United States
Environmental Protection
Agency
EPA/540/F-93/508
August 1993
&EPA
SUPERFUND INNOVATIVE
TECHNOLOGY EVALUATION
Emerging Techno
ogy Bulletin
Spouted Bed Reactor
Technology Description: The Spouted Bed Reactor (SBR)
technology utilizes the unique attributes of the "spouting " fluidi-
zation regime, which can provide heat transfer rates comparable
to traditional fluid beds, while providing robust circulation of
highly heterogeneous solids, concurrent with very aggressive
comminution (particle size reduction through abrasion.) The pri-
mary spouted bed provides a zone for volatilization, pyrolysis,
and gasification reactions. The gaseous products can then be
applied to highly efficient oxidation/incineration in conventional
combustion equipment, used for power production in prime mov-
ers or, alternatively, chemical products can be recovered. Thus,
gasification provides much greater opportunity for product recov-
ery through Advanced Recycling.
The EER pilot plant process flow is shown in Figure 1. Waste is
fed into the primary spouted bed reactor via conveyor belt to the
extrusion feeder. The extrusion feeder is a very rugged screw
type extrusion device which extrudes the heterogeneous feed
material into the spouted bed thermpchemical reaction zone
where solids are comminuted and gasified at medium tempera-
ture (1000-1600 °F). Large solids remain in the bed until they are
reduced in size through attrition, pyrolysis, and gasification reac-
tions.
Steam and gaseous products elutriate fine particles out of the
primary reactor into the secondary slagging hot cyclone where
the temperature is increased significantly by addition of oxygen.
Fifty to 75% of the solids may be recovered as a vitrified product
from the slagging hot cyclone when it is operated at slagging
temperatures. The gas stream is then cooled via heat exchange
to recover heat and raise steam for the process and the fine
participate is then removed in a traditional baghouse. Dry scrub-
bing techniques are used to remove acid gases. Baghouse ash
may be recycled to the primary spouted bed.
Steam is used as the spouting fluid, highly superheated by a
small in-line oxy-fuel burner. The resulting high velocity spouting
gases cause aggressive size reduction of heterogeneous feed-
stocks concurrent with the promotion of thermochemical gasifica-
tion reactions. Particle size is rate limiting for heat and mass
transfer reactions, including pyrolysis and carbon gasification.
Therefore, rapid size reduction through comminution in the spouted
bed significantly improves reaction rates resulting in greater
throughput for a given equipment size. Superheated steam pro-
vides heat for endothermic pyrolysis reactions, along with partial
oxidation of wastes which react with sub-stoichiometric levels of
oxygen injected into the spouted bed primary.
Advanced recycling technology development
Secondary 0.
Fines Injection
EER
Spouted Bed
Technology
Slagging Cyclone
Technology
Syn-Gas
Product
Inert Granular Solids
Tramp Metals Removal
Figure 1. SBR thermochemical waste recycling system.
^g§> Printed on Recycled Paper
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A secondary hot cyclone fs fired with additional oxygen to further
rats* the temperature of gasification products to slagging tem-
p*«tae when a vMled product is desired, hi the presence of
excess steam at high temperature, toxic oiganic compouncfs that
may resuft during fcsw or medium temperature waste pyrolysis are
r«dueed t& H^ CO, (X)8, and HZO. Subsequent purification of the
stream can fa© accomplished using conventional
_i6S,
WaiJte Applicability: The SBR Advanced Recycling technol-
ogy is primarily applicable to waste wfth significant heat content
thai are contaminated with tqxfc organic compounds and heavy
maids. The heat content of the waste may range from 3,QGO to
12,000 Btu par pound, Soils contaminated with coal tar residues,
pwfroloum refinery wastes, and municipal solid wastes are appro-
priata for processing in the SBR Advanced Recycling system.
Chemical wast®, munftfons and rockei propellants are also candi-
date feed materials,
Pilot P&nf Test Results; Accomplishments to date have
included the design, construction, shakedown, and preliminary
operation of a pilot scale SBR facifry capable of processing 10QO-
1500 iblhr of waste. Trouble-free feeding of "raw" unsegregated
Auto Shredder Residue (ASR) plastics has been accomplished at
a feed rate of 1400 Ma, Limited data obtained during test runs
(we demonstrated Hie conversion of ASR to hydrocarbon rich
process gas 0330-480 Btu/tecf), with negi^lble tar formation, and
with 1-2% carbon remaining in the ash constituents. ASR product
ash analysis {recovered from the hoi cyclone) indicated metals
leaohabUy betow regulated limits* lead and cadmium, the two
metals of primary concern in ASR, were 0,4 & 0,06 mg/l respec-
Ifvely, the Mmfts being e.o and 1.0,
United Steles
Environmental Protection Agency
Center lor Environmental Research Information
Cincinnati, OH 45268
Official Business
Penalty tor Private Use
S3GG
Preliminary tests with ASR have been limited to several short
duration runs, and some further modification and testing is re-
quired in order to complete fhe development of the SBR gasifica-
tion technology and to demonstrate tts effectiveness at pilot
scale. Later phases of development will then focus on issues
related to In-process and back-end clean-up of the product gas,
Advanced recycling fjhermochemfcal conversion) of high Bta
content wastes can generate a variety of end products. These
include pyrolysate liquids^ oiefins, and synngas. EER's SBR tech-
nology can be operated at low, medium, or high temperature in
order to generate these respective end products* Bed materials
tested to date Include 1W and 1/4" silica sand, 1/4" alumina
balls, and 1 mm steel shot. The effects of bed materials and
reactive addilives will require careful characterization.
For Further Information:
EPA Project Manager
Teri Richardson
US Environmental Protection Agency
26 West Martin Luther King Drive
Cincinnati, Ohio 46268
(513) 569-7949
EER Project Manager
Donald G, Taylor
Energy and Envfronmental Research Corporation
18 Mason
Irvine, CA 92718
(714) 859-8851 *U.&.CtoramB»ntP
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