DE3123032A1 - METHOD FOR REDUCING NITROGEN OXIDE EMISSIONS RESULTING FROM THE COMBUSTION OF FUEL OILS - Google Patents

Description

Methods of reducing nitrogen oxide emissions, that arise from the combustion of fuel oils

Since the crude oil reserves are depleted more and more and since the world market price for crude oil rises higher and higher, win now previously uneconomical sources of crude oil, such as the so-called "heavy oil", of interest. Heavy fuel oil or heavy crude oil is a thick, tarry petroleum which, like any crude oil, usually has an API gravity · ". is defined as 20 or less on the American Petroleum Institute's density measurement scale. This oil must be heated or injected with water and / or steam to cause drilling

holes in which it can be pumped out of the ground.

The most common method used to extract the heavy crude oil is known as augmented oil recovery or steam flooding. With steam flooding, steam is produced by burning some of the recovered heavy Crude oil produced, and the injection of the steam obtained in this way into the subsoil, which the in situ crude oil heats up, lowers its viscosity and flushes it against one or more recovery wells.

A disadvantage of the current augmented oil recovery technology is the requirement that steam be recovered by burning part of the heavy crude oil must be produced. This requires the consumption of about 160 liters (1 barrel) Crude oil for an additional 480 liter (3 barrel) recovery of in situ crude oil. E.g., San Joaquin crude oil at a rate of 3.2 million liters (20,000 bar rice) per day in plants for increased oil recovery burned in Bakersfield, California. In addition, with the burning of heavy crude oil the Production of undesirable environmental pollutants is inevitably linked. Recently during a Bakersfield temperature inversion is the burning of heavy fuel oil as part of increased oil recovery operations Causes emissions that exceeded the maximum permissible air quality standards to have. As a result of this, the future of augmented oil recovery plants is twofold of solving Problem dependent, namely on the one hand to produce steam in an energy- and cost-saving manner while on the other hand, the production of undesirable environmental pollutants must be minimized.

Because the heavy crude oil or crude oil is an easily available source of energy for steam generation in increased Represents oil recovery equipment is the use of expensive, light, clean-burning oils or gas not acceptable for economic reasons. Emphasis The aim was therefore to increase the calorific value of the available heavy crude oil by adding fuel oil extenders in combination with stretching. For example, combining coal with a fuel oil to produce a coal / fuel oil slurry is successful burned in fuel oil burners. Because NO

Ji

and sulfur emissions from coal / fuel oil slurry burns are still high, the coal / oil slurry does not solve the problem of emission of Environmental pollutants; however, this enables the calorific value of fuel oil for steam generation in increased oil recovery plants stretch.

Another carbonaceous material used for Possible use as a fuel oil extender has been suggested is coke. R. Shelton, et al. suggested in their Acurex report 79-330 of February 1979 that it might be viable to use petroleum coke burn as finely ground particles suspended in a fuel oil. However Petroleum coke is harder to burn than coal because it has a lower VCM (volatile combustible matter), and in R. Shelton et al.'s hypothesis no reduction in gaseous emissions was predicted. Hence there was little point in this theory too pursue as a much more desirable fuel extender in the form of readily available and relative

cheaper coal is available.

In accordance with the present invention it has now surprisingly been found that not only carbon-rich material with a low volatile combustible content Substances (VCM), such as coke, can be burned in a slurry form with crude oil, but that beyond that a significant reduction in NO (= NO or nitrous oxides ^ emissions over those that occur during the Combustion of crude oil alone was found to take place.

The present invention is based on the blending of a low-VCM, carbonaceous material Fuel oil prior to combustion to form a fuel oil slurry that is up to 60 wt% low VCM, Contains carbonaceous material. The fuel oil slurry is then burned according to well known oil burning technology. Made from coal Charcoal can be used as a suitable low-VCM, carbonaceous material; but because of the lower ash content in the coke compared to that of the charcoal made from coal the use of coke is preferred. The preferred slurry composition is from 30 to 50% by weight Contains coke and / or charcoal.

The viscosity of the slurry becomes sufficiently low held to allow combustion in conventional fuel oil burners. This is done through regulation the slurry temperature and the amount of coke or charcoal in the slurry compositions achieved. The particle size of the coke or the charcoal is optionally restricted to a Prevent clogging and blockage of the fire apparatus.

J (ZdLUZ

In general, NO is generated during combustion by both the conversion of fuel nitrogen to NO and also produced by thermal conversion of atmospheric nitrogen into NO '. During fuel oil combustion Most of the NO emissions are produced from the fuel nitrogen. A typical San Joaguin Valley (SJV) crude heavy oil contains approximately 0.6 wt% nitrogen. If it's SJV crude or crude among the typical Conditions with 3 vol .-% oxygen remaining in the flue are burned, the NO emissions are reached an average of about 380 ppm. Petroleum coke, and coke in general, has a much higher nitrogen content from between about 1 to 3% by weight and even higher depending on the starting material from which the coke is made.

The NO emissions from coke combustion are because of the inherent difficulties in coke combustion not clearly stated because of its low VCM content. However, some attempts indicate that petroleum coke with a fuel nitrogen content of 1.2 wt .-% nitrogen emits 270 ppm NO when he with 13 wt .-% other, highly volatile, low nitrogen fuels is burned.

According to the present invention, there is a slurry produced by combining a fuel oil that is 0.65 Containing about 2.4 wt.% Nitrogen with a petroleum coke containing about 2.4 wt.% Nitrogen, the slurry total fuel nitrogen content of about 1.18 wt%.

When you burn this slurry, the NO emissions are Surprisingly reduced to about 230 ppm. This level of NO emissions is below that

expected level even if the coke has little or no NO to the emissions during combustion contributes. Since coke does not emit NO during combustion, the reduction in NO emissions is the key Slurry even more unexpected. Furthermore, the Reduction in NO emissions caused by the addition of Coke to the heavy crude fuel oil becomes, particularly surprising in view of the NO -

Emission increases observed during the combustion of a coal / fuel oil slurry.

Although coke or charcoal are not used in larger quantities of VCM found in coal and therefore * to extend the calorific value of fuel oil is not so desirable, the added benefit of reducing NO emissions makes the present invention an attractive alternative to coal / fuel oil technology,

Furthermore, coke and charcoal produce undesirable amounts of particulate solids when they are burned alone in fixed beds or the like. By mixing the coke or the artificial ones Using coal with fuel oil before burning can reduce the dust problem. In addition, it is off Charcoal made charcoal is inherently pyrophoric. This has the use of artificial ones made from coal Coal because of the inherent hazards associated with the transport and storage of a spontaneously volatile fuel decreased; however, by mixing the charcoal made from coal with the fuel oil in accordance with the present invention, the char made from coal can be used as a non-pyrophoric charcoal / fuel oil slurry shipped and stored. In addition, coke and charcoal can be used

- ίο -

can be conveniently transported via pipeline when slurried with a suitable fuel oil are.

These and many other features and related advantages of the present invention are set out in US Pat Dimensions will become apparent as the invention is better understood with reference to the following detailed description will.

The low-volatile, combustible material (VCM) that is carbonaceous, the present invention can be any carbonaceous material such as e.g. Coke or charcoal containing from 1 wt% up to about 20 wt% VCM. Preferably that will Low-VCM carbonaceous material can be petroleum coke, which is made from heavy fuel oil. More typical Petroleum coke can contain up to 10 to 15 wt% VCM. Artificial coal made from coal can be made in accordance can also be used with the present invention. Typically the artificial Coal contain up to 20 wt% VCM and is made by removing at least 50 wt% of the VCM from the raw coal.

The size of the coke or the charcoal particles is not particularly critical. The particle sizes should be kept sufficiently small to prevent clogging of the connecting lines, the filters and the various To prevent burners applied to fuel oil combustion systems. The particle size should also be relative should be kept small (less than 0.16 cm = 1/16 inch) to avoid the need for continuous stirring of the Slurry and the problems resulting from the settling of the

Coke or the charcoal particles from the fuel oil can result to reduce.

The fuel oil that is in accordance with the present Invention used is not important. Any of the various fuel oils such as Crude oil, diesel oil, fuel oil or heavy residues, can be burned. Heavy crude oil is the preferred fuel because of its general use in the increased oil recovery, in which the NO (= NO or nitrous oxide) emissions control is a bigger problem.

The fuel oil slurry composition is also not particularly critical. In operating modes in which the NO reduction is the greater concern during the fuel-oil combustion is, the amount of coke and / or charcoal in the fuel oil can be low Level of between 5 and 10% by weight. Conversely, the amount of coke and / or charcoal in the fuel oil can be increased to a level of can be decreased as low as 1 wt%.

In operating modes in which, in addition to NO reduction, coke and / or artificial coal are mainly used as fuel f extender can be used, the amount of coke and / or charcoal in the fuel oil Levels of up to 60 wt% can be maintained. In general, however, both the NO emission reduction properties are used and taking advantage of the fuel extender properties of the coke and charcoal, a fuel oil slurry with a coke and / or charcoal content of about 30 to 50% by weight is preferred. The fuel oil slurry can be only coke or only contain charcoal. The slurry can be in

equally as well, if necessary, contain a mixture of both coke and charcoal.

To the extent that the relative amount of coke or charcoal in a given fuel oil is increased, the viscosity of the oil will generally increase. To avoid the fuel oil slurry The fuel oil slurry can become unpumpable or otherwise difficult to handle heated to bring the viscosity to acceptable levels for various systems and applications to lower. For pumping and firing in common oil burner systems, the viscosity of the fuel oil slurry is used preferably held at about 2000 centipoise.

After mixing the coke and / or the charcoal with a desired fuel oil the fuel oil slurry in any of the well well-known oil-fired stoves, which are commonly used for such to be used for a purpose, to be burned. The particular oven configuration is not important and can be varied within wide limits as long as the limits of the particle size are taken into account, to prevent clogging of the system and as long as the viscosity of the slurry within the pumping and transport capabilities of a given system are controlled. With fuel oil Fired steam generator boilers have a special application for increased oil production and can Use fuel oil slurry. Furthermore Other boilers, stoves, or any heat generating stoves can use the fuel oil slurry as use a suitable fuel.

The examples describe the invention.

San Joaquin Valley (SJV) crude oil with a petroleum coke content of 30% by weight was found to be useful burned under oil burning conditions. The coke burnout was under the test conditions 94 to 95%.

The SJV-Crude or SJV-Crude Oil was made by TOSCO Coporations AVON Refinery in Martinez, California. The basic analysis of the crude is given in Table 1 .

Avon
Fluid coke
(RF1-6932) TABLE 1 of test fuels 30% by weight fluid coke
Slurry
with SJV crude 30% by weight
Delayed coke
Aufschlärm
with SJV crude 2 Investigations San Joaquin Valley
SJV crude oil
(RF1-6756) _4 5 properties
Elemental analysis
Dry weight,
Wt% 89.95 Hobil (Torrance)
Delayed Coke
(RF1-6931) _3 86.78 ²⁾ 87.14 ²⁾ split 1.97 2 85.42 8.74 ² > 9.27 ²⁾ carbon 2.50 91.15 11.64 1.21 ²⁾ 1.18 ²⁾ hydrogen 2.18 3.74 0.65 1.44 ²⁾ 1.29 ²⁾ nitrogen 0.63 2.41 1.12 O, 2O ²⁾ O, 14 ² > sulfur 2.77 1.68 0.02 ¹⁾ 1.63 ² > O, 98 ²⁾ ash 100.00 0.42 1.15 100.00 100.00 oxygen
(by difference) 0.60 100.00 6.00 100.00 N / A N / A Quick analysis
Dry weight,
Wt% 93.40 N / A N / A N / A volatile portion 0.60 10.60 N / A N / A N / A bonded coals
material 100.00 89.00 N / A ash 0.40 100.00

Continuation from TABLE 1

split
Higher calorific value

Btu / lb 14.284 Btu / bbl 7.6 χ 10 Weight-volume specific weight
(g / co 60 / 6O ⁰ F) 1.53 Pounds / bbl 535 API specific weight N / A Particle size
(Wt%)

+100 mesh (US) 0.1

-100 +200 O, O

-200 +325 26.0

-325 +400 4.8

-400 69.1

3)

15, O89

7.2 χ

1.37

479

N / A

0.1 5.7

16.9 8.8

68.5

4)

18,600 6.3 χ 10 ^€

0.9652 338

15.1

N / A N / A N / A N / A N / A

17.305

2)

6.6 χ 10

6 2)

1.083 2)

2)

379

2)

O, 8

N / A N / A N / A N / A N / A

17,547

2)

6.5 χ

6 2)

1.059 37O

, 2)

2.1

N / A N / A N / A N / A N / A

2)

NJ CaJ CD OJ KJ

Continuation from TABLE 1

split

viscosity
(Centipoise)

27 ° C (8O ⁰ F)
38 ° C (100 ° F)
49 ° C (12O ° F)

N / A

N / A N / A

N / A N / A N / A

3,686

1,840
819

4.555 2.225

890

N / A = not applicable

N / D = not determined

1) = From Chas. Cameron (Avon) based on previous rehearsals

2) = calculated

3) = pulverizing in 2 passes at Vortec. Sample RF1-6965B. Tosco laboratory wet sieve analysis.

4) = pulverizing in 2 passes with Vortec plus classification. Sample RF1-6965D, Tbsco laboratory wet sieve analysis.

The petroleum coke was fluid coke, which was also supplied by the AVON refinery. The basic analysis of flowing coke is also listed in Table 1. The flowing coke was made using two passes pulverized by an impact mill to obtain a pulverized coke having a particle size distribution as listed in Table 1. Passage of the flowing coke through the mill resulted in particle sizes consisting of about 80% particles that have passed through a sieve with a mesh size of 0.074 mm (200 mesh) go through. This mixture of particle sizes clogged the 440 micron filter of the device used for the example and was not tested further.

The fuel oil slurry was made by mixing the powdered AVON flowing coke into an SJV crude oil that was heated to 65 ° C (150 ° F), with vigorous stirring. Typically 90 kg (200 pounds) of the crude oil was placed in a 208 l (55 gallon) drum pumped and heated to 65 C (150 ° F). About 39 kg (85 pounds) of the powdered coke was then added to obtain a 30% strength by weight flowing coke / SJV crude slurry. The temperature of the slurry was maintained at about 65 ° C (150 ° F) to allow pumping through a to enable positive displacement pump.

A 40% flowing coke / SJV crude slurry was made prepares; however, the pumping system could produce this particular slurry at a temperature of 65 ° C (150 F) do not pump sufficiently. The reason for this problem was probably the increased viscosity caused by caused the higher (40 wt.%) coke content in the slurry.

An 80 hp fire tube boiler was used to evaluate the combustion the fuel oil slurry used. the Unit was modified to allow flexibility in combustion configuration, fuel / air measurement and the ongoing monitoring of the draft gases. A steam atomizer just like the one for use by field steam generators was used for these examples. The unit was at Operated at atmospheric pressure and the generated steam was vented to the atmosphere. The oil and slurry fuels were fed to the burner by a plunger-type metering pump from the 208 l (55 gallon) drums

by
pumped. The fuel was heated to the furnace temperature by an electric circulating heater rated at 6 kW (Chromolox Division, Emerson Electric Co., Colton, California). The thermostat built into the heater was only used as a safety shutdown device as it was unsuitable for tight temperature control. Normally the heater remained on and was regulated by manual operation of a three phase rheostat to give the desired fuel temperature. A cartridge filter (Nupro TF) with a 440 micron sieve was used to filter the oil upstream of the oil gun.

Air was supplied to the burner by a high pressure blower via a venturi meter. The Brenner had one Air valve with 16 blades, with the blade angle was variable to swirl the airflow. The paddles were rotatable about their center line. A Peabody Y-jet atomizer that used steam as the atomizing liquid was made for all of that Trials used. This atomizer is designed to use unheated No. 2 oils and No. 6 and No. 5 oils, which have a viscosity of about 100 SUS

heated to atomize.

The fuel pressure was measured using a Bourdon tube measured. Air pressures were measured using a vertical or inclined manometer measured.

The boiler jacket was an 80 hp Scotch fire tube boiler. As mentioned above, the steam generated by this boiler is blown off at an atmosphere. The boiler was at a firing rate of 3 MMBtu / h volumetric combustion intensity 1 435 000 Btu / h · m

(38 500 Btu / h · ft) what an industrial boiler application is typical. A typical # 2 fuel oil was used to start up and shut down the boiler.

Feuerzuggasproben were drawn by a vacuum pump on the chart type at three points in the straight upward stream, where the gas temperature (500 ⁰ F) was approximately 2 6O ° C. The flow rates of these samples were approximately balanced by passing each sample through a water-filled, gas bubble generating vessel and adjusting the bubble velocity to about the same level. The samples were then mixed into a single stream which was then passed through a filter and dryer (Hankinson Series E refrigerator type) to remove water vapor.

The dry level concentrations of NO, O ₂ , CO ₂ and CO were continuously measured using a chemiluminescent nitrogen oxide analyzer (Beckman Model 742) and a non-scattering infrared "analyzer for carbon monoxide and carbon dioxide (Horiba).

-3V / 3U32

Smoke was measured according to ASTM designation D 2156-65 and listed as Bacharach soot number. Smoke number measurements were obtained by swiping a certain Volume of draft gas through a standardized filter paper. The color (or shade) of the stains so produced were visualized using a standard smoke number scale compared. The standard smoke gas scale consists of a series of 10 spots ranging from 0 to 9 are numbered and in the same photometric steps from white to neutral shades of gray black range.

The concentrations of SOp and unburned hydrocarbons were also measured, on a wet basis, continuously using a Dupont Model 411 and Beckmann Model 402 analyzer.

Since there was initially noticeable doubt as to whether coke could be burned in a fuel oil slurry or not, the following basic procedure has been devised to determine whether it is possible the 30% fluid coke slurry would be successful to burn. The boiler and burner have been set so that both operate smoke-free No. 2-Ö1 and the SJV crude oil for all excess oxygen levels with a single stage combustion and with a total excess oxygen level of approximately 3.5% and a theoretical burner air down to 75% has been reached. Once that has been achieved was the slurry in the boiler without any further adjustments of any burners or Boiler controls with the exception of the fuel pumps, which were set so that the level on excess air in the duct remained constant when switching from one fuel to the other. as

once it was established that a 30% by weight, flowing coke / crude oil slurry could be fired with success, the following procedure was used to make the test gaseous emissions.

The boiler was fired using the No. 2 oil, until the system warmed up. The fuel oil heater were then turned on and the firing rate was increased to approximately 3 χ 10 kJ / h (3 χ 10 Btu / hr). The fuel temperature at the burner injection (gun) was 65 C (150 F) fixed. The SJV crude oil was then introduced into the system by operating valves. Gas emission samples were along with an EPA Method 5 particle sample obtain. After completing the crude oil tests, a momentary switch was made back to # 2-Ö1 to start pumping the slurry into the To enable fuel storage system. The system was then fired with the slurry. The oil pump was adjusted so that the level of excess oxygen remained constant. Gaseous emissions were then obtained and other particle tests were done. When these attempts were completed, the system was switched back on No. 2-Ö1 to clean the system.

The results of the gas emission tests are shown in Tables 2, 3 and 4. Table 2 shows test results for the combustion of SJV crude oil alone, while Tables 3 and 4 show the results show during the combustion of the 30% strength by weight flowing coke slurry. As can be seen for that Combustion with primary air alone, the NO emissions for the SJV-Crude alone are remarkably higher than that NO emissions for the 30 wt% flowing coke slurry, which is unexpected because of the fuel nitrogen content of the slurry is - as can be seen from Table 1 - twice as high as that of the SJV crude. the

percentage conversion of fuel nitrogen into NO is three to five times greater when burning SJV crude than when burning coke is slurried in it.

TABEL KVB combustion tests - SJV crude oil

fuel
(Conditions)

Loading

m Btu

Time per hour

1151
1153

(NH, addition)

SJV Crude

alone 1142 2.84

(primary air only) ₁₁₄₆ ^ ₉₁

2.92 3.00

2.89

{stepwise 1200 2.94 combustion)

2.94

12O7 2.94

2.94

2.56

2.56

2.56

2.62

2.62

2.62

% Air

at the

burner

112.7 118.3 123.5 133.8 102.2

98.3 90.6 86 78

89.1 89.1 89.1 76.5 76.5 76.5

Excess air ¹ )

19.0 24.5 29.7 39.8 8.4

17.1 16.1 17.1 17.1

17.1 17.1 17.1 17.1 17.1 17.1

NH3 / NO Molar ratio

0 O 0 0 O

0 0 0 0

1.35 1.74

1.61 2.07

Fire train gas composite. Emissions

2)

O _n

3.5 4.3 5.0 6.2

1.7

3.2 3.1 3.2 3.2

3.1 3.2 3.1 3.2 3.2 3.2

14.1 13.5 12.6 11.5 15.8

14.7 14.4 14.6 14.5 14.4 14.4 SO ₂ 00 NO NO (dry) (wet) (dry) (dry) (3% O ₂ )

620
620
620
590
590
595

40
45
50
55
4O

40
40
40
35

35
40
40
40
5O
50

400

430 445 435 280

300 240 24O 380

260 120 108 213 125 110

411 463 501 529 261

303 241 243 384

261 121 109 215 126 111

implement,
from
N to NO _x
(%) Bacharach
No. 46.9 1 52.9 1 57.2 1 60.3 1 29.8 3, 34.5 M.
2.0 ^w 27.5 2.5 ' 27.8 2.5 43.8 2.5 29.8 2.0 13.8 N / D 12.4 N / D 24.5 1.5 14.4 1.5 12.7 1.0

N / D = not determined

1) - Some air is entering through the secondary air outlet all the time.

2) = unburned hydrocarbons were measured and were less than 10 ppn over the whole

Test duration

GO O GO

TABLE 3 - KVB combustion tests on a 30% by weight AVON FLUID coke slurry

fuel
(Conditions)
30% by weight
Avon FIuid-
Coke slurry Time Loading
kung
MM Btu % Air
at the Air-
above-.,)
shot NH3 / NO
Molver
holds Fire
train gas
Assemble CO ₂ Emissions _fppn) 2) 00 ND
(dry) (dry) 1
215 NO (dry)
(3% O ₂ ) Implementation,
from Bacharach
No. mung 1705 per hour burner (%) nis (VoI.-
° 2 14.6 SO ₂
(wet) 65 210 220 N to NO _x 2
6th split
Series No.1
(only primary
air) 1709 2
~ 3 2
112.1 4_
18.3 5
0 6i
3.4 14.7 750 60 195 218 8th_
12.9 6th 1713 * 3 114.3 20.3 0 3.7 13.7 720 65 170 215 12.8 6th 1717 λ.3 121.5 27.4 0 4.7 12.7 710 75 225 201 12.6 6th 1723 - ~ -3 130.5 36.2 0 5.8 15.4 695 50 220 217 11.8 6th 1727 - ³ 105.4 11.7 0 2.3 14.9 750 60 200
197 225 12.7 6th (Stages 1733
1737 ~ 3 101.0 18.3 0 3.4 14.4
14.5 730 60
60 167 207
203 13.2 6th
6th wise ver
burning) 1743 ~ 3 93.4
87.4 19.7
19.3 0
0 3.6
3.5 15.0 710
705 65 92 170 12.1
11.9 6th 1802 * ~ 3 77.5 17.7 0 3.3 14.7 695 80 275 93 10.0 6th (NH ₃ addition) 1414 ^ 3 76.9 17.1 4.9 3.2 15.5 715 65 290 270 5.4 6th Series No.2 1417 2.95 105.5 14.0 0 2.7 15.1 830 65 285 295 15.8 5 (only primary
air) 1419 3.08 109.6 17.7 0 3.3 14.4 820 70 260 303 17.3 5 1421 ^ 3 115.1 23.0 0 4.1 13.6 800 80 240 294 17.8 5 1425 -V3 122.7 30.5 0 5.1 12.5 770 90 260 240 17.3 5 1427 «3 132.3 38.9 0 6.1 15.6 705 65 247 14.1 6th ^ v 3 101.9 10.6 0 2.1 810 14.5

Continuation from TABLE 3

split

(stages
wise ver
burning) 1431
1433
1435 "3 1437 * 3 (NH ₃ addition) 1443
1446 U) ul 1451 ♦ 3 1455 4.3 1457 * 3 1459 t3 1501 -v3 N / D = 1) = ■ 2) -

95.0 14.6 0 91.1 16.4 0 86.9 17.7 0 77.9 17.1 0 111.0 17.7 0 93.08 19.7 0 93.8 19.7 1.52 93.8 19.7 1.90 82.0 22.3 0 82.0 22.3 1.70 82.0 22.3 2.12

2.8 15.3 790 65 3.1 15.1 770 65 3.3 15.0 760 70 3.2 14.8 750 70 3.3 780 65 3.6 14.7 760 60 3.6 14.7 765 68 3.5 14.8 765 70 4.0 14.3 735 75 3.9 14.3 735 80 3.8 14.4 740 85

250 247 220 221 200 203 175 177 260 264 225 233 170 175 155 159 200 212 125 131 110 115

14.5 6.5 13.0 6.5 11.9 7th 10.4 7th 15.5 6.5 13.7 6.5 10.3 N / D 9.3 N / D 12.4 6.5 7.7 N / D 6.7 N / D

not determined

Some air is entering through the secondary air outlet all the time *

Unburned hydrocarbons were measured to be less than 10 ppm over the

entire duration of the experiment

K)

on

TABLE 4 - KVB combustion

Fuel conditions Time 3O% AVON Fluid

Coke slurry

mang

Loading MM Btu per hour

look for a 30 wt% AVON FLUID coke slurry

% Air

at the

burner

Air above

shot

NH3 / N0 molar ratio

Fire draft gas composition.

Emissions

(ppm)

2)

SO ₂
(

CO

NO NO (dry)

₂
(wet) (trek) (dry) (3% 0 ~)

Implementation

from

N to NO

Bacharach

No.

Series # 3

(primary air only)

Series # 4

(only primary

(Primary air,

preheated

to 250 ° C

(53O ⁰ F))

1507 1537 1540 1543 1545 1548 1552 1554 1557 1600 1602

-3 <~ 3

~ 3 «-3 -3 ~ 3

-ν-:

1227 1230 1232 1239

1251

3)

2.9 2.9 2.9 2.9 2.9

99.6 106.9 114.2 100.0 108.0 116.2 111.7 106.9 99.6 99.1 104.1 110.9

112.8 107.1 115.5 107.2 112.1

8.4 15.2 22.3

8.9 16.4 24.5 19.7 15.2

8.4

7.8 12.3 19.0

17.7 12.3 20.3 12.3 17.1

0 0 0 0 0 0 0 0 0 0 0 0

0 0 0 0 0

1.7 N / D 745 80 210 196 2.9 N / D 770 95 240 239 4.0 N / D 750 100 240 244 1.8 N / D 770 90 220 206 3.1 N / D 760 100 215 217 4.3 N / D 780 130 210 227 3.6 N / D 795 125 205 211 2.9 N / D 780 110 205 204 1.7 N / D 780 100 200 186 1.6 N / D 760 90 180 167 2.4 N / D 800 105 205 198 3.5 N / D 870 100 205 211 3.3 15.6 800 100 185 187 2.4 16.2 800 95 180 174 3.7 15.2 810 110 190 196 2.4 16.8 810 90 180 174 3.2 15.8 775 100 200 202

11.5
14.0
14.3
12.1
12.7
13.3
12.4
12.0
10.9
9.8
11.6
12.4

11.0
10.2
11.5
1O, 2
11.9

4.5 6.0 6.0 7.0 7.0 7.0 7.0 6.0 7.0 8.0 6.5 8.0

8.5 9.4 8.5 7.0 5, O

ι to

KJ CO CD CO

N / D - Not determined

1) = Some air is coming through the secondary air outlet all the time

about a.

2) = unburned hydrocarbons were measured and were less

than 10 ppm over the entire duration of the experiment.

3) = EPA 5 Particulate Test was performed at this point.

V
\

K) OJ O OJ KJ

The experiments were also carried out using a two-stage (staged) combustion in which maintain a reduced (less than 100% air) atmosphere in the burner and complete combustion secondary air has been added to the fuel. Again, as can be seen from Tables 2, 3 and 4, were the NO emissions from the flowing coke slurry remarkably lower than the NO emissions for the SJV crude oil alone. Similar relative results were obtained also obtained when ammonia was injected during the combustion process.

In another example, De.layed coke became that SJV crude added instead of flowing coke. The delayed coke was from Mobil Oil of Torrance, California, delivered. The basic analysis of delayed coke is shown in Table 1.

A 30 weight percent slurry of delayed coke in SJV crude oil was prepared. Same procedure was followed in the preparation of the delayed coke and the 30 wt% delayed coke / SJV crude oil slurry, as in the example relating to flowing coke. The combustion conditions were also equivalent.

The results of the 30% by weight delayed coke / SJV crude oil slurry are shown in Table 5. As it can be seen that the NO emission levels for the delayed coke slurries are also remarkably lower than those for the SJV crude oil alone. Two-stage combustion and ammonia injection were also used with the delayed coke slurry performed (but not shown in Table 5) with similar reductions in NO emissions. Attempts have not been carried out with charcoal-made charcoal or other low-VCM materials, such as anthracite coal and coke made by coking coal; however, that would be observed

Reduction in NO emissions can also be expected if when fuel oil is slurried with these materials will.

TABLE 5 - KVB combustion tests on a 30% by weight delayed coke slurry

fuel

(Conditions) application

30% delay coverage

Coke pulp- M4 Btu

time per hour

Series # 1

(primary air only)

145O
1455
1457
1502
15O4
1507
1510
1515

3)

3.2
3.2
3.2
3.2
3.2
3.2
3.2
3.2

% Air

at the

burner

111.6
106.9
123.7
120.7
117.4
106.9
109.2
112.4

Air- NH3 / NO over- molar screw D holds - (%) nis

17.7 13.4 29.7 26.7 23.7 13.4 15.8 18.4

Fire train gas combination.

CO-,

3.3 2.6 5.0 4.6 4.2 2.6 3.0 3.4

15.3 15.5 14.1 14.7 14.7 15.0 15.5 15.2

Emissions (ppn)

2)

SO2 00 NO N0 (troc]

(wet) (dry) (dry) (3% Cb.)

680
680
670
650
630
650
650
670

95
100
130
140
130
105

80
120

230 220 200

205 210 210 205 210

234 215 225 225 225 205 205 215

Unsetz.
from
N to NO _x Bacharach
No. 13.9 5 12.8 8.5 13.4 8.5 13.4 8.0 13.4 7.5. · 12.2 8.5 g 12.2 8.0 ι 12.8 5.0

1) = Some air is entering through the secondary air outlet all the time.

2) = unburned hydrocarbons were measured and were less than 10 ppn above

the entire duration of the experiment.

3) = EPA 5 Particulate Test was performed at this point.

Approx. N.

ο -ι

From the above examples it can be seen that the addition of low-VCM carbonaceous Material on fuel oils in accordance with the present invention brings the advantages of stretching the calorific value of fuel oil while at the same time the NO emissions are reduced. This is an improvement over the coal / fuel oil slurries, in which the coal may contribute just as much to the calorific value, but not additionally that Reduces the level of NO emissions. Optionally, the charcoal can first be pyrolyzed to provide VCM for to remove a separate fuel consumption; the resulting charcoal-made charcoal is slurried with fuel oil for the purpose of the artificial coal made from coal to gain the remaining calorific values through combustion, while also reducing the NO emissions of the fuel oil be reduced. In this way, the same amount of calorific value is obtained from the coal as with the Coal / fuel oil slurry technology while the NO emissions are kept at a low level.

Claims (11)

PATENT LAWYERS: Γ Ι DR. DIETER V. BEZOLD " DIPL. ING. PETER SCHÜTZ DIPL. ING. WOLFGANG HEUSLER MARIA-THERESIA-STRASSE 22 PO Box 86 02 60 D-8OOO MUNICH 86 APPROVED BY THE EUROPEAN PATENT OFFICE EUROPEAN PATENT ATTORNEYS MANDATAIRES EN BREVETS EUROP £ ENS TELEPHONE 089/4 7O6O TELEX 532 638 TELEGRAM SOMBEZ U.S. Serial No. 158,706 Filing date: June 12, 1980 11037 V / m TOSCO Corporation
100 Santa Monica Blvd.
Los Angeles, California 90067
V.St.A. Methods of reducing nitrogen oxide emissions, that arise from the combustion of fuel oils Claims Methods of reducing nitrogen oxide emissions, arising from the combustion of fuel oils, characterized by the steps of mixing a sufficiently combustible, carbonaceous one Low volatility material with the fuel oil prior to combustion to form a Fuel oil slurry containing up to 60% by weight high carbon material with a low volatile content Contains combustible substances, and burning the fuel oil slurry, thereby reducing nitrogen oxide emissions among the nitrogen oxide emissions from the combustion of fuel oils alone arise, be reduced. 2. The method according to claim 1, characterized in that the fuel oil slurry contains between 30 and 50% by weight of combustible, carbonaceous material of low volatility. 3. The method according to claim 2, characterized in that the combustible, carbon-containing Contains low volatility material up to 20% by weight volatile combustible material. 4. The method according to claim 2, characterized in that the combustible, carbon-containing Low volatility material is coke. 5. The method according to claim 4, characterized in that the combustible, carbon-containing Low volatility material is petroleum coke. 6. The method according to claim 4, characterized in that the combustible, carbon-containing Low volatility material is an artificial coal made from coal. 7. The method according to claim 1, characterized in that the particle size of the combustible Renal, low volatility carbonaceous material is less than about 0.16 cm (1/16 inch). 8. The method according to claim 7, characterized in that the particle size is smaller is than corresponds to a clear mesh size of 0.074 mm (200 mesh). 9. The method according to claim 7, characterized in that the temperature of the fuel oil slurry is high enough to keep the viscosity of the fuel oil slurry below about 2000 cP (centipoise) to hold. 10. The method according to claim 3, characterized in that the fuel oil is heavy Is crude oil. 11. The method according to claim 9, characterized in that the temperature of the fuel oil slurry is about 65 ° C (150 ⁰ F).