Evonik Operations GmbH v. Air Products Chemicals Inc

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Evonik Operations GmbH (Germany) and Evonik Corporation (Alabama)
  • Defendant: Air Products and Chemicals, Inc. (Delaware) and Greenlane Biogas US Corp. (Delaware)
  • Plaintiff’s Counsel: Tarter Krinsky & Drogin LLP
• Case Identification: 1:22-cv-01543, D. Del., 11/29/2022
• Venue Allegations: Venue is alleged to be proper in the District of Delaware because both defendants are organized under the laws of Delaware and are subject to personal jurisdiction in the district.
• Core Dispute: Plaintiff alleges that Defendants’ biogas upgrading systems, which use membrane components supplied by Air Products, infringe two patents related to multi-stage membrane-based gas separation processes.
• Technical Context: The technology concerns apparatuses and methods for separating gas mixtures, such as purifying biomethane from carbon dioxide to produce renewable natural gas, a process critical to the clean energy sector.
• Key Procedural History: The complaint notes that U.S. Patent No. 8,999,038 survived an ex parte reexamination, with a certificate issued on March 29, 2022, confirming the patentability of its claims. Additionally, the complaint alleges Defendant Air Products had pre-suit knowledge of the '038 patent family by at least November 21, 2017, due to its opposition to the patent's European counterpart.

Case Timeline

Date	Event
2010-07-01	Priority Date for U.S. Patent No. 8,999,038
2013-04-25	Alleged knowledge date for '038 Patent (application publication)
2014-12-29	Priority Date for U.S. Patent No. 10,471,380
2015-04-07	Issue Date for U.S. Patent No. 8,999,038
2017-11-21	Alleged knowledge date for '038 Patent (via European Opposition)
2017-12-28	Alleged knowledge date for '380 Patent (application publication)
2019-11-12	Issue Date for U.S. Patent No. 10,471,380
2022-03-29	Reexamination Certificate issued for U.S. Patent No. 8,999,038
2022-11-29	Complaint Filing Date

II. Technology and Patent(s)-in-Suit Analysis

U.S. Patent No. 8,999,038 (the “Ungerank Patent”), “Process for separation of gases,” issued April 7, 2015

The Invention Explained

• Problem Addressed: The patent addresses the challenge in membrane-based gas separation of simultaneously achieving high purity in both the permeate (gas passing through the membrane) and retentate (gas retained by the membrane) streams without incurring high energy costs from recompressing gas streams or suffering from significant loss of the desired product ('038 Patent, col. 2:1-23).
• The Patented Solution: The invention is a three-stage membrane separation apparatus with a specific configuration of recycling loops. It separates a feed stream in a first stage; the resulting retentate is further purified in a second stage, and the permeate from that second stage is recycled back to the feed. The permeate from the first stage is purified in a third stage, and the retentate from that third stage is also recycled to the feed ('038 Patent, col. 4:20-37; Fig. 11). Key aspects are the avoidance of recompression for the first permeate stream and a limitation that the total recycled gas volume is less than 60% of the initial crude gas stream ('038 Patent, col. 5:50-65).
• Technical Importance: This design seeks to optimize for both high purity and high yield in two separate output streams while minimizing energy consumption, making processes like biogas upgrading more economically efficient ('038 Patent, col. 3:31-40).

Key Claims at a Glance

• The complaint asserts independent claims 1 (apparatus), 12 (process), and 34 (process for methane/CO2 separation) (Compl. ¶19).
• The essential elements of independent claim 1 include:
  • An apparatus with three membrane separation stages: a feed stream stage, a retentate stage, and a permeate stage.
  • The retentate stage separates a first retentate stream into a second permeate stream (recycled to the feed) and a second retentate stream (withdrawn as a product).
  • The permeate stage separates a first permeate stream into a third retentate stream (recycled to the feed) and a third permeate stream (withdrawn as a product).
  • The apparatus is configured not to subject the first permeate stream to any recompression.
  • The feed stream stage uses a membrane with a mixed gas selectivity of at least 30.
  • The total volume of recycled gas is less than 60% of the crude gas stream volume.
  • The apparatus is configured to increase the concentration of the permeate gas in the feed stream compared to the crude gas stream.
• The complaint reserves the right to assert additional claims as the case progresses (Compl. ¶65).

U.S. Patent No. 10,471,380 (the “Priske Patent”), “Process for separation of gases with reduced maintenance costs,” issued November 12, 2019

The Invention Explained

• Problem Addressed: The patent identifies a different economic problem: in locations where energy is inexpensive, the primary costs of gas separation are the initial investment and ongoing maintenance, particularly the replacement of expensive, highly selective membranes ('380 Patent, col. 4:43-53). Energy-optimized processes, like that of the Ungerank Patent, do not necessarily solve this cost issue.
• The Patented Solution: The invention discloses a method for gas separation that prioritizes reduced maintenance costs. It employs a similar three-stage architecture but operates under different parameters: the volume of recycled gas is increased to 60-100% of the crude gas stream, and the total membrane capacity of the second (retentate) stage is higher than that of the first (feed) stage ('380 Patent, col. 4:27-35; col. 10:9-19). This allows the system to achieve high product purity even with less selective, and therefore less expensive, membranes ('380 Patent, col. 4:45-48).
• Technical Importance: This approach provides an alternative design philosophy for membrane systems, optimizing for capital and maintenance expenditures rather than energy consumption, which is valuable in specific industrial and economic contexts ('380 Patent, col. 6:1-11).

Key Claims at a Glance

• The complaint asserts independent claim 1 (method) (Compl. ¶24).
• The essential elements of independent claim 1 include:
  • A method using a three-stage (feed, retentate, permeate) membrane separation apparatus to produce two product streams.
  • The second permeate stream and third retentate stream are combined with the crude gas stream to form the feed stream.
  • The combined volume of the recycled gas streams is from 60% to 100% of the crude gas stream volume.
  • The total capacity of the membranes in the retentate separation stage is higher than the total capacity of the membranes in the feed stream separation stage.
  • The quotient of the pressure ratio over the permeate stage to the pressure ratio over the feed stage is in a range of from 0.5 to 8.
• The complaint reserves the right to assert additional claims as the case progresses (Compl. ¶65).

III. The Accused Instrumentality

Product Identification

• The accused instrumentalities are three-stage gas-separation systems sold by Defendant Greenlane (“Accused Systems”) and the membrane components within them, identified as PRISM® membranes manufactured and supplied by Defendant Air Products (“Accused Products”) (Compl. ¶¶29, 34, 42).

Functionality and Market Context

• The Accused Systems are marketed as biogas upgrading systems that "cleanse the impurities in biogas and separate the carbon dioxide from the biomethane to create a clean, high-purity low-carbon fuel" (Compl. ¶39). The complaint alleges these systems use a "three stage high efficiency" membrane process to achieve this separation (Compl. ¶39).
• The complaint alleges that Air Products' PRISM® membranes are used in each stage of Greenlane's systems, and further specifies that different types of membranes (e.g., "PB6050-P3 for 'roughing'" and "PB6050-N1 for 'polishing'") are used in different stages, which allegedly allows for different permeation characteristics (Compl. ¶¶42, 49, 55).
• A diagram provided in the complaint shows a three-stage process for converting biogas to renewable natural gas (RNG), which the plaintiff has annotated to map to the claimed separation stages (Compl. p. 14, Exhibit 6).

IV. Analysis of Infringement Allegations

’038 Patent Infringement Allegations

Claim Element (from Independent Claim 1)	Alleged Infringing Functionality	Complaint Citation	Patent Citation
An apparatus for separating gases, comprising: membrane separation stages; and, a compressor...	The Accused Systems comprise three membrane separation stages and a compressor (Compl. p. 14).	¶43-44	col. 4:21-25
wherein the membrane separation stages comprise a feed stream separation stage, a retentate separation stage, and a permeate separation stage	The complaint maps Stage 1 of the Accused System to the claimed feed stream stage, Stage 2 to the retentate stage, and Stage 3 to the permeate stage (Compl. p. 14).	¶44	col. 4:26-28
the retentate separation stage is configured to divide the first retentate stream into a second permeate stream and a second retentate stream, wherein the second permeate stream is supplied to the feed stream...	Stage 2 allegedly separates the first retentate stream, with the resulting second permeate stream recycled to the feed stream. A diagram shows this "Recycle" path (Compl. p. 15).	¶46	col. 4:32-37
...and the second retentate stream is withdrawn as a product...	The second retentate stream is identified as the final RNG, which is withdrawn as product (Compl. p. 15).	¶46	col. 4:37-38
the permeate separation stage is configured to divide the first permeate stream into a third retentate stream and a third permeate stream, wherein the third retentate stream is supplied to the feed stream...	Stage 3 allegedly separates the first permeate stream, with the resulting third retentate stream recycled to the feed stream (Compl. p. 16).	¶47	col. 4:39-44
...and the third permeate stream is withdrawn as a product...	The third permeate stream is identified as "Exhaust" and is alleged to be withdrawn as a product (Compl. p. 16).	¶47	col. 4:44-45
the apparatus is configured not to subject the first permeate stream to any recompression	The complaint alleges the Accused Systems do not recompress the first permeate stream.	¶48	col. 5:50-52
the feed stream separation stage comprises a gas separation membrane module having a mixed gas selectivity of at least 30	The complaint alleges that the Air Products membranes used in the feed stage can have a mixed gas selectivity of at least 30, citing marketing materials about available selectivities (Compl. p. 17).	¶49	col. 5:53-55
the apparatus is configured such that a gas volume recycled... totals less than 60% by volume of a crude gas stream	The complaint alleges on information and belief that the recycled gas volume is less than 60% of the crude gas stream.	¶50	col. 5:56-59

• Identified Points of Contention:
  • Scope Question: A primary issue may be whether the "Exhaust" stream from the accused system qualifies as being "withdrawn as a product" as required by claim 1. If "product" is construed to require commercial value or a specific utility beyond mere disposal, the allegation may be contested, as "exhaust" suggests waste.
  • Technical Question: The complaint's allegations regarding the quantitative limitations—specifically, that the feed stage membrane selectivity is "at least 30" and the recycled volume is "less than 60%"—are asserted on "information and belief" with limited specific evidence. Proving these operational parameters during discovery will be critical for the plaintiff.

’380 Patent Infringement Allegations

Claim Element (from Independent Claim 1)	Alleged Infringing Functionality	Complaint Citation	Patent Citation
A method for separating gases... comprising... a feed stream separation stage, a retentate separation stage and a permeate separation stage...	The Accused Systems allegedly perform a method using three membrane separation stages (Compl. p. 18).	¶53	col. 9:43-49
f) the second permeate stream and the third retentate stream are combined with the crude gas stream to give the feed stream	A diagram in the complaint is used to show the alleged combination of the second permeate and third retentate streams with the crude gas to form the feed stream (Compl. p. 23).	¶61	col. 10:5-7
i) the combined gas volume of the second permeate stream and the third retentate stream is from 60 to 100% of the volume of the crude gas stream	The complaint alleges on information and belief that the combined recycled gas volume is within the 60-100% range.	¶62	col. 10:9-12
ii) the total capacity of the gas separation membranes in the retentate separation stage is higher than the total capacity... in the feed stream separation stage...	The complaint alleges this is met by using different types of Air Products membranes in Stage 1 ('roughing') versus Stage 2 ('polishing'), which allegedly results in a higher total capacity in Stage 2.	¶55, ¶63	col. 10:13-19
iii) the quotient of the pressure ratio over the permeate separation stage to the pressure ratio over the feed stream separation stage is in a range of from 0.5 to 8	The complaint alleges on information and belief that the system is configured to operate within this pressure ratio quotient range.	¶64	col. 10:25-28

• Identified Points of Contention:
  • Technical Question: The infringement case for the ’380 Patent hinges entirely on proving the three specific quantitative limitations in the "wherein" clause. While the allegation of using different membrane types provides a basis for the "total capacity" limitation, the actual ratios for capacity, recycled volume, and pressure will be a central factual dispute requiring technical evidence obtained through discovery.
  • Scope Question: The complaint asserts infringement of two patents with what appear to be mutually exclusive requirements for the recycled gas volume ('038 patent requires <60%; '380 patent requires ≥60%). While pleading in the alternative is permissible, this raises a core factual question of which, if either, operational mode the accused systems actually employ.

V. Key Claim Terms for Construction

For the ’038 Patent

• The Term: "withdrawn as a product"
• Context and Importance: This term appears twice in independent claim 1 and is critical because one of the allegedly infringing outputs is labeled "Exhaust" in the complaint's own diagrams (Compl. p. 16). The viability of the infringement allegation for this element depends on whether "exhaust" can be considered a "product."
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: The patent specification does not appear to provide an explicit definition of "product." A plaintiff could argue the term simply means any stream that is intentionally separated and removed from the apparatus, regardless of its end use or value.
  • Evidence for a Narrower Interpretation: The patent’s background discusses achieving "high purities" for "two fractions" ('038 Patent, col. 2:4-6), and describes separating valuable gases like methane and CO2. This context may support a narrower construction where a "product" must have a use or value beyond being waste, a position a defendant would likely advance.

For the ’380 Patent

• The Term: "total capacity"
• Context and Importance: The requirement that the "total capacity" of the retentate stage membranes is higher than that of the feed stage membranes is a central limitation of independent claim 1. The definition of this term is essential for determining how this comparison is made.
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: Practitioners may focus on this term because, while the patent provides an explicit definition, its application is not straightforward. The patent defines capacity as "the product of the membrane surface and the permeance of the membrane... determined for nitrogen (Grade 4.8) under standard conditions" ('380 Patent, col. 4:53-58). A plaintiff might argue for a straightforward application of this formula based on manufacturer specifications.
  • Evidence for a Narrower Interpretation: A defendant could argue that the "standard conditions" in the definition are not representative of actual operating conditions with a biogas mixture, and that a more nuanced, context-specific calculation is required. The fact that the complaint alleges different types of membranes are used in different stages (Compl. ¶55) will make the methodology for calculating and comparing their respective "total capacity" a key technical and legal battleground.

VI. Other Allegations

• Indirect Infringement: The complaint alleges that Air Products induces infringement by supplying its PRISM® membranes to Greenlane and other customers, knowing they are especially adapted for use in the patented processes (Compl. ¶68). It is also alleged to be a contributory infringer on the grounds that the membranes are a material component of the invention, are not a staple article of commerce, and have no substantial non-infringing uses (Compl. ¶¶30, 69).
• Willful Infringement: Willfulness is alleged based on both pre-suit and post-suit knowledge. The complaint asserts pre-suit knowledge based on the publication dates of the patent applications and, more specifically, on Air Products’ alleged opposition to the European counterpart of the '038 Patent since at least November 21, 2017 (Compl. ¶37). Post-suit knowledge is based on the filing of the complaint itself (Compl. ¶¶73, 84).

VII. Analyst’s Conclusion: Key Questions for the Case

• A central issue will be one of quantitative operation: The two asserted patents claim mutually exclusive ranges for the volume of recycled gas (<60% for the ’038 Patent vs. 60-100% for the ’380 Patent). The case will likely turn on an evidentiary dispute over whether the accused systems can be proven to operate consistently within either of these specific, numerically-defined regimes.
• A key question will be one of claim interpretation: Can the term "product," as used in the ’038 Patent, be construed to cover an "exhaust" stream? The outcome of this definitional dispute could be dispositive for the infringement analysis of that patent.
• The dispute will also focus on evidentiary proof of technical parameters. The patents require meeting specific thresholds for membrane selectivity, membrane capacity ratios, and pressure ratios. The ability of the plaintiff to obtain and present evidence confirming that the accused systems meet every element of at least one asserted claim will be paramount.