Method for the manufacture of a low water content gasified fuel from raw fuels

The present invention provides a method for manufacturing a gasified fuel. The fuel is gasified by partial oxidation of a fuel layer obtained from a raw fuel which contains water and has decreased viscosity. The fuel layer is subjected to partial oxidation by being exposed to oxygen, producing a gasified fuel having a low water content. The separation of the raw fuel into a water layer and a fuel layer can be accelerated by adding an emulsion breaker to the raw fuel or by applying an electric field.

FIELD OF THE INVENTION 
The present invention relates to a method for manufacturing gasified fuel 
from raw fuel, and more specifically, to a method of manufacturing a low 
water content gasified fuel from a raw fuel which contains water. Also, 
the present invention relates to a method and apparatus for heat recovery 
in manufacturing gasified fuel, and more specifically, a process wherein a 
gasified fuel is cooled to a temperature below the temperature at which 
water vapor condenses, and sulfur compounds are absorbed and separated 
from the cooled gas by an absorbent. 
BACKGROUND OF THE INVENTION 
Conventionally, a method has been used in which a raw fuel such as coal, 
heavy oil, and OLIMULSION.TM. is partially oxidized into a gasified fuel. 
The gasified fuel is used as the fuel for gas turbines, etc. In recent 
years, various new fuels have been used as raw fuels. 
For example, a technology for utilizing a natural tar called Olinoco tar as 
a fuel has been developed. Olinoco tar, which is obtained at the basin of 
the River Olinoco in Venezuela, South America, has a high viscosity in its 
normal state. Despite this high viscosity, Olinoco tar has a sufficient 
heating value, exhibiting properties of super-heavy oil. As shown in FIG. 
2, Olinoco tar can be classified according to specific gravity (unit in 
the oil industry: API Baume degree); the lower the specific gravity, the 
higher the viscosity (kinematic viscosity). Therefore, Olinoco tar has the 
common characteristic in that its viscosity decreases with an increase in 
its temperature, though different specific gravity gives different 
temperature-viscosity characteristics. 
Because Olinoco tar has such a high specific gravity at low temperatures, 
special methods are used for extraction and transportation of the tar. For 
the extraction, water is poured in Olinoco tar, and water and a surface 
active agent are added for getting an emulsion with a decrease in the high 
viscosity of the natural tar, which enables pumping-up and transportation 
of the emulsion by pipeline, etc. An emulsion obtained by adding water 
(about 30%) and a surface active agent to natural Olinoco tar (about 70%) 
has been commercialized as OLIMULSION.TM. (registered trade name of 
Bitumens Olinoco S.A.). 
However, when a raw fuel is gasified and used as a gasified fuel, the 
gasification of the fuel is carried out at a high temperature of several 
hundred degrees centigrade. Therefore, when the raw fuel contains large 
quantities of water or it has water added to it prior or during 
gasification, the quantity of heat required for gasification is greatly 
increased, as a greater amount of heat is used to for heating or 
evaporating a large amount of water during gasification. Furthermore, when 
excess water is present in the fuel to be gasified, the size of the 
facility required to process the fuel into a gasified fuel increases. 
Additionally, the presence of excess water in the fuel to be gasified can 
lead to corrosion of the facility used, due to the generation of corrosive 
materials such as hydrogen chloride gas, which dissolve in condensed 
water. 
Previously, natural Olinoco tar has been used as an emulsion when used as a 
fuel, such that the emulsion contains about 30% water. When this emulsion 
is then gasified in the presence of oxygen, the resulting gasified fuel 
contains about 14% water. Therefore, when this gas is cooled in order to 
remove impurities in the gas such as hydrogen sulfide, water is condensed 
and lost, resulting in a large heat loss. Moreover, since large quantities 
of water are contained in the gasified gas, sulfur content cannot be 
removed sufficiently by the dry gas refining method which utilizes iron 
oxide, etc. 
Furthermore, when a raw fuel has a high water content, or has water added 
prior to gasification, the resultant gasified fuel has a high temperature 
above several hundred degrees centigrade and contains a large quantity of 
water vapor and sulfur compounds such as hydrogen sulfide. When 
desulfurization is carried out by bringing the gasified fuel into contact 
with an absorbent which is typically an amine, the gasified fuel must be 
cooled to a temperature close to ambient temperature to enhance the 
absorbing efficiency so that acidic gases such as hydrogen sulfide and 
carbon dioxide are absorbed. For this reason, high-temperature gasified 
fuel is cooled by using cooling water by means of a heat exchanger, and 
therefore the heat of condensation generated when water vapor turns to 
liquid water is lost. 
SUMMARY OF THE INVENTION 
An object of the present invention is to provide a method for manufacturing 
gasified fuel, in which a raw fuel which contains water and has decreased 
viscosity can be gasified, such that water is removed from the raw fuel 
prior to gasification, such that a gasified fuel having a low water 
content can be produced. 
Another object of the present invention is to provide a method and 
apparatus for heat recovery in manufacturing gasified fuel, in which the 
heat of condensation of water vapor dissipated in cooling a 
high-temperature gasified fuel can be recovered and restored to the 
gasified fuel.

DETAILED DESCRIPTION 
The inventors earnestly studied the methods for manufacturing gasified fuel 
from a raw fuel containing water, such that the raw fuel had a decreased 
viscosity over its natural state. As the result of the study, the 
inventors found that a raw fuel which contains water and has decreased 
viscosity can be separated into a water layer and a fuel layer. It was 
further found that the fuel layer obtained by this separation could be 
partially oxidized by oxygen to produce a gasified fuel, by which the 
aforementioned problems can be solved, to arrive at the present invention. 
The present invention provides a method for manufacturing a gasified fuel. 
This gasified fuel is made by partial oxidation of a portion of a raw 
fuel. The raw fuel, which has a decreased viscosity and contains water, is 
separated into a fuel layer and a water layer. The fuel layer is separated 
from the water layer, and the fuel layer is heated in the presence of 
oxygen to produce a gasified fuel having a low water content. 
In the present invention, a raw fuel which contains water and has decreased 
viscosity (hereinafter referred simply to as a raw fuel) means a fuel in 
which a fuel such as crude oil, heavy oil, super-heavy oil, and oil sand 
is made into a water emulsion. The resulting emulsion has viscosity of a 
degree such that the raw fuel can be transported by a pump or burned by a 
burner. That is, the viscosity of this raw fuel at ambient temperature is 
50 to 100 centipoises. 
For example, OLIMULSION.TM. is a reduced viscosity raw fuel which is 
produced by pouring water into Olinoco tar, and then by adding water and a 
surface active agent. OLIMULSION.TM. contains about 70% Olinoco tar and 
about 30% water, and its viscosity is 50 to 100 centipoises at ambient 
temperature. 
However, the viscosity of fuel such as Olinoco tar is as shown in FIG. 2, 
and the fuel exhibits sufficient flowability at temperatures above 
100.degree. C., preferably above 120.degree. C. to allow its transport and 
use. Even after water is separated from the raw fuel, the fuel layer has 
flowability of a degree such that it can be transported by a pump, or a 
gasified fuel can be obtained by partially oxidizing it by a burner. 
Separation of water from a raw fuel is effected by heating the raw fuel to 
a temperature above 150.degree. C., preferably at 150.degree. C. to 
180.degree. C., to separate the raw fuel into a water layer and a fuel 
layer. The layers are separated by effecting liquid-liquid separation by 
using the difference in specific gravity in the layers after being allowed 
to stand. Heating is effected in a pressurized state to prevent water from 
boiling. 
Olinoco tar has different characteristics depending on its type as shown in 
FIG. 1 (classify according API Baume degree), but it is common in that the 
specific gravity (here, ordinary specific gravity) decreases significantly 
with an increase in temperature. Since the specific gravity of water does 
vary greatly with changes in temperature, the difference in specific 
gravity between Olinoco tar and water increases when the temperature of 
Olinoco tar increases, so that the separation becomes easy. This is 
clearly shown in FIG. 1 which illustrates that various Olinoco tars have 
specific gravities of about 0.970 in 100.degree. C. 
When a raw fuel is heated, the separation of the raw fuel into a fuel layer 
and a water layer can be accelerated by adding an emulsion breaker. The 
emulsion breaker used is dependent on the type of surface active agent 
used in the raw fuel. The surface active agent in the raw fuel may be a 
cation or anion type surface active agent, and the reverse ion type is 
used as the emulsion breaker, If a nonionic surface active agent is used 
in the raw fuel, a compound to which alcohol, ether, fatty acid ester, 
ethylene glycols, silicone oil, etc. is added is used as the emulsion 
breaker. 
The separation of the raw fuel into a water layer and a fuel layer is 
accelerated by applying an electric field to the heated raw fuel. The 
electric field can be applied in a settling vessel such as a dehydrator. 
The dehydrator, which is, for example, of an electrostatic type, has many 
electrodes in a drum-shaped vessel and separates the raw fuel emulsion 
into a fuel layer and a water layer by applying an electric field by a DC 
or AC voltage between these electrodes and the drum body. The principle of 
acceleration of water separation due to application of electric field is 
that the water molecule has a dipole, and when an electric field is 
applied to this dipole, the water molecules are arranged readily, so that 
they are aggregated easily. Thereby, the emulsion state is destroyed, by 
which the separation of the raw fuel into a fuel layer comprising Olinoco 
tar and a water layer comprising water is effected. 
As described above, the separation of water can be effected by heating 
only, by the combination of heating and an emulsion breaker, by the 
combination of heating and application of electric field, or by the 
combination of heating, an emulsion breaker, and application of electric 
field. 
By the aforementioned separation of water, the water content in the fuel 
layer can be decreased usually to a value below 3%, preferably to 1.0 to 
1.5%. 
The gasified fuel is a gaseous fuel obtained by partially oxidizing various 
raw fuels in a reducing atmosphere by using oxygen (in this specification, 
the term "oxygen" is defined as an oxygen-containing gas such as air) in a 
gasifying device. The gasified fuel contains hydrogen and carbon monoxide 
as main components and also contains carbon dioxide, water, nitrogen, 
sulfur compounds such as hydrogen sulfide and carbonyl sulfide, or 
ammonia, hydrogen chloride, etc. and further sometimes contains soot and 
dust. 
In the present invention, the raw fuel is separated into a water layer and 
a fuel layer at the stage just before gasification, liquid-liquid 
separation is effected to produce the layers, and only the fuel layer is 
gasified. The stage just before gasification means that the fuel layer 
from which water is substantially separated is used immediately in the 
next partial oxidation process. A strainer, a heat exchanger, etc., and an 
agitator, etc., may be interposed between the process in which separation 
into a water layer and a fuel layer is effected, and the partial oxidation 
process. 
The gasified fuel obtained by partial oxidation may be pressurized, be 
under ordinary pressure, or be decompressed, but it is obtained usually in 
a pressurized state of several atmospheres to several tens of atmospheres, 
and it contains water of about 2 to 5 vol %. 
In the above-described configuration, wherein the fuel is heated to a high 
temperature just before the gasification system, water is removed by, for 
example, a dehydrator. Therefore, the viscosity of the fuel layer is 
sufficiently low even with the removal of water, so that smooth supply of 
the fuel layer to the gasification system is possible. 
According to the present invention, even a fuel to which water is added to 
decrease the viscosity can be partially oxidized after water is separated. 
Therefore, the water content in the gasified fuel is reduced 
significantly, and the size of the facility required after the partial 
oxidation reactor can be greatly decreased. 
Also, the inventors discovered that when a high-temperature gasified fuel 
is cooled by a saturator to a temperature below the temperature at which 
water vapor condenses, and water is poured in the desulfurized gasified 
fuel and such fuel is heated by the saturator, the heat of condensation of 
water vapor dissipated in cooling is efficiently recovered by the 
desulfurized gasified fuel. 
A first mode of the present invention provides a heat recovery method in 
manufacturing gasified fuel, characterized in that a gasified fuel 
containing water vapor and sulfur compounds, which is obtained by 
partially oxidizing fuel by using oxygen, is cooled by a saturator to a 
temperature below the temperature at which water vapor condenses, the 
cooled gasified fuel is brought into contact with an absorbent and the 
sulfur compounds are absorbed and separated to obtain a desulfurized 
gasified fuel, and then water is added to the desulfurized gasified fuel 
and the fuel is heated by the saturator. 
A second mode of the present invention provides a heat recovery apparatus 
which comprises a saturator for cooling a gasified fuel containing water 
vapor and sulfur compounds, which is obtained by partially oxidizing fuel 
by using oxygen, by a saturator to a temperature below the temperature at 
which water vapor condenses, a desulfurizing device for bringing the 
cooled gasified fuel into contact with an absorbent to absorb and separate 
the sulfur compounds, and a cooling device before desulfurization in which 
water is added to the desulfurized gasified fuel after the desulfurized 
gasified fuel is obtained, and in which water is added to the desulfurized 
gasified fuel and the fuel is heated by the saturator. 
FIG. 3 is a schematic view of a heat recovery apparatus in accordance with 
the present invention. In FIG. 3, reference numeral 1 denotes a raw fuel 
gasifying device. To this raw fuel gasifying device are connected a dust 
removing device 2, a heat exchanger 3 before reduction of carbonyl 
sulfide, a carbonyl sulfide reducing device 4, a saturator 5, a cooling 
device 6 before desulfurization, and a desulfurizing device 7 in sequence. 
A gas turbine 8 is connected to the heat exchanger 3 before reduction of 
carbonyl sulfide. The desulfurizing device 7 is also connected to the 
saturator 5. The cooling water from the cooling device 6 before 
desulfurization is supplied to the top of the saturator 5 by a pump 9. 
Reference numeral 11 denotes exhaust gas discharged from the gas turbine 
8, 12 denotes a sulfur compound absorbent supplied to the desulfurizing 
device 7, 13 denotes gas such as hydrogen sulfide and carbon dioxide 
discharged from the desulfurizing device 7, and 14 denote cooling water. 
In the present invention, the gasified fuel is a gaseous fuel obtained by 
partially oxidizing a raw fuel such as crude oil, heavy oil, coal, 
OLIMULSION.TM., oil sand, and oil slurry in a reducing atmosphere by using 
air or oxygen (hereinafter both are called oxygen) in the raw fuel 
gasifying device 1. The gasified fuel contains hydrogen, carbon monoxide, 
carbon dioxide, water, nitrogen, sulfur compounds such as hydrogen sulfide 
and carbonyl sulfide, or ammonia, hydrogen chloride, etc. and sometimes 
contains oxygen and further sometimes contains soot and dust. 
The gasified fuel obtained by partial oxidation has a high temperature of 
several hundred degrees centigrade, and may be pressurized, may be under 
ordinary pressure, or may be decompressed. Usually, it is obtained in a 
pressurized state of several atmospheres to several tens of atmospheres, 
and it contains water of about 2 to 20 vol %. Therefore, the temperature 
at which water vapor condenses is determined by water content and 
pressure. 
The saturator 5 used in the present invention can heat-exchanging (A) 
high-temperature side fluid containing water vapor and (B) low-temperature 
side fluid containing water by a heat transfer wall in terms of sensible 
heat and latent heat, and the heat of condensation of water vapor in (A) 
is converted into the heat of evaporation of water in (B). Then, by using 
the desulfurized gasified fuel as the low-temperature side fluid, energy 
is concentrated to one gasified fuel, so that the gasified fuel can 
efficiently be used for the gas turbine, etc. 
The type of the saturator 5 includes, for example, a tube type heat 
exchanger separated into a shell side and a tube side, which may be of 
single tube type or multiple tube type. A high-temperature gas is made to 
pass on the shell side, and a low-temperature gas and water are poured on 
the tube side, by which evaporation may be accelerated by boiling heat 
transfer, or the reverse case may be possible. 
The condensed water produced when the gasified fuel is cooled in the 
cooling device 6 before desulfurization or the water from the outside may 
be used for the saturator, by which the energy concentration to the 
gasified fuel can be increased. FIG. 3 shows an example in which the 
condensed water is used. In this case, make-up water 25 may be supplied if 
necessary, if the amount of water produced from the condensation is 
insufficient. 
When a corrosive matter is contained in the gas before desulfurization, 
condensed water is produced containing such corrosive substances. 
Therefore, the materials used to make the devices after the saturator 5 
are selected by considering corrosion factors. These materials may be 
carbon steel, molybdenum steel, chrome-molybdenum steel, austenitic 
stainless steel, ferritic stainless steel, nickel alloys, etc. 
When the gasified fuel obtained by partial oxidation contains soot and 
dust, it is preferable that soot and dust be removed by using the dust 
removing device 2, which may be, for example, a cyclone, electric dust 
collector, and filter. Thereby the levels of soot and dust of several ten 
thousand ppm can be decreased to several ppm. 
When the dust-removed gasified fuel contains carbonyl sulfide, it is cooled 
to a suitable temperature by the heat exchanger 3 before reduction of 
carbonyl sulfide. In this case, cooling can preferably be effected by the 
desulfurized gasified fuel which has passed the saturator. 
When the gasified fuel contains carbonyl sulfide, it is reduced to hydrogen 
sulfide in advance in the presence of catalyst in the carbonyl sulfide 
reducing device 4, by which sulfur compounds are removed in the subsequent 
desulfurizing process. As the catalyst, for example, alumina series 
catalyst is used. 
The gasified fuel, in which dust is removed and carbonyl sulfide is reduced 
to hydrogen sulfide as described above, still has a high temperature of 
200 to 400.degree. C., and also has much sensible heat and latent heat due 
to water. Therefore, heat exchanging is performed by contacting the 
desulfurized gasified fuel with the saturator 5. 
The gasified fuel-condensed water mixture after heat exchanging in the 
saturator 5 is further cooled to a temperature suitable for the 
desulfurizing process, for example, 60.degree. C. to 30.degree. C., by 
bringing it into contact with a cooled medium in the cooling device 6 
before desulfurization if necessary. The cooling of the medium in the 
cooling device 6 before desulfurization may be effected by heat exchanging 
with cooling water, or can be effected by a liquid absorbing sulfur 
compounds. For example, the heat exchange is effected by making an 
absorbent flow on the shell side or the tube side and making the gasified 
fuel-condensed water mixture pass on the tube or shell side. Thereby, the 
heat of the gasified fuel-condensed water mixture after being heat 
exchanged in the saturator can be turned into heating energy when the 
absorbent absorbing sulfur compounds is regenerated. The cooling may be 
effected at one stage, or can be effected in multiple stages. 
The gasified fuel-condensed water mixture cooled to a temperature suitable 
for the desulfurizing process comes in contact with the absorbent in the 
desulfurizing device 7, by which sulfur compounds such as hydrogen sulfide 
are absorbed and removed. As the absorbent, for example, amine series 
absorbent can be used. The amine series absorbent is water soluble, and 
may contain water. 
The absorbent sulfur compounds are regenerated by discharging acidic gases 
such as hydrogen sulfide and carbon dioxide by heating, decompression, 
etc. 
The desulfurized gasified fuel after being heat exchanged in the saturator, 
or the desulfurized gasified fuel after being heat exchanged with the 
gasified fuel after dust is further removed, is used as a fuel for the gas 
turbine 8, a fuel cell, etc., after small amounts of sulfur compounds and 
gases such as hydrogen chloride are further removed as necessary. 
The present invention can be carried out in a batch mode, semi-batch mode, 
or continuous mode. 
As described above, according to the present invention, the heat of 
condensation dissipated when a gasified fuel containing large quantities 
of water is cooled to a temperature necessary for the desulfurizing 
process can be recovered efficiently. 
The method of the present invention will be explained specifically by a 
description of the following working examples. 
EXAMPLE 1 
An example using OLIMULSION.TM. is described. OLIMULSION.TM. (water content 
29%) was liquidized by mixing natural Olinoco tar (70%) with water (30%) 
containing small amounts of sulfonic acid type surface active agent, and 
was stored in a tank. The temperature of the OLIMULSION.TM. in the tank 
was 20.degree. C. to 30.degree. C., which is close to the ambient 
temperature. This OLIMULSION.TM. was pressurized to about 20 kg/cm.sup.2 
by a pump, and supplied to a heat exchanger. The heat source for the heat 
exchanger was high-temperature water removed by a later-described 
dehydrator, being heated to 50.degree. C. to 60.degree. C. The 
OLIMULSION.TM. was further heated to 150.degree. C., and the heated 
OLIMULSION.TM. was supplied to the dehydrator and allowed to stand, and 
then it was separated into a fuel layer at the upper layer and a water 
layer at the lower layer. This was liquid-liquid separated to obtain a 
fuel layer containing about 2.0% water content. This fuel layer was 
further heated and partially oxidized by using a partial oxidation 
reactor. Thus, a gasified fuel containing hydrogen and carbon monoxide as 
main components and containing hydrocarbon, water, hydrogen sulfide, etc. 
was obtained. 
Alternatively, the separated water was supplied to the heat exchanger as 
described above, treated after heat exchange, and discharged to the 
outside of the system. 
EXAMPLE 2 
A cation type emulsion breaker of an amount exceeding the equivalent amount 
of surface active agent was added to the OLIMULSION.TM. used in Example 1, 
and the OLIMULSION.TM. was heated to 50.degree. C. and agitated. It was 
further heated to 150.degree. C. and supplied to the dehydrator, where it 
was allowed to stand, and then separated into a water layer and a fuel 
layer. The fuel layer was made to overflow and then supplied to the 
partial oxidation reactor. The water content in the fuel layer was about 
1.8%. 
EXAMPLE 3 
A cation type emulsion breaker of an amount exceeding the equivalent amount 
of surface active agent was added to the OLIMULSION.TM. used in Example 1, 
and the OLIMULSION.TM. was heated to 50.degree. C. and agitated. It was 
further heated to 120.degree. C. in an extracting vessel and agitated by 
adding heavy oil. After the separation into a water layer and a fuel layer 
was accelerated, the OLIMULSION.TM. was supplied into a precipitate 
separating tank. After the supernatant fuel layer was made to overflow, it 
was supplied into the partial oxidation reactor. The water content in the 
fuel layer was about 1.6%. 
EXAMPLE 4 
The dehydrator used in Example 2 was changed to an electrostatic type 
having many electrodes in a drum-shaped vessel. A 200 V DC voltage was 
applied between these electrodes and the drum body of the vessel in order 
to accelerate separation by applying an electric field. The overflowing 
fuel layer contained a water content of 1.5%. The fuel layer was further 
heated to 150.degree. C. and supplied into the partial oxidation reactor 
for partial oxidation, by which a gasified fuel containing hydrogen and 
carbon monoxide as main components and containing hydrocarbon, water and 
gases containing hydrogen sulfide etc. was obtained. 
Table 1 gives the composition and higher heating value (wet) before 
gasification of raw OLIMULSION.TM. and dehydrated OLIMULSION.TM. obtained 
by separating water from raw OLIMULSION.TM.. Table 2 gives the gas 
composition and higher and lower heating values (wet) of the fuel gases 
obtained by gasifying these materials. 
TABLE 1 
______________________________________ 
Dehydrated 
Composition wt % 
OLIMULSION.sup..TM. 
OLIMULSION.sup..TM. 
______________________________________ 
Carbon 59.83 83.06 
Hydrogen 10.38 
Oxygen 0.28 
Nitrogen 0.69 
Sulfur 3.74 
Ash 0.35 
Water 1.50 
Total 100.0 
Higher heating 7113 
9875 
value HHV (kcal/kg) 
______________________________________ 
TABLE 2 
______________________________________ 
Dehydrated 
Gas composition 
OLIMULSION.sup..TM. 
OLIMULSION.sup..TM. 
______________________________________ 
vol % Gasified fuel 
gasified fuel 
______________________________________ 
Hydrogen 36.404 38.407 
Oxygen 0.000 
Nitrogen & ammonia 
0.729 
0.856 
Water 3.064 
Cabonmonoxide 55.014 
Carbon dioxide 0.820 
Argon 0.894 
Methane 0.002 
Hydrogen sulfide 
0.683 
0.803 
Carbonyl sulfide 
0.120 
0.140 
Sulfur dioxide 0.000 
Total 100.00 
Specific weight 
0.8054 
(kg/Nm.sup.3) 
Higher heating 2887 
value HHV(kcal/kg) 
Lower heating 2286 2703 
value LHV (kcal/kg) 
______________________________________ 
As seen from this result, the gasified fuel obtained from dehydrated 
OLIMULSION.TM. has a low water content and a high heating value. 
EXAMPLE 5 
In the following Example, the invention was carried out by using the 
aforementioned heat recovery apparatus shown in FIG. 3. 
OLIMULSION.TM. containing 29% water was used as a raw fuel. The following 
Tables 3 and 4 give the composition, temperature, etc. of gasified fuel 
obtained by partial oxidation using oxygen. 
TABLE 3 
______________________________________ 
Fluid 
15 16 17 18 19 
Temperature .degree. C. 
450 450 300 300 
70 
Pressure atm 
Composition 
26.0 25.5 25.3 25.0 24.8 
______________________________________ 
H.sub.2 (vol %) 
37.0 37.0 37.0 37.0 42.3 
CO 43.4 43.443.4 
43.4 
49.7. 
CO.sub.2 4.4 4.4 
4.4 
5.0 
H.sub.2 O 13.7 13.7 
13.7 
13.7 
1.3 
H.sub.2 S 0.7 0.7 
0.7 
0.8 
0.9 
COS 0.1 0.10.1 
5 ppm 
5 ppm 
N.sub.2 0.7 0.7 
0.7 
0.8 
O.sub.2 0.0 0.0 
0.0 
0.0 
Total (vol %) 
1000 100.0 
100.0 
100.0 
______________________________________ 
TABLE 4 
______________________________________ 
Fluid 
20 21 22 23 24 
Temperature .degree. C. 
40 40 240 390 
40 
Pressure atm 
Composition 
24.6 24.0 23.8 23.6 24.0 
______________________________________ 
H.sub.2 (vol %) 
42.0 
43.1 37.9 37.9 37.9 
CO 50.7 44.4 50.2 
44.4 
44.4 
CO.sub.2 5.1 4.5 4.5 5.1 
4.5 
H.sub.2 O 0.3 12.4 0.3 
12.4 
12.4 
H.sub.2 S 15 ppm 0.9 
15 ppm 
15 ppm 
15 ppm 
COS 5 ppm 5 ppm 5 ppm 
5 ppm 
5 ppm 
N.sub.2 0.8 0.7 0.7 0.8 
0.7 
O.sub.2 0.1 0.1 0.1 0.0 
0.1 
Total (vol %) 
100 100.0 100 
100.0 
100.0 
______________________________________ 
As shown in FIG. 3, the heat recovery apparatus in accordance with this 
embodiment comprises a raw fuel gasifying device 1, a dust removing device 
2 connected sequentially to the raw fuel gasifying device 1, a heat 
exchanger 3 before reduction of carbonyl sulfide, a carbonyl sulfide 
reducing device 4, a saturator 5, a cooling device 6 before 
desulfurization, a desulfurizing device 7, and a gas turbine 8 connected 
to the heat exchanger 3 before reduction of carbonyl sulfide, and is 
configured so that the desulfurizing device 7 is connected to the 
saturator 5 and cooling water from the cooling device 6 before 
desulfurization is supplied to the top of the saturator 5 by a pump 9. 
Reference numerals 15 to 24 in FIG. 3 denote fluids having a composition 
given in Tables 3 and 4. Accordingly, by the heat exchange in the 
saturator 5, the gasified fuel 18 (300.degree. C., water content 13.7 vol 
%) before desulfurization is heat-recovered as the desulfurized gasified 
fuel 22 (240.degree. C., water content 12.4 vol %) in spite of 
desulfurizing operation at a low temperature. 
The above description of the present invention has been an explanation of 
embodiments in the case of OLIMULSION.TM., but the present invention is 
not limited to the case of OLIMULSION.TM.. The present invention can, 
needless to say, be applied to all liquid fuels from super-heavy oil which 
must be made into a flowable liquid by adding water because it generally 
has high viscosity. The above description has been given regarding 
super-heavy oil of an API Baume degree below 10, but the raw fuel in the 
present invention includes one with an API Baume degree of 10 to 20, which 
is called a heavy oil.