Chromatography Forum

Hello Everyone. I am new to this site and was hoping I could get some help.

I have been asked to develop a gas chromatography method for analysing syngas from biomass.

I need to describe the chromatography method I would use including the column choice and the reason for the choice.

The column diameter, length, injection type and all the other parameters that would affect efficiency of the result.

I also need to choose a detector and the reason behind my choice, the response factor and linear range.

A description of the standards used and quantification method.

Right now I am thinking of the Thermal conductivity detector, capillary thick filled column and gas-solid chromatography because of the insoluble compounds in syngas.
Any help would be appreciated or even links to useful resources. Thank you

lupefiasco,

I have a very different take on this. I wouldn't use a TCD, I would use an HID. The reason being... HID will see hydrogen and all the other fixed gases without jumping through carrier gas hoops. However, I build an HID so I have a vested interest in this route, so, in the interest of not sounding like a commercial, if you want to contact me, I will be happy to further advise. AICMM at flash.net

Best regards,

AICMM

lupefiasco,

I also would have used a TCD to analyze the syngas - to reduce the possibility of getting split peaks with the hydrogen that will likely be in your sample, I'd use argon as a carrier gas and I would likely start with a packed column - a 5A molecular sieve or a ShinCarbon ST MicroPacked column (by restek). I've had luck with both of those columns in the past in the analysis of light gases. typical gas flows for columns of this sort are ~10-15 mL/min (again, in my experience) and you'd want to use a packed column injection port (I think this is universal across GC's, but i'm very familiar with the 5890). The temperatures of your injector and detectors will effect the efficiency of your result as well - if you've got any more questions feel free to shoot them my way

If you wish to normalize (or ALMOST normalize) the products from the reaction you wish to monitor then some type of Helium Ionization Detector is optimal.

(You can measure hydrogen, water, fixed gases, hydrocarbons, sulfurs, etc)

Then you only need a chromatographic system to separate the components.

Two column selectivities are required: mole sieve and porous polymer.

One is optional: a back flush column (Unibead 3S or a long heavily loaded methyl silicone column) to reverse the C3+ components onto a column to separate C3 through C6? .

Search the web and even this Forum for details of the system you require, but be aware, it is not a trival endeavor for a beginner chromatographer.

best wishes,

Rod

I have used an SRI 8610 for years on a similar problem.
You can get with TCD/HID/FID and FPD if needed.
Restek could not supply a column to fit so I use a Haysep D for the permanent gases, Gaspro for the hydrocarbons and a 5u methyl silicone for the sulphurs.
HID allows a check down to ppm levels but is a pain to keep stable, most Helium is wet.

I like the ShinCarbon (having used a number of them) but in this case, if you use one, you must be aware that the heavies will take forever to come off. Okay if you have lots of time and no money, not so good if you have money and less time. In the latter case, porous polymer to fixed gases column with a backflush valve configuration is probably a better route to go.

Best regards,

AICMM

Hi kbrodw01,
Saw you writing abt the hydrogen peak split using GC TCD. May I know what is the cause for this split? I am facing this problem with some analysis I am carrying out. Thanks,
Jayasree