AEP Generation Resources Inc. v. Midwest Energy Emissions Corp.

1. Case Identification

• Case #: IPR2020-01294
• Patent #: 10,343,114
• Filed: July 15, 2020
• Petitioner(s): AEP Generation Resources Inc., Aep Texas Inc., and Southwestern Energy Power Co.
• Patent Owner(s): Midwest Energy Emissions Corp.
• Challenged Claims: 1-9, 12-30

2. Patent Overview

• Title: Sorbents for the Oxidation and Removal of Mercury
• Brief Description: The ’114 patent relates to methods for removing mercury from a flue gas generated by coal combustion. The method involves adding a halogen promoter (specifically bromine species) to the coal or combustion chamber and injecting a sorbent material (such as activated carbon) into the flue gas downstream to capture the mercury.

3. Grounds for Unpatentability

Ground 1: Claims 1-2, 4-9, 12-28, and 30 are obvious over Sjostrom in view of Eckberg.

• Prior Art Relied Upon: Sjostrom (a 2005 conference presentation titled “Full-Scale Evaluations of Mercury Control Technologies with PRB Coals”) and Eckberg (a 2005 conference presentation titled “Mercury Control Evaluation of Halogen Injection into a Texas Lignite-Fired Boiler”).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Sjostrom taught the core elements of the claimed invention, including a method for separating mercury from flue gas by combusting coal, adding a halogen ("Br") to enhance mercury removal, injecting an activated carbon sorbent downstream, separating the resulting mercury/sorbent composition, and monitoring emissions to control the sorbent injection rate. However, Sjostrom did not specify the exact bromine-containing chemical or its injection rate. Eckberg was argued to supply these missing details, disclosing the injection of a specific bromide compound (calcium bromide, CaBr2) into a coal-fired boiler to facilitate mercury removal and providing details on feed rates and concentrations.
  • Motivation to Combine: A Person of Ordinary Skill in the Art (POSITA) would combine the references to implement Sjostrom's general system using the specific, well-known chemical substances and parameters taught by Eckberg. Petitioner asserted that further motivation existed because both presentations were delivered consecutively in the same technical session (“Mercury – Control”) at the 2005 EUEC conference, shared a common author, and described nearly identical processes, making them complementary.
  • Expectation of Success: A POSITA would have a reasonable expectation of success because both references describe using bromine in conjunction with activated carbon sorbents to improve mercury removal in similar coal-plant systems. Combining the teachings would involve applying Eckberg's specific bromine compound to Sjostrom's system without requiring significant modification.

Ground 2: Claims 1-9 and 12-30 are obvious over Sjostrom in view of Olson-646.

• Prior Art Relied Upon: Sjostrom (as in Ground 1) and Olson-646 (Application # 2006/0048646).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Sjostrom established the foundational mercury control system, and Olson-646 provided the specific chemical details and process optimizations to render the claims obvious. Olson-646, which is an application in the challenged patent's own family tree, allegedly taught the use of specific bromine species like gaseous HBr or Br2 as promoters to enhance mercury capture by activated carbon. It also disclosed achieving over 70% mercury removal and using a feedback control system with a continuous emissions monitor (CEM) to regulate the injection of sorbent and/or promoter.
  • Motivation to Combine: A POSITA would have been motivated to look to Olson-646 to understand the underlying chemical reactions and to identify specific, effective bromine compounds (HBr or Br2) to use in the system disclosed by Sjostrom. Olson-646 provided the implementational details, such as workable bromine-to-sorbent ratios and the chemical mechanisms, that were not explicitly detailed in Sjostrom.
  • Expectation of Success: Success was expected because both references teach using conventional halogen promoters to increase the effectiveness of activated carbon for mercury capture. Both references also describe achieving the same result (over 70% mercury removal) and use the same commercial activated carbon (Norit Darco FGD), indicating that applying the specific chemical teachings of Olson-646 to Sjostrom's system was a matter of routine optimization.

4. Key Technical Contentions

• Priority Date Challenge: Petitioner dedicated a significant portion of its argument to contending that the ’114 patent is not entitled to a priority date earlier than its filing date of May 14, 2018.
  • The argument centered on the claim limitation requiring the addition of specific bromine-containing species (Br2, HBr, Br-, or a bromine compound) to the coal or upstream of the combustion chamber. Petitioner asserted this "Newly-Introduced Limitation" lacks written description support in the parent applications, including the original provisional application.
  • Petitioner further argued that any incorporation by reference of the provisional application's disclosure into the intervening applications was legally defective under 37 C.F.R. §1.57 because it was not specific and attempted to incorporate "essential material" from a non-patent or non-published application.
  • As a result, Petitioner contended the 2005 and 2006 effective dates of the Sjostrom, Eckberg, and Olson-646 references pre-date the ’114 patent’s valid priority date, making them proper prior art.

5. Arguments Regarding Discretionary Denial

• Petitioner argued that the Board should not exercise its discretion to deny institution under either §314(a) or §325(d).
  • Against Fintiv Denial (§314(a)): The parallel district court proceeding was in its earliest stages, with a trial date set for June 2022. Petitioner asserted that a Final Written Decision (FWD) in the IPR would likely issue by the end of 2021, well before the trial, thus favoring institution.
  • Against Same-Art Denial (§325(d)): Petitioner argued that the examiner did not consider the primary references, Sjostrom and Eckberg, during prosecution. While Olson-646 was cited on the face of the patent, it was one of many references in a long list and was never applied in a substantive rejection, meaning the arguments presented in the petition were not previously considered by the Office.

6. Relief Requested

• Petitioner requested that the Board institute an inter partes review and cancel claims 1-9 and 12-30 of the ’114 patent as unpatentable.