Use of microwaves in petroleum refinery operations

Petroleum refinery operations involving catalytic reactions are improved by subjecting hydrocarbon reactants in contact with catalytic material to the influence of wave energy in the microwave range.

Patent Application Ser. No. 954,302 filed Oct. 24, 1978 is a division 
thereof and is directed to the reduction of the sulfur content of 
petroleum liquids by subjecting the petroleum liquid and hydrogen to 
microwave energy. Attention is also directed to Patent Applicaton Ser. No. 
831,171 filed Sept. 7, 1977, which teaches the recovery of oleaginous 
products from shale by subjecting shale in contact with hydrogen to 
microwave energy; and to Patent Application Ser. No. 896,003 filed Apr. 
13, 1978, which teaches decreasing the sulfur content of coal by 
contacting a slurry of dry coal in a solvent of microwave energy; and to 
Patent Application Ser. No. 896,004 filed Apr. 13, 1978, which teaches the 
regeneration of cracking catalyst deactivated in a process of cracking 
petroleum hydrocarbons by subjecting the deactivated catalyst in contact 
with hydrogen to microwave energy. 
The use of microwaves to generate heat in a uniform and controlled fashion 
is well known. Thus U.S. Pat. No. 3,503,865, issued Mar. 31, 1970, teaches 
liquifying coal by subjecting coal particles to microwaves under 
conditions including a temperature of from 100.degree. C. to 500.degree. 
C. U.S. Pat. No. 3,449,213 teaches obtaining chemicals from coal by first 
heating coal to an elevated temperature and then increasing the 
temperature to about 800.degree. F. using microwaves wherein the final 
heating with mircowaves is done in a partial vacuum. 
The use of catalytic reactions in petroleum refining to convert petroleum 
hydrocarbons to other hydrocarbons by reaction or rearrangement has long 
been known. Catalytic processes commonly used include catalytic reforming, 
catalytic cracking, catalytic hydrocracking, catalytic alkylation, and 
catalytic polymerization. Much effort has been expended in developing 
catalysts for these reactions and in particular to developing active 
catalysts which will cause rapid conversion of the reactants to the 
desired products with a minimal increase in undesired products. It is also 
entirely possible to have catalysts which are too active for the purpose 
intended. Thus, in catalytic cracking, an overactive catalyst will produce 
disproportionately high quantities of coke and gas rather than the desired 
distillate products. 
An object of the present invention is to provide a novel process for 
performing catalytic reactions. A specific object is to provide a novel 
process for performing petroleum refinery operations under conditions less 
severe than heretofore have been obtained. Another object is to obtain a 
high throughput for a given process; i.e., to carry out a given process 
with high reactant-catalyst ratios. A further object is to provide a 
process in which reactors can be used containing less catalyst than has 
heretofore been possible. 
DETAILED DESCRIPTION OF THE INVENTION 
It has now been found that catalytic reactions, including molecular 
rearrangements, involving petroleum hydrocarbons are accelerated by the 
application of microwave energy to the hydrocarbons undergoing catalytic 
reaction. For example, processes commonly used in petroleum refineries 
including catalytic reforming, catalytic cracking, catalytic 
hydrocracking, hydrodealklation and catalytic polymerization give enhanced 
results wherein the reaction involved is carried out under the influence 
of microwave energy. The application of microwave energy to catalytic 
reaction, in general, permits the reaction in question to be perfomed 
under less severe conditions, such as a lower temperature, and/or lower 
pressures, and/or shorter catalyst contact times. This results in a 
substantial saving in utility costs. The lower catalyst contact times make 
possible the use of smaller reaction vessels containing smaller than usual 
amounts of catalyst, which results in a significant saving in capital 
investment for equipment and for catalyst inventory. Also, as has been 
found, catalyst life is greatly extended, especially where the catalytic 
process is performed in the presence of hydrogen, making regeneration 
significantly less frequent. This makes the present invention especially 
applicable to the catalytic process carried out in the presence of 
hydrogen, and the hydrogen may be added to or generated in the process. 
While it is not desired to be limited by theoretical considerations, it is 
believed that the microwave or microwaves, where a plurality of microwave 
frequencies is used, induces resonance in specific bonds of the reactive 
materials and/or causes the active sites of the catalyst to become 
increasingly active so that the desired reactions occur rapidly under less 
severe conditions than could be otherwise obtained. The input frequency of 
the microwave energy is therefore selectively tuned to induce resonance at 
the hydrocarbon bond or bonds to undergo transformation; where different 
hydrocarbon bonds are involved in the same operation, two or more 
frequencies are used to great advantage in accordance with the present 
invention. 
The wave energy to use in the present process is in the microwave range and 
may be from 2.5 to 1,000 gigacycles per second (2.5 .times.10.sup.9 to 
10.sup.12 cycles per second respectively). These frequencies may be 
expressed using the Hertz (Hz) Unit, and are the same as from 2.5 to 1,000 
gigahertz (1,000 GHz). As used herein "megacycles" means "megacycles per 
second" unless otherwise stated. With some catalytic reaction it may be 
advantageous to use two or three or even more frequencies simultaneously 
or consecutively, as above described, as this may be the most efficient 
operation. While again it is not desired to be limited by theoretical 
consideration, it is believed that a single frequency does not give 
optimum activation at all of the bonds where reaction occurs, or of the 
active catalyst sites. Thus, the bond connecting a tertiary carbon atom of 
an aliphatic-type molecule may receive maximum activation at one 
frequency, while the double bond of an olefinic molecule may receive 
maximum activation at a different frequency. Also, with two independent 
microwave sources, frequencies of at least 2 .times.10.sup.12 Hz can be 
obtained and, when properly tuned, the combined microwave can be used to 
excite, or activate, specific types of bonds or atoms with little or no 
effect on adjacent atoms or bonds of a different type. For a given 
catalytic reaction, the microwave or combination of microwaves for optimum 
results is best determined experimentally. For simultaneous operation, the 
reactant or reactants in contact with the catalyst is subjected to two or 
more wave energy sources of different frequencies at the same time. For 
consecutive operation, the reactant or reactants in contact with the 
catalyst is subjected to wave energy sources of different frequencies at 
different times, usually one immediately following the other. An 
alternative means for consecutive operation which is especially useful 
where moving or fluidized bed operations are used is to space microwave 
energy sources of different frequencies along the path of the reactants 
and catalyst particles in the reactor. When using different frequencies, 
the total time of exposure of the reactants and catalyst to the wave 
energy will be relatively short because of the high efficiency of the 
operation, so that times of exposure in the lower portions of the operable 
ranges give good results. The desirability of using a multiplicity of wave 
energy sources and the frequencies to use are best determined by 
experimentation for given reactants and catalyst, as above stated. The 
equipment for generating microwaves is well known to those skilled in the 
art. Continuous wave magnetrons with accompanying electronic equipment, 
which usually will include an amplifier and a radiation device for 
transmitting the wave energy, give good results, and the choice and use of 
such equipment will be apparent to those skilled in the art.

In FIG. 1, crude oil is introduced from storage tank 1 into fractionation 
tower 2 through line 4. This tower is conventional, and gas is removed 
from fractionation tower 2 through line 5. Naphtha, kerosene, diesel fuel 
and gas oil are removed from fractionation tower 2 as separate fractions 
through lines 6, 8, 9 and 10 respectively; and each fraction is passed to 
a catalytic hydrogen treating process. The primary purpose of each of 
these catalytic hydrogen treating processes is to reduce the sulfur 
content of the fraction and to saturate unsaturated bonds. Nitrogen and 
oxygen contents of the fractions are also significantly reduced. Thus, the 
mentioned fractions are treated in vessels 11, 12, 13 and 14 respectively 
by contacting with hydrogen in the presence of known hydrogenation 
catalysts. Oxides and sulfides of cobalt, molybdenum, nickel, or 
combinations thereof, extended on bauxite, synthetic alumina, or 
silica-alumina give good results. Molybdenum sulfide extended on 
silica-alumina is a preferred catalyst. Hydrogen is maintained at a 
pressure of from about 5 psi (pounds per square inch) to 3,000 psi 
although higher pressures can be used. A temperature of from about 
60.degree. F. to 400.degree. F. is advantageously maintained and it will 
be noted this temperature is significantly below the 750.degree. F. 
normally used for this type of reaction. Ambient temperature may be used 
to good advantage in many instances. A space rate of from about 1 to 10 
V/V/H (volume of hydrocarbon per volume of catalyst per hour). This space 
rate is significantly higher, about 20% to 60%, than the space rate 
normally employed in comparable operations without microwave energy being 
used. During the hydrogen treating reaction the mixture of naphtha and 
hydrogen contacting the hydrogenation catalyst is subjected to microwave 
energy from microwave source (MWS) 15. Two microwave sources are 
advantageously used and for the hydrogen treating process a frequency of 
at least 2.5 GHz is used. It is this use of microwaves that permits the 
use of the relatively low temperatures and pressures and the high space 
velocities obtainable. Also the high space velocities permit the use of 
smaller reactors and the maintaining of a smaller inventory of catalyst. 
In like manner, kerosene, diesel fuel and gas oil are treated in their 
respective separate catalytic hydrogen treating vessels under the 
influence of MWS 7, 18 and 19 respectively. The same catalyst as described 
for treating naphtha and substantially the same conditions may be used 
although, with increasing boiling range of the treated material, somewhat 
higher temperatures may be employed. For example, the kerosene treating is 
advantageously carried out at 100.degree. to 200.degree. F., the diesel 
fuel treating at 150.degree. to 350.degree. F., and the gas oil treating 
at 300.degree. to 500.degree. F. It is understood that the introduction of 
hydrogen to the reaction zone and the removal of contaminated hydrogen, 
its purification and return to the treating zones, are all by known means 
and are not shown in the diagram. 
As shown in the diagram, kerosene and diesel fuel subjected to catalytic 
hydrogen treatment under the influence of microwave energy form stable, 
clean burning products with the diesel fuel being of high cetane number. 
Naphtha, which has been treated in zone 11 to remove sulfur, nitrogen and 
oxygen compounds of low octane number, is advantateously passed through 
line 3 to caralytic reforming zone 16. This zone contains MWS 23. 
Catalytic reforming is a well known process and the present process 
essentially differs from the teachings of the art by applying microwave 
energy to the hydrocarbons in contact with the catalyst, in the use of 
less severe conditions of temperature and pressure, and in the use of a 
faster space rate. As the catalyst, a platinum catalyst having the 
platinum extended on a carrier material such as alumina is preferred, and 
the addition of a halogen to the process gives excellent results, as is 
well known in the art. Temperatures of from 850.degree. F. to 
1,000.degree. F. and pressures of from 200 psi to 700 psi are commonly 
employed in the art with a space velocity of 1 to 4 pounds of naphtha per 
pound of catalyst per hour giving good results. In accordance with the 
present invention, generally less severe conditions or conditions in the 
lower portions of the known ranges, are used, although one or more of the 
conditions may overlap with the broader ranges taught by the art. Thus, in 
the present invention, while subjecting the naphtha in contact with the 
platinum reforming catalyst to microwave energy, a temperature of from 
300.degree. F. to 800.degree. F. at pressures of from 100 psi to 400 psi 
and space velocities of from 4 to 10 pounds of naphtha per pound of 
catalyst per hour give excellent results. In the reforming process, 
naphthene rings are dehydrogenated to form aromatic rings and produce 
benzene, toluene and xylenes with the concomitant production of hydrogen. 
It is believed the presence of this hydrogen in the reforming operation 
carried out under the influence of microwave energy gives an exceptionally 
long catalyst life so that the regeneration of the catalyst may be 
extended from the usual 2 to 5 months to 10 months or more. The other 
reactions well known in catalytic reforming occur, including 
dehydrocyclization, isomerization and dehydroisomerization, and the 
product is advantageously separated into a light reformate and a heavy 
reformate for further use as for gasoline, which are shown schematically 
being removed as products through lines 27 and 20 respectively. 
The product from catalytically treating gas oil in vessel 14 is removed 
therefrom through line 21 and passed to catalytic cracking zone 22. 
Advantageously the catalytic cracking is with a fluidized operation, as 
described in my Patent Application Ser. No. 896,004, filed Apr. 13, 1978. 
The cracking operation is performed as described by the art except that 
the material being cracked in contact with a cracking catalyst is 
simultaneously subjected to microwave energy shown schematically as MWS 
24. In actual operation the microwave source is advantageously spaced in 
the riser cracker and, where desirable, an additional source, which may be 
of a different frequency, is spaced in the reactor. Generally fluid 
catalytic cracking is performed under temperatures of 850.degree. F. to 
1,000.degree. F., at pressures of about 30 psi to 50 psi and space 
velocities of about 1 to 3 V/V/H. In accordance with the present 
invention, less severe conditions can be used and advantageously the 
reactor temperature is maintained in the range of from 400.degree. F. to 
800.degree. F., pressures of from 20 to 40 psi and a space velocity of 
from about 3 to 8 V/V/H. The microwave energy is advantageously at a 
frequency of 2.5 GHz, but 10 GHz or a combination gives good results. In 
the present process, as has been noted, required regeneration of the 
catalyst is less severe than in the usual cracking process; and it is 
believed that the presence of microwave energy activates catalyst sites 
which render them more active for cracking reactions but that the 
reactions occur at a sufficiently high rate to prevent the formation of 
coke, which would deactivate the catalyst, and undesired gaseous products. 
Catalyst used are those generally used in fluid cracking operations and 
include naturally occuring clays which have been activated and 
synthetically prepared composites such as silica-alumina, silica-zirconia 
and silica-magnesia. Zeolites in a silica-alumina matrix give excellent 
results. In the fluidized process the catalyst particles are in the form 
of a powder generally of size rage of from 20 to 150 microns. Products 
from the catalytic-cracking, gas, gasoline,, heating oil, and cycle oil, 
are moved through lines 37, 38, 39 and 46, respectively. The cycle oil 
removed through line 46 is advantagously used in the manufacture of high 
grade lubricating oils. 
Gas oil from fractionator 2 may bypass catalytic treater 14 and pass via 
line 25 to catalytic hydrocracking as shown by 26. During the catalytic 
hydrocracking reaction, the reactants and catalyst are simultaneously 
subjected to the influence of microwaves from MWS 28. In accordance with 
the present invention, the use of MWS in catalytic cracking is 
particularly advantageously because the presence of added hydrogen, shown 
as added via line 39, enhances the action of the microwaves to achieve the 
desired products. In hydrocracking there is very little carbonizing of the 
active cracking sites of the catalyst; the formation of coke and gas is 
almost completely inhibited. Reactions of olefin saturation, the cleavage 
of chains from ring compounds, the splitting of non-fused bicyclic 
structures into separate rings, and rupture of the ring of various ring 
compounds all occur simultaneously with the destruction of sulfide bonds 
to form hydrogen sulfide. Any hydrogen sulfide formed is removed with the 
gas product via line 30 and is separated by known means. Major products 
are usually gasoline, naphtha, jet or diesel fuel, furnace oils and low 
sulfur resid, and are recovered via lines 31, 32, 34, 35 and 36, 
respectively. In general, the products are almost totally saturated and 
stable (assuming aromatics to be classed as saturated), which contain 
substantially no sulfur and no nitrogen. The diesel fractions are of high 
cetane number; the furnace oils, including kerosene, of high smoke point; 
and the jet fuels are substantially non-smoking. The low sulfur resid 
(line 36) is advantageously used for burning or may be sent to a viscosity 
breaking operation. Highly active cracking catalysts give good results. 
Silica-alumina or other base material containing natural or synthetic 
zeolites gives good results. Noble metals such as platinum have been 
described as assisting the catalytic reaction. Where desired, a two-stage 
process can advantageously be used wherein the gas oil is first contacted 
with hydrogen in a hydrotreater, as shown by 14, using a cheaper, more 
more resistant catalyst than used in the hydrocracker, such as sulfided 
nickel, molybdenum, or cobalt. This removes the sulfur and hydrogen 
compounds so that the second, more expensive catalyst will last longer and 
can be easily regulated. Fixed bed, moving bed and ebullating bed, in 
which the catalyst particles are suspended in liquid and agitated by 
hydrogen may be used. In the present invention the efficiency of operation 
with the use of microwave enegy is such that only a single stage of 
cracking is preferred, i.e., the use of a preliminary hydrogen treating is 
not necessary. Temperatures commonly used in the hydrodesulfurization 
process are in the range of 500.degree. F. to 850.degree. F. and pressures 
are from about 750 psi to 2,000 psi with an excess of hydrogen being used 
to maintain the pressure. In the present invention significantly lower 
temperatures of from 200.degree. F. to 450.degree. F. are employed with 
good results although, of course, higher pressures may be used. Also lower 
pressures in the range of from 500 psi to 1,000 psi give good results. 
Hydrogen for use in the process is advantageously from catalytic reforming 
16 (not shown) and when necessary, additional hydrogen can be provided by 
known processes such as reforming methane or hydrocarbon gases in the 
presence of steam. My invention in this phase of petroleum refinery 
operation is the conducting of catalytic hydrocracking in which the 
reactants, hydrogen, and catalyst are contacted while under the influence 
of microwave energy. This permits the catalytic hydrocracking to occur 
under relatively low temperatures and pressures and relatively high space 
rates so that the size of the catalytic reactor can be decreased and the 
inventory of catalyst can be decreased significantly, say from 10% to 50% 
below that required in the usual catalytic hydrocracking processes. 
The bottoms from fractionation 2 pass via line 50 to vacuum still 51. 
Vacuum gas oil from still 51 passes via line 52 to mix with gas oil in 
line 10. Reduced crude is passed via line 54 to viscosity breaking or 
coking via line 55, or via lines 56 and 25 to catalytic hydrocracking. 
Hydrodealkylation is a refinery process in which short chains are removed 
from aromatic hydrocarbons. Thus toluene may be converted to benzene or 
xylenes to toluene and benzene, the toluene and/or xylenes being 
recoverable from catalytic reforming 16 (not shown). With reference to 
FIG. 2, hydrodealkylation is shown taking place in vessel 40 by 
introducing toluene through line 41 and hydrogen through line 42 with 
benzene, the product of the process, being removed through line 44. In 
hydrodealkylation a cracking catalyst such as chromia-alumina, 
silica-alumina or silica-magnesia, or a natural or synthetic zeolite 
material, give good results. In accordance with the present invention, the 
reactants while in contact with the catalyst are subjected to MWS as shown 
by 45. Temperatures in the range of 1,000.degree. F. to 1,200.degree. F. 
and pressures of 500 psi to 1,200 psi give good results and are about 20% 
to 40% below the required temperatures and pressures to get good results 
in prior processes. When using dual sources 2.5 megaHz properly tuned, the 
temperature can be reduced to 400.degree. F. to 500.degree. F. Fixed bed 
catalyst operation or other type operation as known to the art may be 
used. 
Gaseous olefins, principally ethylene and propylene, are prepared in the 
several refinery cracking operations and may be separated by fractionation 
and absorption techniques well known in the art. The polymerizations of 
these olefins give valuable products and are considered refinery 
operations. For simplicity, these operations are herein described without 
reference to schematic flow diagrams. Ethylene may be polymerized to 
polyethylene and propylene to polypropylene. These polymerizations are 
advantageously carried out using a Ziegler-type catalyst. A catalyst which 
is especially effective for the polymerization of normally gaseous olefins 
to relatively high molecular weight, solid polymers is the combination of 
a lower halide of a metal, such as titanium trichloride, and an aluminum 
triethyl. This catalyst can be prepared by admixing, for example, titanium 
tetrachloride and aluminum triethyl in an inert liquid such as isooctane. 
On admixing the two components, a finely divided solid phase is formed as 
a dispersion in the inert liquid. This solid phase is a catalyst for 
polymerizing normally gaseous olefins to solid polymers. If desired, a 
lower halide such as titanium trichloride can be preformed, dispersed in 
an inert liquid, and an activator such as an aluminum trialkyl added. In 
performing the polymerization step, a normally gaseous olefin is contacted 
with the solid catalyst by passing the olefin through a suspension of the 
finely divided solid in the inert liquid, and is thereby polymerized to 
solid polymers. 
The polymerization of a normally gaseous olefin is performed in an inert, 
liquid reaction medium. Saturated hydrocarbons including the pentanes, 
hexanes, heptanes, decanes, mixtures thereof and the like, cycloparaffins 
such as the cyclopentanes, and cyclohexanes, and mixtures thereof with 
each other and with paraffins can be used with good results. 
The polymerization can be carried out batchwise or as a continuous process 
in the hydrocarbon diluent at moderate temperatures, usually from 
20.degree. C. to about 120.degree. C., and at pressures of from 1 to 40 
atm. The propylene is added at a controlled rate to the catalyst slurry 
and the crystalline polymer precipitates as a finely divided granular 
solid enveloping the catalyst particles. After the polymerization, a 
suitable reagent is added to kill the catalyst activity and to dissolve 
the catalyst particles from the polymer. Atactic, or noncrystalline, 
polymer is separated from the isotactic or crystalline polymer by 
dissolving the atactic material in a solvent such as heptane. Molecular 
weights of from 50,000 to 200,000 and higher are commonly obtained. The 
addition of hydrogen to the propylene feed can be used to regulate the 
molecular weight since the hydrogen acts as a chain stopper. Partial 
pressures of hydrogen are advantageously from about 50 psi to 500 psi for 
usual operation. In accordance with the present invention, microwave 
energy is applied to propylene while contacting the slurry of solid 
catalyst particles and, as has beeen found, greatly enhanced results are 
obtained. Thus, the speed of reaction is increased from two to eight 
times, the quantity of isotactic polymer is decreased significantly and 
the molecular weight spread of the crystalline polymer can be regulated to 
a relatively narrow range by using properly tuned microwaves. Also the use 
of hydrogen can be discontinued although advantages may be obtained by its 
presence in assisting to regulate the molecular weight. A particular 
advantage is the relatively large amount of polymer which can be obtained 
per unit of catalyst. For example, under equivalent conditions, an 
increase of ten to fifty times (pounds of polymer per pound of catalyst) 
is obtained when using the present invention. Also, an increase of the 
polymerization rate of from two times and up to ten times can be achieved 
using properly tuned microwaves. The very small amount of catalyst used, 
for most uses of the polymer, need not be removed therefrom, thus 
eliminating a step in the usual polymerization process. 
In like manner, microwave energy is advantageously applied to the 
polymerization of ethylene with Ziegler type catalyst, and substantially 
the same results and advantages are achieved as for preparing 
polypropylene. 
To illustrate preferred refinery operations in accordance with the 
invention, a paraffin-base, midcontinent crude oil containing about 85% C, 
14% H, 0.05% N, 1.4% O and 1.0% S is passed through line 4 from storage 1 
to fractionation tower 2. Gas is removed from line 5 and consists of 
hydrocarbons boiling below about 90.degree. F. The naphtha fraction 
removed through line 6 is the next higher boiling fraction, has an end 
point of about 400.degree. F., and is passed to catalytic hydrogen 
treating as indicated by 11, where it is treated with hydrogen in contact 
with a fixed bed of catalyst under the influence of MWS shown at 15. The 
catalyst was commercially available and consisted of cobalt and molybdenum 
sulfide supported on silica-alumina. The hydrogen treating is conducted at 
a temperature of 200.degree. F., a space rate of 6 V/V/H, and a pressure 
of 200 psi using an excess of hydrogen so that substantialy all the sulfur 
is converted to hydrogen sulfide. The MWS 15 is advantageously a dual 
source of 2.5 GHz microwaves. A hydrogen treated naphtha, being 
substantially free of sulfur, nitrogen and oxygen compounds, is then 
passed to catalytic reforming 16 via line 3. 
The next higher fraction is a kerosene fraction removed from fractionation 
2 via line 8. It has a boiling range of about 300.degree. F. to 
600.degree. F. and is catalytically treated with hydrogen in 12 under the 
influence of MWS 7 as for the naphtha fraction to form the kerosene 
product removed by line 17. The catalytic treating step is carried out 
under substantially the same conditions and catalyst as for the naphtha in 
11. The kerosene product is a stable, clean burning kerosene of 
substantial commercial value, and is recovered via line 17. 
The next higher boiling fraction is diesel fuel boiling in the range of 
from about 400.degree. F. to 650.degree. F., and is removed from 
fractionation 2 via line 9 and passed to catalytic hydrogen treater as 
shown at 13 under the influence of MWS 18. The diesel fuel product is 
removed through line 23 and is a high cetane, stable diesel fuel. The 
conditions of catalytic hydrogen treating may be substantially the same as 
described for treatment in 11, including the catalyst used. 
The next higher boiling fraction is a gas oil boiling in the range of from 
about 500.degree. F. to 800.degree. F. and is removed from fractionation 2 
via line 10 to catalytic hydrogen treating 14 under the influence of MWS 
19. Here again the catalytic treatment can be substantially the same as 
described for 11 except that a somewhat higher temperature, say around 
400.degree. F., is advantageously employed. The catalytic treated material 
leaves 14 via line 21 and is passed to catalytic cracking 22. A portion of 
the gas oil removed from fractionation is passed via line 25 to catalytic 
hydrocracking 26. 
The residual or bottoms fraction from fractionation 2 is passed via line 50 
to vacuum still 51, wherein the vacuum gas oil having a boiling range of 
from about 600.degree. F. to 800.degree. F. is flashed off and recovered 
via line 52 and returned to gas oil line 10 for catalytic hydrogen 
treating in 14 or catalytic hydrocracking in 26. Reduced crude boiling 
from about 800.degree. F. to 1,200.degree. F. is passed via lines 54 and 
56 to hydrocracking 26 with a portion or all of the reduced crude going to 
viscosity breaking or coking operations (not shown) as desired via line 
55. The bottoms fraction from the vacuum still is advantageously passed 
through line 58 to lubricating oil manufacture, which forms no part of the 
present invention. 
The effluent from catalytic hydrogen treating 11 is passed via line 3 to 
catalytic reforming 16. A platinum on alumina commercially available 
catalyst is used and MWS 18 is at 2.5 GHz frequency. The well known 
reforming reactions occur giving a net production of hydrogen, which is 
recovered and advantageously passed to catalytic hydrocracking 26 (by 
means not shown). Catalytic reforming conditions are used except that a 
lower temperature and faster space velocity than normal are used. Thus the 
catalytic reforming conditions include a temperature of about 600.degree. 
F., a space velocity of about 4 pounds of naphtha per pound of catalyst 
per hour, and a pressure of about 300 psi. The light reformate, which is a 
valuable high octane component for gasoline, is recovered via line 27 and 
a heavy reformate, which is a valuable high octane hydrocarbon stream 
useful in gasoline or chemical manufacture, is recovered through line 20. 
Gas oil from fractionation 2 through line 25, vacuum gas oil from vacuum 
still 51 via lines 52 and 25, and reduced crude from vacuum still 51 via 
lines 54 and 56, or any combination thereof, are introduced to catalytic 
hydrocracking 26. In hydrocracker 26 the hydrocarbon materials are reduced 
in molecular weight and are saturated to form stable products with 
substantially no sulfur or nitrogen content. The presence of hydrogen 
almost eliminates the formation of coke and gaseous materials. Catalytic 
hydrocracking conditions are employed except that the temperature is lower 
than normal and the space velocity is higher than normal so that a 
temperature of about 400.degree. F., a space velocity of about 6 V/V/H, 
and a pressure of about 800 psi are preferred, and these relatively mild 
conditions are made possible by MWS 28, which comprises two sources of 
microwaves spaced apart in the reactor with one being tuned to 2.6 GHz and 
the other to 10 GHz. The products of the hydrocracking, gas gasoline, 
naphtha, jet or diesel fuel, furnace oils and low sulfur resid, are 
recovered through lines 30, 31, 32, 34, 35 and 36, respectively. These 
constitute products of the process although certain of the fractions, such 
as naphtha recovered through line 32, are advantageously recycled to line 
3 for catalytic reforming in 16; further catalytic hydrogen treating as in 
11 is not necessary because the sulfur compounds have been substantially 
removed in 26. 
Gas oil from hydrogen treater 14 is passed via line 21 to catalytic 
cracking 22. MWS 24 operating at 10 GHz frequency is applied to the 
reactants in contact with the catalyst at a temperature of 600.degree. F., 
a pressure of 30 psi, and a space rate of 8 V/V/H. Catalyst deactivation 
is greatly retarded so that the removal of spent catalyst and the addition 
of make-up catalyst is reduced about 12%. 
Many variations in my invention can be made, which is the conducting of 
petroleum refinery operations involving catalytic reactions of petroleum 
hydrocarbons by subjecting the catalyst and hydrocarbon reactants, while 
in contact, to microwave energy.