Wrong diesel exhaust SCC profile used for CB05/CB06?

Hi all, I was trying to compare diesel exhaust SCC (speciation classification code) from the diesel exhaust SCC profile in Speciation Tool and CB05 and CB06 diesel profiles in SMOKE, it turns out that there is one VOC species missing - acetone. Is there any reason for this?

While this is not my area of expertise, my colleague tells me that acetone is exempted from the definition of VOC. Therefore the VOC/TOG ratio is used to account for the exempt VOC and give the correct speciation for the VOC emissions.

Thanks for reply. However, based on the lumping species of CB06, there is definitely one lumping species (ACET) named for acetone. Therefore this should not be the reason why acetone is not included in VOC. If this is the case, then formaldehyde should also be exempted from VOC.

FYI, ACET is not a CBO5 species but it is a CB06 species

For CB05, acetone is lumped into PAR, which doesn’t mean it is not belonging to VOC.

Shengpo - can you provide more detail on the profile code(s) in question? Is your question why is the profile missing the model species “ACET” or the SPECIATE species “acetone”? Have you looked at the SPECIATE database to find the SPECIATE species in this profile? Also, for your information, SCC means source classification code, not speciation classification code.

mstrum: Thanks for clarification of the SCC long-name. I have looked up the SPECIATE (version 4.0, 4.2, 4.3, 4.4, 4.5, 5.0, 5.1) species of diesel profile (#4674, Diesel Exhaust - Medium Duty Trucks), and cross-checked the individual species listed in the reference (Schauer et al., 1999). It turns out there is one species (acetone) missing in the SPECIATE table. Therefore, the following lumping processes are missing this species. Currently I checked CB05 and CB06, and their diesel profilings are wrong. Possibly all other chemical mechanisms are also misleading for diesel while using SPECIATE database.

profile 4674 is a VOC profile and not a TOG profile. The reason it is not a TOG profile is that methane and ethane were not measured. In SPECIATE, you can’t make a VOC profile and put acetone in it because acetone is NOT a VOC; therefore, Schauer’s acetone data were removed. You can see this based on the notes in the calculation workbook for this profile which you can access at https://gaftp.epa.gov/Air/emismod/SPECIATE_supportingdata/v4_0/ (select "Schauer_paper72_.mddiesel-9-27-4.xlsx) So actually, the very first answer was correct. ACETONE cannot be present in a VOC profile because it is NOT a VOC. If ethane were measured, then this could have been an “NMOG” profile (non-methane organic gases) and in that case it would have had the acetone. You may want to choose a different diesel exhaust profile. I looked at the SPECIATE database and there are several mobile diesel exhaust profiles (off road and onroad) with acetone in them such as 95332 and 95335a (there are many more). You may also want to look at the documentation of speciation profiles used in EPAs emissions model MOVES3 at https://nepis.epa.gov/Exe/ZyPDF.cgi?Dockey=P1010THD.pdf to review the profiles used in that model for diesel exhaust.

Thanks for reply. I can understand 4674 is a VOC profile and not a “TOG” profile, but this cannot explain why acetone is not included. If acetone is not a VOC you mentioned, what is the definition of VOC as you suggest? Also, if acetone is not in 4674 profile just because it is a OVOC, what about formaldehyde and acetaldehyde? They are also OVOC but included in 4674.

In the emissions inventory and SPECIATE, we use EPA’s regulatory definition of VOC, which is in the Code of Federal regulations, Title 40, Chapter I, Subchapter C, part 51, 51.100 (definitions). Note that under that definition, formaldehyde and acetaldehyde are both VOC but acetone, ethane, methane and many other organic gaseous compounds are NOT VOC. The underlying excel workbook (the link from my last reply) clearly indicates the reason acetone was not included, and that is because this is a VOC profile and acetone is NOT a VOC.

Here is where you can find the regulatory definition of VOC.

https://www.ecfr.gov/cgi-bin/text-idx?SID=e977cf7de99b5cf85fbb2fb7d9ce6778&mc=true&node=pt40.2.51&rgn=div5

I have copied that definition in the below:

(s) Volatile organic compounds (VOC) means any compound of carbon, excluding carbon monoxide, carbon dioxide, carbonic acid, metallic carbides or carbonates, and ammonium carbonate, which participates in atmospheric photochemical reactions.

(1) This includes any such organic compound other than the following, which have been determined to have negligible photochemical reactivity: Methane; ethane; methylene chloride (dichloromethane); 1,1,1-trichloroethane (methyl chloroform); 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113); trichlorofluoromethane (CFC-11); dichlorodifluoromethane (CFC-12); chlorodifluoromethane (HCFC-22); trifluoromethane (HFC-23); 1,2-dichloro 1,1,2,2-tetrafluoroethane (CFC-114); chloropentafluoroethane (CFC-115); 1,1,1-trifluoro 2,2-dichloroethane (HCFC-123); 1,1,1,2-tetrafluoroethane (HFC-134a); 1,1-dichloro 1-fluoroethane (HCFC-141b); 1-chloro 1,1-difluoroethane (HCFC-142b); 2-chloro-1,1,1,2-tetrafluoroethane (HCFC-124); pentafluoroethane (HFC-125); 1,1,2,2-tetrafluoroethane (HFC-134); 1,1,1-trifluoroethane (HFC-143a); 1,1-difluoroethane (HFC-152a); parachlorobenzotrifluoride (PCBTF); cyclic, branched, or linear completely methylated siloxanes; acetone; perchloroethylene (tetrachloroethylene); 3,3-dichloro-1,1,1,2,2-pentafluoropropane (HCFC-225ca); 1,3-dichloro-1,1,2,2,3-pentafluoropropane (HCFC-225cb); 1,1,1,2,3,4,4,5,5,5-decafluoropentane (HFC 43-10mee); difluoromethane (HFC-32); ethylfluoride (HFC-161); 1,1,1,3,3,3-hexafluoropropane (HFC-236fa); 1,1,2,2,3-pentafluoropropane (HFC-245ca); 1,1,2,3,3-pentafluoropropane (HFC-245ea); 1,1,1,2,3-pentafluoropropane (HFC-245eb); 1,1,1,3,3-pentafluoropropane (HFC-245fa); 1,1,1,2,3,3-hexafluoropropane (HFC-236ea); 1,1,1,3,3-pentafluorobutane (HFC-365mfc); chlorofluoromethane (HCFC-31); 1 chloro-1-fluoroethane (HCFC-151a); 1,2-dichloro-1,1,2-trifluoroethane (HCFC-123a); 1,1,1,2,2,3,3,4,4-nonafluoro-4-methoxy-butane (C4F9OCH3 or HFE-7100); 2-(difluoromethoxymethyl)-1,1,1,2,3,3,3-heptafluoropropane ((CF3)2CFCF2OCH3); 1-ethoxy-1,1,2,2,3,3,4,4,4-nonafluorobutane (C4F9OC2H5 or HFE-7200); 2-(ethoxydifluoromethyl)-1,1,1,2,3,3,3-heptafluoropropane ((CF3)2CFCF2OC2H5); methyl acetate; 1,1,1,2,2,3,3-heptafluoro-3-methoxy-propane (n-C3F7OCH3, HFE-7000); 3-ethoxy- 1,1,1,2,3,4,4,5,5,6,6,6-dodecafluoro-2-(trifluoromethyl) hexane (HFE-7500); 1,1,1,2,3,3,3-heptafluoropropane (HFC 227ea); methyl formate (HCOOCH3); 1,1,1,2,2,3,4,5,5,5-decafluoro-3-methoxy-4-trifluoromethyl-pentane (HFE-7300); propylene carbonate; dimethyl carbonate; trans-1,3,3,3-tetrafluoropropene; HCF2OCF2H (HFE-134); HCF2OCF2OCF2H (HFE-236cal2); HCF2OCF2CF2OCF2H (HFE-338pcc13); HCF2OCF2OCF2CF2OCF2H (H-Galden 1040x or H-Galden ZT 130 (or 150 or 180)); trans 1-chloro-3,3,3-trifluoroprop-1-ene; 2,3,3,3-tetrafluoropropene; 2-amino-2-methyl-1-propanol; t-butyl acetate; 1,1,2,2- Tetrafluoro -1-(2,2,2-trifluoroethoxy) ethane; cis-1,1,1,4,4,4-hexafluorobut-2-ene (HFO-1336mzz-Z); and perfluorocarbon compounds which fall into these classes:

(i) Cyclic, branched, or linear, completely fluorinated alkanes;

(ii) Cyclic, branched, or linear, completely fluorinated ethers with no unsaturations;

(iii) Cyclic, branched, or linear, completely fluorinated tertiary amines with no unsaturations; and

(iv) Sulfur containing perfluorocarbons with no unsaturations and with sulfur bonds only to carbon and fluorine.