PURAC BIOCHEM BV

Patent Trials and Appeals Board

Jun 28, 2021

2020003062 (P.T.A.B. Jun. 28, 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.
15/129,431 09/27/2016 Andr¿ Banier DE HAAN 172983 2673
25944 7590 06/28/2021
OLIFF PLC
P.O. BOX 320850
ALEXANDRIA, VA 22320-4850
EXAMINER
NGUYEN, NGOC YEN M
ART UNIT PAPER NUMBER
1734
NOTIFICATION DATE DELIVERY MODE
06/28/2021 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):
OfficeAction25944@oliff.com
jarmstrong@oliff.com
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte ANDRÉ BANIER DE HAAN, JEROEN BOKHOVE, and
FESIA LESTARI LAKSMANA
Appeal 2020-003062
Application 15/129,431
Technology Center 1700
Before JAMES C. HOUSEL, N. WHITNEY WILSON, and
JANE E. INGLESE, Administrative Patent Judges.
WILSON, Administrative Patent Judge.
DECISION ON APPEAL
STATEMENT OF THE CASE
Pursuant to 35 U.S.C. § 134(a), Appellant1 appeals from the Examiner’s
November 30, 2018 decision to reject claims 1–6, 8–10, 15–23, 27, and 28
(“Non-Final Action”). We have jurisdiction under 35 U.S.C. § 6(b).
We reverse.

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 Purac
Biochem BV (Appeal Br. 1).
Appeal 2020-003062
Application 15/129,431

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CLAIMED SUBJECT MATTER
Appellant’s disclosure is directed to a method of converting
magnesium chloride to magnesium oxide and HCl (Abstract). The method
involves producing a magnesium chloride hydrate having a specified amount
of water from a solution of magnesium chloride, and then subjecting the
magnesium chloride hydrate to thermohydrolysis at a temperature of at least
300°C. Details of the claimed process are set forth in independent claims 1
and 21, which are reproduced below from the Claims Appendix:
1. Method for conversion of magnesium chloride into
magnesium oxide and HCl, comprising the steps of
- subjecting a magnesium chloride solution to a drying
step at a temperature of 100–160°C, which drying step forms a
magnesium chloride compound comprising at least 50 wt.% of
MgCl2.4H2O and comprising less than 40 wt.% of the total of
magnesium chloride anhydrate, magnesium chloride
monohydrate, and magnesium chloride dihydrate,
- providing the magnesium chloride compound to a
thermohydrolysis reactor, the reactor being at a temperature of
at least 300°C, and
- withdrawing MgO from the thermohydrolysis reactor in
solid form, and withdrawing a HCl containing gas stream from
the thermohydrolysis reactor.
21. Method for conversion of magnesium chloride into
magnesium oxide and HCl, comprising the steps of:
- providing a magnesium chloride compound to a
thermohydrolysis reactor, the reactor being at a temperature of
at least 300°C; and,
- withdrawing MgO from the thermohydrolysis reactor in
solid form, and withdrawing a HCl containing gas stream from
the thermohydrolysis reactor,
wherein the magnesium chloride compound provided to
the thermohydrolysis reactor is a solid magnesium chloride
compound which comprises at least 50 wt.% of MgCl2.4H2O
and which comprises less than 40 wt.% of the total of
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Application 15/129,431

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magnesium chloride anhydrate, magnesium chloride
monohydrate, and magnesium chloride dihydrate, and
wherein the method is conducted with a residence time,
calculated from the provision of the magnesium chloride
compound to the thermohydrolysis reactor to the removal of the
corresponding magnesium oxide from the reactor, of at most 30
minutes.
REFERENCES
The prior art relied upon by the Examiner is:
Name Reference Date
Collings et al. (“Collings”) US 1,479,982 January 8, 1924
Gattys (“Gattys”) US 4,425,314 January 10, 1984
Dancy et al.2 (“DE ‘712”) DE 1 102 712 March 28, 1957

REJECTION
Claims 1–6, 8–10, 15–23, 27, and 28 are rejected under 35 U.S.C.
§ 103 as unpatentable over DE ‘712 in view of Collings and Gattys.
OPINION
The Examiner finds that DE ‘712 discloses a process for the
preparation of magnesium oxide by thermal decomposition of magnesium
chloride hydrate, wherein the solid magnesium chloride contains about 1.5
to 3.5 moles of water of hydration per mole of magnesium chloride (Non-
Final Act. 2, citing DE ‘712, ¶ 1). The Examiner, using the molecular
weights of the various magnesium chloride hydrates and the average number
of moles of water of hydration per mole of magnesium chloride, calculates
the weight percentages of the tetrahydrate, the dihydrate, and the

2 We, like Appellant and the Examiner, refer to the English translation of
record.
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Application 15/129,431

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monohydrate in various configurations, and determines that DE ‘712
suggests weight percentage ranges which overlap with those set forth in the
claims (at least 50 wt% of the tetrahydrate and no more than 40 wt% of the
monohydrate and dihydrate) (Ans. 12–15).
In response, Appellant argues, inter alia, that DE ‘712 teaches that
magnesium chloride dihydrate is the predominant form of magnesium
chloride used in its method, and, therefore, that it does not teach or suggest
using a magnesium chloride where less than 40% of the magnesium chloride
is in the form of the magnesium chloride anhydrate, magnesium chloride
monohydrate, and magnesium chloride dehydrate (Appeal Br. 9, Reply Br. 4).
Appellant’s argument is persuasive. DE ‘712 states:
It can find a use magnesium chloride hydrate, which is a
mixture of [magnesium chloride monohydrate], [magnesium
chloride dihydrate] and [magnesium chloride tetrahydrate]
substantially and has about 1.5 and about 3.0 moles of water
of hydration per mole of magnesium chloride. A magnesium
chloride hydrate, produced by controlled dehydration of
magnesium chloride, is usually free of anhydrous magnesium
chloride or [magnesium chloride hexahydrate] and essentially
contains a larger amount of magnesium chloride dihydrate
and a lower proportion of [magnesium chloride tetrahydrate].
The mixture used herein as the feed preferably contains
between about 2.0 and 2.6 moles water of hydration per mole
of magnesium chloride.

(DE ‘712, ¶ 12, emphasis added). Thus, DE ‘712 indicates that its
preference is for a magnesium chloride in which the predominant form is the
dihydrate, which would be outside the scope of the appealed claims (which
are limited to a maximum amount of less than 40% of the dehydrate).
Moreover, DE ‘712 also states:
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The magnesium chloride hydrate used in the present invention
contains an average of from about 1.5 to about 3 moles of water
of hydration per mole of [MgCl2] and includes [magnesium
chloride dihydrate] alone or mixed with [magnesium chloride
tetrahydrate] or [magnesium chloride monohydrate].

(DE ‘712, ¶ 5). Thus, although ¶ 1 of DE ‘712 suggests that the maximum
amount of water is 3.5 moles per mole of magnesium chloride, this is not
entirely consistent with the disclosures in ¶¶ 5 and 12, which suggest that the
maximum amount of water is 3 moles per mole of magnesium chloride.
It is axiomatic that a prior art reference is not limited to its preferred
embodiments and is valuable for all it teaches to one of skill in the art. See
In re Burckel, 592 F.2d 1175, 1179 (CCPA 1979); In re Preda, 401 F.2d
825, 826 (CCPA 1968). In this instance, we determine that a fair reading of
DE ‘712 would suggest to a person of skill in the art that the maximum
amount of water would be 3.5 moles per mole of magnesium chloride in
mixtures which would include the hexahydrate form, but that in the
preferred system, which essentially excludes the hexahydrate form, the
maximum amount of water would be 3 moles per mole of magnesium
chloride.
Thus, we agree with Appellant that the Examiner’s calculations which
rely on systems which exclude the hexahydrate but include 3.5 moles of
water per mole of magnesium chloride are outside the scope of what DE
‘712 would reasonably have suggested to a person of skill in the art.
Moreover, the calculations which rely on systems which include the
tetrahydrate and the monohydrate but exclude the dihydrate are based on
hypothetical compositions which do not appear to be realistically available
to a person of skill in the art. That is, the Examiner has not provided an
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adequate explanation of how one would produce a mixture which includes
substantial amounts of both the monohydrate and the tetrahydrate, but
excludes the dihydrate.
Thus, on balance, we agree that the preponderance of the evidence of
record does not support the Examiner’s finding that DE ‘712 would have
taught or suggested the use of a magnesium chloride compound comprising
at least 50 wt.% of MgCl2.4H2O and comprising less than 40 wt.% of the
total of magnesium chloride anhydrate, magnesium chloride monohydrate,
and magnesium chloride. Moreover, the Examiner does not rely on Collings
and Gattys to remedy this deficiency in DE ‘712. As Appellant argues,
Collings and Gattys both disclose processes for producing the dihydrate, and
only mention the hexahydrate as an intermediate. Also, Collings and Gattys
fail to teach or suggest that the tetrahydrate should be present in the claimed
amount in a thermohydrolysis process.
The Examiner has the initial burden of establishing a prima facie case
of obviousness based on an inherent or explicit disclosure of the claimed
subject matter under 35 U.S.C. § 103. In re Oetiker, 977 F.2d 1443, 1445
(Fed. Cir. 1992) (“[T]he examiner bears the initial burden, on review of the
prior art or on any other ground, of presenting a prima facie case of
unpatentability.”). To establish a prima facie case of obviousness, the
Examiner must show that each and every limitation of the claim is described
or suggested by the prior art or would have been obvious based on the
knowledge of those of ordinary skill in the art. In re Fine, 837 F.2d 1071,
1074 (Fed. Cir. 1988). In this instance, the evidence does not establish the
obviousness of using a magnesium chloride composition with the claimed
mixture of hydrates in DE ‘712’s thermohydrolysis process.
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Accordingly, we reverse the rejection.

DECISION SUMMARY
In summary:
Claim(s)
Rejected
35 U.S.C.
§
Reference(s)/Basis Affirmed Reversed
1–6, 8–10,
15–23, 27,
28
103 DE ‘712, Collings,
Gattys
1–6, 8–10,
15–23, 27,
28
REVERSED