I have run biomass samples for three different heating rate like 5, 10, 15 degree C under inert gas reference as Nitrogen. When I analyses the data the TG curve showing perfect percentage weight loss but the DTA curve is flat.
Is it possible that percentage weight loss with temperature or time will not show any decomposition of biomass sample? I have also attached the PDF file of data.
Dear Dr. Kumar,
the DTA curve is the flat black one on the bottom of the graph with constant 56.86 resp. 62.69 in your two runs? If that is the case, than to me, this looks more like a problem of the equipment (soft- or hardware). With increasing temperature, I would expect some change in the DTA signal since the pyrolytic processes are usually not enthalpy-neutral. Maybe you check your equipment with some reference sample with known DTA curve and an expected peak (e.g. from melting)?
Dear Dr. Sanjay Kumar,
According to your TG curve, your DTG curve should not be flat.
I guess that the x axis is cutting the y-axis at 56.86 and 21 (for Ca10 file), respectively, just for graphic representation.
So I think that your PC program is not plotting the DTG. As you know, the DTG is obtained from TG curves, so the problem is not from the TG oven. It is working perfectly. You should see the software and check whether the DTG record is on.
Greetings from Spain!
Is there any possibilities that the reference gas I had used make some resisting from decomposition of biomass samples?
I had analysed the same biomass samples for DSC and I had get the good data from the analysis. I had run the samples in Argon inert gas mode for analysis of biomass samples upto 600 degree C at 5, 10 , 15 degree C/min.
Please suggest.
The weight curve implies that there is actual decomposition of your biomass, so this could not be the case. Again, please check if all parts of your equipment including hard- and software are working correctly by using a sample with known TGA behaviour.
I agree with Dr Andreas Ortwein. If the TG curve is OK, then there must be some decomposition, regardless of the gas you use.
Greetings.
Hello,
The TG profile looks quite standard for a Biomass sample. However, at the final stage, the weight loss continues to drop, which seems to be a bit strange if you are running with Ar as sweep gas. Once you decompose the lignocellulose, which lignin is more difficult to convert (and slower), then around 550 + C you should get a reasonable flat curve. However, this may vary within biomass sources.
With regard to the DTA curve, I do not see it. You may have a software / plotting issue.
If the Red Line is the Heat Flow, then it should indicate a predominant -overall-endothermal trend. Around water (moisture) evaporation region < 100 C, there are no major changes, assuming a typical 6 - 10 % moisture. You should see a peak indicating water evap. (endothermal)
Is this a MT equipment ?
Check the software graphing features, instrument leaks, gas flow control, .. hope this helps
Regards
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