Abstract:
A process to prepare a sweet crude from an ash containing and heavy fraction of a tar sand oil by:
   (a) supplying an atmospheric distillation bottoms of a tar sands originated feed to a vacuum distillation to obtain a vacuum gas oil and a vacuum bottoms,   (b) contacting the vacuum gas oil with hydrogen in the presence of a suitable hydrocracking catalyst to obtain a sweet synthetic crude   (c) separating the vacuum bottoms obtained in step (a) into an asphalt fraction comprising between 0.1 and 4 wt % ash and a de-asphalted oil,   (d) feeding said asphalt fraction to a burner of a gasification reactor where the asphalt fraction is partially oxidized in the presence of an oxidizer gas in a burner to obtain a mixture of hydrogen and carbon monoxide,   (e) performing a water gas shift reaction on the mixture of hydrogen and carbon monoxide,   (f) separating hydrogen sulphide and carbon dioxide from the shifted gas in an acid removal unit thereby obtaining crude hydrogen,   (g) purifying the crude hydrogen to obtain pure hydrogen and   (h) using part of the pure hydrogen in step (b), wherein in step (d) the asphalt fraction is provided to the burner in a liquid state and wherein in case separation step (c) fails to provide sufficient feed for step (d), step (d) is performed by feeding the vacuum bottoms of step (a) to the burner in a liquid state.

Description:
[0001]    This application claims the benefit of U.S. Provisional Application No. 60/868,678 filed Dec. 5, 2006 and European Application No. 06125232.6 filed Dec. 1, 2006, both of which are incorporated by reference. 
     
    
     BACKGROUND 
       [0002]    The present invention is directed to a process to prepare a sweet crude from an ash containing and heavy fraction of a tar sand oil. 
         [0003]    Such a process is described in U.S. Pat. No. 6,702,936. 
         [0004]    In this process various distillate fractions of a tar sands feed are subjected to a hydroprocessing step to obtain a sweet synthetic crude. From a vacuum residue fraction of the tar sands feed an asphalt fraction is isolated and fed to a gasification unit to obtain a mixture of carbon monoxide and hydrogen. From this mixture substantially pure hydrogen is recovered and used in the hydroprocessing unit. 
         [0005]    A disadvantage of this process is that it is sensitive for process failure. For example the hydroprocessing unit requires a very high availability of hydrogen. On the other hand it is known that gasification units and de-asphalting units do not have the high reliability to ensure a high hydrogen availability. 
         [0006]    The present invention provides a solution to the above problem. 
       SUMMARY OF THE INVENTION 
       [0007]    The present invention provides a process to prepare a sweet crude from an ash containing and heavy fraction of a tar sand oil by: 
         [0000]    (a) supplying an atmospheric distillation bottoms of a tar sands originated feed to a vacuum distillation to obtain a vacuum gas oil and a vacuum bottoms,
 
(b) contacting the vacuum gas oil with hydrogen in the presence of a suitable hydrocracking catalyst to obtain a sweet synthetic crude
 
(c) separating the vacuum bottoms obtained in step (a) into an asphalt fraction comprising between 0.1 and 4 wt % ash and a de-asphalted oil,
 
(d) feeding said asphalt fraction to a burner of a gasification reactor where the asphalt fraction is partially oxidized in the presence of an oxidizer gas in a burner to obtain a mixture of hydrogen and carbon monoxide,
 
(e) performing a water gas shift reaction on the mixture of hydrogen and carbon monoxide,
 
(f) separating hydrogen sulphide and carbon dioxide from the shifted gas in an acid removal unit thereby obtaining crude hydrogen,
 
(g) purifying the crude hydrogen to obtain pure hydrogen and
 
(h) using part of the pure hydrogen in step (b), wherein in step (d) the asphalt fraction is provided to the burner in a liquid state and wherein in case separation step (c) fails to provide sufficient feed for step (d), step (d) is performed by feeding the vacuum bottoms of step (a) to the burner in a liquid state.
 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]      FIG. 1  is a cross-sectional view of a reactor vessel according to an embodiment of the invention. 
           [0009]      FIG. 2  is a cross-sectional view taken along the line A-A′ of  FIG. 1 . 
           [0010]      FIG. 3  is a flow diagram of a process according to the invention. 
           [0011]      FIG. 4  is a flow diagram of a process according to an aspect of the invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0012]    Applicants found that by performing step (d) on a liquid asphalt feed it is possible to quickly change to a liquid vacuum bottoms feed in case the de-asphalting operation fails. If separation step (c) fails to provide sufficient feed for step (d) the hydrogen manufacture is not disturbed because step (d) can then be performed on the vacuum bottoms of step (a). 
         [0013]    In order to further improve the reliability of the hydrogen production it is preferred to perform step (d) in n parallel-operated gasification reactors, wherein n is at least 2, preferably at least 3 and more preferably at least 4. In case one gasification reactor would fail, the hydrogen availability would then only be reduced by at least 33% or 25% in the latter cases. By designing some extra capacity for these gasification reactors one can also avoid any loss in hydrogen production by increasing the production in the remaining reactors in case one of the reactors fails. 
         [0014]    The reliability may be further improved by positioning in parallel a spare gasification reactor in addition to the parallel-operated asphalt fed gasification reactors. In the event of a failure of one of the asphalt fed gasification reactors additional mixtures of hydrogen and carbon monoxide can be provided by partial oxidation of a methane comprising gas in the spare gasification reactor. The use of a methane fed gasification reactor is advantageous because these reactors are not very complicated and because they can advantageously make use of the oxidizer which is at that moment not used in one or more of the asphalt fed reactors. The methane feed is preferably natural gas, coal bed methane or the off-gas as separated from the effluent of hydroprocessing step (b). The gasification process for such methane comprising feeds are for example the “Shell Gasification Process” (SGP) as described in the Oil and Gas Journal, Sep. 6, 1971, pp 85-90. Other publications describing examples of such processes are EP-A-291111, WO-A-9722547, WO-A-9639354 and WO-A-9603345. 
         [0015]    Steps (a), (b), (c), (f), (g) and (h) may be performed as described in for example U.S. Pat. No. 6,702,936, which publication is hereby incorporated by reference. 
         [0016]    The burner in step (d) is preferably a multi-orifice burner provided with an arrangement of separate co-annular passages, wherein the hydrocarbon feed flows through a passage of the burner, an oxidizer gas flows through a separate passage of the burner and wherein the passage for hydrocarbon feed and the passage for oxidizer gas are separated by a passage through which a moderator gas flows and wherein the exit velocity of the moderator gas is greater than the exit velocity of the oxidizer gas. 
         [0017]    Applicants found it advantageous to perform step (d) with said burner in said manner to avoid burner damage. A problem with the gasification of an asphalt fraction originating from a tar sands is that the feed will contain ash and that the feed will be very viscous. The highly viscous feed will require high feed temperatures in order to improve the ability to flow of the feed. In addition the feed may contain next to the ash also solid hydrocarbon agglomerates and lower boiling fractions. The high feed temperatures and/or the presence of lower boiling fractions or solids in the feed could give cause to a short burner life-time because of burner tip damage. By operating step (d) as above it has been found that burner damage can be avoided. 
         [0018]    Without wishing to be bound to the following theory, applicants believe that the more stable and less damaging operation of the burner results by using a moderator gas having a high velocity as a separate medium between oxidizer gas and hydrocarbon feed. The moderator gas will break up the hydrocarbon feed and act as a moderator such that reactions in the recirculation zone at the burner tips are avoided. The result will be that the hydrocarbon droplets will only come in contact with the oxidizer gas at some distance from the burner surface. It is believed that this will result in less burner damage, e.g. burner tip retraction. The invention and its preferred embodiments will be further described below. 
         [0019]    As explained above the relative velocity of the hydrocarbon feed and the moderator gas is relevant for performing the present invention. Preferably the exit velocity of the moderator gas is at least 5 times the velocity of the hydrocarbon feed in order to achieve a sufficient break up of the liquid feed. Preferably the exit velocity of the hydrocarbon feed is between 2 and 40 m/s and more preferably between 2 and 20 m/s. The exit velocity of the moderator gas is preferably between 40 and 200 m/s, more preferably between 40 and 150 m/s. The exit velocity of the oxidizer gas is preferably between 30 and 120 m/s, more preferably between 30 and 70 m/s. The respective velocities are measured or calculated at the outlet of the said respective channels into the gasification zone. 
         [0020]    Oxidizer gas comprises air or (pure) oxygen or a mixture thereof. With pure oxygen is meant oxygen having a purity of between 95 and 100 vol %. The oxidizer gas preferably comprises of a mixture of said pure oxygen and moderator gas. The content of oxygen in such a moderator/oxygen mixture the oxidizer gas is preferably between 10 and 30 wt % at standard conditions. As moderator gas preferably steam, water or carbon dioxide or a combination thereof is used. More preferably steam is used as moderator gas. 
         [0021]    The asphalt feed is liquid when fed to the burner and preferably has a kinematic viscosity at 232° C. of between 300 and 6000 cSt more preferably between 3500 and 5000 cSt, having a bulk density of between 650 and 1200 Kg/m 3 . The ash content is between 0.1 and 4 wt %, especially between 1 and 4 wt %. The ash may comprise silicium, aluminium, iron, nickel, vanadium, titanium, potassium, magnesium and calcium. The feed may comprise halogen compounds, such as chloride. The sulphur content is between 1 and 10 wt %. 
         [0022]    An example of a typical asphalt as obtained in step (c) is provided in Table 1. 
         [0000]    
       
         
               
               
               
               
             
           
               
                   
                 TABLE 1 
               
               
                   
                   
               
             
             
               
                   
                 Specific Density 
                 Kg/m 3   
                 1181 
               
               
                   
                 Bulk Density 
                 Kg/m 3   
                 670 
               
               
                   
                 Chloride 
                 ppmw 
                 10 
               
               
                   
                 Carbon 
                 % w 
                 85.7 
               
               
                   
                 Hydrogen 
                 % w 
                 6.7 
               
               
                   
                 Sulphur 
                 % w 
                 4.4 
               
               
                   
                 Nitrogen 
                 % w 
                 1.6 
               
               
                   
                 Ash 
                 % w 
                 1.3 
               
               
                   
                 Oxygen 
                 % w 
                 0.2 
               
               
                   
                 Ash 
                 % w 
                 1.3 
               
               
                   
                 Viscosity 
               
               
                   
                 @ 330° F. 
                 cP 
                 26700 
               
               
                   
                 @ 410° F. 
                 cP 
                 1340 
               
               
                   
                 @ 232° C. 
                 cSt 
                 4660 
               
               
                   
                   
               
             
          
         
       
     
         [0023]    The multi-orifice burner is provided with an arrangement of separate, preferably co-annular passages. Such burner arrangements are known and for example described in EP-A-545281 or DE-OS-2935754. Usually such burners comprise a number of slits at the burner outlet and hollow wall members with internal cooling fluid (e.g. water) passages. The passages may or may not be converging at the burner outlet. Instead of comprising internal cooling fluid passages, the burner may be provided with a suitable ceramic or refractory lining applied onto or suspended by a means closely adjacent to the outer surface of the burner (front) wall for resisting the heat load during operation or heat-up/shut down situations of the burner. Advantageously, the exit(s) of one or more passages may be retracted or protruded. 
         [0024]    The burner preferably has 4, 5, 6 or 7 passages. In a preferred embodiment the burner has 6 or 7 passages. In an even more preferred embodiment the burner has 7 passages wherein a shielding gas flows through the outer most passage at a velocity of between 5 and 40 m/s. The shielding gas is preferably the same gas as used for the moderator gas. In the embodiment wherein the number of passages are 7, preferably the following streams flow through the below listed passages: 
         [0025]    an oxidizer flows through the inner most passage  1  and passage  2 , 
         [0026]    a moderator gas flows through passage  3 , 
         [0027]    a hydrocarbon feed flows through passage  4 , 
         [0028]    a moderator gas flows through passage  5 , 
         [0029]    an oxidizer flows through passage  6 , and 
         [0030]    a shielding gas flows through outer most passage  7 , preferably at a velocity of between 5 and 40 m/s. 
         [0031]    Alternatively the number of passages is 6 wherein passage  1  and  2  of the above burner are combined or wherein the passage  7  is omitted. 
         [0032]    The process according to the present invention is preferably performed at a syngas product outlet temperature of between 1000 and 1800° C. and more preferably at a temperature between 1300 and 1800° C. The pressure of the mixture of carbon monoxide and hydrogen as prepared is preferably between 0.3 and 12 MPa and preferably between 3 and 8 MPa. The ash components as present in the feed will form a so-called liquid slag at these temperatures. The slag will preferably form a layer on the inner side of the reactor wall, thereby creating an isolation layer. The temperature conditions are so chosen that the slag will create a layer and flow to a lower positioned slag outlet device in the reactor. The slag outlet device is preferably a water bath at the bottom of the gasification reactor to which the slag will flow due to the forces of gravity. 
         [0033]    The temperature of the syngas is preferably reduced by directly contacting the hot gas with liquid water in a so-called quenching step. Preferably the slag water bath and the water quench are combined. A water quench is advantageous because a water-saturated synthesis gas is obtained which can be readily used in the water shift step (e). Furthermore a water quench avoids complicated waste heat boilers, which would complicate the gasification reactor. 
         [0034]    The direct contacting with liquid water is preferably preceded by injecting water into the flow of syngas steam. This water may be fresh water. In a preferred embodiment a solids containing water may partly or wholly replace the fresh water. Preferably the solids containing water is obtained in the water quenching zone as will be described below and/or from the scrubber unit as will be described below. For example the bleed stream of the scrubber unit is used. Use of a solids containing water as here described has the advantage that water treatment steps may be avoided or at least be limited. 
         [0035]    In a preferred embodiment of the present invention the liquid water of the quenching step and the water bath for receiving the slag for is combined. Such combined slag removing means and water quench process steps are known from for example in U.S. Pat. No. 4,880,438, U.S. Pat. No. 4,778,483, U.S. Pat. No. 4,466,808, EP-A-129737, EP-A-127878, U.S. Pat. No. 4,218,423, U.S. Pat. No. 4,444,726, U.S. Pat. No. 4,828,578, EP-A-160424, U.S. Pat. No. 4,705,542, EP-A-168128. 
         [0036]    The temperature of the synthesis gas after the water quench step is preferably between 130 and 330° C. 
         [0037]    The process is preferably performed in a reactor vessel as illustrated in  FIG. 1 . The Figure shows a gasification reactor vessel ( 1 ), provided at its upper end with a downwardly directed multi-orifice burner ( 2 ). Burner ( 2 ) is provided with supply conduits for oxidizer gas ( 3 ), hydrocarbon feed ( 4 ) and moderator gas ( 5 ). The burner ( 2 ) is preferably arranged at the top end of the reactor vessel ( 1 ) pointing with its outlet in a downwardly direction. The vessel ( 1 ) preferably comprises a combustion chamber ( 6 ) in the upper half of the vessel provided with a product gas outlet ( 7 ) at its bottom end and an opening for the outlet of the burner ( 2 ) at its top end. Between the combustion chamber ( 6 ) and the wall of vessel ( 1 ) an annular space ( 9 ) is provided. The wall of the combustion chamber protects the outer wall of vessel ( 1 ) against the high temperatures of the combustion chamber ( 6 ). The combustion chamber ( 6 ) is preferably provided with a refractory lined wall ( 8 ) in order to reduce the heat transfer to the combustion chamber wall. The refractory wall ( 8 ) is preferably provided with means to cool said refractory wall. Preferably such cooling means are conduits ( 10 ) through which water flows. Such conduits may be arranged as a spirally wound design in said tubular formed refractory wall ( 8 ). Preferably the cooling conduits ( 10 ) are arranged as a configuration of parallel-arranged vertical conduits, which may optionally have a common header at their top ( 11 ) and a common distributor at their bottom ( 12 ) for discharging and supplying water respectively from the cooling means. The common header ( 11 ) is fluidly connected to a steam discharge conduit ( 13 ) and the common header ( 12 ) is fluidly connected to a water supply conduit ( 14 ). More preferably the cooling conduits ( 10 ) are interconnected such that they form a gas-tight combustion chamber ( 6 ) within the refractory wall as shown in  FIG. 2 . Such interconnected conduit type walls are also referred to as a membrane wall. 
         [0038]    The cooling by said conduits ( 10 ) may be achieved by just the cooling capacity of the liquid water, wherein heated liquid water is obtained at the water discharge point. Preferably cooling is achieved by also evaporation of the water in the conduits ( 10 ). In such an embodiment the cooling conduits are vertically arranged as shown in  FIG. 1  such that the steam as formed can easily flow to the common header ( 11 ) and to a steam outlet conduit ( 13 ) of the reactor vessel ( 1 ). Evaporation is preferred as a cooling method because the steam may find use in other applications in the process, such as process steam for shift reactions, heating medium for liquid feed or, after external superheating, as moderator gas in the burner according to the process according to the present invention. A more energy efficient process is so obtained. 
         [0039]    The gasification vessel ( 1 ) preferably comprises a vertically aligned and tubular formed outlet part ( 16 ) fluidly connected to the lower end of the combustion chamber ( 6 ), which tubular formed outlet part ( 16 ) is open at its lower end, further referred to as the gas outlet ( 17 ) of the tubular outlet part ( 16 ). The outlet part ( 16 ) is provided at its upper end with means ( 18 ) to add a quenching medium to the, in use, downwardly flowing mixture of hydrogen and carbon monoxide. Preferably the vessel ( 1 ) is further provided at its lower end with a combined water quenching zone ( 19 ) and slag discharge water bath ( 20 ) as described above. The water quenching zone ( 19 ) is present in the pathway of the synthesis gas as it is deflected at outlet ( 17 ) in an upwardly direction (see arrows) to flow upward through, preferably an annular space ( 21 ) formed between an optional tubular shield ( 22 ) and outlet part ( 16 ). In annular space ( 21 ) the synthesis gas will intimately contact the water in a quenching operation mode. The upper end ( 23 ) of the annular space is in open communication with the space ( 24 ) between outlet part ( 16 ) and the wall of vessel ( 1 ). In space ( 24 ) a water level ( 25 ) will be present. Above said water level ( 25 ) one or more synthesis product outlet(s) ( 26 ) are located in the wall of vessel ( 1 ) to discharge the quenched synthesis gas. Between space ( 24 ) and annular space ( 9 ) a separation wall ( 27 ) may optionally be present. 
         [0040]    At the lower end of vessel ( 1 ) a slag discharge opening ( 28 ) is suitably present. Through this discharge opening ( 28 ) slag together with part of the water is charged from the vessel by well known slag discharge means, such as sluice systems as for example described in U.S. Pat. No. 4,852,997 and U.S. Pat. No. 67,559,802. 
         [0041]      FIG. 3  illustrates how the process according to the present invention and the reactor of  FIG. 1  can be applied in the production of pure hydrogen. In this scheme to a gasification reactor  105  an asphalt feed  101 , oxygen  102  and super heated steam  119  from a gas turbine/steam turbine utilities block  114  are fed to a burner according to the process of the present invention as present in combustion chamber  106 . Oxygen  102  is prepared in air separation unit  104 . Nitrogen  103  as prepared in the same unit is used as purge gas in the gasification reactor  105 . In gasification reactor  105  slag  108  flows to a water quench  107  to be disposed as slag via  110 . The flash gas  112  separated from the slag  110  is send to Claus unit  109 . A water bleed  111  is part of the process as illustrated. 
         [0042]    The wet raw synthesis gas  113  as prepared is optionally treated in a scrubber unit to remove any solids and ash particles which have not been removed in the water quench before being further processed in a sour water gas shift step  122  yielding a shifted gas  123  and sour water, which is recycled via  124  to water quench  107 . Between sour water gas shift step  122  and the gas turbine/steam turbine utilities block  114  heat integration  121  takes place. The shifted gas  123  is send to an acid gas removal step  126  yielding a carbon dioxide rich gas  131 , crude hydrogen  130 , H 2 S  129  and steam condensate  128 . The carbon dioxide rich gas  131  is compressed in compressor  136  to yield compressed carbon dioxide gas  137 . The carbon dioxide may be advantageously disposed of by CO 2  sequestration in for example sub-surface reservoirs. The crude hydrogen  130  is further processed in a pressure swing absorber (PSA) unit  138  to yield pure hydrogen  140 . Part  134  of the crude hydrogen  130  may be used as feed in the gas turbine/steam turbine utilities block  114 . The hydrogen rich PSA off-gas  139  is compressed in compressor  133  and used, optionally blended with nitrogen  132 , as feed in the gas turbine/steam turbine utilities block  114 . Gas turbine/steam turbine utilities block  114  is further provided with a fuel gas, natural gas, feed  115 , a water feed  116  and a flue gas outlet  117  and an optional high pressure outlet  119 . 
         [0043]    In Table 2 an example is provided of the composition of the streams of  FIG. 4  when a feed according to Table 1 is used. The numerals in Table 2 refer to  FIG. 1 . 
         [0044]    The process according to the invention is further illustrated by means  FIG. 4 . Tar sand derived oil  31  is diluted with naphtha  32  to obtain diluted tar sand derived oil  33 , which is supplied to atmospheric distillation unit  34 . In atmospheric distillation unit  34 , diluted tar sand derived oil  33  is distilled and two atmospheric distillate streams, i.e. naphtha stream  32  and atmospheric gasoil stream  35 , and atmospheric residue  36  are obtained. Atmospheric residue  36  is vacuum distilled in vacuum distillation unit  37 . Vacuum gasoil stream  38  is obtained as distillate stream and vacuum residue  39  as bottoms stream. Vacuum residue  39  is supplied to solvent deasphalting unit  40  to obtain deasphalted oil  41  and liquid asphaltic fraction  42 . The liquid asphaltic fraction  42  is fed to a gasification unit  43 . In case of a failure of solvent deasphalting unit  40  vacuum residue  45  is fed directly to gasification unit  43 . In gasification unit  43  hydrogen  44  is prepared as illustrated in  FIGS. 1 and 2 . Distillate streams  35  and  38  are combined with deasphalted oil  41  to form combined hydrocracker feedstock  48 . Combined feedstock  48  is hydrodemetallized in hydrodemetallization unit  49  in the presence of hydrogen  50 . The hydrodemetallized combined feedstock  51  and additional hydrogen  52  are supplied to hydrocracking unit  53  comprising a first catalytic zone  54  comprising preferably a non-noble metal hydrotreating catalyst for hydrodesulphurization of the feedstock and a second catalytic zone  55  comprising preferably a non-noble metal hydrocracking catalyst. The effluent  56  of the second catalytic zone  55  is separated in gas/liquid separator  57  into upgraded sweet crude oil product  58  and a hydrogen-rich gas stream  59  that is combined with make-up hydrogen  60  to form hydrogen stream  52  that is supplied to the first catalytic zone  54 . Make-up hydrogen  60  and/or hydrogen  50  are hydrogen  44  as produced in gasification unit  43 . Upgraded sweet crude oil product  58  may be fractionated into several upgraded distillate fractions (not shown). 
         [0000]    
       
         
               
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
               
               
             
           
               
                 TABLE 2 
               
               
                   
               
               
                   
                   
                 Gas ex 
                   
                   
                   
                   
                   
               
               
                   
                 Wet raw 
                 shift 
                   
                   
                 Raw 
                 Pure 
                 PSA 
               
               
                   
                 syngas 
                 section 
                 Sour 
                 CO 2   
                 Hydrogen 
                 Hydrogen 
                 offgas 
               
               
                 Component 
                 113 
                 123 
                 gas 112 
                 137 
                 130 
                 140 
                 139 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 Methane 
                 % mol 
                 0.05 
                 0.07 
                 &lt;0.01 
                 0.05 
                 0.11 
                 — 
                 0.74 
               
               
                 Argon 
                 % mol 
                 0.02 
                 0.03 
                 — 
                 — 
                 0.04 
                 0.04 
                 0.06 
               
               
                 COS 
                 % mol 
                 0.04 
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
               
               
                 H 2 S 
                 % mol 
                 0.48 
                 0.74 
                 61 
                 5 ppm 
                 — 
                 — 
                 — 
               
               
                 H 2 0 
                 % mol 
                 56.18 
                 — 
                 5 
                 0.05 
                 — 
                 — 
                 — 
               
               
                 H 2   
                 % mol 
                 15.36 
                 59.23 
                 &lt;0.01 
                 0.7 
                 93.81 
                 99.82 
                 60.87 
               
               
                 N 2   
                 % mol 
                 0.53 
                 0.76 
                 — 
                 — 
                 1.20 
                 0.14 
                 7.04 
               
               
                 CO 2   
                 % mol 
                 0.54 
                 38.01 
                 34 
                 99.1 
                 3.01 
                 — 
                 19.53 
               
               
                 CO 
                 % mol 
                 26.79 
                 1.15 
                 &lt;0.01 
                 0.1 
                 1.82 
                 — 
                 11.78 
               
               
                 HCN 
                 % mol 
                 0.01 
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
               
               
                 NH 3   
                 % mol 
                 0.01 
                 0.02 
                 0.01 
                 — 
                 — 
                 —