U.S. patent application number 13/051174 was filed with the patent office on 2011-10-06 for use of well mixed, backmixed reactors for processing of unstable bio feedstocks.
This patent application is currently assigned to UOP LLC. Invention is credited to Andrea G. Bozzano, Richard E. Marinangeli.
Application Number | 20110239530 13/051174 |
Document ID | / |
Family ID | 44707968 |
Filed Date | 2011-10-06 |
United States Patent
Application |
20110239530 |
Kind Code |
A1 |
Marinangeli; Richard E. ; et
al. |
October 6, 2011 |
USE OF WELL MIXED, BACKMIXED REACTORS FOR PROCESSING OF UNSTABLE
BIO FEEDSTOCKS
Abstract
In the present invention, pyrolysis oil is processed in a well
mixed or a back mixed reactor to prevent the plugging up of a
reactor that otherwise occurs. The pyrolysis oil can then be
further upgraded in a hydroprocessing reactor through use of an
appropriate catalyst.
Inventors: |
Marinangeli; Richard E.;
(Arlington Heights, IL) ; Bozzano; Andrea G.;
(Northbrook, IL) |
Assignee: |
UOP LLC
Des Plaines
IL
|
Family ID: |
44707968 |
Appl. No.: |
13/051174 |
Filed: |
March 18, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61319019 |
Mar 30, 2010 |
|
|
|
Current U.S.
Class: |
44/307 |
Current CPC
Class: |
C10L 1/04 20130101; Y02P
30/20 20151101; C10G 2300/42 20130101; C10L 1/02 20130101; C10G
3/42 20130101; C10G 2300/205 20130101 |
Class at
Publication: |
44/307 |
International
Class: |
C10L 1/00 20060101
C10L001/00 |
Claims
1. A process of upgrading a pyrolysis oil comprising sending said
pyrolysis oil to a well-mixed reactor or a back-mixed reactor to
produce an upgraded pyrolysis oil.
2. The process of claim 1 further comprising sending said upgraded
pyrolysis oil to a reactor to further upgrade said upgraded
pyrolysis oil.
3. The process of claim 1 wherein metals are removed from said
pyrolysis oil in said well-mixed reactor or said back-mixed
reactor.
4. The process of claim 1 wherein reactive species are removed from
said pyrolysis oil in said well-mixed reactor or said back-mixed
reactor.
5. The process of claim 2 wherein said upgraded pyrolysis oil is
reacted with a catalyst in said reactor to cause said upgraded
pyrolysis oil to be deoxygenated/hydroprocessed within said
reactor.
6. The process of claim 1 wherein said upgraded pyrolysis oil is
less likely to result in precipitation of solids and plugging of a
reactor than a pyrolysis oil that has not been upgraded.
7. The process of claim 1 wherein said pyrolysis oil is subjected
to hydroprocessing within said well mixed or said back-mixed
reactor.
8. The process of claim 1 wherein said well-mixed or back mixed
reactor is selected from the group consisting of stirred tank
reactors, plug flow reactors with recycle, slurry reactors,
gas-lift reactors and jet reactors.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority from Provisional
Application No. 61/319,019 filed Mar. 30, 2010, the contents of
which are hereby incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] The present invention generally relates to methods for
producing biofuels, and more particularly relates to methods for
producing biomass-derived pyrolysis oils having increased phase
stability.
[0003] The use of biofuels is of growing interest due to an
increased environmental awareness. Biomass-derived pyrolysis oils
obtained from the pyrolysis of biomass are considered to be a
promising biofuel. Biomass-derived pyrolysis oils have the
potential to replace up to 60% of transportation fuels thereby
reducing the dependency on conventional petroleum and reducing its
environmental impact.
[0004] Fast pyrolysis is a process in which organic materials are
rapidly heated to 450.degree. to 600.degree. C. in the absence of
air. Under these conditions, organic vapors, pyrolysis gases and
char are produced. The pyrolysis gases contain small amounts of
reducing gases, such as hydrogen, carbon monoxide, etc. The vapors
are condensed to biomass-derived pyrolysis oil. Pyrolysis of
biomass under conditions of such rapid heating and short reactor
residence times can produce low-viscosity, single-phase
biomass-derived pyrolysis oil. Most projected uses of
biomass-derived pyrolysis oil require that it retain these initial
physical properties during storage, shipment and use. Pyrolysis is
the chemical decomposition of condensed substances by heating, that
occurs spontaneously at high enough temperatures. Pyrolysis is a
special case of thermolysis, and is most commonly used for organic
materials, being then one of the processes involved in charring.
This chemical process is heavily used in the chemical industry, for
example, to produce charcoal, activated carbon, methanol and other
chemicals from wood, to convert ethylene dichloride into vinyl
chloride to make PVC, to produce coke from coal, to convert biomass
into syngas, to turn waste into safely disposable substances, and
for transforming medium-weight hydrocarbons from oil into lighter
ones like gasoline. These specialized uses of pyrolysis may be
called various names, such as dry distillation, destructive
distillation, or cracking
[0005] Pyrolysis differs from other high-temperature processes like
combustion and hydrolysis in that it does not involve reactions
with oxygen, water, or any other reagents. However, the term has
also been applied to the decomposition of organic material in the
presence of superheated water or steam (hydrous pyrolysis), for
example in the steam cracking of oil.
[0006] Pyrolysis is the basis of several methods that are being
developed for producing fuel from biomass, which may include either
crops grown for the purpose or biological waste products from other
industries.
[0007] Although synthetic diesel fuel cannot yet be produced
directly by pyrolysis of organic materials, there is a way to
produce similar liquid ("bio-oil") that can be used as a fuel,
after the removal of valuable bio-chemicals that can be used as
food additives or pharmaceuticals. Higher efficiency is achieved by
the so-called flash pyrolysis where finely divided feedstock is
quickly heated to between 350.degree. and 500.degree. C. for less
than 2 seconds.
DESCRIPTION OF THE INVENTION
[0008] The present invention involves a process of upgrading a
pyrolysis oil in which pyrolysis oil is sent to a well-mixed
reactor or a back-mixed reactor to produce an upgraded pyrolysis
oil.
[0009] Bio-based feedstocks, particularly pyrolysis oils, are
unstable during processing. The instability may be thermal,
chemical, or physical. These pyrolysis oils are difficult to
hydroprocess due to formation of solids. This instability may be
caused by high temperature excursions at the reactor inlet for an
exothermic reaction, by depletion of reactants such as hydrogen
needed to stabilize reactive intermediates, high concentrations of
reactants which condense to form solids, or phase instability.
These conditions may lead to precipitation of solids and reactor
plugging. A well-mixed or backmixed reactor has uniform
concentration and temperature throughout the reactor. Consequently,
thermal and chemical instability are unlikely. Well mixed, or
back-mixed reactors include stirred tank reactors, plug flow
reactors with recycle, slurry reactors, as well as gaslift or jet
reactors, all of which are well known to those skilled in the
chemical arts.
[0010] The purpose of the first reactor is to process the feedstock
to the point that its plugging propensity is reduced. Hence, the
reactive species are reduced. The first reactor also needs to
achieve the goal of metals removal. The reason for doing this in a
backmixed reactor is to avoid plugging and also to potentially
remove catalyst which has been loaded with metals. The effluent
from the first feedstock now is routed to a fixed bed reactor, in
which a more conventional processing approach can be taken. The
catalyst used here is a more conventional
deoxygenation/hydroprocessing catalyst.
EXAMPLE 1
[0011] A feed comprising Pyrolysis Oil was tested in an autoclave
reactor to simulate a backmixed reactor. A 300 cc autoclave was
charged with 50 cc of feed and 10% by feed weight of a
Pd/Al.sub.2O.sub.3 catalyst. After pressure testing, the autoclave
was stirred at 300 to 500 rpm and pressurized with hydrogen to 8274
kPa (1200 psig). The temperature was ramped to the target and held
for 2 hours. After cooling and depressurizing, the reactor, a
two-phase liquid product, was removed from the reactor and
analyzed. An equivalent space velocity was calculated based on the
volume of feed and catalyst and the reaction time.
EXAMPLE 2
[0012] The same feed was tested in a tubular reactor to simulate a
plug flow reactor. The reactor tube was loaded with 15 cc of the
same Pd/Al.sub.2O.sub.3 catalyst and 45 cc of an alumina diluent
and a metal spacer to occupy the void volume in the reactor. The
loaded reactor was mounted in a furnace and pressure tested. The
catalyst was pretreated with 5 to 10 cc/min of flowing hydrogen at
ambient temperature. The reactor temperature was increased to
200.degree. C. for 1 hour and then to 400.degree. C. for 1 hour.
The reactor was cooled to the target temperature and feed was cut
in to the reactor at the target rate for 1 hr.sup.-1 space
velocity. The reactor was run overnight and a two-phase liquid
product was collected throughout the run and analyzed.
TABLE-US-00001 Example 1 Example 2 Temperature, .degree. C. 150 170
Pressure, kPa (psig) 10,340 (1500) 5,171 (750) Space velocity,
hr.sup.-1 2.7 1 Top Phase amount, vol-% 56 71 Top Phase, carbon,
wt-% 20.7 20.9 Top Phase, hydrogen, wt-% 8.8 9.1 Bottom Phase,
vol-% 44 29 Bottom Phase, carbon, wt-% 48.7 54.0 Bottom Phase,
hydrogen, wt-% 8.0 6.9
[0013] The pressure for Example 1 was based on the start of the
experiment and decreased during the run as hydrogen was consumed.
The table shows that at less severe conditions (higher space
velocity, lower temperature), an equivalent product was produced in
Example 1, the backmixed system.
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