United States
Environment Protection
Agency
Air and Energy Engineering
Research Laboratory
Research Triangle Park, NC 27711
Research and Development
EPA/600/S7-86/007 May 1986
SERA Project Summary
Environmental Assessment:
Source Test and Evaluation
Report Addendum — Lurgi-Type
Medium-Btu Gasification
Karl J. Bombaugh
This report is an addendum to "Envi-
ronmental Assessment: Source Test and
Evaluation Report-Lurgi Type (Kosovo,
Yugoslavia) Medium-Btu Gasification, Final
Report," EPA-600/7-81-142, August 1981.
It contains analytical data on 21 gasifica-
tion plant streams, not included in the
original report.
Condensable organics from the plant's
major gas, solid-phase, and selected liquid-
phase streams were characterized by the
EPA protocol for a Level 1 source assess-
ment to determine the mass distribution
of chemical classes which they contained.
GC-MS analyses were performed on gas
stream condensates to quantify their
levels of hazardous PNAs. Profiles of the
sulfur- and nitrogen-bearing species in
these condensates were obtained with
element-specific GC detectors.
This Project Summary was developed
by EPA's Air and Energy Engineering
Research Laboratory, Research Triangle
Park, NC, to announce key findings of the
research project that is fully documented
in two separate volumes of the same
title (see project Report ordering infor-
mation at back).
Introduction
Coal, because of its abundance, is a poten-
tial replacement for depleting U.S.
petroleum reserves and may eventually
become a principal source of hydrocarbon
fuels and chemical feedstocks. Conse-
quently, substantial efforts have been
devoted to evaluating coal utilization
technologies for their economic and en-
vironmental performances. Among the
leaders in the rapidly developing
technology for converting coal to clean
fuel is steam/oxidant gasification.
The purpose of this study was to obtain,
from a commercial facility, data that could
be used in an environmentally based
evaluation of Lurgi-type technology. The
test facility, in the Kosovo region of
Yugoslavia, uses 3.4 m pressurized gasi-
fiers to convert lignite to medium-Btu gas.
The study, sponsored by the U.S. EPA, was
conducted over a period of several years
as a cooperative effort among scientists
from the U.S. and Yugoslavia. The four-
phase program investigated several
aspects of plant-related environmental
contamination including: source dis-
charges, fugitive emissions, and ambient
air pollution. Results from each of these
programs have been reported separately.
However, during Phase II of the Source
Test, samples of process liquids and gas
stream condensates were collected which
were not analyzed in time for the results
to be included in the Phase II report
(EPA-600/7-81-142). These analyses have
been completed, and the results are the
subject of an addendum to the Phase II
report. The addendum provides informa-
tion on the mass distribution of chemical
classes in the condensable organics from
the plant's significant discharge streams.
It also provides information on specific
polycyclic aromatics and on the distribu-
tion of heteroaromatic hydrocarbons con-
taining nitrogen and/or sulfur.
For data obtained from the study to be
properly interpreted, it must be recognized
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that the Kosovo plant does not include all
of the design and operating features of
modern Lurgi-type facilities. For example,
the Kosovo plant does not employ many
of the pollution control processes that will
be incorporated in U.S. gasification facil-
ities. Therefore, many of the "uncon-
trolled" discharges from the Kosovo plant
are not representative of the "controlled"
discharges which are expected from future
U.S. plants based on similar technology.
However, the Kosovo plant's uncontrolled
discharge streams characterized in this
program are expected to be similar in com-
position and relative flow rates to
analogous internal streams in future U.S.
plants (unless specific design or opera-
tional features for these plants cause
significant differences). Therefore, the
compositions of the uncontrolled dis-
charge streams at Kosovo will be, in many
cases, representative of the inlet streams
to pollution control processed in future
U.S. plants based on similar technology.
Within these constraints, the data ob-
tained in this study can be used to:
Indicate the nature of the organics
found in uncontrolled discharges
from the processing units of a gas-
ification plant based on similar
technology. (Most of these streams
are expected to be routed to pollution
control units in future U.S. plants.)
i
• Assess the need for pollution control
processes for potential discharge
streams from future U.S. plants based
on similar technology.
• Indicate the nature of the organics
that may be present at low levels in
the discharges from pollution control
devices.
Plant Description
The Kosovo coal gasification plant is an in-
tegral part of a large minemouth industrial
complex that includes a coal mine, a coal
preparation plant, a coal gasification plant,
an air separation plant, an ammonia-based
fertilizer plant, a power generating plant,
and a steam generating plant.
The gasification facility, hereafter called
the "gasification plant," consists of nine
unit-operations as shown in Figure 1. The
gasification plant consumes dried lignite
and produces two primary products: a
medium-Btu fuel gas having a net heating
value of about 14 MJ/m (360 Btu-scf) at
25 °C (77 °F), and hydrogen which is used
as an ammonia synthesis feedstock. Also
produced are four liquid by-products:
crude phenol, tar, medium oil, and
naphtha. The plant's operation is ex-
plained below.
Upgraded coal from the Kosovo mine is
dried in autoclaves (Fleissner process) to
reduce the moisture content from about
50 to 20 percent and then sized to select
particles ranging from 6 to 60 mm. After
being sized, the dried coal is reacted with
oxygen and steam in Lugi-type gasifiers at
2.5 MPa (25 atm) pressure to produce gas
which is quenched, cooled, and then
cleaned by the Rectisol process prior to its
transport to the utilization site for use as
fuel or as feedstock for ammonia produc-
tion. As the hot gas is quenched and
cooled, condensable organics are removed
with the quench liquor and hot gas con-
densate, after which acid gases (H2S and
CO2) are removed by sorption with cold
methanol. The methanol, rich in acid gas,
is regenerated by staged depressurizing
and heating, releasing a CO2-rich gas
(which is vented to the atmosphere) and
an H2S-rich gas (which is routed to a
flare). The condensable organics in the
quench liquor and hot gas condensate are
separated by decantation into a series of
Fines to
Steam and Power
Generation
Waste
Gases
Steam
Flare
Flue Gases
Steam A
Run-of-Mine
Coal —
Coal
Preparation
Dried,
Sized Cc
I
Rectisol
Wastewater
Gas
Liquor
Clean
Gas
[Naphtha
Tar/Oil
Separation
I
Tars &
Oils
Phenolic
Water
Phenosolvan
Wz
Purification
Hi to NHs
Synthesis
Gas
Distribution
By-Product
Storage
Medium
• Btu Gas
to Pipeline
By-Products
to Steam and
* Power
Generation
Phenols
Wastewater
Figure 1. Simplified flow diagram of the Kosovo coal preparation/gasification plant operations.
2
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fractions: heavy tar, tar, medium oil, and
naptha. The residual waters are combined,
stripped to remove ammonia, then ex-
tracted with diisopropyl ether to remove
organics (crude phenol), and finally
discharged.
Experimental Approach
A primary objective of Phase II testing
was to characterize the trace organics that
are being transported by the plant's
discharge streams as aerosols and vapors.
The 21 streams, selected for sampling,
provided a representative cross-section of
the Kosovo facility. Their selection was
based on a high discharge rate and/or a
potential source of organics. EPA meth-
ods, modified when needed to satisfy
sample or stream conditions, were used to
collect condensable organics from
gaseous streams. The organics were col-
lected by a train consisting of: an entrain-
ment separator, an ice-cooled condenser,
and a resin-filled absorber, in series.
Conventional grab sampling was used
for liquids; grab and composite sampling,
for solids. Samples were refrigerated dur-
ing both transport and the storage period
between collection and analysis. Sorbed
vapor samples were recovered from their
collection resin by Soxhlet extraction with
methylene chloride and combined with the
organic extracts of their streams' conden-
sate prior to analyses.
Sample characterization consisted of a
combination of the following methods:
EPA's protocol for Level
Assessment using:
Source
— GC-FID to determine volatile
organics
— Gravimetric analysis to determine
nonvolatile organics
— Liquid chromatography to frac-
tionate mixtures according to
polarity/chemical class,
• GC-MS with a liquid crystal GC col-
um to identify and quantify selected
polynuclear aromatics, and
• Gas chromatography with a selected
detector to obtain stream profiles of
heteroatomic species containing
nitrogen and sulfur.
The streams sampled and the analyses
performed are summarized in Table 1.
Test Results
The Kosovo trace organics study pro-
vides the following information:
• Concentration and mass flow data
for condensable organics in gasifica-
tion plant discharge streams,
• Comparisons for quality control,
• Composition data of the various
types of organics transported by
these streams, and
• Levels of selected polynuclear
aromatics transported by gasification
plant streams.
Organic Concentrations and
Mass Flow
The concentrations and mass flow of
condensable organics are summarized in
the report for the gasification plant's 10
gaseous streams: the start-up vent, am-
monia stripper vent, phenolic water tank
vent, HP and LP coal lock vents, H2S- and
CO2-rich waste gases, tar separation
waste gas, medium-oil tank vent, and
naphtha tank vent. The concentrations
range from 14 mg/m3 to 125 g/m3; and
the mass flows, from 8 g/hr to 120 kg/hr.
The start-up vent and the ammonia strip-
per vent, when operating, transport most
of the condensable organics. However, the
start-up vent discharge changes from
Table 1, Analyses Performed on Kosovo Gas Stream Condensates, Process Liquid, and Solid Wastes
Analyses
Stream
Paniculate
Determination
TOO
Grav
LC
GC
Sulfur
GC
Nitrogen
GC-MS
PNAs
Gas Stream
Fleissner Autoclave Vent
Low Pressure (LP/ Coal Lock Vent
High Pressure (HP) Coal Lock Vent
Start-up Vent
H2S-Rich Waste Gas
C02-Rich Waste Gas
Crude Product Gas
Tar Tank Vent
Medium-Oil Tank Vent
Tar Separation Waste Gas
Phenolic Water Tank Vent
Ammonia Stripper Vent
Naphtha Storage Tank Vent
Waste Gases to Flare
Other Streams
Fleissner Condensate
Gasifier Ash
Heavy Tar
Phenolic Water
Tar
Medium Oil
Naphtha
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
©
+
©
©
©
©
x — analyzed in Yugoslavia.
+ — analyzed in U.S. using random grab samples.
Q — Data not included in this report but included in EPA-600/7-81-142.
-------
combustion gas to product gas over a
start-up period; and the values shown may
represent a worst casa On the other hand,
the mass flow value of the ammonia strip-
per vent is based on a flow with one
gasifier in continuous operation.
The phenolic water tank discharge con-
tains the highest concentration of organics
but, because of its smaller volume, its
mass flow is comparable to those of the
coal lock vent and the H2S-rich waste gas
stream.
Total organic (TO) concentrations were
determined as the sum of volatile (VOs)
and nonvolatile organics (NVOs). VOs
were determined chromatographically,
while NVOs were determined
gravimetrically.
Although the major emphasis of this ad-
dendum was on gas stream condensates,
organics from other streams (e.g., process
liquids and solid wastes) were included in
the test results. However, aqueous ef-
fluent from the Phenosolvan extraction
process could not be obtained at the time
of testing so a total organics measurement
by the test protocol is not included in the
addendum.
Quality Control Comparisons
Comparisons made between these
values and relatable data from other deter-
minations and other gasifiers supported
the validity of these results. Comparisons
made were:
• VO concentration with light aromat-
ics determined on the same stream
during Kosovo Phase II testing,
• NVO concentration with tar and oil
as obtained from the paniculate
determination on the same stream,
and
• Kosovo organics (VO and NVO) with
some values from Wellman-Galusha
(Ft. Snelling), Chapman (Holston),
and Riley Products (Worcester)
gasifiers.
Composition of Kosovo
Organics
The distribution profile of Kosovo
organics as indicated by column chroma-
tography on silica gel is shown in Figure
2. Percentages indicated are based on the
mass eluted from the column so that the
sum for each stream totaled 100%. The
large portion of eluent found in Fraction
1 of several streams suggested that the
aromatics eluted early. This and other
anomalies are addressed in the parent
report. Concentrations of organics in each
fraction and in the sample stream are
shown in Table 2. All data expressed as
milligrams per cubic meter represent
stream concentration. LC fraction numbers
coincide with those shown in Figure 2.
Figure 2. Distribution of chemical classes across the LC fractions of Kosovo gas stream condensates.
4
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Table 2. Concentrations of Organics Found in Each Liquid Chromatographic Fraction and in the Sample Stream
Source
Fleissner autoclave Vent*
LP Coal Lock Vent
HP Coal Lock Vent*
Start-up Vent*
H2S-Rich Waste Gas
Tar Tank Vent
Medium-Oil Tank Vent
Tar Separation Waste Gas*
Phenolic Water Tank Vent
Ammonia Stripper Vent
Naphtha Storage Tank Vent
1
229
167
395
458
19
3,734
2,275
266
32,190
1,880
342
2
47
79
285
430
5
449
229
105
3,335
2,607
25
LC
3 '
80
426
145
1,743
12
410
246
154
2,458
2,222
40
Fraction, mg/m3
4
47
1,456
168
160
7
652
250
129
3,650
16,923
44
5
73
1,281
282
268
8
753
335
183
4,185
17,692
34
6
203
2,297
563
1,595
18
2,179
1,061
649
10,847
27,949
380
7
20
266
67
302
4
225
76
38
857
4,145
37
Total
Recovered
mg/m3
699
5,981
1,912
4,956
73
8,402
4,471
1,525
51,737
73,419
902
Concentration
In Stream
mg/m3
1,114
7,739
2,872
5,540
130
14,412
21,118
3,302
124,884
99,218
5,589
All values computed to stream concentration and expressed as milligrams per normal cubic meter of gas.
*The concentration values for this stream were corrected for a procedural error that involved an unequally divided sample.
Results from the characterization of
process liquids and solid wastes by the
Level 1 procedure show that both phenolic
water and Fleissner condensate contain
about 10 g of organics per liter; gasifier
ash contains virtually no extractable
organics; and heavy tar, consisting of
about 85% extractable organics, contains
a relatively high (53%) volatile content.
Results from silica gel chromatography
show that tar, heavy tar, medium oil, and
phenolic water have similar distribution
profiles.
Infrared
The infrared spectra of samples and
fractions from this study are not repre-
sentative of the condensable organics
from the streams of origin: only the very
high boiling material is represented.
Although these spectra show evidence of
contamination, they provide useful infor-
mation about the structure of the samples'
heavy ends.
Gas Chromatography for
Nitrogen- and Sulfur-
Containing Species
Gas chromatograms of nitrogeneous
species in samples from four streams
(HP and LP coal lock vents, tar separation
waste gas, and tar tank vent) were very
similar; those from three other streams
(ammonia stripper vent, phenolic water
tank vent, and medium oil tank vent) were
dissimilar. The dissimilar streams showed
different mixtures of unidentified com-
pounds. Chromatograms of sulfur species
also show many differences among
streams. Some differences relate to the
types of components; others, to the
relative component quantities.
Insight into the complexity of these
heteroatomic species is provided by
nitrogen- and sulfur-specific chromat-
ograms of medium-oil fractions. Chro-
matograms of acid extractables, base
extractables, neutrals, a reconstituted
acid-precipitate, head space vapor, steam
distillate, and still-pot water indicate the
wide range of nitrogen and sulfur com-
pound classes found in Kosovo
condensate.
Chromatograms illustrate the range of
compounds in the acid, base, and neutral
fractions. Compounds shown on the
chromatograms represent proton donors,
proton acceptors, and neutrals. Some
compounds in each class contain nitrogen;
some, sulfur; and some, probably both.
Classes present could include: pyridines,
cyanophenols, hydroxypyridines, pyridyl-
mercaptans, diazines, pyridazines, nitrites,
thiazoles, and oxazoles, as well as the
complete distribution of aliphatic and
paraffinic hydrocarbons.
Polynuclear Aromatics
The concentrations of selected
polynuclear aromatics (PNAs) in Kosovo
condensates are shown in Table 3. Al-
though all concentration values were
obtained by GC-MS, different levels of
detectability were achieved because of
dilution effects. All measurements were
made to a sensitivity of 0.1 ppm in the ex-
tract on which the GC-MS measurement
was performed. The concentration of BaP
in the LP coal lock condensate (670
ng/m3) was in close agreement with the
estimated value (500 ug/m3) that was
reported in the Phase II report. The esti-
mate was based on the level of tar/oil in
the paniculate aerosol collection and the
concentration of BaP in medium oil.
Table 3.
Source
Concentrations of Selected Polynuclear Aromatics in
Kosovo Gaseous Discharge Streams
Concentration,
BaA
BaP
dBahA
BhF
LP Coal Lock Vent
Ammonia Stripper Vent
Naphtha Storage Tank Vent
Start-up Vent
Tar Tank Vent
Phenolic Water Tank Vent
Medium-Oil Tank Vent
H2S-Rich Waste Gas
CO2-Rich Waste Gas
163
85
<0.06
—
—
—
—
—
—
670
20
0.085
139
252
<50
<6.5
<0.6
<0.7
52
<2.1
0.06
<2.1
<10
<50
<6.5
<0.6
<0.7
670
12
0.11
_
_
—
_
—
-
All «) values are calculated from a minimum detectable concentration of 0.1 ppm in the
measuring solution.
— Not determined.
BaA — Benzotalanthracene
BaP — Benzolalpyrene
dBahA — dibenz(ah)anthracene
BhF — Benzolhlfluoranthene
U. S. GOVERNMENT PRINTING OFFICE:1986/646 116/20816
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