JPS58162692A - Treatment of substance containing mineral carbonate and carbonaceous residues - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for recovering oil from oil shale. Oil and ale are marl-type inorganic substances mixed with an organic polymer called kerogen. The three key points in the production of sierre oil are mining, crushing and drying. The present invention relates to a method for carbonizing oil shale. As is well known, kerogen in its natural form is not suitable for mausoleum-intensive use. Kerogen must be pyrolyzed at high temperatures or carbonized to decompose it into volatile products, oil and gas.

Steam, which is a product of these thermal decompositions, is extracted from the retort and subjected to condensation and fractional distillation.

The solid residue of shattered oil shale remaining in unresolved bales is commonly referred to as spent shale.

Typically, used shale contains combustible carbonaceous residues in amounts ranging from about 10% by weight to more depending on the oil shale source and carbonization conditions. This combustible residue is universal! l! Distributed throughout the spent seal particles. In order to prevent this combustible material from being discarded as waste, the combustible residue was stored in a used shale combustion chamber.
It is burned in a greenhouse above the pyrolysis temperature within the range of "C (1100-1'FOO" F). The heat generated by the combustion of this carbonaceous residue can be extracted from the combustion casing and used as the bulk heat needed for the entire process. The final residue that remains after the combustion of used sierre is a waste! 11*
It contains less than Ilt% residual carbon and is called sierre ash. In some pyrolysis processes, abrasion-resistant, high-temperature siere ash is circulated through the retort to provide the heat needed to decompose the kerogen.

In other processes, the siere is cooled and disposed of as waste.

A common problem that occurs while heat is generated by the combustion of spent sier is the decomposition of the mineral carbonates present in the spent sier. Oil shale, which is typically found in large reserves over vast areas of Utah, Wyoming, and Colorado, contains relatively large amounts of dolomite and calcite. In the spent shale furnace, the magnesium carbonate and calcium carbonate present in these minerals undergo thermal decomposition to form magnesium oxide and calcium oxide, respectively. As is well known, carbonate decomposition is an endothermic reaction which essentially reduces the amount of heat that can be recovered from the combustion of the carbon residue present in the spent coal.

What about burning used sierre? Preferably, the temperature is as high as possible to maintain complete combustion of the entire carbonaceous residue and to increase heat transfer when recirculating the siere ash to the retort.

On the other hand, the reaction rate of endothermic decomposition of carbonate depends on the temperature; the higher the temperature and the longer the residence time, the faster the reaction time.

Therefore, the benefits gained from high temperature operation are offset by heat losses due to endothermic decomposition of the carbonate. The purpose of burning spent shale is to maximize heat recovery from the spent shale. It would therefore be desirable to provide a method for burning spent shale that either reduces heat loss due to carbonate decomposition or increases the heat that can be recovered from combustion.

Another issue related to the combustion of used oil shale is the disposal of the shale ash produced during combustion. Shale Atush is a non-toxic material that is disposed of by simply dumping it into the area surrounding the oil shale processing plant. A typical example is Tejasier Atshu, which contains dolomite [and calcite charcoal a!] that are originally present in oil shale. Contains large amounts of magnesium oxide and capped calcium resulting from the decomposition of salts. This ash undergoes water leaching, such as due to rainfall, resulting in a leachate having a high pH and high conductivity. Conductivity is a measure of total dissolved solids. F!Alkaline leachate with high conductivity is released from the vast fly ash dumping site. It is environmentally undesirable for this to occur over the delivery period. It is therefore presently desirable to provide a method for producing fly ash which, when subjected to water leaching, produces a leachate having a low pH and low conductivity.

In addition to increasing the heat l that can be recovered from the combustion process, the present invention provides for the calcination of spent sier to produce a sier ash that, when subjected to water leaching, produces a leachate with a relatively low pH and a relatively low conductivity. provide a method.

The present invention provides a combustion apparatus for used siel during the combustion of residual carbon in used siel! This is based on the discovery that the heat recovery rate increases when a oxidizing sulfur compound is added. The increase in heat recovery is due to the fact that sulfur dioxide is free lime (calcium oxide) and a! This is thought to be due to the reaction with the chlorine to form calcium sulfate and oanorinite compounds. This reaction is exothermic and the heat loss due to endothermic decomposition of the carbonate mineral is at least partially replaced by the reaction.

As a particular feature of the present invention, oxidizable sulfur compounds are added to the burnt Sière combustion system in the form of hydrogen sulfide.

It is believed that hydrogen sulfide is oxidized to sulfur dioxide and then reacts with QaO. The oxidation of hydrogen sulfide to sulfur nitride is an exothermic reaction, which further contributes to heat recovery during the combustion of spent sierre.

As specifically contemplated by the present invention, the hydrogen sulfide present in the pyrolysis vapors exiting the oil shale retort
and adsorption into a hydrogen sulfide amine solution present in acidic water which has been driven off by water vapor produced in other steps of the pyrolysis process. The hydrogen sulfide is then driven out of the amine solution and added to the spent seal combustor. This particular process has the advantage of eliminating the costly multi-Olaus plant traditionally used to remove hydrogen sulfide from retort gas. Furthermore, hydrogen sulfide from amine plants is highly concentrated, so
The blower cost required to add hydrogen sulfide to the furnace-fired lids of used shells is reduced. When pyrolyzing oil shale in the western United States, the amount of hydrogen sulfide present in the retort gas is sufficient to neutralize all the calcium monoxide produced by the decomposition of carbonates during combustion of the shale gas. The amount of oxidizable sulfur compounds typically is less than the average amount of oxidizable sulfur compounds, and therefore oxidizable sulfur compounds from sources other than pyrolysis operations are desirable.

Another feature of the invention is that the calcium sulfate produced by adding oxidizable sulfur compounds during the combustion of used shale reacts with the clay present in the shale to form ice-insoluble canculinite compounds. do. As a result, a sierre-assier with a small amount of solute and alkali in water and a large ml is produced.

The invention will now be described by way of example with reference to the accompanying drawings, in which: FIG.

The present invention improves upon conventional methods of incinerating carbonaceous residues present in used shale.

The present invention shows that when an oxidizable sulfur compound is added to used sier during combustion of residual carbon, the combustion of used sier is reduced.
It was discovered that the heat loss that occurs in the pig iron is reduced, and that Sierre Atsushi with a small amount of dissolved substances is produced.

Seventy sheets of an example of the method of the invention are shown in the accompanying drawings. As is known in the art, a rettle (rettle), that is, a heat fraction lO, is provided to heat the oil shale in a reducing air. Oil shale is 98.8-815.6℃ (200℃
It can be heated to a temperature of ~600°C and introduced into the retort 10 via line 1z. Although the present invention will be described here using oil shale, the present invention can also be applied to other carbonaceous materials in which mineral carbon salts are present. Green River, USA
er), Pioeanoe 0
reek) Oyohi VZ Yaky Paysence (Washa
ki Ba5ins) We will present the representative analysis results of the minerals present in Recière.

Table 1 Analysis results of minerals in crude shale Components Weight % Dolomite 82 Calcite 16 Quartz 15 Illite 19 Soda immersion 1゜imitation platinum 6 Iron sulfide 1 Analzite 1 Mineral parts of oil shale are representative In the example, 80-90
It is outside the weight range. The remaining 10-20% by weight is ringed carbon in the form of kerogen. In the retort 1°, the oil shale weighs 486.7 to 59 g under reducing conditions, JI
It is heated to a WA jet of 800 to 1100 degrees Fahrenheit. The specific technology used to pyrolyze oil shale is not critical. Any of the well known pyrolysis techniques using, for example, rotating retorts or moving bed retorts) or fluidized bed retorts can be used. Furthermore, the particular means of heating the oil shale to pyrolytic temperatures is also not critical. heat carrier,
Processes that utilize the combustion of dirt sier using, for example, ceramic balls, recycled abrasion resistant sier ash or other conventional heat carriers can also be used.

The three basic products produced during conventional oil shale pyrolysis in 10 are product gas or M gas and spent shale. Generation 41! I steamer contains oil, gas, water and relatively small amounts of sulfur and nitrogen compounds. The product vapor is transferred by line 18 to a downstream conventional fractionator, such as shown as condenser 14. rtv;a! The pyrolysis product vapor is transferred to the condenser 14
and separate into gas and liquid products. The gaseous product contains relatively high amounts of sulfur-containing compounds and nitrogen-containing compounds. Therefore, the gaseous products can be further purified downstream.
It is necessary to remove both nitrogen compounds and sulfur compounds. For removal of sulfur compounds, a typical example uses a Claus apparatus. The Claus apparatus is based on the Claus process, which involves a gas phase catalytic reaction in which appropriate proportions of hydrogen sulfide and sulfur dioxide are reduced to elemental sulfur and water.

The equilibrium of this reactor is controlled so that the reaction mixture recovers only 70-75% of the sulfur normally present in the gaseous pyrolysis products. To achieve sulfur removal levels in excess of 90%, a second Claus apparatus is commonly used. Purification of gaseous pyrolysis products by the Claus process is expensive.

In a preferred embodiment of the present invention, an amine scrubber is installed to remove hydrogen sulfide from the kerosene oil shale rut gas without using a Claus sulfur removal process.

Such an amine scrubber is indicated at 16 in the accompanying drawings.

Product gas from condensate 9914 enters scrubber 16 through line 15. Amine scrubbers use conventional amine solutions such as diethylamine.

As is known in the art, hydrogen sulfide present in the pyrolysis product vapor is absorbed into an amine solution in an amine scrubber 16. The saturated amine solution is then passed through the slipper zone 18 via conduit SO. In the scrubber zone 18, the hydrogen sulfide absorbed in the amine solution is removed from the amine solution by conventionally known methods.The sulfur-free amine solution is removed from the amine scrubber 16 by line ms, depending on the jurisdiction.
and used again to remove hydrogen sulfide from pyrolysis product vapor. The hydrogen sulfide removed from the amine solution in the streak ripper zone 18 is a particularly preferred source of oxidizable sulfur compounds for use in the process of the present invention, as discussed below.

The residue remaining in the retort 10 after pyrolysis consists of the minerals present in the lusiere. Most of these minerals remain unchanged? Pass through Tort.

At retort humidity higher than 587.7°C (1000A), some decomposition of mineral coal #I#1 occurs to generate mineral oxides. In addition, retort wet conditions have a high rate of reaction in which iron sulfide decomposes into various sulfur compounds containing hydrogen sulfide. Spent shale is substantially composed of minerals, but typically contains 1-5% carbonaceous residue. The present invention relates to an improved method of burning such carbonaceous residues present in used sierre.

The used shell is passed from the route 10 to the spent shell combustion apparatus 24 by line z1. The spent sheer combustor 1514 may be a used sheer combustor conventionally used to burn residual carbon present in the spent sheer. ``Combustion is preferably carried out by conventional dense phase fluidized bed sintering. Combustion is 648.9-926.7"C (11100-1700'
Perform at a humidity of P). The oxygen required for grilling horse mackerel is the conventional line 26.
is supplied by the fluidizing air sent to the combustion device g4 by the combustor g4. Appearance of fluidizing air is 10.76 to 10 liters per day.
, 88 m (1,fi to 6.0 ft) in the range of 7 seconds. At such air flow rates, a large excess of phase elements is present in the combustor to ensure complete combustion of the carbon. The particle size of the spent sierre is not critical as long as the particles can be properly fluidized within the combustion device 24. The residence time of the particles in the combustion device can also be varied within a wide range. The fundamental purpose of burning the remaining spent shale is to recover the fixed residual carbon, and therefore the residence time can be varied to achieve the desired combustion of the residual carbon.

The mineral coal-fII#i present in the spent sier undergoes endothermic decomposition during combustion in the combustion device B4.

Decomposition of carbonates! The guest is warm, residence time, particle size and various other V! Depends on the cause. The dedication carbonate, consisting primarily of magnesium carbonate and calcium carbonate, decomposes according to the following reaction equation: MgCo, ten heat → M, medium heat + Go.

caco, medium heat → cao + Cog Mineral acid products produced from the decomposition of carbonic acid are relatively soluble in ice. As a result, the sier ash produced during the combustion of spent sier and disposed of via line 28 undergoes a slow but sweeping leaching process when exposed to the action of rain and other moisture at the dumping site. . This leaching process is used to remove 100% of Sierre ash, which is stored as waste.
In addition to lacking integrity above 1M, it also produces a highly alkaline leachate, which is obviously undesirable for environmental reasons.

In the present invention, an oxidizable sulfur compound is added to a used sier combustion device to "generate" an insoluble calcium sulfate compound.
It is preferable to repeat the operation at ?Mf of C (1400 to 170 G"p).
~1600'F) is preferred. If the spent sier does not contain sufficient residual carbon to raise the fluidized bed wetness to the above levels when burned, supplementary aqueous additives can be added as required @ used The particular oxidizable sulfur compound added to the shale combustor is not critical so long as it is capable of reacting with calcium oxide to form calcium sulfate compounds under the conditions present in the spent shale combustor. Preferred oxidizable sulfur compounds include sulfur dioxide, hydrogen sulfide, organic sulfur compounds and pyrite. Hydrogen sulfide is the preferred oxidizable sulfur compound to add to the combustion device. As explained above with regard to the scale drawings, at least a portion of the hydrogen sulfide is
Preferably, the feed is from hydrogen sulfide removed from the retort products steam and acid water by zone 18.

It is believed that oxidizable sulfur compounds added to the spent sier during combustion react with the calcium oxide to form calcium sulfate and cancrinite-like compounds. Cancrinite compounds are commonly found as a component of steam boiler scale and are formed from the reaction of calcium sulfate with clay-type minerals present in spent sierre. Canculinite compounds used herein include canculinite and v'1shnevite. Kankurinai (is represented by the following general formula: % formula %. Vishnepai) is represented by the following general formula: (Na,
Oa+K)6,4(Mut6si6 o,,) (So,
Too, 5at) 0. Q~1. @ ・1 to 61 (represented by ,0.

Canclinite-bijuite bite minerals form a series of solid solutions mainly composed of GO3 and So6.

Among this series of solid solutions, the carbonate-rich ones are much larger than those of the sulfur salts: the calcium ions per unit of mass are considerably larger, but there is no corresponding increase in the number of sodium ions in the Vishnevite mineral. , (Na+Oa+K) ions in Bisienebish minerals and < 00. +5o4
) ions are smaller than in cancrinite. Cancrinite raw material increases as the temperature of the used sierre burner increases. Therefore, about 87
It is particularly preferred to maintain a temperature of 1.1°C (1700v) to maximize cancrinite formation. For example 815
Combustion of used sierre under conventional conditions at , 6°C (1600″F) yields approximately 10,000 μTJ/c+
A leachate is produced with a conductivity of m. What is the conductivity of the leachate when 6% sulfur is added to the combustion air in the combustion equipment? It decreases to l$OOμU/e1K. Melting temperature is 871
．． When increasing to 1'C (1600"F), the leachate conductivity decreases to 84001 EI O/ell. This decrease in leachate conductivity is due to the increased formation of canculinite compounds in Sierre-a-Noche. This may be possible.

It is believed that the oxidizable sulfur compound added to the used Sier combustion equipment does not react with magnesium oxide and does not produce magnesium sulfate. This is 41 advantageous.

The reason for this is that magnesium sulfate is water-bathable and thus contributes to increased leaching of the siere anche after clam fractionation. Therefore, it is thought that the decrease in the solubility of siere is due to the conversion of calcium oxide into less water-soluble calcium sulfate and canculinite compounds. In the method of the present invention, it is preferable to add it to the used siere combustion equipment. The amount of oxidizable sulfur compound is 0.5 to 8 parts by weight of used Sierre's baking soda. As mentioned above, hydrogen sulfide is preferred as the oxidizable sulfur compound. The above addition range of oxidizable sulfur compounds provides excess sulfur in the chain to promote complete conversion of #fhycalcium and to reduce The combustion conditions, including temperature, oxygen level, oxidizable compound loading and residence time, were fixed to avoid problems with excess secondary sulfur contamination.
The sier ash exiting the spent sier combustor 24 through line 28 is maintained to contain at least 6% by weight of calcium sulfate compounds. It is more preferred that the sierre ash contains 5 to 85 duck weight - calcium compounds. The calcium sulfate compounds used herein are both calcium sulfate and canculinite. Although the relative amount of calcium sulfate in the sierre ash is usually greater than the amount of cancrinite compound, it is preferred to maximize the amount of cancrinite compound when possible. A preferred ratio of calcium sulfate to camphtonite compound is 0.5-2. Preferably, the level of canclinite predominant compound is 10 to 15% by weight of Sierre Atshu.

Other advantages achieved by the present invention are increased heat recovery during the combustion of spent sierre. The production of calcium sulfate compounds from calcium oxide is an exothermic stirrup reaction.
The heat generated during the reactions that produce calcium sulfate and cancrinite compounds therefore increases the heat that can be recovered during the combustion of spent shale. In this regard, a particularly preferred oxidizable sulfur compound for addition to the spent sier combustion system is hydrogen sulfide. When hydrogen sulfide is added to the spent Sierre burner, it is first oxidized to sulfur dioxide and then reacts with calcium oxide. The initial oxidation of hydrogen sulfide is also an exothermic reaction, thus providing additional heat that can be recovered during the combustion of the spent sierre. For example, 815% of used Sier containing 4% residual carbon by weight.
Conventional combustion, which burns at temperatures between 6 and 871.1"C (1500 and 1600"F), produces a unit weight of used shells.
Approximately 284 Kcal/119 (4jl OBt
u/jb). 8% by weight of used sierre
When adding sulfur dioxide to the combustion equipment, the heat recovered is approximately 445 KOeLl/'i (800 Bt%) per unit weight of used sierre.
increases to If an equivalent amount of water sulfide, elemental, is added to the combustion device instead of sulfur dioxide, the heat recovered from the spent sier will be 1001 i per unit weight of used sier.
coa/, /Ig (1800 Btu/jb). This increase in recoverable heat is believed to be due to the exothermic reaction in which hydrogen sulfide is oxidized to sulfur dioxide.

Evidently, the addition of oxidizable sulfur compounds to the spent sierre, as described above, during combustion not only reduces the solute content of the sierre assier produced, but also significantly increases the heat that can be recovered during the combustion process.

Oxygen is required to generate sulfur m* compounds in the used sierre. Preferably, an excess of elI element is present. When using air as a fluidizing gas,
Oxygen is supplied in an amount sufficient to burn off the residual carbon in the spent shale and at the same time provide the #I element necessary to produce the desired sulfur salt compounds in the process of the present invention.

As mentioned above, the present invention reduces the solutes of the Sierre Ash, ie, reduces the conductivity of the effluent. moreover,
The PH of the leachate from the Sier Ash produced during the combustion of the used Sier Ash according to the method of the present invention is also less alkaline than the conventional Sier Ash leachate. for example,
815.6~871.1"C (1500~1600"'
F) Conventional combustion of used sierre in the warm
pH of approximately 11.8 when subjected to leaching treatment with aqueous solution
The leaching with 1'l produces a sierre ash. Adding 8 parts by weight of sulfur dioxide of spent Sierre to the combustor reduces the pH of the leachate to 11.1.

Furthermore, when 8% by weight of used Schier's hydrogen disulfide is added to the combustor, the pH of the Schier's exuded eyelids further decreases to pH 9.0. The leachates with reduced l)H values obtained by the process of the invention are environmentally preferable to the highly alkaline leachates produced in the absence of sulfur treatment.

As is clear from the above description, the present invention provides a low conductivity solution in which the heat recovery from the spent shale is maximized and the final shale ash produced has low solute content and reduced alkaline content.

To provide an excellent method for burning used sierre, which can produce leachate.

[Brief explanation of drawings]

The accompanying drawing is a 70-sheet example of the method of the invention. 10... Retort (heat separation layer) 14... Condenser 16...Scrubber 18...s [ripper area] Ha... Used Sierre combustion device.

Claims (1)

[Scope of Claims] L. Treating a material containing mineral coal #I salt and carbonaceous residue in the presence of #I element at high temperature and burning the carbonaceous residue to generate heat and oxidize the soluble mineral. In producing the ash containing the ash, an oxidizable sulfur compound is added to the material and reacted with @* and the mineral saponified product to produce an insoluble mineral sulfate compound, thereby A method for treating mineral carbonate and carbonaceous residues characterized by reducing the solubility. 2. The method of claim 1, wherein the material containing mineral coal and carbonaceous residue is spent sierre, and the ash is sierre ash. & The oxidizable sulfur compound and the S! 9. The method of claim 8, wherein the reaction between the mineral and the ore-oxide is an exothermic reaction, thereby increasing the amount of heat produced during processing of the spent seal. Also, the saponifiable compound may be sulfur dioxide, hydrogen sulfide, or
9. The method according to claim 8, wherein the sulfur compound is selected from the group consisting of sulfur compounds and pyrite. 5. The method according to claim 4, wherein the oxidizable compound is hydrogen sulfide. a. The method according to claim 5, wherein the amount of hydrogen sulfide added to the used sheer is 0.5 to 8% by weight of the used sheer. I The above warm temperature is 648.9~9 ffi 6,7°C (
1200-17001')
The method described in section. L ME warm it? 60.0~9i86.7℃(
1400-170 G'''F). The method according to claim 7, wherein an oxidizable sulfur compound is added to the ILIM+ used sierre, so that 6 to 85% by weight of the sierre A method according to claim 2 for producing said insoluble mineral sulfur #I salt compound. lα consisting essentially of said insoluble mineral sulfur #I compound and a calcium sulfate compound. The method according to claim 8. The method according to claim 10J1m, wherein the IL lt+JIe calcium sulfate compound is a canclinite compound. % of said cancrinite compound.