineering-experts-testimony-on-catalyst-damage-excluded/chemical-engineering-experts-testimony-on-catalyst-damage-excluded)![Plant Pathology Expert Allowed to Opine on HLVd Infection](https://ewp-blog.expertwitnessprofiler.org/wp-content/uploads/2026/04/blog-pic-640X480-2026-04-10T122000.228.jpg) [**Plant Pathology Expert Allowed to Opine on HLVd Infection**](https://expertwitnessprofiler.com/chemical-engineering-experts-testimony-on-catalyst-damage-excluded/plant-pathology-expert-allowed-to-opine-on-hlvd-infection)![Chemical Engineering Expert Allowed to Opine on Railcar Switching](https://ewp-blog.expertwitnessprofiler.org/wp-content/uploads/2026/04/blog-pic-640X480-2026-04-08T195023.873.jpg) [**Chemical Engineering Expert Allowed to Opine on Railcar Switching**](https://expertwitnessprofiler.com/chemical-engineering-experts-testimony-on-catalyst-damage-excluded/chemical-engineering-expert-allowed-to-opine-on-railcar-switching)![Industrial Hygiene Expert Not Allowed to Opine on Falling Debris](https://ewp-blog.expertwitnessprofiler.org/wp-content/uploads/2026/04/blog-pic-640X480-2026-04-08T175126.051.jpg) [**Industrial Hygiene Expert Not Allowed to Opine on Falling Debris**](https://expertwitnessprofiler.com/chemical-engineering-experts-testimony-on-catalyst-damage-excluded/industrial-hygiene-expert-not-allowed-to-opine-on-falling-debris)![Architecture Expert Not Allowed to Opine on the Safety of Retail Escalators](https://ewp-blog.expertwitnessprofiler.org/wp-content/uploads/2026/04/blog-pic-640X480-2026-04-08T143944.585-1.jpg) [**Architecture Expert Not Allowed to Opine on the Safety of Retail Escalators**](https://expertwitnessprofiler.com/chemical-engineering-experts-testimony-on-catalyst-damage-excluded/architecture-expert-not-allowed-to-opine-on-the-safety-of-retail-escalators)