TECHNICAL UNIVERSITY OF DENMARK et al.

Patent Trials and Appeals Board

Apr 21, 2021

2020005114 (P.T.A.B. Apr. 21, 2021)

UNITED STATES PATENT AND TRADEMARK OFFICE
UNITED STATES DEPARTMENT OF COMMERCE
United States Patent and Trademark Office
Address: COMMISSIONER FOR PATENTS
P.O. Box 1450
Alexandria, Virginia 22313-1450
www.uspto.gov
APPLICATION NO. FILING DATE FIRST NAMED INVENTOR ATTORNEY DOCKET NO. CONFIRMATION NO.
14/353,299 08/04/2014 Irini Angelidaki BIOGAS-201 9183
90150 7590 04/21/2021
Hoffberg & Associates
29 Buckout Road
West Harrison, NY 10604
EXAMINER
MOSS, NATALIE M
ART UNIT PAPER NUMBER
1653
NOTIFICATION DATE DELIVERY MODE
04/21/2021 ELECTRONIC
Please find below and/or attached an Office communication concerning this application or proceeding.
The time period for reply, if any, is set in the attached communication.
Notice of the Office communication was sent electronically on above-indicated "Notification Date" to the
following e-mail address(es):
roberta@hoffberglaw.com
steve@hoffberglaw.com
uspto@dockettrak.com
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
_____________

BEFORE THE PATENT TRIAL AND APPEAL BOARD
_____________

Ex parte IRINI ANGELIDAKI, POUL LYHNE, and GANG LUO
_____________

Appeal 2020-005114
Application 14/353,299
Technology Center 1600
_____________

Before ERIC B. GRIMES, JEFFREY N. FREDMAN, and
JOHN E. SCHNEIDER, Administrative Patent Judges.

FREDMAN, Administrative Patent Judge.

DECISION ON APPEAL

This is an appeal1,2 under 35 U.S.C. § 134 involving claims to a
method of manufacturing an upgraded biogas in situ. The Examiner rejected
the claims as indefinite, as failing to comply with the written description
requirement, and as obvious. We have jurisdiction under 35 U.S.C. § 6(b).
We affirm the indefiniteness rejection but reverse the written description and
obviousness rejections.

1 We use the word “Appellant” to refer to “applicant” as defined in 37
C.F.R. § 1.42. Appellant identifies the Real Party in Interest as the
AgroFora Ap5 (see Appeal Br. 1).
2 We have considered the Specification of Apr. 22, 2014 (“Spec.”); Final
Office Action of May 31, 2019 (“Final Act.”); Appeal Brief of Jan. 6, 2020,
(“Appeal Br.”); and Examiner’s Answer of Apr. 29, 2020 (“Ans.”).

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Statement of the Case
Background
“Biogas is envisioned as a key element in emerging renewable energy
strategies” (Spec. 1:11–12). The cost of “common methods of biogas
upgrading . . . are relatively high since they need either high pressure or
addition of chemicals” (id. at 1:21–24). “To circumvent these
disadvantages and use milder treatments with minimal chemical and
energy, anaerobic microorganisms can be used to convert CO2 to CH4 for
biogas upgrading” (id. at 1:26–28). “However, as the process progresses,
the CO2 of the culture medium is consumed resulting in an increased pH of
the culture medium. When pH exceeds 8.3 the process is inhibited” (id. at
3:7–9). The “present inventors have demonstrated that the anaerobic
digestion of the biomass, such as manure can be made in the presence of an
acidic composition such as acidic waste from industry and/or agriculture,
resulting in a sustained and high-performing process for upgrading biogas”
(id. at 3:10–13).
The Claims
Claims 1–9, 11, 13–21, and 24 are on appeal. Claim 1 is
representative and reads as follows:
1. A method of manufacturing an upgraded biogas in situ,
said method comprising the steps of:
a. initiating an anaerobic digestion process in a bioreactor
comprising:
i. substrate,
ii. anaerobic inoculum comprising anaerobic
hydrogenotrophic methanogenic organisms,
b. feeding the bioreactor with an acidic waste substrate to
lower the pH in the bioreactor, to maintain a between 7 and 8,
c. feeding the bioreactor with biomass,
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d. injecting H2 containing gas into the bioreactor, and
e. collecting the upgraded biogas thus produced, wherein
said upgraded biogas derived from the substrate, acidic waste
substrate, and the biomass, has a CH4 concentration of at least
90%.

The Rejections
A. The Examiner rejected claims 1–9, 11, and 13–21 under 35 U.S.C.
§ 112(b) as indefinite (Final Act. 3).
B. The Examiner rejected claims 1–9, 11, 13–21, and 24 under 35 U.S.C.
§ 112(a) as failing to comply with the written description requirement (Final
Act. 3–5).
C. The Examiner rejected claims 1–6, 8, 9, and 11 under 35 U.S.C.
§ 103(a) as obvious over Magaña-Ramírez,3 Finck,4 and Walter5 (Final Act.
5–11).
D. The Examiner rejected claims 7 and 24 under 35 U.S.C. § 103(a) as
obvious over Magaña-Ramírez, Finck, Walter, Comino,6 and Pumphrey7
(Final Act. 14–18).

3 J. Luis Magaña-Ramírez et al., Anaerobic treatment of lactic waste and
goat manure, 31 Ingeniería E Investigación 93–98 (2011).
4 Finck et al., FR 2537992 A1, published June 22, 1984. We rely on the
English translation with pages numbered 1–10.
5 Walter et al., DE 10 2009 053 593 B4, published May 19, 2011. We rely
on the machine-generated English translation. We recognize that the author
is Professor Walter Graf, but for consistency with the Examiner, we refer to
the reference as Walter.
6 Elena Comino et al., Development of a pilot scale anaerobic digester for
biogas production from cow manure and whey mix, 100 Bioresource
Technology 5072–78 (2009).
7 Brian Pumphrey & Christian Julien, An Introduction to Fermentation
(1996) (The pages are unnumbered so we number the pages consecutively
1–23 from the first page titled “Fermentation Basics” skipping blank pages).
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E. The Examiner rejected claims 13–16 and 19–21 under 35 U.S.C.
§ 103(a) as obvious over Magaña-Ramírez, Finck, Walter, and Mets8 (Final
Act. 18–21).
F. The Examiner rejected claim 17 under 35 U.S.C. § 103(a) as obvious
over Magaña-Ramírez, Finck, Walter, and Hitzman9 (Final Act. 21–22).
G. The Examiner rejected claim 18 under 35 U.S.C. § 103(a) as obvious
over Magaña-Ramírez, Finck, Walter, and Tokutomi10 (Final Act. 22–23).

A. 35 U.S.C. § 112(b)
The Examiner finds
Claim 1 has been amended to recite a step of feeding the
bioreactor with an acidic waste substrate to lower the pH in the
bioreactor, “to maintain a between 7 and 8”. It is unclear what
“to maintain a between 7 and 8” is referring to. It is unclear if
Applicant is referring to the pH in the bioreactor, or something
else. Further it is unclear what to lower to maintain means. If
the pH is being lowered, it has not been maintained.
(Final Act. 3).
Appellant contends the “pH as specified is maintained within a range,
and therefore can be lowered against an influence that tends to increase it,
without the language being logically inconsistent” (Appeal Br. 13).
We find the Examiner has the better position. Claim 1, as written,
does not clearly indicate that its pH is maintained between 7 and 8. While
this might be a likely and reasonable interpretation, the “between 7 and 8”
could refer to amounts or parameters of the acidic waste substrate itself, the

8 Mets et al., WO 2008/094282 A1, published Aug. 7, 2008.
9 Hitzman, US 4,798,801, issued Jan. 17, 1989.
10 Tokutomi et al., JP 2010-162463, published July 29, 2010 (We rely on the
machine-generated English translation and cite by paragraph).
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amount of methanogenic organisms, or some other parameter. “[D]uring
patent prosecution when claims can be amended, ambiguities should be
recognized, scope and breadth of language explored, and clarification
imposed.” In re Zletz, 893 F.2d 319, 322 (Fed. Cir. 1989). We therefore
affirm this rejection.

B. 35 U.S.C. § 112(a), Written Description
The Examiner finds two written description concerns regarding the
limitation: “upgraded biogas derived from the substrate, acidic waste
substrate, and the biomass, has a CH4 concentration of at least 90%.” First,
the Examiner appears to interpret this as requiring that upgraded biogas is
“only derived from the substrate, acidic waste substrate and the biomass”
(Final Act. 4). The Examiner finds Appellant “does not point to the section
of the disclosure that provides support for this limitation” (id.).
Second, the Examiner finds that replacement of the phrase “CH4
content” with “CH4 concentration” represents new matter because
“concentration is an amount of any type per volume of a liquid or gas, while
content is an amount of any type per mass of a liquid or gas” (Final Act. 4).
Appellant11 acknowledges that “a concentration is an amount of any
type per volume of liquid or gas system, whereas content is an amount of
any type per mass of liquid or gas or solid system” but contends “these terms
are not universally understood to mean one or the other” (Appeal Br. 14;

11 We recognize Appellant’s statement that they “sought three times to
amend the claims to address this issue, and each time the Examiner refused
to enter the amendment to appease the Examiner’s concerns” but decisions
to enter amendments after-final may be petitionable, but are not appealable.
See, e.g., MPEP § 1002(c)(3).
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citing Fuentes-Arderiu12). Appellant contends “the resolution of the
interpretation should refer to the specification of the application, which in
this case makes clear that the biogas production according to the
embodiments of the present invention is measured in terms of volume (see
Tables 3-5), and therefore there is no ambiguity” (id.).
The issue with respect to this rejection is: Does a preponderance of
the evidence of record support the Examiner’s finding that the Specification
fails to provide descriptive support for claims 1 and 24?
Findings of Fact
1. Claim 1 recites the term “comprising” and therefore as a matter
of law does not limit the claim to the recited steps, but permits the inclusion
of additional steps and therefore permits the upgraded biogas to be derived
from additional components.
2. The Specification teaches: “Upgrading of biogas to CH4
content higher than 90% can not only increase the heating value, but also
reduce corrosion caused by acid gas and therefore extend the biogas
utilization as a renewable energy source” (Spec. 1:16–19).
3. The Specification teaches: “Landfill gas typically has methane
concentrations around 50%. Advanced waste treatment technologies can
produce biogas with 55-75% CH4, which for reactors with free liquids can
be increased to 80-90% methane using in-situ gas purification techniques”
(Spec. 7:4–7).
4. Table 3 of the Specification measures the CH4 production rate
in ml/L·dCO2 (see Spec. 31).

12 Xavier Fuentes-Arderiu et al., Concentration and Content, 23 Biochem.
Med. 141–2 (2013).
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Principles of Law
“[I]t is the specification itself that must demonstrate possession. And
while the description requirement does not demand any particular form of
disclosure . . . or that the specification recite the claimed invention in haec
verba, a description that merely renders the invention obvious does not
satisfy the requirement.” Ariad Pharms., Inc. v. Eli Lilly and Co., 598 F.3d
1336, 1352 (Fed. Cir. 2010).
Analysis
We agree with Appellant on both issues. As to the Examiner’s
concern that upgraded biogas is “only derived from the substrate, acidic
waste substrate and the biomass” (Final Act. 4), we find that the claim is not
so limiting. Claim 1 uses the term “comprising” and therefore while the
upgraded biogas must be derived from at least substrate, acidic waste
substrate and biomass, the open nature of the claim is reasonably interpreted
as encompassing the inclusion of additional elements (FF 1).
As to the Examiner’s rejection of the phrase “CH4 concentration of at
least 90%,” we agree with Appellant that Table 3 shows measurement of gas
in volumetric form (FF 4). Moreover, while the Specification certainly
suggests the desirability of CH4 content of 90% or more (FF 2), the
Specification does expressly teach upgrading landfill gas with methane
concentrations of “around 50%” using reactors and purification steps to
obtain “80-90% methane” (FF 3). Thus, the Specification does have both
implicit and explicit descriptive support for obtaining upgraded biogas with
a “CH4 concentration of at least 90%” as recited in claims 1 and 24.
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Conclusion of Law
A preponderance of the evidence of record does not support the
Examiner’s finding that the Specification fails to provide descriptive support
for claims 1 and 24.

C. 35 U.S.C. § 103(a) over Magaña-Ramírez, Finck, and Walter
The issue with respect to this rejection is: Does a preponderance of
the evidence of record support the Examiner’s finding that Magaña-Ramírez,
Finck, and Walter render the rejected claims obvious?
Findings of Fact
5. Magaña-Ramírez teaches a method of manufacturing biogas
where: “Anaerobic digestion was carried out to obtain biogas from lactic
waste in combination with goat manure. Waste from lactic products such as
cream, cheese and whey was mixed with goat manure” (Magaña-Ramírez
93, abstract).
6. Magaña-Ramírez teaches, as to step (a)(i), an anaerobic
digestion reactor system where substrates including “[l]actic residues such as
cheese, cream and whey from cheese factories in the small dairy industry
were used in combination with goat manure” (Magaña-Ramírez 95).
7. Magaña-Ramírez teaches, as to step (a)(ii), that
“[m]ethanogenic bacteria obtained from previous goat manure digestion
were used to inoculate the experimental assays” (Magaña-Ramírez 95).
8. Magaña-Ramírez teaches, as to step (b) that “milk whey and
other lactic residues which had low bicarbonate alkalinity and tended to
acidify quickly” so “supplemental alkalinity was added using calcium
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bicarbonate, and pH increased to 7.0” and “pH was adjusted in formulation
III and maintained at 7.0 for all 15 days” (Magaña-Ramírez 96).
9. Magaña-Ramírez teaches, as to step (c) that “[g]oat manure was
increasingly added” (Magaña-Ramírez 95).
10. Magaña-Ramírez teaches, as to step (e) that a “methane peak
was seen and 82% concentration measured” (Magaña-Ramírez 96).
11. The Examiner acknowledges that Magaña-Ramírez “does not
teach injecting a hydrogen containing gas into the disclosed reactor to
produce an upgraded biogas with a methane concentration of at least 90%”
(Final Act. 6).
12. Finck teaches that “biogas produced that contains a high
proportion of CO2 cannot always be used directly as a fuel and in this case
requires a scrubbing operation” (Finck 3).
13. Finck teaches “a methane production process by anaerobic
fermentation of a fermentable organic substrate under traditional
fermentation conditions characterized in that one injects molecular hydrogen
into the fermentation unit” (Finck 3).
14. Finck teaches to “inject a quantity so that it represents four
moles of hydrogen per mole of CO2 theoretically produced. Naturally, the
flow rate of hydrogen injected could be adjusted during operation of the
fermentation unit based on the CO2 content of the biogas produced” (Finck
4).
15. Finck teaches that “substrate can be of animal origin, liquid
manure for example . . . discharges from dairies, canneries, and the paper
industry” (Finck 3–4).
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16. Finck teaches “the average CH4 content of the produced biogas
is about 83% and . . . this yield surpasses 90% after twenty days to reach
99% beyond the thirtieth day. In this case it is practically ‘pure’ methane”
(Finck 7–8).
17. Walter teaches “a method and apparatus for increasing the
performance potential of biogas plants, mainly by the entry of hydrogen into
the methane fermenter” (Walter ¶ 1).
18. Walter teaches “H2 could be the limiting factor of the methane
concentration in the biogas. This means that increasing the amount of H2
(metabolically or artificially induced) can lead to higher levels of
performance” (Walter ¶¶ 8–9).
Principles of Law
A prima facie case for obviousness “requires a suggestion of all
limitations in a claim,” CFMT, Inc. v. Yieldup Int’l Corp., 349 F.3d 1333,
1342 (Fed. Cir. 2003) and “a reason that would have prompted a person of
ordinary skill in the relevant field to combine the elements in the way the
claimed new invention does.” KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398,
418 (2007).
Analysis
Appellant contends:
According to Ramirez et al., the fermentation begins at a
pH of 7, and declines below that level, which is a process
distinct from maintaining the pH between 7 and 8, since at least
between additions of base (i.e., calcium bicarbonate) the pH
falls below 7. None of the references properly teaches
maintaining the pH between 7 and 8, and in particular, Ramirez
teaches starting at 7 and immediately deviating outside the
range of pH 7-8. Further, the claims require that the pH be
maintained between 7 and 8 by addition of acidic waste, i.e.,
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that the fermentation produce excess base which must be
neutralized. On the other hand, Ramirez et al. teaches that the
fermentation as conducted produces excess acid, which must be
neutralized by inorganic base (“supplemental alkalinity”)
addition.
(Appeal Br. 18).
The Examiner responds:
Ramirez teaches the pH is maintained at 7.0 for all 15 days of
the reaction. Further, the art adds acidic substrates (i.e., milk
and cheese wastes) as claimed. While Applicant argues
Ramirez also adds sodium bicarbonate, the claims do not
exclude the addition of any other pH adjusters in addition to
acidic waste substrates. While Appellant argues the art teaches
away from the addition of whey, claim 1 does not require the
addition of whey. Further, claims 5-6 only recite adding acidic
waste. No limitations regarding the amount are recited. Because
Ramirez adds acidic waste, and maintains a pH of 7.0, the
reference is interpreted to teach the claim limitation.
(Ans. 26).
We begin our analysis with claim construction of the phrase at issue
“feeding the bioreactor with an acidic waste substrate to lower the pH in the
bioreactor, to maintain a between 7 and 8” (Claim 1, step b; cf. Claim 24 “a
ratio of the acidic waste substrate to the biomass being controlled to reduce
the pH in the bioreactor to a pH between 7 and 8”). For purposes of this
analysis, we will interpret this phrase as requiring maintenance of “pH”
“between 7 and 8,”13 consistent with the position argued by Appellant.
Thus, step b of claim 1 not only requires feeding a bioreactor with an acidic
waste substrate, but also requires that the acidic substrate itself perform the
function of maintaining the pH range between 7 and 8.

13 We note that this interpretation is also consistent with the unentered After-
Final Amendments filed by Appellant on Sept. 3, 2019 and Sept. 27, 2019.
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This interpretation is consistent with Appellant’s Specification, which
recognizes “the following problem - when hydrogen is injected into a
bioreactor comprising methanogens, and reacts with CO2 to produce CH4,
the pH increases due to bicarbonate consumption. When the pH exceeds 8.3,
the biological conversion process will be inhibited, because methanogens
cannot grow well at this high pH” (Spec. 8:28–32). The Specification
explains the inventors resolve this problem by including acidic waste
because “biogas can be produced by co-digestion of manure with acidic
wastes. . . . The acidic waste thus contributes to keeping the pH in an
optimal range of between 7 and 8” (Spec. 8:33 to 9:3).
When we apply our interpretation to claims 1 and 24, we find the
claims require that the addition of the acidic waste substrate itself maintains
the pH between 7 and 8. So even though Magaña-Ramírez teaches “pH was
adjusted in formulation III and maintained at 7.0 for all 15 days,”
“supplemental alkalinity was added using calcium bicarbonate, and pH
increased to 7.0” (FF 8). Thus, as Appellant argues, it is not the acidic waste
in Magaña-Ramírez that maintains the pH range, but rather calcium
carbonate. Thus, the Examiner has provided no reason to add acidic waste
for the purpose of maintaining the pH.
Moreover, while the Examiner cites Finck for the addition of
hydrogen to reduce CO2 levels and improve yields to exceed 90%
concentration of methane (FF 12–16), the Examiner does not identify a
teaching in Finck or Walter suggesting that acidic materials, particularly
acidic wastes, should be added to reduce pH to allow the reaction to proceed.
And so while both of Finck and Walter teach the addition of hydrogen to
biogas synthesis methods, there is no evidence that either appreciates that
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acidic waste is required for pH maintenance when hydrogen is incorporated
into the reaction.
Therefore, while claims 1 and 24 would not encompass the method of
Magaña-Ramírez where acidic wastes were added for reasons other than
maintaining pH, neither does the combination of Magaña-Ramírez, Finck,
and Walter suggest the method of the instant claims.
Conclusion of Law
A preponderance of the evidence of record does not support the
Examiner’s finding that Magaña-Ramírez, Finck, and Walter render the
rejected claims obvious.

D.–G. 35 U.S.C. § 103(a)
Having reversed the obviousness rejection of claims 1 and 24 over
Magaña-Ramírez, Finck, and Walter for the reasons given above, we also
find that the further combinations do not provide reasons or motivation to
include and maintain the pH using acidic waste substrates. We therefore
reverse these rejections for the same reasons as given above.

DECISION SUMMARY
In summary:
Claim(s)
Rejected
35
U.S.C. §
Reference(s)/Basis Affirmed Reversed
1–9, 11,
13–21
112(b) Indefiniteness 1–9, 11,
13–21

1–9, 11,
13–21, 24
112(a) Written Description 1–9, 11,
13–21, 24
1–6, 8, 9,
11
103 Magaña-Ramírez, Finck,
Walter
1–6, 8, 9,
11
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Claim(s)
Rejected
35
U.S.C. §
Reference(s)/Basis Affirmed Reversed
7, 24 103 Magaña-Ramírez, Finck,
Walter, Comino,
Pumphrey
7, 24
13–16,
19–21
103 Magaña-Ramírez, Finck,
Walter, Mets
13–16, 19–
21
17 103 Magaña-Ramírez, Finck,
Walter, Hitzman
17
18 103 Magaña-Ramírez, Finck,
Walter, Tokutomi
18
Overall
Outcome
1–9, 11,
13–21
24

No time period for taking any subsequent action in connection with
this appeal may be extended under 37 C.F.R. § 1.136(a).

AFFIRMED IN PART