Ex Parte Tate et al

Patent Trial and Appeal Board

Oct 19, 2016

11885212 (P.T.A.B. Oct. 19, 2016)

UNITED STA TES p A TENT AND TRADEMARK OFFICE
APPLICATION NO. FILING DATE FIRST NAMED INVENTOR
111885,212 06/02/2008 James D. Tate
109 7590 10/21/2016
The Dow Chemical Company
P.O. BOX 1967
2040 Dow Center
Midland, MI 48641
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
ATTORNEY DOCKET NO. CONFIRMATION NO.
63824A-WO-PCT 1850
EXAMINER
NEGIN, RUSSELL SCOTT
ART UNIT PAPER NUMBER
1631
NOTIFICATION DATE DELIVERY MODE
10/21/2016 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):
FFUIMPC@dow.com
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte JAMES D. TATE, CHRISTOPHER H. DOMKE,
CHRISTOPHER J. REED, LINH LE,
MARY BETH SEASHOLTZ, CHARLES LIPP,
and ANDY WEBER 1
Appeal2014-000298
Application 11/885,212
Technology Center 1600
Before LORA M. GREEN, JEFFREY N. FREDMAN, and JOHN G. NEW,
Administrative Patent Judges.
NEW, Administrative Patent Judge.
DECISION ON APPEAL
1 Appellants state the real party-in-interest is The Dow Chemical Company.
App. Br. 2.
Appeal2014-000298
Application 11/885,212
SUMMARY
Appellants file this appeal under 35 U.S.C. § 134(a) from the
Examiner's Final Rejection of claims 1 and 5-92 as unpatentable under the
35 U.S.C. § 103(a) as being obvious over the combination ofD. S. Baer et
al., Sensitive Absorption Measurements in the Near-Infrared Region Using
Off-Axis Integrated-Cavity-Output Spectroscopy, 75 APPL. PHYS. B 261---65
(2002) ("Baer"), Eric R. Crosson et al., Stable Isotope Ratios Using Cavity
Ring-Down Spectroscopy: Determination of 13C/12Cfor Carbon
Dioxide in Human Breath, 74 ANAL. CHEM. 2003---07 (2002) ("Crosson"),
Andy Wheeler et al., Lower Cost, Higher Value On-Line Analyzer
Technology for Application in the Manufacture Of Ethylene, 112 ISA
TECH/EXPO TECHNOLOGY UPDATE CONFERENCE PROCEEDINGS 225-38
(1997) ("Wheeler"), Noble Gas (definition), Chambers 21st Century
Dictionary (2001) ("Noble Gas"), Cooper et al., (US 5,684,580, November
4, 1997) ("Cooper"), and Taylor et al. (US 5,206,701, April 27, 1993)
("Taylor").
We have jurisdiction under 35 U.S.C. § 6(b)
We REVERSE.
NATURE OF THE CLAIMED INVENTION
Appellants' invention is directed to an apparatus for spectroscopic
analysis, which includes a tunable diode laser spectrometer having a digital
output signal and a digital computer for receiving the digital output signal
from the spectrometer, the digital computer programmed to process the
2 Claims 2--4 are canceled. App. Br. 29.
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Application 11/885,212
digital output signal using a multivariate regression algorithm. Appellants'
invention is also directed to a spectroscopic method of analysis using such
apparatus and a method for controlling an ethylene cracker hydrogenator.
Abstract.
REPRESENTATIVE CLAIM
Appellants argue all of the claims together. See App. Br. 6. Claim 1
is representative of the claims on appeal and recites:
1. A chemical analysis method for determining the
concentration of at least one gaseous component of interest in a
sample gas, comprising the steps of: (a) directing light from a
tunable diode laser through an inert gas contained in a sample
cell over a selected range of n wavelengths to a light detector to
produce a range of baseline signals Ion from the light detector,
the inert gas being essentially transparent over the selected
range of n wavelengths; (b) digitizing the range of baseline
signals I0 n from the light detector; ( c) storing the digitized
baseline signals I0 n in a digital computer; ( d) directing light
from the tunable diode laser through the sample gas contained
in the sample cell over the selected range of n wavelengths to
the light detector to produce a range of sample signals Isn from
the light detector; ( e) digitizing the range of sample signals Isn
from the light detector; (f) storing the digitized sample signals
Isn in a digital computer; (g) calculating a spectrum I(n) in the
digital computer according to the equation I(n)= (Ion- Isn)/ Ion;
(h) producing a signal from the computer indicative of the
concentration of each gaseous component of interest by using
spectra of a known concentration of the component of interest
in the inert gas stored digitally in the computer, the spectrum of
step (g) and a multivariate regression algorithm programmed in
the computer, wherein the gaseous components of interest are
acetylene and methylacetylene and the sample gas comprises
ethylene and methylacetylene from an ethylene cracker
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Application 11/885,212
hydrogenator, and wherein the pressure in the sample cell is
about 100 torr. 3
App. Br. 28-29.
ISSUE
Appellants argue that the combined references fail to teach or suggest
all of the limitations of the claims and that there would have been no reason
for a person of ordinary skill in the art to combine the references, nor any
reasonable expectation of being able to successfully combine them. App.
Br. 26.
FINDINGS OF FACT
F 1. Baer teaches an "instrument that employs a high-finesse optical cavity
as an absorption cell has been developed for sensitive measurements of gas
mixing ratios using near-infrared diode lasers and absorption-spectroscopy
techniques." Baer Abstr.
F2. Baer teaches measurement of an acetylene (C2H2) absorption
measurement (100-ppbv in inert N2 at 50-Torr total pressure) obtained by
wave-length tuning a DFB diode laser across the P(l 1) transition (v1 + V3
3 "Cracking" refers to a process in which large hydrocarbon molecules are
broken down into smaller and more useful ones. See The Essential
Chemical Industry Online, available at:
http://www. essentialchemicalindustry. org/processes/ cracking-isomerisati on-
and-reforming.html (last visited October 4, 2016). Consequently, a "cracked
gas" is one in which the larger hydrocarbons have been "cracked" into
smaller hydrocarbons, particularly, in this case, ethylene.
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Application 11/885,212
band) [22] near 1532 nm at a 500-Hz rate in a 1-s integration time (500-
sweep average). Id. at 264---65.
F3. Baer explicitly teaches: "For measurements in industrial process
flows, such as those in olefin plants where C2H2 may be a contaminant, an
effective instrument would have to account for absorption features due to
other hydrocarbons (e.g. C2H4 and C3H4) in the probed flow that interfere
spectrally with the probed C2H2 transition." Id. at 265.
F4. Crosson teaches a cavity ring-down spectroscopy ("CRDS") method
for determining isotope ratios by examining 1.0 cm3 of 5%C02 in inert N2
in which the ratio of 13C02 is compared to 12C02 with a value of -27.76%0
± 0.22%0. Crosson 2004.
F5. Crosson teaches:
The spectra were obtained at 5 Torr to decrease pressure
broadening effects, which has the benefit of allowing the
identification of possible contaminants. The peaks at 6261.83
and 6262.25 cm-1 attributed to absorption by 13C160 160 and
12C160 160, respectively, were chosen to measure the relative
abundance of the two carbon isotopes. These peaks are close to
one another in frequency and, despite the disparity in relative
concentrations of each form of carbon dioxide, have about the
same intensity. The 12C160 160 peak at 6261.65 cm-1 was not used
because it overlaps an absorption feature attributed to 12C160 180
as seen in the simulated spectra.
Crosson 2005.
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F6. Wheeler teaches applications that use gas chromatography and gas
filter correlation infrared ("GFCIR") spectroscopy in a typical ethylene
plant, and determines which ones are prime candidates for replacement with
photometric technology. Wheeler Abstr.
F7. Wheeler teaches, as an example, the analysis of 0-2000 ppm CO in a
cracked gas. Wheeler 227.
F8. Wheeler teaches cracked gas (for the purpose of the study) is
composed ofH2, CO, C02, CH4, C2H2, C2H4, C2H6, C3H4, C3H6, C3Hs and
C4s, ranging from 1000 ppm to 35% and that the relative concentrations of
the components in cracked gas varies with feedstock and process conditions.
Id.
F9. Wheeler teaches that control of CO concentration to control catalyst
activity is important to ensure complete reduction of acetylene while
minimizing conversion of ethylene to ethane. Id. at 230.
PIO. Wheeler explicitly teaches: "The development of a reliable,
interference free photometric acetylene analyzer is the current topic of
research by the authors and is not described in this paper." Id.
F 11. Cooper teaches that concentration of benzene and substituted aromatic
hydrocarbons can be predicted within± 0.31 % volume or better, using
Raman NIR spectroscopy and multivariate analysis, with optional fiberoptics
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Application 11/885,212
multistreaming, and preferably with Partial Least Squares regression
analysis. Cooper Abstr.
F 12. Taylor teaches that light intensities measured by an IR photodiode
array detector are converted into digital signals and designed to be
compatible with a computer or other means to digitally process spectral
information. Taylor col. 14, 11. 44--47.
F13. Noble Gas teaches that a noble gas is: "any of the colourless[,]
odourless[,] tasteless gases in group 0 of the periodic table of the elements,
i[.]e[.,] helium, neon, argon, krypton, xenon, and radon, in order of
increasing atomic number." Noble Gas 1 (internal citation omitted).
ANALYSIS
The Examiner finds Baer teaches an apparatus and method for
sensitivity absorption measurements in the near-infrared region using off-
axis integrated-cavity-output spectroscopy. Final Act. 4. The Examiner
points to Figure 1 of Baer, which the Examiner finds illustrates the apparatus
with the sample cell suitable for holding a gaseous sample. Id. The
Examiner finds Baer teaches the signals obtained from the apparatus were
converted to a digital signal and input into a personal computer. Id. at 4--5
(citing Baer 262). The Examiner finds the measurements made using
gaseous FTIR are conducted at a pressure of 75 torr. Id. at 5.
The Examiner finds Crosson teaches detecting stable isotope ratios
using cavity ring-down spectroscopy to determine the carbon isotope ratio in
human breath. Final Act. 5. The Examiner finds the apparatus depicted in
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Figure 1 Crosson is similar to the apparatus of Baer, however, Crosson
teaches use of a tunable diode laser. Id. (citing Crosson 2004). The
Examiner also finds Crosson teaches digitizing the signal obtained from the
apparatus of Figure 1. Id.
The Examiner next finds Wheeler teaches an on-line analysis system
for assessment of the manufacture of ethylene. Final Act. 5. The Examiner
finds Wheeler teaches the measurement of ethylene gas using gaseous
fourier transform infrared spectroscopy ("FTIR"), and, specifically, those
constituent gases that do not absorb energy, including argon and nitrogen.
Id. (citing Wheeler 231 ). The Examiner finds Wheeler teaches calculation
of a relative concentration of CO gas using nitrogen gas as a standard in a
manner similar to that of Crosson. Id. (citing Wheeler 236). The Examiner
finds Wheeler further teaches on-line measurement of cracked gas at the
outlet of an ethylene to acetylene converter, and points to Table VI of
Wheeler, which, the Examiner finds teaches that the gases that derived from
the cracker (i.e., as measured by spectrometry) comprise acetylene, ethylene,
and methylacetylene, and other gases, in various concentrations. Id. at 6.
The Examiner next finds Cooper teaches obtaining spectra of a
mixture of hydrocarbons and then dispersing/transforming this first set of
spectra into a second set of spectra, and subsequently using multivariate
regression to analyze this second set of spectra wherein the concentrations of
components of the mixture being assessed are based on mixtures with known
concentrations of hydrocarbons. App. Br. 6.
Appellants answer that Baer teaches measuring acetylene only in an
inert nitrogen atmosphere, so that it does not interfere with the spectroscopic
measurements and does not generate a signal that overlaps with the
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Application 11/885,212
acetylene spectrum. App. Br. 7 (citing Baer 264, Fig. 7). Appellants argue
that Baer acknowledges that signals were purposely isolated signals and
teaches: "[t]he individual transitions were selected based on their relative
strength and spectral isolation in typical industrial and atmospheric flows."
Id. (emphasis omitted) (citing Baer 263, 261).
More importantly, Appellants contend, Baer states that measuring
acetylene in the presence of ethylene (C2H4) would be difficult because
ethylene interferes spectrally, i.e., it overlaps, with the acetylene signal.
App. Br. 7-8 (citing Baer 265).
Therefore, Appellants argue, Baer teaches that measuring the
acetylene contaminant would require accounting for the presence of other
hydrocarbons, which would interfere with the acetylene signal. App. Br. 8.
However, Appellants assert, Baer neither teaches nor suggests how a person
of ordinary skill in the art would be able to determine the absorption of
acetylene due to the masking effect of the other hydrocarbon spectra, but
merely identifies the issue. Id.
Appellants next argue that Crosson teaches use of cavity ring-down
spectroscopy, in contrast to Baer, which teaches "off-axis integrated-cavity-
output spectroscopy." App. Br. 13 (citing Crosson, Abstr.; Baer Abstr.).
Appellants assert that there is no reason or teaching of record that equates
the teachings of the two references, nor are there any teachings of record that
imply the teachings from either of the techniques applies to the other. Id.
Therefore, Appellants argue, applying the teachings from Baer to Crosson
(or vice versa) is improper because a person of ordinary skill in the art
would not be motivated to combine the references. Id.
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Appellants argue further that: ( 1) Crosson does not discuss or teach
the use of lasers to measure acetylene or methyl acetylene in gas that has
been through an ethylene cracker hydrogenator, but rather measures 13C/12C
isotope ratios in human breath; (2) Crosson teaches conducting the
measurements in an inert atmosphere (N2); and (3) Crosson is also aware of
the problem of spectral overlap, but chooses to ignore the overlapping
signal. App. Br. 14 (citing Crosson 2004, 2005).
With respect to Wheeler, Appellants argue Wheeler is directed
towards methods and devices that employ infrared spectroscopy, rather than
a tunable diode laser-based method, to measure CO in cracked gas. App. Br.
16. Appellants argue that Wheeler explicitly states that acetylene is not
being measured in its teachings, as is required by the claims. Id. (citing
Wheeler 230). Therefore, Appellants argue, Wheeler neither teaches nor
suggests any methods or devices that can be used to measure acetylene,
whether in a cracked gas or not. App. Br. 17.
The Examiner responds that, whereas Baer teaches that acetylene may
be a potential contaminant, Baer never teaches that acetylene is always a
contaminant and that, even assuming, arguendo, that acetylene is a
contaminant, the other gases requiring measurement to correct for this
acetylene comprise small organic gases such as ethylene. Ans. 3. The
Examiner points out that the claims require measurement of the acetylene
and the correction standard of ethylene, regardless of whether the gases are
contaminants or correction standards. Id.
The Examiner next finds, Appellants' arguments to the contrary
notwithstanding, Baer and Crosson teach analogous experimental techniques
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Application 11/885,212
because both documents are drawn to using variants of IR spectroscopy to
measure gas concentrations. Ans. 5.
With respect to the teachings of Wheeler, the Examiner notes that
Appellants acknowledge that Table VI of Wheeler teaches measuring the
concentrations of the species within the cracked gas using IR spectrometry
(including acetylene, methylacetylene, and ethylene). Ans. 5. Despite
Appellants' argument that acetylene is not being measured, the Examiner
finds Table VI explicitly lists the acetylene concentration in the cracked gas.
Id. Furthermore, the Examiner finds the final paragraph on page 234 of
Wheeler suggests that the data in Wheeler's Table VI is derived from the IR
spectra in Wheeler's Figure 6.
We find Appellants have the better position. Claim 1 explicitly recites
that "the gaseous components of interest are acetylene and methylacetylene
and the sample gas comprises ethylene and methylacetylene from an
ethylene cracker hydrogenator." Claim 1 thus requires that, to determine the
concentrations of the gases of interest, the user of the invention be able to
determine the concentration of acetylene and/or methylacetylene against a
background comprising ethylene and methylacetylene in a cracked gas.
Of Baer, Crosson, and Wheeler, only Baer teaches laser spectroscopy
determination of acetylene concentrations, and that determination is made
against a background of inert nitrogen so there will be no spectral
interference. See F 2. Crosson teaches using tunable laser spectroscopy to
detect the ratio of 12C to 13C in a breath sample, again against an inert
nitrogen background. See F 4. Only Wheeler teaches measuring the
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Application 11/885,212
concentrations of components in a cracked gas, 4 however, Wheeler is
explicitly directed to the detection of carbon monoxide (CO), rather than
acetylene, in the cracked gas, with the aim of comparing and contrasting the
efficiency and efficacy of gas chromatography versus gas filter correlation
infrared spectroscopy as measurement techniques. See F 6. Consequently,
we find that none of references cited in support of the Examiner's prima
facie conclusion of obviousness, in this respect, teach or suggest determining
the concentration of gaseous acetylene and methylacetylene components
against the background of ethylene and methyl acetylene in a cracked gas
from an ethylene cracker hydrogenator.
More importantly, we find that both Baer and Wheeler explicitly state
that they do not teach the disputed limitation of claim 1. Baer states:
Since the ambient mixing ratio of C2H2 is approximately 0.1
ppbv, these results suggest that the present measurement strategy
may be applied for atmospheric monitoring with increased signal
averaging. For measurements in industrial process flows, such
as those in olefin plants where C2H2 may be a contaminant, an
effective instrument would have to account for absorption
features due to other hydrocarbons (e.g. C2H4 and C3H4) in the
probed flow that inteifere spectrally with the probed C2H2
transition.
Baer 265 (emphasis added and internal citation deleted). Baer thus
explicitly admits that, to satisfy the disputed limitation of Appellants'
claims, an instrument, as yet neither invented nor disclosed, would be
required to detect acetylene against the background of other hydrocarbons in
4 Typically consisting of a mixture of components such as of H2, CO, C02,
CH4, C2H2, C2H4, C2H6, C3H4, C3H6, C3Hs, and C4s. See F 8.
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Application 11/885,212
a cracked gas. Baer thus identifies the problem, but offers no teaching or
suggestion of a solution.
Even more explicitly, Wheeler states: "[t]he development of a
reliable, interference free photometric acetylene analyzer is the current topic
of research by the authors and is not described in this paper." Wheeler 230
(emphasis added). Although both Wheeler and Baer recognize the issue of
detecting low levels of acetylene against the background spectral
interference in a cracked gas, neither provides an explicit teaching or
implicit suggestion that would have made the method obvious to a person of
ordinary skill in the art.
Furthermore, Crosson does not cure the deficiencies of Baer and
Wheeler in this respect. Crosson is directed to the use of a tunable laser to
determine the relative ratio of isotopes of oxygen in a breath sample. F4.
Crosson is entirely silent with respect to detecting acetylene concentrations
in a cracked gas. Similarly, Cooper and Taylor are not relied upon by the
Examiner as teaching "the gaseous components of interest are acetylene and
methylacetylene and the sample gas comprises ethylene and methylacetylene
from an ethylene cracker hydrogenator," and therefore do not cure the
deficiencies of the other cited prior art.
Nor are we persuaded by the Examiner's reliance on Table VI of
Wheeler in finding that Wheeler teaches determining the concentration of
acetylene in a cracked gas. See Ans. 5. With respect to Table VI, Wheeler
states:
Initially a single beam, dual filter, photometric analyzer was
chosen for this application. This was due to the kinds of
analyzers commercially available when the Light Hydrocarbon 8
plant was built. While offering all of the maintenance and cost
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Application 11/885,212
of ownership benefits desired, this design did not offer the
spectral resolution and background interference rejection
necessary. The supplier interpreted the stream data for CO in
cracked gas to imply a relatively constant hydrocarbon
background, when, in fact, variation was the norm. This
variation is illustrated in Table VI.
TQbf-e VI, Pmit1.l C~I~~ ul'Crad>:ed Gu
,...,..L§~i?m-i~---~---=....,,t.,...1§~~-.-~,,,.,""""""'",~:::+~""P'~nd," tRaiii!l~r"V1v1 l
t~en "-"-1Jt:% ..... _ !~::"-~···~·~ -·j
L§ti!eoo :: :_o-5% fau:J£~"---" ~::· ___ ,~--J
LEt!t~en_a ~" lu!S-.50% u-autene ~ (H % !
! Ethane o--15% : 1-Buti:n.-e ~ 0-2%
[·~1~ful,l~wieoo 0--1% ,~,~-To~umne= I &-2% "-=:::::= ............ Ji
! Proti&ci!ene 0-1% .! Benzene i 0.-2%
~...-~~~~~-~"" - ~---:;---. ~~
In practice, the analyzer had little or no correlation with CO
analyses performed in the plant laboratory. Figure 6 below
shows why. It contains a spectral plot of the CO band, along with
those for cracked gas for three grab samples. The data were
collected using an FTIR analyzer, at 8 cm-1 resolution using a
600 mm path length heated IR cell.
Wheeler 234. Figure 6 of Wheeler is reproduced below:
i""'lO M:i 2llOO ~W ·1t300 ~ i~oo ~':1!t11J!l1i>~f (-roi' l i
Figure 6 of Wheeler depicts infrared spectra for 1000 ppm CO
and cracked gas from 3 grab samples, taken at 8 cm-1
resolution in a 600 mm infrared cell.
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Application 11/885,212
We agree with Appellants that Wheeler does not, in the quoted
passage, or in Figure 6, teach or suggest the method recited in Appellants'
claims, either by themselves or in combination with Baer and Crosson.
Rather, Wheeler teaches that cracked gases usually display a variety of
hydrocarbon concentrations, including acetylene, despite the fact that the
suppliers' data concerning carbon monoxide, gathered via a dual filter
photometric analyzer, implied otherwise. Wheeler does not describe or
suggest the method by which the variations in acetylene in cracked gases
were determined. Nor does Figure 6 of Wheeler depict any spectral peak for
acetylene, which is, as has been taught by the prior art, obscured by the
overall spectrum of the cracked gas.
Finally, although not explicitly addressed by the Examiner, we are
persuaded by Appellants that performing the laser spectroscopic analysis at
the lower pressure of approximately 100 torr provides unexpected results in
that the acetylene peak becomes visible against the background of the
cracked gas. The Second Declaration of Dr. James D. Tate (the "Tate
Declaration"), one of the co-inventors of Appellants' invention, is
particularly persuasive upon this point. In the Declaration, Dr. Tate attests:
Ultimately, we determined that the ethylene gas, which has a
very strong and broad spectral signal, overlaps with and hides the
much weaker and narrower acetylene and methylacetylene
spectral signals. So, the ethylene gas absorbs most of the light
generated by the tunable diode laser. But we discovered that
upon reducing the pressure in the sample, the spectral
absorbance of the ethylene gas was reduced, and it was possible
to measure the acetylene and methylacetylene concentrations.
This result was surprising and unexpected. And consequently,
we concluded that it was necessary to reduce the pressure of the
sample cell, in order to measure the acetylene concentration.
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Application 11/885,212
Tate Deel. 2, il 7 (emphasis added). As Dr. Tate states, and as is required by
Appellants' claims, it is the reduced pressure that is the solution to the
problem identified (but not solved) by both Baer and Wheeler, and is the
inventive concept of Appellants' invention. We agree with Appellants that
the limitation reciting "wherein the pressure in the sample cell is about 100
torr," is neither taught nor suggested by the combined cited prior art.
We consequently reverse the Examiner's rejection of claims 1 and 5-
9.
DECISION
The Examiner's rejection of claims 1 and 5-9 as unpatentable under
35 U.S.C. § 103(a) is reversed.
REVERSED
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