Table Of ContentStudies in Surface Science and Catalysis
Advisory Editors: B. Delmon and J.T. Yates
Vol. 36
METHANE CONVERSION
Proceedings of a Symposium on the Production of Fuels and Chemicals
from Natural Gas, Auckland, April 27-30, 1987
Editors
D.M. Bibby
DSlR Chemistry Division, Private Bag, Petone, New Zealand
C.D. Chang
Mobil Research and Development Corporation, Central Research Laboratory,
P. 0. Box 1025, Princeton, NJ 08540, U.S.A .
R.F. Howe
Chemistry Department, University of Auckland, Private Bag, Auckland, New
Zealand
and
S. Yurchak
Mobil Research and Development Corporation, Paulsboro Research
Laboratory, Paulsboro, NJ 08066, U.S.A .
- - -
ELSEVl ER Amsterdam Oxford New York Tokyo 1988
ELSEVIER SCIENCE PUBLISHERS B.V.
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LIBRARY OF CONGRESS
Library of Congress Cataloging-in-Publication Data
Methane conversion proceedings of a symposium on the production of
fuels and chemicals from naturai gas. Auckland, April 27-30. 1987
editors. D.M. Bibby ... [et ai.1.
p. cm. -- (Studies in surface science and catalysis . 36)
InCludeS index.
ISBN 0-444-42935-2 (U.S.) fl 300.00 cest.)
1. Synthetic fuels--Congresses. 2. Gas. Natural--Congresses
I. Bibby. C. M. (David M.) 11. International Symposiufr on Methane
Conversion (1987 Univepsity of Aucklano) 111. Series.
TP360.M47 1988
665.7 3--dC19 87-34762
CIP
ISBN 0-444-42935-2 (Vol. 36)
ISBN 0-444-4 180 1-6 (Series)
0 Elsevier Science Publishers B.V., 1988
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Printed in The Netherlands
XI
F0REkD)RD
It is with pleasure that we present the Proceedings of the International
Symposium on Methane Conversion which took place in New Zealand from
27-30 April, 1987.
The Symposium marked the successful inauguration in October 1985 of the
world's first comnercial plant for production of gasoline from natural gas,
based on the Mobil methanol-to-gasoline process. The plant is operated by the
New Zealand Synthetic Fuels Corporation, of which Mobil is a shareholder. The
symposium was held at the University of Auckland and concluded with a tour of
the synfuel gas-to-gasoline plant at Motunui, near New Plymouth.
The objectives of the Symposium were to present both fundamntal research and
engineering aspects of the development and comrcialization of gas-toqasoline
processes. These included steam reforming, methanol synthesis and
methanol-to-gasoline. Possible alternative processes e.g. MOGD, Fischer
Tropsch synthesis of hydrocarbons, and the direct conversion of methane to
higher hydrocarbons were also considered. More than 130 delegates from a wide
range of disciplines attended and the Symposium was successful in prmting
interchange of ideas between scientists developing processes in the laboratory
and engineers responsible for comrcialization.
The Symposium prcgrarnne consisted of a series of invited lectures from
industrial, university and government speakers, contributed papers and two
poster sessions. The call for contributed papers resulted in submission of 85
abstracts, a large proportion of which came from industrial laboratories.
Follming the grouping of papers at the Symposium, we present them here in
the following broad categories:
- Inethane conversion via methanol
- alternative routes to methane conversion
- zeolites and other catalysts
- comrcialization of the gas-tc-gasoline process
The work presented at the poster sessions is included in this volume as short
papers.
The Editors have felt obliged to carry out editorial changes in papers where
obvious typing errors or lack of clarity affected the understanding. W e
apologise for not being able to obtain an authorisation in every case but this
was because of lack of time. The alternative of not accepting these papers, or
XI1
of delaying publication of these Proceedings further was not justified in view
of the high quality and imnediacy of the work presented.
The Editors would like to thank the Authors for the quality of their
presentations, and for participating in this volume.
The Editors also thank the Organizing Committee for willingly giving their
time and expertise to the Symposium, the Chairman of Sessions and the referees
for their numercus contributions.
We thank George Dibley and his staff of the Auckland University Centre for
Continuing Education for arranging the Symposium and associated
extra-curricular activities, and Neil Milestone for assistance in the
preparation of this volume.
Finally, we thank Dame Catherine Tizard, Mayor of Auckland, for opening the
Symposium and welcoming the delegates to New Zealand and the City of Auckland.
DAVID M BIBBY
CLARENCE D CHANG
RUSSELL F HOWE
SEFGEI WRCHAK
XI11
ORGANIZING AND SCIENTIFIC COMMITTT
K.G. Allum New Zealand Synthetic Fuels Corporation
D.M. Bibby DSIR Chemistry Division
C .D. Chang Mobil Research and Developnent Corporation
R.P. Cooney University of Auckland
R.F. Howe University of Auckland
N.B. Milestone E I R Chemistry Division
R. Nicol DSIR Industrial Processing Division
C.G. Pope University of Otago
S. Yurchak Mobil Research and Development Corporation
FINANCIAL SUF'poRT
This Symposium was wde possible by financial support sponsorship from
the following organizations:
American Chemical Society
American Institute of Chemical Engineers
Mobil Research and Development Corporation
Mobil Oil New Zealand
Mobil South, Inc.
New Zealand Department of Scientific and Industrial Research,
Chemistry Division
New Zealand Institute of Chemistry
New Zealand Synthetic Fuels Corporation, Ltd
University of Auckland
D.M. Bibby, C.D. Chang, R.F. Howe and S. Yurchak (Editors), Methane Conversion 1
1988 Elsevier Science Publishers B.V., Amsterdam - Printed in The Netherlands
THE NEW ZEALAND GAS-TO-GASOLINE PROJECT
C.J. MAIDEN
Chairman, New Zealand Synthetic Fuels Corporation Ltd., New Zealand
ABSTRACT
The Synfuel gas-to-gasoline complex is sited within 180 hectares of land
at Motunui, Taranaki. It is designed to convert 52-55 PJ per annum of
natural gas into 570,000 tonnes (14,450 barrels per stream day) of high
octane gasoline.
The conversion of gas to gasoline (GTG) takes place in two stages: first
gas to methanol (GTM) and second methanol to gasoline (MTG). The two stages
are integrated into a single complex to achieve optimum efficiency in
management and operation.
The GTM plant employs the ICI low-pressure Methanol Process sub-licensed
from Davy McKee, and incorporates two methanol trains each capable of
producing 2200 tonnes per day of methanol.
The MTG plant employs Mobills fixed bed catalytic process using the Mobil
proprietary zeolite catalyst, ZSM-5. The process is very similar to
conventional vapour phase catalytic petroleum refinery processes, such as
hydro-treating and platinum reforming.
The plant is owned and operated by New Zealand Synthetic Fuels Corporation
Limited (Synfuel) with a shareholding of Government 75 percent and Mobil
25 percent. Mobil provides technical and management services to the company.
The plant was mechanically complete by June 30, 1985, ahead of schedule
and about 17 percent under the original budget of US$1475 million.
Commissioning and startup proceeded satisfactorily with the first gasoline
produced on October 17, 1985. The gasoline is within specification and
739,000 tonnes have been produced to the end of March 1987.
INTRODUCTION
With more than a year's successful operation of the world's first gas-to-
gasoline (GTG) plant it is an appropriate time to review the history and
development of the project. The New Zealand Synthetic Fuels Corporation Ltd
(NZSFC) was incorporated in September 1980 with the objective of. designing,
constructing and operating a plant to manufacture gasoline. The Company was
to convert natural gas owned by the Crown into gasoline, via methanol as an
intermediate product, for a processing fee. Gasoline produced from the plant
was to be owned by the Crown and subsequently sold to the oil marketing
companies for distribution to the consumer. The project has its origins in
recommendations from Liquid Fuels Trust Board to Government in 1979.
2
THE LIQUID FUELS TRUST BOARD
In 1973, prior to the first energy crisis, New Zealand imported virtually
all its liquid fuel requirements in the form of oil or its products. At this
time such imports represented about 60 percent of New Zealand's primary energy
requirements and cost less than 5 percent of the country's export earnings.
After the first oil shock the cost of liquid fuels jumped to between 20 and
30 percent of export earnings and thereby severely weakened the economy.
The second oil shock in 1979 further weakened the economy and a high
reliance on Iranian crudes led to the introduction of "carless days", a
(temporary) attempt to reduce the amount of car usage.
The Liquid Fuels Trust Board (LFTB) was formed just prior to the Iranian
revolution with the aims of assessing ways of reducing the need for imported
fuels for transport purposes in New Zealand. The second oil shock created
immediate pressure on the Board to determine how the products of New Zealand's
natural gas fields could be used as or converted into transport fuels.
New Zealand's two largest gas fields are the Kapuni and Maui fields. The
Kapuni field has estimated recoverable gas reserves of 419 petajoules (PJ)
and i s on-shore in Taranaki; whereas the Maui field with estimated
recoverable gas reserves of 5193 PJ is 33 km off the coast of Taranaki.
A number of alternatives were examined by the LFTB including compressed
natural gas (CNG), liquefied petroleum gas (LPG), methanol as a gasoline
extender, pure methanol as a gasoline or diesel substitute and the production
of synthetic fuels. This work resulted in the presentation of two reports to
Government, in August and October 1979, containing recommendations on an
initial strategy for transport fuels supply and gas utilisation in New
Zealand. Two major projects were recommended:
A synthetic gasoline project to produce 500-600,000 tonnes per annum
of gasoline from methanol produced from natural gas using a process
developed by the Mobil O i l Corporation;
A "stand-alone" methanol project, using natural gas as a feedstock,
with the majority of product dedicated to export as chemical grade
methanol and the remainder for local use as a fuel or as a chemical.
It was also recommended that the approved expansion of the Refinery at
Marsden Point in northern New Zealand take account of future production of
synthetic gasoline.
The canbined use of synthetic gasoline, indigenous condensate from Kapuni
and Mad, and CNG and LPG in vehicles, was predicted to make New Zealand about
3
50 percent self-sufficient in transport fuels in the middle 19801s, and
thereby save several hundred million dollars annually in overseas funds.
The LFTB's recommendation to use natural gas to produce gasoline using the
Mobil process was made following a comprehensive analysis of alternative
synthetic fuel technologies. To assist them in their studies during 1979 the
LFTB contracted overseas consultants including Ralph M. Parsons, the Badger
Company, Davy McKee and Lurgi. These consultants undertook investigations
into the state of the art of methanol and synthetic fuel technology and
carried out comparative studies between the Mobil methanol-to-gasoline (MTG)
process and the Fischer-Tropsch synthetic fuel process as used by SASOL in
South Africa.
The LFTB concluded, on the basis of these studies, that the Mobil process
provided a more economic and efficient method of producing synthetic fuel
than did Fischer-Tropsch synthesis. The Board also concluded that it was not
possible for New Zealand to reach 50 percent self-sufficiency in transport
fuels by the middle 1980's without synthetic fuel. With only condensate, CNG
and LPG a realistic cmparable goal would be about 25 percent self-
.
sufficiency
THE MOBIL PROCESS
The success of the unique Mobil process lies in the zeolite catalyst ZSM-5.
This catalyst is the most efficient known for the conversion of methanol to
hydrocarbons in the gasoline range.
The process has its origins during the 1960's. Originally looking for a
means of VrackingtV or breaking down components of crude oil Mobills
scientists researched a range of chemical catalysts including
aluminosilicates. This work resulted, in 1968, in the synthesis of the
zeolite ZSM-5 which was found to convert methanol into water and a mixture of
hydrocarbons. This hydrocarbon mixture is essentially the same as gasoline
produced by the traditional refining of crude oil.
Development studies on the MTG process have been conducted since the early
1970's. Using a fixed-bed process, catalyst ageing tests of over 200 days
were carried out, optimum process conditions were defined, and the quality of
the gasoline produced was determined.
In response to a request from the New Zealand Government, Mobil Research
and Development Corporation built a four barrels per day fixed-bed pilot plant
to demonstrate the feasibility of the gas-to-gasoline process. This was a
major scale-up of the laboratory work and the pilot plant performed precisely
as predicted. Reports to the LFTB by Lurgi and Badger also indicated
confidence that the process would scale successfully from the pilot plant to
4
commercial size.
The ZSM-5 catalyst does not have only one use. Mobil has commercialised
six processes using ZSM-5, five of which are licensed for use in 25 chemical
and refinery plants around the world. These varied applications have given
Mobil wide experience in directly scaling up laboratory-size units to large
commercial plants. Commercial experience has also confirmed laboratory
predictions of high stability and long life for the catalyst.
PROJECT CONCEPTS
The project concepts were developed under the terms of a 1980 Government/
Mobil Memorandum of Understanding. By this acjreement a Joint Executive
Committee (JEC) was to prepare a report which would include a plan for the
design, construction, and operation of a plant to manufacture gasoline, and
an assessment of the viability of such a project.
Mobil assumed responsibility for overall project management, subject to
the direction of the JEC, and Bechtel Petroleum Inc. was employed as Project
Services Contractor.
The JEC Report, completed in July 1981, concluded that the venture was
clearly technologically feasible and commercially attractive. The Government
and Mobil elected to proceed and concluded the various contracts in February,
1982.
It was agreed that the plant would be owned and operated by the New Zealand
Synthetic Fuels Corporation Ltd (Synfuel) with a Government shareholding of
75 percent and a Mobil shareholding of 25 percent. Mobil contracted to
provide technical and management services to the company.
The company was to operate on a tolling basis, with the Crown supplying
the natural gas to the plant for processing into gasoline for a tolling fee.
Title to the hydrocarbons was to remain with the Crown, which would sell the
gasoline to the New Zealand petrolem marketing companies. Synfuel gasoline
was to be priced competitively with gasoline produced from the Refinery at
Marsden Point.
Under the terms of the Processing Agreement between NZSFC and the Crown,
the tolling fee to be paid by the Crown, when the plant operated at design
capacity, was to cover all of NZSFC's costs including tax and debt service.
Also, at design capacity, the fee was to provide the shareholders with a tax
paid discounted cash flow rate of return on qualifying capital at risk of
16 percent adjusted for inflation.
DESIGN OF TM PLANT
The Synfuel plant is sited within 180 hectares of land at Motunui, Taranaki
5
TARANAKI
I
WAITARA / MOTUNUI
Fig. 1. Location of Synfuel Complex
