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Cong,
I think the order does matter.
Depending on the order of capture, the fugitives and can be
different.
Your calculation is correct for the controlled
emissions. You'll always get the same answer, independent of the
order. But change the order for the fugitive calculations, and you'll see
that you get different answers.
Fugitive Emission = [Total Emission * (1-CAP1/100)]
+
[Total
Emission * (CAP1/100) * (1-CEF1/100) * (1-CAP2/100)]
I think I got that right...
Mark
From: owner-airtoxics@great-lakes.net [mailto:owner-airtoxics@great-lakes.net] On Behalf Of Doan, Congtru (ENE) Sent: Thursday, May 17, 2007 2:56 PM To: Mark Young; Airtoxics Subject: RE: Control Device Information Mark, For a system of two control devices
of the same pollutant: C1: Capture efficiency CAP1,
Control efficiency CEF1 C2: Capture efficiency CAP2,
Control efficiency CEF2 Controlled Emission = Total
Emission * (CAP1/100) * (1-CEF1/100) * (CAP2/100) *
(1-CEF2/100) Does it matter if which control
device captures first? Even if both CAP1 and CAP2 are less than
100%. Cong, From:
owner-airtoxics@great-lakes.net [mailto:owner-airtoxics@great-lakes.net]
On Behalf Of Mark
Young Cong, Some users may be
using NIF just to import data into RAPIDS and store it there--including
precalculated emissions. However, imagine using NIF formats to import
everything EXCEPT emissions into RAPIDS. In that case, we would need
enough information to calculate. With the CE format
(NIF control systems), there's enough information to calculate emissions, as
is. Theoretically, at least. That's what you and Tom are both
saying. I agree. We don't need the efficiency details of individual
devices, just the system as a whole. So, in using the NIF approach,
everything should work okay--IF the necessary efficiency fields are actually
filled in. In the case of
moving data from older versions of RAPIDS, we may have other issues where we
need to know the efficiency data for each control device in order to calculate
the overall system values. In that case, the order of equipment is only
important if more than one device has a capture efficiency <100%. In a
case like that, we'd need to know which one captures first.
I am in favor of
using the "Control System" approach, myself. It seems the only way to
generalize all the possible cases. Storing information for individual
devices is only a suggestion, and those records would not be used for any reason
other than "accounting", nor would they be required. The big question
is: do we really need or want the ability to record devices
individually? Mark From:
owner-airtoxics@great-lakes.net [mailto:owner-airtoxics@great-lakes.net]
On Behalf Of Chun
Yi, Do you mean three
control devices within a control equipment record? I believe there is no limit
on number of control equipment records for a process. In other words, one
process can have one control equipment record for Sox, one for NOx, one for VOC,
one for PM …… I might be wrong. I know very little about
NIF! Mark, Why is the order of
control devices important to you? Could you provide an example where the
order of control device configuration results different emissions (control
emission and fugitive emission). We did not have enough time in the meeting to
verify this! Thanks. Cong, From:
owner-airtoxics@great-lakes.net [mailto:owner-airtoxics@great-lakes.net]
On Behalf Of Wu, Chun
Yi The new NEI Facility
Inventory Data Collections request us to report up to three control
devices. Is it feasible if we pick up the first member of the control
device within the control group as the primary control device and so
on? Chun Yi
-----Original
Message----- Chun
Yi It seems that you are in agreement
in having a control group instead of individual control devices. The NEI
control equipment file lists up to four control sequential device
codes. NEI control equipment file structure does not specify how
the control devices are configured (Parallel or Series) but it does define
the order. This file should be sufficient to calculate controlled
emissions. Tom.
First, I
want to say that NIF Import files for point sources do not have an importance to
us. We will compile our own data for point sources and submit to EPA.
To simplify the
RAPIDS3 structure, I think using control groups is an easy approach. The
Overall Capture Efficiency and Overall Capture/Control Efficiency (combined)
should provide us total fugitive emissions and total stack emissions for the
process. We can have characteristics of each control device under the
control device group, but these parameters will not be used in emission
calculation and report. When we use controlled emission factors, RAPIDS
could go to the group and find a match of control device codes. The only
thing we lose is the order of control devices. Anyone feels the order of
control devices is a critical piece? Chun Yi
Wu, Ph.D., P.E. -----Original
Message----- Mark We are dealing with three
distinct possibilities/challenges of importing data in
RAPIDs: 1. NIF Import files and
2. RAPIDS Import
files 3. Manual
Entry. The NIF import is projected to be
the most popular import mechanism. Beginning
with inventory year 2008, every State is
required to submit NIF files for CAPs and
HAPS every three years to U.S.EPA.
Every State is prepared to meet this reporting requirement and that also
applies for the Great Lakes States. For the
import of NIF files to
RAPIDs, I suggest doing the minimum processing of records and
make no assumptions on the
data. Having the data represented identically in RAPIDS and
NEI, is the best approach in storing
data and avoid having to deal with transparency
issues. The RAPIDs import files will be an
alternative method of importing data. I anticipate it to be
a less popular format because of the
additional burden in having to prepare RAPIDs files.
However, it is an option for some States who
wish to take the time and prepare control device files with
individual control and capture
efficiencies. Furthermore, States can distinguish fugitive
emission records from Stack records, report
multiple stacks for a process, etc, etc, etc. I personally do not
see the purpose of doing all the
extra work. Is it for the few States that plan to estimate point
source HAP emissions in RAPIDs? If that is
the main reason, I do not see how having detailed information will
assist with the calculation of emissions.
Controlled FIRE factors are pretty much worthless for inventory
purposes. All that is needed for the
calculation of emissions is the activity, an uncontrolled factor and the
Total capture/control efficiency. Also, when data are
exported to USEPA, the records will have to be processed and
aggregated to meet NIF format. The manual entry is the
State's last resort of entering data and there is no need to even
discuss it. Thanks for listening (less is
more). Tom. |