Oils and Gases from Coal. a Symposium of The United Nations Economic Commission for Europe

297 Pages·1980·6.879 MB·English

United Nations Economic Commission for Europe
Some other titles in this series from Pergamon Press
HOUSING FOR SPECIAL GROUPS
BEHAVIOUR OF WOOD PRODUCTS IN FIRE
PROTEIN AND NON-PROTEIN NITROGEN FOR RUMINANTS
FROZEN AND QUICK-FROZEN FOOD
FACTORS OF GROWTH AND INVESTMENT POLICIES
COAL: 1985 AND BEYOND
NON-WASTE TECHNOLOGY AND PRODUCTION
THE GAS INDUSTRY AND THE ENVIRONMENT
BUILDING RESEARCH POLICIES
STATISTICAL SERVICES IN TEN YEARS' TIME
HUMAN SETTLEMENTS AND ENERGY
ELECTRICAL LOAD-CURVE COVERAGE
ENGINEERING EQUIPMENT FOR FOUNDRIES
INTEGRATED STATISTICAL INFORMATION SYSTEMS 1977
FINE PARTICULATE POLLUTION
PROBLEMS OF THE AGRICULTURAL DEVELOPMENT OF
LESS-FAVOURED AREAS
SELECTED WATER PROBLEMS IN ISLANDS AND COASTAL AREAS
ENVIRONMENT AND ENERGY
THE GAS SITUATION IN THE ECE REGION AROUND THE YEAR 1990
TRENDS IN AIRBORNE EQUIPMENT FOR AGRICULTURE AND OTHER AREAS
ENERGY ASPECTS OF THE FOREST INDUSTRIES
NOTICE TO READERS
Dear Reader
If your library is not already a standing order customer or subscriber to this series, may we recommend that
you place a standing or subscription order to receive immediately upon publication all new volumes
published in this valuable series. Should you find that these volumes no longer serve your needs your order
can be cancelled at any time without notice.
ROBERT MAXWELL
Publisher at Pergamon Press
Oils and Gases from Coal
A review of the state-of-the-art in Europe and North America
based on the work of the Symposium on the Gasification and
Liquefaction of Coal held under the auspices of the United Nations
Economic Commission for Europe, Katowice, Poland, 23-27 April
1979
Published for the
UNITED NATIONS
by
PERGAMON PRESS
OXFORD NEW YORK TORONTO SYDNEY PARIS FRANKFURT
U.K. Pergamon Press Ltd., Headington Hill Hall,
Oxford OX3 OBW, England
U.S.A. Pergamon Press Inc., Maxwell House, Fairview Park,
Elmsford, New York 10523, U.S.A.
CANADA Pergamon of Canada, Suite 104, 150 Consumers Road,
Willowdale, Ontario M2J 1P9, Canada
AUSTRALIA Pergamon Press (Aust.) Pty. Ltd., P.O. Box 544,
Potts Point, N.S.W. 2011, Australia
FRANCE Pergamon Press SARL, 24 rue des Ecoles,
75240 Paris, Cedex 05, France
FEDERAL REPUBLIC Pergamon Press GmbH, 6242 Kronberg-Taunus,
OF GERMANY Hammerweg 6, Federal Republic of Germany
Copyright© 1980 United Nations
All Rights Reserved. No part of this publication may be
reproduced, stored in a retrieval system or transmitted in
any form or by any means: electronic, electrostatic,
magnetic tape, mechanical, photocopying, recording or
otherwise, without permission in writing from the
copyright holders.
First edition 1980
British Library Cataloguing in Publication Data
Symposium on the Gasification and Liquefaction
of Coal, Katowice, 1979
Oils and gases from coal.
1. Coal liquefaction - Congresses
2. Coal gasification - Congresses
I. Title II. Economic Commission for Europe
662'.6622 TP352 79-41362
ISBN 0 08 025678 3
In order to make this volume available as economically
and as rapidly as possible the authors' typescripts have
been reproduced in their original forms. This method has
its typographical limitations but it is hoped that they in
no way distract the reader.
Printed and bound in Great Britain by
William Clowes (Beccles) Limited, Beccles and London
Preface
The economic viability of coal gasification and liquefaction has substantially
improved during the last few years. In particular circumstances gases and liquids
from coal can already compete with natural crudes. New, second generation techno-
logies enter the pilot plant stage: they promise higher conversion efficiencies,
are better suited to the different qualities and properties of coal and lend them-
selves to more extensive automation. Hence, there is promise for a further improve-
ment of the technical feasibility and competitiveness of coal gasification and
liquefaction.
These basic problems approaching solutions, growing efforts are presently directed
towards reducing the environmental impact of coal "refining" and to the sharing of R
and D risks and costs by means of bilateral and multilateral international
co-operation. While coal gasification and liquefaction has been in the past an
interesting R and D option, it now enters medium-term policies as a real possibi-
lity. It offers the opportunity of smoothening the constraints of oil supplies in
the future, but it also raises policy questions such as: selecting the most promis-
ing technologies: accelerating large-scale industrial demonstration; standardising
equipment; ensuring the necessary coal supplies either from indigenous or foreign
sources; facilitating international technology transfer and solving siting and
environmental issues.
The United Nations Economic Commission for Europe (ECE) has organised co-operation
among its member States-/ in this field since 1974. In 1976, a symposium on the
Gasification and Liquefaction of Coal was held at Düsseldorf in the Federal
Republic of Germany-Λ A second symposium took place in Katowice (Poland) from
23 to 27 April 1979 from which this present publication has been drawn under the
responsibility of the secretariat.
^./Comprising the following 34 countries in Europe and North America: Albania;
Austria; Belgium; Bulgaria; Byelorussian SSR; Canada; Cyprus; Czechoslovakia;
Denmark; Finland; France; German Democratic Republic; Germany, Federal Republic of;
Greece; Hungary; Iceland; Ireland; Italy; Luxembourg; Malta; Netherlands; Norway;
Poland; Portugal; Romania; Spain; Sweden; Switzerland; Turkey; Ukrainian SSR;
USSR; United Kingdom; United States of America and Yugoslavia.
?/For a report see: UN ECE "Symposium on the Gasification and Liquefaction of Coal,
Düsseldorf 1976", Verlag Glückauf, Essen (Federal Republic of Germany), 1976.
vii
Efficiency of Coal Gasification and
Liquefaction Processes
Opening Lecture
Wlodzimierz Lejczak
Minister of Mining, Polish People's Republic
Owing to the worsening supply of energy and raw materials since the mid-seventies,
everyone is aware that a rational and economic use of resources, particularly all
energy resources, is the real challenge facing the world economy.
In the next centuries coal is the only primary energy capable of covering world
energy needs, in addition to supplying raw material for the chemical industry. As
a matter of fact world reserves of coal are ten times greater than those of natural
gas and oil.
Coal resources are not only abundant, but also favourably located near industrial-
ized centres. According to forecasts by 2000, 43 per cent of oil reserves and 23
per cent of gas reserves, but only 1.4 per cent of coal reserves will have been
exhausted. At the same time it is expected that before the end of this century
the level of oil production will reach its maximum, while the highest level of coal
output will not have been attained before 2000.
An increase of electric power production from nuclear power stations sufficient to
allow a replacement of the diminishing reserves of hydrocarbons at least for
electric power generation and, on this basis, the possibility, for instance, of
using limestone for chemical syntheses, seem very remote alternatives.
Thus, an essential factor to improve the energy situation would be an increase in
coal production. However, great technical and social problems are involved.
May I illustrate the scale of the problem on the basis of a theoretical example:
in 1978, world energy consumption reached eight billion tons of coal equivalent.
To meet this demand by coal alone, it would have been necessary to mine at least an
extra 20-22 billion tons of hard coal and brown coals. This would have required an
increase of present output by six times and, using the most up-to-date methods of
underground and opencast extraction, the employment of 10-12 million workers.
This number could hardly be handled unless long-term mining programmes coupled with
high capital investments and with recruitment schemes would have been envisaged.
The ever closer economic and political ties between different regions of the world,
which produce and consume energy, provided a period of ample supplies and low
prices of liquid and gaseous fuels. This period was followed by a steep rise in
prices, which also made it indispensable to raise consumer prices, and by the
introduction of new forms of international co-operation including customer
1
2 Wlodzimierz Lejczak
participation in investments. In these circumstances, traditional means of fuel
competition will disappear in the near future, to permit a more co-ordinated use
of all forms of energy, including advanced and comprehensive coal conversion into
so-called clean forms of energy and chemical feedstock.
I must emphasize that the security of primary energy supplies is a prerequisite to
the development of key industries such as metallurgy, chemical syntheses and others.
Fuel processing may have an impact on increasing or decreasing profits, while a
stop in supplies would de-stabilize the economies as a whole.
Assumptions are justified that in a few decades in some regions of the world basic
energy supplies for use as raw materials for the chemical industry may become
short. Oil and gas reserves will, to a large extent, have been exhausted and
nuclear power, particularly nuclear fusion, as well as other unconventional sources
of energy will not yet be in common use.
Coal is in a position to fill a considerable portion of the gap, provided compre-
hensive conversion makes better use of its inherent properties than is presently
done.
The anticipated transformation of the world energy situation calls for specific
solutions for any given country. One solution would be the intensification of
scientific and technical research to allow an optimum utilization of the vast coal
reserves, particularly the production of synthetic fuels, both liquid and gaseous.
There is a real chance for the industrial use of the results of research and develop-
ment in the field of coal conversion into liquid and gaseous fuels. This means that
coal-derived forms of energy will be available to permit a flexible adjustment to
the market, and to stimulate technical-economic progress with no threat to the
environment. This should be an industry based on production-conversion plants with
an improved technological operation and structure in which the feedstock - coal -
would be taken both as a primary energy and as an organic substance providing fuels
and chemical products.
May I bring to your attention the result of some recent studies based on Polish data
which are of interest in this respect. A comparison of the economics of the process-
ing of 11 million tons of crude oil (including higher fractions, solvents, ethylene
etc.) with the economics of coal processing yielding similar end-products, shows
that:
- the capital expenditure for coal conversion will be 2.4 times higher than those
for oil processing
- but as regards fuel there will be an advantage for coal, thus permitting to
amortize the higher capital expenditure within nine years.
It should be emphasized that the direct introduction of coal products as substitutes
for oil, though in many ways convenient, is certainly not the best and final way of
solving our problems. In this connexion I wish to highlight a new generation of
organic chemical syntheses based on carbon monoxide instead of, e.g. ethylene. As
a matter of fact, the range of chemical products being obtained in this way includes
ethylene oxide and glycol, acetic acid, higher organic acids and other compounds.
Progress in this respect will lead to new products and other avenues to obtain gas
from coal, differing from the presently widespread use of pyrolysis. The interest
of many well-known chemical companies in this problem is evidence of its opportune-
ness, as well as of the imminence of its commercial application.
Of high economic importance is the progress in converting low-grade coals, contain-
ing much mineral matter and sulphur. Now there are better possibilities for these
coals to be utilized than previously, i.e. as gases for chemical syntheses with the
prospects of conversion that have already been mentioned.
Efficiency of Coal Gasification 3
Coal conversion has been used for a long time and has attained a high degree of
perfection. It should not be forgotten that the development of the chemical
industry was based on coal until such times when the ample supply of low priced oil
and natural gas prompted the change in the raw material base. The present high
level of achievement affects the development of coal conversion methods of the
second and third generation.
At present, apart from conventional coking plants, processes of coal-dust gasifica-
tion with oxygen and steam in fluidized bed and steam-oxygen gasification of coal
breeze in a quasi-static bed under pressure have found a wide application.
In one of the plants gasification is connected with the production of liquid fuels
by the Fischer-Tropsch method.
Without going into the technological details of newly-developing gasification
processes, it should be stressed that the second generation techniques feature
increased unit sizes and output capacity as well as efforts to make the technology
adaptable to various coal properties and to reach a higher degree of automation of
the process.
At present, dozens of coal gasification processes are being developed at a different
stage of achievement. It is hard to foresee which of them will have the widest use,
but I think that in a few years a selection will take place among on-going techno-
logies.
Design and test work in Poland is geared towards a generator construction and
gasification process which will minimize all external technological circuits. The
generators currently used account for only 8 to 12 per cent of total expenditure of
a gasification plant, followed by gas scrubbing, then treatment of water and eff-
luents and the costs of energy. If new solutions in the field of generators allow
to simplify those - to some extent - external circuits, there appear prospects for
industrial application even when the generator itself becomes more complicated.
Therefore, further work on the development of new coal gasification methods should
concentrate first on efforts to find processes with high thermal efficiency and to
reduce the number of those side processes which, to a considerable degree, affect
the system efficiency.
Other research activities aim at the development of coal liquefaction technologies
on the basis of solvents and direct hydrogenation. A number of processes are in
the preliminary stage of research, while others are at the pilot plant stage. Also
large-scale installations are being designed.
The main problem connected with this group of coal liquefaction technologies is the
decomposition of the organic coal substance, thereby possibly avoiding secondary
condensation processes. The product should be ash free and also free of incompletely
processed coal. The mastering of the problem is fraught with many difficulties of
a technological and engineering nature, the solution of which is the main pre-
requisite for the use of coal liquefaction methods to obtain a wide variety of fuels
and chemical stock.
Primary products of coal liquefaction may be used in the following fields:
- direct use as ash-free, low-sulphur energy fuel
- post-catalytic conversion into motor fuels or light combustion oils used for
motor transport
- processing into chemical feedstock, mainly as aromatic hydrocarbons
- processing into non-energy products, such as electrode cokes, graphitic
materials, binding agents etc.
4 Wlodzimierz Lejczak
A promising use is the application of the coal hydrogenizate äs an additive to feed
blends for metallurgical coke manufacturing. Research going on in Japan and other
countries including Poland predicts good results.
It should be mentioned that the processing of coal liquefaction products is much
easier from the technical point than the production itself.
All coal liquefaction methods give rise to problems which hamper the speed of
research and their industrial application. The most important problems are:
- separation of non-reacted coal and ash from liquefied coal products
- production of cheap and effective catalysts for processes of direct hydro-
genation of coal or coal extracts
- achievement of high thermal efficiency with the coal liquefaction process.
The solution of these problems should soon have a beneficial effect on the
competitiveness of coal liquefaction technologies as a source of liquid fuels
compared with oil.
New ideas are now emerging in this field, e.g. the synthesis of hydrocarbons from
methanol. It seems adequate to look at coal liquefaction as a source from the
point of view of the problems of getting hydrogen. In hydrogenation about 50 per
cent of coal or char coke in relation to the bulk of processed feedstock has to be
used for hydrogen production. This requires a large gasification plant. One may
wonder whether it would be more economical to go the synthesis gas route. The
answer is apparently affirmative with regard to some types of liquid products
obtained, i.e. motor fuels. In this respect, I think that already now the problem
of using methanol as a component of petrol and as an additive to air in high-
pressure engines can be considered as successfully solved.
The coupling of coal conversion systems with electric power generation may become
one of the more profitable solutions. At present, discussions concentrate most
frequently on the gas-steam circuit which improves the efficiency of the transform-
ation of coalTs chemical energy into electric power by more than 40 per cent. It
is well-known that transformation in an up-to-date conventional power station has
an efficiency of about 36 per cent, or at best 38 per cent.
It has been suggested that as soon as high-temperature reactors are on stream, a
revolutionary change will happen in coal conversion. I believe that this matter
depends on the availability of cheap energy for allothermic processes of coal
conversion. If nuclear power is going to be cheaper than that of coal, it will
certainly be more economical to bring heat in from the nuclear power stations
rather than to take it from coal. However, many difficulties have been encountered
in the development of technologies with the use of high-temperature reactors
connected mainly with materials. The whole problem needs further wide-ranging
technical research carried out on different scales, as well as a thorough economic
analysis which would take into account the influence of a number of factors that
are not only technological .
Quite often mention is made of the high capital costs required by coal conversion
and, in this connexion, of the unprofitability of industrial undertakings under
present market conditions. However, a closer examination of the problem shows that
such opinions are arrived at on the basis of incomplete data. I suggest to consider
the economic issues connected with the exploitation of deposits of fossil fuels,
such as gas, oil and coal in the light of the following:
- each deposit of fossil fuels possesses a non-renewable raw materials and energy
po ten ti al
- this raw materials and energy potential cannot be fully exhausted
Efficiency of Coal Gasification 5
- exploration, development and exploitation of the deposits requires energy
- the processing of primary forms of energy into its secondary form, as well as
its transportation and delivery to consumers requires energy.
It should be remembered that the rate of capital investment and present operational
costs is, to a certain extent, proportionate to energy consumption.
A relevant indicator for this relationship is the ratio between the energy extracted
from a given deposit in a given time, i.e. one year and supplied to the consumer,
and the amount of energy used for the development and exploitation of the deposit
also in a year. The ratio for comparable conditions is:
- for gas deposits 1.0-2.2 (with secondary/tertiary methods)
- for oil deposits 2.0-4.0 (without refining and with
secondary/tertiary methods)
1.7-3.2 (with refining and secondary/
tertiary methods)
- for hard coal 4.6-1.5 (with conversion into gas and
liquid fuels)
With the present price systems, if the ratio is below 1.0, there is no hope of a
satisfactory return on capital and of adequate economic viability. However, an
examination of coal conversion technologies shows that the concentration of energy
supply industries in large installations can contribute to the reduction, by half,
of conversion losses (amounting to 40 per cent). At the same time, it can bring
the above ratio to a figure higher than 1.0. In the long run, the ratio of energy
extracted from the deposit during the whole exploitation period, to the energy
consumed in the development and exploitation of the deposit is very important.
The ratios are as follows:
- for gas deposits from 6-14
- for oil deposits from 3-20
- for coal deposits from 30-60 (without conversion)
from 20-24 (with conversion).
Taking into account the typical energy and raw materials balance for our country,
as well as the demands of the growing national economy, we prefer solutions result-
ing in high ratios. In view of the geological conditions in our country, such
solutions are possible only for hard coal, assuming its comprehensive conversion at
some later stage. Indeed, the magnitude and potential of energy contained in our
coal deposits is extraordinary.
If compared with the deposits of the various forms of fossil energy (gas, oil,
coal), the present structure of market prices appears abnormal. This situation
reflects the extremely advantageous conditions of oil and gas exploitation, as well
as the effect of protectionist measures adopted in a number of countries. The
recently observed scope of price adaptations for gas, oil and coal on the inter-
national market confirms this conclusion.
Whatever the results of our analysis concerning the net energy requirements of
supplying energy or chemical feedstocks to the end-user may have been: I should
like to make it clear once more that we do not believe that in the near future coal
could be taken as an all-purpose primary form of energy to displace other fuels.
The analysis refers to conditions in countries having easily workable coal deposits
and has been elaborated on the basis of United States and Polish conditions. It is
probable that the conclusions drawn from it can also be adopted by other countries
with a similar coal structure. After all, technical progress which is being
6 Wlodzimierz Lejczak
developed in research centres all over the world may bring many changes improving
the value of coal. Here, I have in mind, inter alia, the great progress achieved
recently in the field of fluidized bed combustion of coal. It can be said now
that due to the development of boilers for fluidized combustion (although, at
present their capacity is still small or medium), the problem is being solved
successfully on an industrial scale, particularly in the United Kingdom where the
combustion of the lowest quality coals, and even of coal waste, is possible.
In Poland, too, we have built boilers for fluidized combustion at the Siemianowice
and Jowisz collieries. The successful mastering of the next step, i.e. the
construction of modular hearths under pressure, will allow the introduction of
fluidized combustion in high capacity plants.
We all know that the development of coal conversion is a problem demanding high
financial expenditure and great human effort. In these circumstances, growing
importance is being attached to various forms of international co-operation, from
the exchange of information, to jointly organized scientific meetings and precise
division of work in research activities and industrial realization. I should like,
here, to express my gratitude to the ECE secretariat which, many times, has under-
taken efforts towards expanding international co-operation in this field.
The symposium about to begin is the second on this subject, the first being
organized in the Federal Republic of Germany in January 1976 under the auspices of
the ECE.
I believe that the impetus of holding symposia on coal gasification and liquefaction
will carry benefit for all participants. I also wish to say that the Government of
the Polish People's Republic will give high priority to international co-operation.
We recently proposed the establishment, by interested countries, of an international
Co-ordinating Centre for co-operation in the development of coal conversion. From
experience gained we are convinced that such activities on an international scale
brings substantial advantages. For example, the CMEA Co-ordinating Centre for New
Methods of Coal Utilization expedites coal conversion programmes undertaken by
research institutes in the Soviet Union, German Democratic Republic, Czechoslovakia,
Poland, Romania, Hungary and Mongolia.
Last December, Poland concluded an agreement with the United Nations Development
Programme (UNDP) on the production of low-sulphur fuels from coal. Provision is
made for training, specially of personnel from developing countries, in Poland.
These examples of multilateral international co-operation do not cover the whole
of the problem. An undeniably important form of bilateral co-operation is also
undertaken not only at the government level, but also between commercial firms.
To sum up, it can be claimed that already now coal conversion methods have reached
a high degree of efficiency. They can meet a number of commercial purposes. The
situation with regard to energy, chemical feedstocks and nuclear energy has
prompted wide-scale research to find more efficient coal conversion methods. One
can expect soon that new technologies will bring a reduction of capital expenditures
and an improvement in efficiency.
I hope that the present symposium which has brought together a great number of very
competent participants from all over the world will allow an in-depth review of
actual achievements in coal conversion, and shed light on its anticipated future
role.