{"id":75751,"date":"2024-03-26T20:46:00","date_gmt":"2024-03-26T20:46:00","guid":{"rendered":"https:\/\/discover.restek.com\/?p=75751"},"modified":"2026-01-08T14:25:39","modified_gmt":"2026-01-08T14:25:39","slug":"column-selections-for-the-renewable-fuel-standard-rfs-program-biogas-analysis","status":"publish","type":"post","link":"https:\/\/discover.restek.com\/zh-hans\/blogs-zh\/column-selections-for-the-renewable-fuel-standard-rfs-program-biogas-analysis\/","title":{"rendered":"Column selection(s) for the Renewable Fuel Standard (RFS) Program \u2013 Biogas analysis"},"content":{"rendered":"\n

The RFS program seeks to increase energy and fuel production within the USA, while also incentivizing reductions and control of pollutants including sulfurs, siloxanes, greenhouse gases, and an assortment of other toxic compounds1<\/sup>. In turn, these compounds need to be monitored consistently and reliably, which can be difficult in biogas matrices. Biogas is produced from sites such as landfills, sewage treatment plants, pig farms, and cattle farms, where high amounts of methane are produced and can be repurposed for energy, removing emissions from the atmosphere. These sites are notoriously difficult to sample since substrate materials vary dramatically, and can be moist, promoting side-reactions during the sampling and analysis processes. For this reason, a variety of equipment is often necessary to test different compound classes.<\/p>\n\n\n\n

To help labs get started and standardize their methods, the RFS Program recommends a variety of regulatory methods related to energy production that can be used to analyze different compounds classes, including ASTM D5504, ASTM D8230, EPA 3C, and EPA 181,2<\/sup>, though many labs also include TO-153<\/sup> or TO-17. While not specified by the RFS Program, TO-15 and TO-17 are used to monitor toxic gases which are also likely to be present in biogas and may be hazardous to the environment rather than to energy production.<\/p>\n\n\n\n

With such a wide range of sample types possible for this program, the specific columns dimensions and selections are likely to vary from industry to industry, but this blog will help identify \u201cstarting points\u201d in column-selection for different compound classes.<\/p>\n\n\n\n

ASTM D5504-20<\/h2>\n\n\n\n

Sulfur-containing volatiles compounds are hazards to both the environment and combustion equipment. Hydrogen sulfide, specifically, is a very reactive compound which can readily decompose to H2<\/sub>SO4<\/sub>, poisoning catalysts or corroding biogas engine and turbines4<\/sup>. Other potential degradation byproducts such as sulfur dioxide and trioxide are environmentally hazardous4<\/sup>. This compound is monitored primarily to determine the cost-benefit of using the biogas, where companies can determine how much wear and tear there may be on the equipment, prior to burning.<\/p>\n\n\n\n

ASTM D5504-20 recommends a 60m x 0.53mmID PDMS phase column5<\/sup>, such as Restek\u2019s Rtx-1, though shorter, narrower ID columns have been demonstrated to work as well, with slightly lower sample capacity. The ASTM method shows an example of retention times possible using a 30m x 0.32mmID x 4\u00b5m equivalent to Restek\u2019s Rtx-1 (cat.# 10198), suggesting it is a good starting point. Below is an example method showing separation of some sulfur compounds on the\u00a0Rtx-1<\/a>:<\/p>\n\n\n

Figure 0: Sulfur Compounds on Rtx-1<\/div>
\n
\"Sulfur<\/div>

GC_PC1271<\/p>

Peaks<\/h4>\n
<\/th>Peaks<\/th>Conc.
(\u00b5g\/mL)<\/th><\/tr><\/thead>\n
1.<\/td>Ethyl mercaptan<\/a><\/td>100<\/td><\/tr>\n
2.<\/td>Dimethyl sulfide<\/a><\/td>100<\/td><\/tr>\n
3.<\/td>Carbon disulfide<\/a><\/td>20<\/td><\/tr>\n
4.<\/td>Isopropyl mercaptan<\/a><\/td>100<\/td><\/tr>\n
5.<\/td>t-Butyl mercaptan<\/a><\/td>50<\/td><\/tr>\n
6.<\/td>n-Propyl mercaptan<\/a><\/td>100<\/td><\/tr>\n
7.<\/td>Ethyl methyl sulfide<\/a><\/td>50<\/td><\/tr>\n
8.<\/td>sec-Butyl mercaptan<\/a><\/td>50<\/td><\/tr>\n
9.<\/td>Thiophene<\/a><\/td>100<\/td><\/tr>\n<\/tbody><\/table>\n\n
<\/th>Peaks<\/th>Conc.
(\u00b5g\/mL)<\/th><\/tr><\/thead>
10.<\/td>Isobutyl mercaptan<\/a><\/td>100<\/td><\/tr>\n
11.<\/td>Diethyl sulfide<\/a><\/td>75<\/td><\/tr>\n
12.<\/td>n-Butyl mercaptan<\/a><\/td>50<\/td><\/tr>\n
13.<\/td>Dimethyl disulfide<\/a><\/td>20<\/td><\/tr>\n
14.<\/td>2-Methylthiophene<\/a><\/td>75<\/td><\/tr>\n
15.<\/td>3-Methylthiophene<\/a><\/td>100<\/td><\/tr>\n
16.<\/td>Diethyl disulfide<\/a><\/td>20<\/td><\/tr>\n
17.<\/td>Benzothiophene<\/a><\/td>75<\/td><\/tr>\n
18.<\/td>3-Methylbenzothiophene<\/a><\/td>100<\/td><\/tr>\n<\/tbody><\/table><\/div>

Conditions<\/h4>
Column<\/th>Rtx-1, 30 m, 0.32 mm ID, 4.00 \u00b5m (cat.# 10198<\/a>)<\/td><\/tr>
Standard\/Sample<\/th>ASTM D5623 standards 1 & 2 from DCG Partnership 1, Ltd.<\/td><\/tr>\n
Injection<\/th><\/td><\/tr>
Inj. Vol.:<\/th>0.2 \u00b5L split (split ratio 10:1)<\/td><\/tr>
Liner:<\/th>4 mm ID cup inlet liner with Siltek deactivation<\/td><\/tr>
Inj. Temp.:<\/th>275 \u00b0C<\/td><\/tr>
Split Vent Flow Rate:<\/th>24 mL\/min<\/td><\/tr>
Oven<\/td><\/tr>
Oven Temp.:<\/th>30 °C (hold 2 min) to 200 °C at 10 °C\/min (hold 10 min)<\/td><\/tr>
Carrier Gas<\/th>He, constant flow<\/td><\/tr>
Flow Rate:<\/th>2.4 mL\/min
Linear Velocity:<\/th>38 cm\/sec @ 30 \u00b0C<\/td><\/tr><\/table>
Detector<\/th>DP SCD @ 800 \u00b0C<\/td><\/tr>
Burner Vacuum:<\/th>363 torr<\/td><\/tr>
Hydrogen Flow Rate:<\/th>40 mL\/min<\/td><\/tr>
Air Flow Rate:<\/th>60 mL\/min<\/td><\/tr>
Instrument<\/th>Agilent 7890B GC<\/td><\/tr>
Notes<\/th>Solvent standard of sulfur components found in gasoline samples utilizing ASTM D5623.
<\/td><\/tr><\/table><\/div><\/div><\/div>
<\/path><\/g><\/path><\/g><\/svg>Download PDF<\/a><\/div><\/div><\/div>\n<\/div><\/div><\/div>\n\n\n

ASTM D8230-19<\/h2>\n\n\n\n

Silicon-containing compounds, primarily polysiloxanes, are present primarily landfills and sewage, from sources such as lubricants and hygienic products6<\/sup>. While volatile methyl siloxanes have the potential to be converted to methane for biogas production, polysiloxanes are more likely to be monitored for their potential to damage equipment4,6<\/sup>. Polysiloxanes, when burnt, leave behind abrasive silica dioxide (SiO2) which abrades and blocks equipment. In addition, some polysiloxanes such as D4 (octamethylcyclotetrasiloxane) and D5 (decamethylcyclopentasiloxane) are known to be hazardous to the environment6<\/sup>.<\/p>\n\n\n\n

ASTM D8230-19 provides GC-MS, GC-ICP-MS, and GC-AED methodologies for the analysis of silicon-containing volatiles7<\/sup>. While there is no specific column phase recommendation, the method specifies a low bleed column is necessary, either composed of diphenyl dimethyl polysiloxane7<\/sup> (i.e. Rtx-5) or 1,4- bis(dimethylsiloxy)phenylene di-methyl polysiloxane7<\/sup> (Rxi-5Sil MS). Column bleed is composed of polysiloxanes which can of course interfere with analysis of polysiloxanes, so column inertness is a top priority.<\/p>\n\n\n\n

However, the need for a thick film will work against another critical need \u2013 low bleed. A balance therefore must be struck in column dimensions to keep the film thick enough for the necessary retention of volatiles, but thin enough to control bleed. Clark\u00a0et al<\/em>., interested in polysiloxanes D4 and D5 in landfill gas, used a 30m x 0.32mmID x 1\u00b5m column6<\/sup>, equivalent to the Rxi-5Sil MS (cat.#13654) With Restek\u2019s exceptionally inert Rxi deactivation, this column is a great starting point for your polysiloxane analysis. As an alternative, the\u00a0Rtx-200<\/a>\u00a0(cat.# 15020) is also well suited to separating polysiloxanes with a unique chemistry that may benefit separation from other components of a mixture.<\/p>\n\n\n\n

EPA 3C<\/h2>\n\n\n\n

Permanent gas analysis is important for understanding the combustion efficiency of biogas. While biogas is primarily methane, there is likely a high presence of other non-combustible gases such as CO2, CO, N2, and O2 which can interfere with energy production efficiency. This is especially important if catalysts are involved for conversation of non-combustible gases to more combustible gases (usually methane), where the presence of certain contaminants may affect catalyst efficiency too.4<\/sup><\/p>\n\n\n\n

EPA method 3C does not recommend a specific column, but encourages separation of methane, CO2, N2, O2, and \u201cother gas components that may be present in the sample\u201d8<\/sup>. Molecular sieves are prone to adsorption of water and CO2, which is why Restek\u2019s ShinCarbon ST column (cat.# 19808) may be a better option. Below is an example of the separation of permanent gases achievable on the\u00a0ShinCarbon ST<\/a>.<\/p>\n\n\n

Figure 1: Permanent Gases and C1+C2 Hydrocarbons on ShinCarbon ST (micropacked)<\/div>
\n
\"Permanent<\/div>

GC_PC00665<\/p>

Peaks<\/h4>\n
<\/th>Peaks<\/th><\/tr><\/thead>\n
1.<\/td>Oxygen<\/a><\/td><\/tr>\n
2.<\/td>Nitrogen<\/a><\/td><\/tr>\n
3.<\/td>Carbon monoxide<\/a><\/td><\/tr>\n
4.<\/td>Methane<\/a><\/td><\/tr>\n
5.<\/td>Carbon dioxide<\/a><\/td><\/tr>\n
6.<\/td>Acetylene<\/a><\/td><\/tr>\n
7.<\/td>Ethylene<\/a><\/td><\/tr>\n
8.<\/td>Ethane<\/a><\/td><\/tr>\n<\/tbody><\/table><\/div>

Conditions<\/h4>
Column<\/th>100\/120 mesh, ShinCarbon ST, 2 m, 1\/16 in. OD, 1.0 mm ID (cat.# 19808<\/a>)<\/td><\/tr>
Standard\/Sample<\/th>Permanent gases-C1+C2 hydrocarbons<\/td><\/tr>\n
Injection<\/th><\/td><\/tr>
Inj. Vol.:<\/th>5 \u00b5L packed on-column<\/td><\/tr>
Inj. Temp.:<\/th>100 \u00b0C<\/td><\/tr>
Oven<\/td><\/tr>
Oven Temp.:<\/th>40 °C (hold 3 min) to 250 °C at 8 °C\/min (hold 10 min)<\/td><\/tr>
Carrier Gas<\/th>He, constant flow<\/td><\/tr>
Flow Rate:<\/th>10 mL\/min<\/td><\/tr><\/table>
Detector<\/th>HID @ 200 \u00b0C<\/td><\/tr><\/table><\/div><\/div><\/div>
<\/path><\/g><\/path><\/g><\/svg>Download PDF<\/a><\/div><\/div><\/div>\n<\/div><\/div><\/div>\n\n\n

Since CO and CO2 do not burn very well, the addition of a methanizer may be helpful to improve detection limits relative to a TCD.<\/p>\n\n\n\n

EPA 18, TO-15 & TO-17<\/h2>\n\n\n\n

While considered \u201cminor impurities\u201d in biogas, there is a wide variety volatile organic compounds (VOC\u2019s) that are produced in biogas sites, many of which are hazardous to the environment, equipment, or both. The VOC\u2019s are produced either from waste itself (ex: solvents) or from the anaerobic breakdown of waste. Since the waste substrate is highly variable, the compounds produced are also highly variable, which means analytical methods need to be flexible as well. It is well established that biogas sites contain hazardous solvents such benzene and vinyl chloride, alongside more benign malodorous compounds like hydrocarbons and oxygenates4,12<\/sup>. To control odor, chlorinated products may be added to landfills, contributing to the generation of hazardous chlorinated halocarbons as well4,13<\/sup>.<\/p>\n\n\n\n

Because of the overlap with toxic compounds, EPA Methods 18, TO-15, or TO-17 can be performed. Method 18 is not very specific about compounds or analytical methods (intentionally)9<\/sup>, while TO-15 and TO-17 provide more details for analysts to work with10,11<\/sup>. However, TO-15 and TO-17 do not include all compounds that may be hazardous to biogas equipment, such as terpenes3,12<\/sup> so methods and equipment may need to be augmented for this wider range of compounds.<\/p>\n\n\n\n

Restek has many options for separating TO-15 compounds, but with the addition of more polar terpenes, the\u00a0Rxi-624Sil MS<\/a>\u00a0is likely the best starting point. Authors Orecchio and Marti both used 60m 624-type columns, such as\u00a0cat.# 13869\u00a0and\u00a0cat.# 138723,13<\/sup>.<\/p>\n\n\n

Figure 2: TO-15 65 Component Mix on Rxi-624Sil MS (30 m)<\/div>
\n
\"TO-15<\/div>

GC_AR1148<\/p>

Peaks<\/h4>\n
<\/th>Peaks<\/th>tR<\/sub> (min)<\/th><\/tr><\/thead>\n
1.<\/td>Propylene<\/a><\/td>1.42<\/td><\/tr>\n
2.<\/td>Dichlorodifluoromethane (CFC-12)<\/a><\/td>1.46<\/td><\/tr>\n
3.<\/td>1,2-Dichlorotetrafluoroethane (CFC-114)<\/a><\/td>1.58<\/td><\/tr>\n
4.<\/td>Chloromethane<\/a><\/td>1.62<\/td><\/tr>\n
5.<\/td>Vinyl chloride<\/a><\/td>1.73<\/td><\/tr>\n
6.<\/td>1,3-Butadiene<\/a><\/td>1.77<\/td><\/tr>\n
7.<\/td>Bromomethane<\/a><\/td>2.02<\/td><\/tr>\n
8.<\/td>Chloroethane<\/a><\/td>2.12<\/td><\/tr>\n
9.<\/td>Trichlorofluoromethane (CFC-11)<\/a><\/td>2.34<\/td><\/tr>\n
10.<\/td>Ethanol<\/a><\/td>2.54<\/td><\/tr>\n
11.<\/td>Acrolein<\/a><\/td>2.71<\/td><\/tr>\n
12.<\/td>1,1-Dichloroethene<\/a><\/td>2.78<\/td><\/tr>\n
13.<\/td>1,1,2-Trichlorotrifluoroethane (CFC-113)<\/a><\/td>2.80<\/td><\/tr>\n
14.<\/td>Acetone<\/a><\/td>2.82<\/td><\/tr>\n
15.<\/td>Carbon disulfide<\/a><\/td>2.95<\/td><\/tr>\n
16.<\/td>Isopropyl alcohol<\/a><\/td>2.99<\/td><\/tr>\n
17.<\/td>Acetonitrile (contaminant)<\/a><\/td>3.05<\/td><\/tr>\n
18.<\/td>Methylene chloride<\/a><\/td>3.20<\/td><\/tr>\n
19.<\/td>trans-1,2-Dichloroethene<\/a><\/td>3.43<\/td><\/tr>\n
20.<\/td>Methyl tert-butyl ether (MTBE)<\/a><\/td>3.44<\/td><\/tr>\n
21.<\/td>Hexane<\/a><\/td>3.67<\/td><\/tr>\n
22.<\/td>1,1-Dichloroethane<\/a><\/td>3.80<\/td><\/tr>\n
23.<\/td>Vinyl acetate<\/a><\/td>3.82<\/td><\/tr>\n<\/tbody><\/table>\n\n
<\/th>Peaks<\/th>tR<\/sub> (min)<\/th><\/tr><\/thead>
24.<\/td>2-Butanone (MEK)<\/a><\/td>4.29<\/td><\/tr>\n
25.<\/td>cis-1,2-Dichloroethene<\/a><\/td>4.29<\/td><\/tr>\n
26.<\/td>Ethyl acetate<\/a><\/td>4.34<\/td><\/tr>\n
27.<\/td>Bromochloromethane (IS)<\/a><\/td>4.50<\/td><\/tr>\n
28.<\/td>Tetrahydrofuran<\/a><\/td>4.52<\/td><\/tr>\n
29.<\/td>Chloroform<\/a><\/td>4.60<\/td><\/tr>\n
30.<\/td>1,1,1-Trichloroethane<\/a><\/td>4.74<\/td><\/tr>\n
31.<\/td>Cyclohexane<\/a><\/td>4.80<\/td><\/tr>\n
32.<\/td>Carbon tetrachloride<\/a><\/td>4.88<\/td><\/tr>\n
33.<\/td>Benzene<\/a><\/td>5.06<\/td><\/tr>\n
34.<\/td>1,2-Dichloroethane<\/a><\/td>5.12<\/td><\/tr>\n
35.<\/td>Heptane<\/a><\/td>5.35<\/td><\/tr>\n
36.<\/td>1,4-Difluorobenzene (IS)<\/a><\/td>5.47<\/td><\/tr>\n
37.<\/td>Trichloroethylene<\/a><\/td>5.69<\/td><\/tr>\n
38.<\/td>1,2-Dichloropropane<\/a><\/td>5.94<\/td><\/tr>\n
39.<\/td>Methyl methacrylate<\/a><\/td>6.01<\/td><\/tr>\n
40.<\/td>1,4-Dioxane<\/a><\/td>6.02<\/td><\/tr>\n
41.<\/td>Bromodichloromethane<\/a><\/td>6.20<\/td><\/tr>\n
42.<\/td>cis-1,3-Dichloropropene<\/a><\/td>6.64<\/td><\/tr>\n
43.<\/td>4-Methyl-2-pentanone (MIBK)<\/a><\/td>6.80<\/td><\/tr>\n
44.<\/td>Toluene<\/a><\/td>6.99<\/td><\/tr>\n
45.<\/td>trans-1,3-Dichloropropene<\/a><\/td>7.26<\/td><\/tr>\n
46.<\/td>1,1,2-Trichloroethane<\/a><\/td>7.47<\/td><\/tr>\n<\/tbody><\/table>\n\n
<\/th>Peaks<\/th>tR<\/sub> (min)<\/th><\/tr><\/thead>
47.<\/td>Tetrachloroethene<\/a><\/td>7.55<\/td><\/tr>\n
48.<\/td>2-Hexanone (MBK)<\/a><\/td>7.72<\/td><\/tr>\n
49.<\/td>Dibromochloromethane<\/a><\/td>7.88<\/td><\/tr>\n
50.<\/td>1,2-Dibromoethane<\/a><\/td>8.01<\/td><\/tr>\n
51.<\/td>Chlorobenzene-d5 (IS)<\/a><\/td>8.54<\/td><\/tr>\n
52.<\/td>Chlorobenzene<\/a><\/td>8.58<\/td><\/tr>\n
53.<\/td>Ethylbenzene<\/a><\/td>8.71<\/td><\/tr>\n
54.<\/td>m-Xylene<\/a><\/td>8.87<\/td><\/tr>\n
55.<\/td>p-Xylene<\/a><\/td>8.87<\/td><\/tr>\n
56.<\/td>o-Xylene<\/a><\/td>9.32<\/td><\/tr>\n
57.<\/td>Styrene<\/a><\/td>9.35<\/td><\/tr>\n
58.<\/td>Bromoform<\/a><\/td>9.56<\/td><\/tr>\n
59.<\/td>4-Bromofluorobenzene*<\/a><\/td>9.99<\/td><\/tr>\n
60.<\/td>1,1,2,2-Tetrachloroethane<\/a><\/td>10.18<\/td><\/tr>\n
61.<\/td>4-Ethyltoluene<\/a><\/td>10.47<\/td><\/tr>\n
62.<\/td>1,3,5-Trimethylbenzene<\/a><\/td>10.55<\/td><\/tr>\n
63.<\/td>1,2,4-Trimethylbenzene<\/a><\/td>11.02<\/td><\/tr>\n
64.<\/td>1,3-Dichlorobenzene<\/a><\/td>11.35<\/td><\/tr>\n
65.<\/td>1,4-Dichlorobenzene<\/a><\/td>11.49<\/td><\/tr>\n
66.<\/td>Benzyl chloride<\/a><\/td>11.65<\/td><\/tr>\n
67.<\/td>1,2-Dichlorobenzene<\/a><\/td>11.93<\/td><\/tr>\n
68.<\/td>1,2,4-Trichlorobenzene<\/a><\/td>13.47<\/td><\/tr>\n
69.<\/td>Hexachlorobutadiene<\/a><\/td>13.59<\/td><\/tr>\n
70.<\/td>Naphthalene<\/a><\/td>13.67<\/td><\/tr>\n<\/tbody><\/table>
*Tuning standard<\/div><\/div>

Conditions<\/h4>
Column<\/th>Rxi-624Sil MS, 30 m, 0.32 mm ID, 1.80 \u00b5m (cat.# 13870<\/a>)<\/td><\/tr>
Standard\/Sample<\/th><\/td><\/tr>
<\/td>TO-15 65 component mix (cat.# 34436<\/a>)<\/td><\/tr>
<\/td>TO-14A internal standard\/tuning mix (cat.# 34408<\/a>)<\/td><\/tr>\n
Diluent:<\/th>Nitrogen<\/td><\/tr>
Conc.:<\/th>10.0 ppbv 200 cc injection<\/td><\/tr>
Injection<\/th>Direct<\/td><\/tr>
Oven<\/td><\/tr>
Oven Temp.:<\/th>32 °C (hold 1 min) to 150 °C at 11 °C\/min to 230 °C at 33 °C\/min<\/td><\/tr>
Carrier Gas<\/th>He, constant flow<\/td><\/tr>
Flow Rate:<\/th>2.0 mL\/min
Linear Velocity:<\/th>51 cm\/sec @ 32 \u00b0C<\/td><\/tr><\/table>
Detector<\/th>MS<\/td><\/tr>
Mode:<\/th>Scan<\/td><\/tr>
Transfer Line Temp.:<\/th>230 \u00b0C<\/td><\/tr>
Analyzer Type:<\/th>Quadrupole <\/td><\/tr>
Source Temp.:<\/th>230 \u00b0C<\/td><\/tr>
Quad Temp.:<\/th>150 \u00b0C<\/td><\/tr>
Electron Energy:<\/th>69.9 eV<\/td><\/tr>
Solvent Delay Time:<\/th>1.0 min<\/td><\/tr>
Tune Type:<\/th>BFB <\/td><\/tr>
Ionization Mode:<\/th>EI <\/td><\/tr>
Scan Range:<\/th>35 – 250 amu<\/td><\/tr>
Scan Rate:<\/th>3.32 scans\/sec<\/td><\/tr>
Preconcentrator<\/th>Nutech 8900DS<\/td><\/tr>
  Trap 1 Settings<\/th><\/td><\/tr>
  Type\/Sorbent :<\/th>Glass Beads <\/td><\/tr>
  Cooling temp:<\/th>-155 \u00b0C<\/td><\/tr>
  Preheat temp:<\/th>5 \u00b0C<\/td><\/tr>
  Preheat time:<\/th>0 sec<\/td><\/tr>
  Desorb temp:<\/th>20 \u00b0C<\/td><\/tr>
  Desorb flow:<\/th>5 mL\/min<\/td><\/tr>
  Desorb time:<\/th>360 sec<\/td><\/tr>
  Bakeout temp:<\/th>200 \u00b0C<\/td><\/tr>
  Flush flow:<\/th>120 mL\/min<\/td><\/tr>
  Flush time:<\/th>60 sec<\/td><\/tr>
  Sweep flow:<\/th>120 mL\/min<\/td><\/tr>
  Sweep time:<\/th>60 sec<\/td><\/tr>
  Trap 2 Settings<\/th><\/td><\/tr>
  Type\/Sorbent:<\/th>Tenax <\/td><\/tr>
  Cooling temp:<\/th>-35 \u00b0C<\/td><\/tr>
  Desorb temp:<\/th>190 \u00b0C<\/td><\/tr>
  Desorb time:<\/th>30 sec<\/td><\/tr>
  Bakeout temp:<\/th>200 \u00b0C<\/td><\/tr>
  Bakeout time:<\/th>10 sec<\/td><\/tr>
  Cryofocuser<\/th><\/td><\/tr>
  Cooling temp:<\/th>-160 \u00b0C<\/td><\/tr>
  Inject time:<\/th>140 sec<\/td><\/tr>
  Internal Standard<\/th><\/td><\/tr>
  Purge flow:<\/th>100 mL\/min<\/td><\/tr>
  Purge time:<\/th>6 sec<\/td><\/tr>
  Vol.:<\/th>20 mL<\/td><\/tr>
  ISTD flow:<\/th>100 mL\/min<\/td><\/tr>
  Standard<\/th><\/td><\/tr>
  Size:<\/th>200 mL<\/td><\/tr>
  Purge flow:<\/th>100 mL\/min<\/td><\/tr>
  Purge time:<\/th>6 sec<\/td><\/tr>
  Sample flow:<\/th>100 mL\/min<\/td><\/tr>
Instrument<\/th>HP6890 GC & 5973 MSD<\/td><\/tr>
Acknowledgement<\/th>Nutech<\/td><\/tr><\/table><\/div><\/div><\/div>
<\/path><\/g><\/path><\/g><\/svg>Download PDF<\/a><\/div><\/div><\/div>\n<\/div><\/div><\/div>\n\n\n

Alternative columns that may be suitable, depending on the specific compounds being investigated, include Rxi-1ms<\/a>, Rxi-5Sil MS<\/a>, and Rtx-VMS<\/a>. To help with the selection, a variety of compounds that may be of interest are included in Restek\u2019s ProEZ<\/em>GC<\/a> libraries. Column phases, dimensions, and oven parameters can be adjusted to determine which column is best for your specific VOC analysis.<\/p>\n\n\n\n

Additional resources:<\/h2>\n\n\n\n

Alan Sensue has additional recommendations for sampling equipment related to your biogas analysis:\u00a0Sampling and analysis of landfill gas biogas an overview (restek.com)<\/a><\/p>\n\n\n\n

References:<\/h2>\n\n\n\n
    \n
  1. Renewable fuel standards Program:\u00a0Renewable Fuel Standard Program | US EPA<\/a><\/li>\n\n\n\n
  2. 40 CFR Parts 80 and 1090 (pg 44535):\u00a0https:\/\/www.govinfo.gov\/content\/pkg\/FR-2023-07-12\/pdf\/2023-13462.pdf<\/a><\/li>\n\n\n\n
  3. Orecchio\u00a0et al<\/em>.:\u00a0https:\/\/doi.org\/10.3390\/ijerph14020195<\/a><\/li>\n\n\n\n
  4. Braganca\u00a0et al<\/em>.:\u00a0https:\/\/doi.org\/10.1016\/j.biombioe.2020.105878<\/a><\/li>\n\n\n\n
  5. ASTM D5504:\u00a0D5504 Standard Test Method for Determination of Sulfur Compounds in Natural Gas and Gaseous Fuels by Gas Chromatography and Chemiluminescence (astm.org)<\/a><\/li>\n\n\n\n
  6. Clark\u00a0et al<\/em>.:\u00a0https:\/\/doi.org\/10.1139\/l2012-051<\/a><\/li>\n\n\n\n
  7. ASTM D8230:\u00a0D8230 Standard Test Method for Measurement of Volatile Silicon-Containing Compounds in a Gaseous Fuel Sample Using Gas Chromatography with Spectroscopic Detection (astm.org)<\/a><\/li>\n\n\n\n
  8. EPA 3C:\u00a0METHOD 3C\u2014DETERMINATION OF CARBON DIOXIDE, METHANE, NITROGEN, AND OXYGEN FROM STATIONARY SOURCES (epa.gov)<\/a><\/li>\n\n\n\n
  9. EPA 18:\u00a0method_18_0.pdf (epa.gov)<\/a><\/li>\n\n\n\n
  10. EPA TO-15:\u00a0https:\/\/www.epa.gov\/sites\/default\/files\/2019-12\/documents\/to-15a_vocs.pdf<\/a><\/li>\n\n\n\n
  11. EPA TO-17:\u00a0Method TO-17 – Determination of Volatile Organic Compounds in Ambient Air Using Active Sampling Onto Sorbent Tubes (epa.gov)<\/a><\/li>\n\n\n\n
  12. Duan\u00a0et al<\/em>.:\u00a0https:\/\/doi.org\/10.1016\/j.wasman.2020.09.015<\/a><\/li>\n\n\n\n
  13. Marti\u00a0et al<\/em>.:\u00a0https:\/\/doi.org\/10.1016\/j.apgeochem.2014.06.018<\/a><\/li>\n<\/ol>\n\n\n\n
    <\/div>\n\n\n
    \n

    Related Products<\/h3>\n
    \n
    \n
    \n
    \n Catalog No. 10198 <\/a> <\/div>\n
    \n
    Rtx-1 GC Capillary Column, 30 m, 0.32 mm ID, 4.00 \u00b5m<\/div>\n <\/div>\n
    \n \u67e5\u770b\u4ea7\u54c1<\/a>\n <\/div>\n <\/div>\n
    \n
    \n Catalog No. 13654 <\/a> <\/div>\n
    \n
    Rxi-5Sil MS GC Capillary Column, 30 m, 0.32 mm ID, 1.0 \u00b5m<\/div>\n <\/div>\n
    \n \u67e5\u770b\u4ea7\u54c1<\/a>\n <\/div>\n <\/div>\n
    \n
    \n Catalog No. 19808 <\/a> <\/div>\n
    \n
    ShinCarbon ST Micropacked GC Column, 100\/120, 2 m, 1 mm ID, 1\/16" OD, Silco<\/div>\n <\/div>\n
    \n \u67e5\u770b\u4ea7\u54c1<\/a>\n <\/div>\n <\/div>\n
    \n
    \n Catalog No. 15020 <\/a> <\/div>\n
    \n
    Rtx-200 GC Capillary Column, 15 m, 0.25 mm ID, 0.25 \u00b5m<\/div>\n <\/div>\n
    \n \u67e5\u770b\u4ea7\u54c1<\/a>\n <\/div>\n <\/div>\n
    \n
    \n Catalog No. 13869 <\/a> <\/div>\n
    \n
    Rxi-624Sil MS GC Capillary Column, 60 m, 0.25 mm ID, 1.40 \u00b5m<\/div>\n <\/div>\n
    \n \u67e5\u770b\u4ea7\u54c1<\/a>\n <\/div>\n <\/div>\n
    \n
    \n Catalog No. 13872 <\/a> <\/div>\n
    \n
    Rxi-624Sil MS GC Capillary Column, 60 m, 0.32 mm ID, 1.80 \u00b5m<\/div>\n <\/div>\n
    \n \u67e5\u770b\u4ea7\u54c1<\/a>\n <\/div>\n <\/div>\n <\/div>\n <\/div>\n \n\n\n
    <\/div>\n","protected":false},"excerpt":{"rendered":"

    The RFS program seeks to increase energy and fuel production within the USA, while also incentivizing reductions and control of pollutants including sulfurs, siloxanes, greenhouse gases, and an assortment of other toxic compounds1. In turn, these compounds need to be monitored consistently and reliably, which can be difficult in biogas matrices. Biogas is produced from…<\/p>\n","protected":false},"author":34,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"_kad_blocks_custom_css":"","_kad_blocks_head_custom_js":"","_kad_blocks_body_custom_js":"","_kad_blocks_footer_custom_js":"","_kadence_starter_templates_imported_post":false,"_kad_post_transparent":"","_kad_post_title":"","_kad_post_layout":"","_kad_post_sidebar_id":"","_kad_post_content_style":"","_kad_post_vertical_padding":"","_kad_post_feature":"","_kad_post_feature_position":"","_kad_post_header":false,"_kad_post_footer":false,"footnotes":""},"categories":[790],"tags":[],"industries-application":[],"post-badge":[],"resource-type":[],"product-library":[],"resource-technique":[],"ppma_author":[454],"class_list":["post-75751","post","type-post","status-publish","format-standard","hentry","category-blogs-zh"],"acf":[],"taxonomy_info":{"category":[{"value":790,"label":"\u535a\u5ba2"}]},"featured_image_src_large":false,"author_info":{"display_name":"Erica Pack, PhD","author_link":"https:\/\/discover.restek.com\/zh-hans\/author\/erica-pack-phd\/"},"comment_info":0,"category_info":[{"term_id":790,"name":"\u535a\u5ba2","slug":"blogs-zh","term_group":0,"term_taxonomy_id":790,"taxonomy":"category","description":"","parent":0,"count":438,"filter":"raw","cat_ID":790,"category_count":438,"category_description":"","cat_name":"\u535a\u5ba2","category_nicename":"blogs-zh","category_parent":0}],"tag_info":false,"authors":[{"term_id":454,"user_id":34,"is_guest":0,"slug":"erica-pack-phd","display_name":"Erica Pack, PhD","avatar_url":{"url":"https:\/\/discover.restek.com\/wp-content\/uploads\/people-pack-erica.jpg","url2x":"https:\/\/discover.restek.com\/wp-content\/uploads\/people-pack-erica.jpg"},"0":null,"1":"","2":"","3":"","4":"","5":"","6":"","7":"","8":""}],"_links":{"self":[{"href":"https:\/\/discover.restek.com\/zh-hans\/wp-json\/wp\/v2\/posts\/75751","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/discover.restek.com\/zh-hans\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/discover.restek.com\/zh-hans\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/discover.restek.com\/zh-hans\/wp-json\/wp\/v2\/users\/34"}],"replies":[{"embeddable":true,"href":"https:\/\/discover.restek.com\/zh-hans\/wp-json\/wp\/v2\/comments?post=75751"}],"version-history":[{"count":3,"href":"https:\/\/discover.restek.com\/zh-hans\/wp-json\/wp\/v2\/posts\/75751\/revisions"}],"predecessor-version":[{"id":75755,"href":"https:\/\/discover.restek.com\/zh-hans\/wp-json\/wp\/v2\/posts\/75751\/revisions\/75755"}],"wp:attachment":[{"href":"https:\/\/discover.restek.com\/zh-hans\/wp-json\/wp\/v2\/media?parent=75751"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/discover.restek.com\/zh-hans\/wp-json\/wp\/v2\/categories?post=75751"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/discover.restek.com\/zh-hans\/wp-json\/wp\/v2\/tags?post=75751"},{"taxonomy":"industries-application","embeddable":true,"href":"https:\/\/discover.restek.com\/zh-hans\/wp-json\/wp\/v2\/industries-application?post=75751"},{"taxonomy":"post-badge","embeddable":true,"href":"https:\/\/discover.restek.com\/zh-hans\/wp-json\/wp\/v2\/post-badge?post=75751"},{"taxonomy":"resource-type","embeddable":true,"href":"https:\/\/discover.restek.com\/zh-hans\/wp-json\/wp\/v2\/resource-type?post=75751"},{"taxonomy":"product-library","embeddable":true,"href":"https:\/\/discover.restek.com\/zh-hans\/wp-json\/wp\/v2\/product-library?post=75751"},{"taxonomy":"resource-technique","embeddable":true,"href":"https:\/\/discover.restek.com\/zh-hans\/wp-json\/wp\/v2\/resource-technique?post=75751"},{"taxonomy":"author","embeddable":true,"href":"https:\/\/discover.restek.com\/zh-hans\/wp-json\/wp\/v2\/ppma_author?post=75751"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}