What are different measurement for elemental composition (C, H, O, N and S) of a biomass?
Combustion would determine carbon content.
Weigh out the biomass, evaporate all water at 100C to get dried biomass. burn in a combustion furnace at around 550 for carbon and above for nitrogen and sulfur.
Its a simple and easy way. You just need a combustion furnace in which you can burn the sample upto 700Cand a precise balance
You can used CHNrlemental analyzer. You can also use sulfure analyzer ( laser). The nitrogen can be also analyzed by kjeldahl method. The carbon content usually by determining the fixed carbon in a TGA.
We've worked the biomass from Hyacinth water and the results with dehydrated samples, were:
Proximal analysis: Moisture 6.35 %wt, volatile matter 64.37 %wt, ash 13.21 %wt, fixed carbon (calculated) 16.06 %wt.
Elemental analysis: Carbon 39.21 %wt, Hydrogen 5.50 %wt, Oxygen (calculated) 40.61 %wt, Nitrogen 1.54 %wt, Sulfur 0.09 %wt, Total moisture 6.66 %wt
A number of instruments have been developed to determine the elemental C, H, N, S and O composition. In some cases C, H, N and S can be determined simultaneously. Most of the systems employ catalytic combustion with pure oxygen to decompose the sample to nitrogen, water, carbon dioxide and sulphur dioxide, which are then determined quantitatively by chromatography using flame ionisation or thermal conductivity detectors. Oxygen is determined by catalytic conversion to carbon monoxide. For the analysis of fast growing biomass samples an instrument (Vario EL) from Elementar GmbH, Hanau, Germany can be used. Elemental analysis of dry biomass can be obtained by means of a C/H/N 2000 LECO(R) analyser.
@ Simrat Kaur Can you provide us a reference where this methodology is adopted for C,H,N, S analysis.
Thanking You.
Hello Zainab Ali,
there is a German standard (DIN 51718 - 51724) to do aproximate and elemental analysis with normal laboratory equipment, but it takes a lot of time.
I skip the aproximate analysis (water content, ash contant and volatiles).
Carbon and hydrogen: A nitrogen purged quarz tube, where the biomass first is completely pyrolysed and afterward burned with oxygen. The gases are freed from sulfur- and nitrogen oxides and halogenides by hot (200 °C) lead-dioxide. Condensed Water is weightend and carbon dioxide is washed.
Sulfur oxides can be determinde by combustion with oxygen and absorption with hydrogen peroxide solution. Then follows titration.
Nitrogen is determined with catalysts in concentrated sulfuric after Kjeldahl. Several steps follow.
Dear Jörg Ho
thank you for your answer and do you have this standard to be attached please?
Dear Z. Mahdi,
There is no known method to determine the composition of C, H, O, N and S of a biomass? It is only possible to determine the CHNS of a sample whereas O is determined by difference.
To this effect, a simple CHNS elemental analyser will suffice. Alternatively, you can determine the compositions of C,N,S and O using an EDX analyser.
Hope this helps.
BBN
Dear Zainab Mahdi ,
I am sorry, that I did not realise, there was a special question to me.
I will try to describe the procedure, as the original is written in German.
Beginning with proximate analysis:
PROXIMATE ANALYSIS
WATER CONTENT:
DIN 51718 - Bestimmung des Wassergehaltes und der Analysenfeuchtigkeit
(Determination of the water content of the sample and analytical moisture)
Method A: 2-Step drying, reference for hard coal
1. Step: drying of the whole sample at 30 (+/- 2) °C and 50 – 70 % relative humidity oft the air until constant mass is achieved to obtain rough moisture. In detail:
· weight a frame stored under dry conditions used for drying with 1 g precision
· distribute at least 1000 g of the sample evenly on the frame
· weight frame with sample with 1 g precision
· dry it in an oven at 30 (+/- 2) °C until constant mass is achieved (12 hours or over night)
o to ensure constant mass, let it cool down to ambient temperature under dry conditions (e.g. inside a closed box with dry silica gel or something alike, e.g. exsikkator)
o after weighting, put it back into the oven for e.g. 2 hours
o let it cool down to ambient temperature under dry conditions (like above)
o if there is no significant change in weight calculate the rough moisture (FG):
FG / % = (m_E – m_R)/m_E x 100 with: m_E = initial net weight, m_R = dry net weight
2. Step: grinding the sample below 1 mm particle size and drying a part of the sample in nitrogen atmosphere at 106 (+/- 2) °C until constant mass is achieved to obtain hygroskopic moisture
· grind a part of the sample to smaller than 1 mm particle size
· weight an empty dry stored shallow shell with lid with 0,1 g precision
· distribute approx. 25 g in the shell
· weight filled shell with lid open with 0,0001 g precision
· dry it in an oven at 106 (+/- 2) °C (if possible in nitrogen atmosphere) until constant mass is achieved
o leave the lid open!
o after drying, at least 4 hours, 12 hours should be suffient, close the lid inside the oven!
o to ensure constant mass, let it cool down to ambient temperature under dry conditions (e.g. inside a closed box with dry silica gel or something alike, e.g. exsikkator)
o after weighting, open the lid and put shell and lid back into the oven for e.g. 1 to 2 hours
o let it cool down to ambient temperature under dry conditions (lid cloesed, like above)
o if there is no significant change in weight calculate the hygroskopic moisture (FH):
FH / % = (m_E – m_R)/m_E x 100 with: m_E = initial net weight, m_R = dry net weight
Total moisture: W / % = FG + FH * (100 – FG)/100
Method B: 1-Step drying, reference for coke
Drying a sample in air at 106 (+/- 2) °C until constant mass is achieved to obtain total moisture
· weight a preheated frame used for drying with 0,1 g precision
· with a particle size below 10 mm take 1000 g, alternatively with a particle size below 20 mm take 2000 g and distribute the sample evenly on the frame
· weight frame with sample with 0,1 g precision
· dry it in an oven at 106 (+/- 2) °C until constant mass is achieved (12 hours or over night)
o to ensure constant mass weight it hot (> 50 °C)
o after weighting, put it back into the oven for e.g. 2 hours
o weight it again hot like before (> 50 °C)
o if there is no significant change in weight calculate the total moisture (W):
W / % = (m_E – m_R)/m_E x 100 with: m_E = initial net weight, m_R = dry net weight
Remark: hot weighting causes an error because of lift, so I recomment to ensure equal temperature when comparing weights
Method C: destillation with xylen, reference for brown coal and peat
Destillation of the sample with Xylen and determining the water content volumetric measurement
Remark: Tom y experience it is not very accurate and personally I only would use it, if there is a significant part of species volatile at 106 °C other than water.
· You need water saturated xylen (stored over a layer of water)
· Weight a 500 ml ballon flask with 0,01 g precision
· Put 50 g sample (25 g if quiet moist) with particles below 1 mm in a 500 ml ballon flask, weight it with 0,01 g precision
· Ad 200 ml xylen (without water)
· Mix sample and xylen by stirring
· Use a cooler, a destillation bridge and the ballon flask in the way of the picture
· Cool the cooler below 20 °C, heat the ballon flask up to at least 140 °C and destillate the mixture between sample and xylen
o Water and xylen will condensate in the cooler and water will be deposited at the part with the scale
o While there is still water in the xylen it will show smear running back tot he flask
o When the xylen running back to flask is clear and schows no smear, you are finished
o Let the apparatus cool down
o Determine the volume of water to calculate the total moisture (W):
W / % = V/m_E x 100 with: m_E = initial net weight, V = volume of water measured
Analytical moisture:
Do it at the same time, when you do other kinds of analysis, e.g. ash content, elemental analysis. Take a sample after pretreatment that you might need for the other analysis!
· Weight at least two, I recommend three, small glass flasks of around 10 ml (25 mm diameter) with lid with 0,0001 g precision
· Fill about 1 g sample into each flask and weight it with lid with 0,0001 g precision
· dry it in an oven at 106 (+/- 2) °C (if possible in nitrogen atmosphere, 135 °C for brown coal) until constant mass is achieved
o leave the lid open!
o after drying, at least 4 hours, 12 hours should be suffient, close the lid inside the oven!
o to ensure constant mass, let it cool down to ambient temperature under dry conditions (exsikkator , e.g. inside a closed box with dry silica gel or something alike)
o after weighting, open the lid and put shell and lid back into the oven for e.g. 1 hour
o let it cool down to ambient temperature under dry conditions (lid cloesed, like above)
o if there is no significant change in weight calculate the anlytic moisture (FA):
FA / % = (m_E – m_R)/m_E x 100 with: m_E = initial net weight, m_R = dry net weight
Differences betwen two measurements schould be below 0,2 % and below 0,5 % for method C
DIN EN 14774-1 – Biomass as energy source
Bestimmung des Wassergehaltes (Determination of the water content) – reference method
Drying a sample in air at 105 (+/- 2) °C until constant mass is achieved to obtain total moisture
· weight two frames used for drying with 0,1 g precision
· distribute a sample of at least 300 g (particles < 30 mm) evenly on one frame
· weight the frame with sample with 0,1 g precision
· weight the packing of the sample with 0,1 g precision
· dry the packing in the oven, i fit can withstand the temperature, otherwise dry it in the laboratory
· dry both frames (filled and empty) in an oven at 105 (+/- 2) °C until constant mass is achieved (at least 4 hours, 12 hours shold be suffient)
o use insulation material between balance and frame for thermal insulation
o to ensure constant mass weight the filled frame hot inbetween 10 s to 15 s after taking it from the oven
o after weighting, put it back into the oven for e.g. 1 to 2 hours
o weight it again hot like before
o if there is no significant change in weight the empty reference frame alike
o weight the dryed packing of the sample with 0,1 g precision
o calculate the total moisture (W), wet weight as basis:
W / % = (m_2 – m_3 + m_5 – m_4 + m_6)/(m_2 – m_1 + m_6) x 100 with: m_1 = initial weight of the frame used for drying the sample m_2 = gross initial weight of frame with sample m_3 = gross final weight of frame with sample m_4 = initial weight of frame without sample (reference frame) m_5 = final weight of frame without sample (reference frame) weightend hot m_6 = mass of water from the packing (difference initial and final weight)
Moisture with dry weight as basis (U): U / % = W/(100 – W) x 100
DIN EN 14774-2 – Biomass as energy source
Bestimmung des Wassergehaltes (Determination of the water content) – simplyfied method
Drying a sample in air at 105 (+/- 2) °C until constant mass is achieved to obtain total moisture
· weight a frames used for drying with 0,1 g precision
· distribute a sample of at least 300 g (particles < 30 mm) evenly on one frame
· weight the frame with sample with 0,1 g precision
· weight the packing of the sample with 0,1 g precision
· dry the packing in the oven, i fit can withstand the temperature, otherwise dry it in the laboratory
· dry both frames (filled and empty) in an oven at 105 (+/- 2) °C until constant mass is achieved (at least 4 hours, 12 hours shold be suffient)
o use insulation material between balance and frame for thermal insulation
o to ensure constant mass weight the filled frame hot inbetween 10 s to 15 s after taking it from the oven
o after weighting, put it back into the oven for e.g. 1 to 2 hours
o weight it again hot like before
o finish, if there is no significant change in weight
o weight the dryed packing of the sample with 0,1 g precision
o calculate the total moisture (W), wet weight as basis:
W / % = (m_2 – m_3 + m_6)/(m_2 – m_1 + m_6) x 100 with: m_1 = initial weight of the frame used for drying the sample m_2 = gross initial weight of frame with sample m_3 = gross final weight of frame with sample m_6 = mass of water from the packing (difference initial and final weight)
Moisture with dry weight as basis (U): U / % = W/(100 – W) x 100
DIN EN 14774-3 – Biomass as energy source
Bestimmung des Wassergehaltes von Analysenproben (Determination of the water content of analytical samples) – analytical moisture
Well, it’s the same as determinig analytical moisture following DIN 51718, but with 105 °C and not with 106 °C
Drying a sample in air at 105 (+/- 2) °C until constant mass is achieved to obtain total moisture. Do it at the same time, when you do other kinds of analysis, e.g. ash content, elemental analysis. Take a sample after pretreatment that you might need for the other analysis!
· Weight at least two, I recommend three, small glass flasks of around 10 ml (25 mm diameter) with lid with 0,0001 g precision
· Fill about 1 g sample into each flask and weight it with lid with 0,0001 g precision
· dry it in an oven at 106 (+/- 2) °C (if possible in nitrogen atmosphere) until constant mass is achieved
o leave the lid open!
o after drying, at least 4 hours, 12 hours should be suffient, close the lid inside the oven!
o to ensure constant mass, let it cool down to ambient temperature under dry conditions (exsikkator , e.g. inside a closed box with dry silica gel or something alike)
o after weighting, open the lid and put shell and lid back into the oven for e.g. 1 hour
o let it cool down to ambient temperature under dry conditions (lid cloesed, like above)
o if there is no significant change in weight calculate the anlytic moisture (FA):
W / % = (m_2 – m_3)/(m_2 – m_1) x 100 with: m_1 = initial weight of the flask with lid used for drying the sample m_2 = gross initial weight of flask with sample and lid open m_3 = gross final weight of flask with sample and lid closed
ASH CONTENT:
DIN 51719 - Bestimmung des Aschegehaltes (Determination of the ash content)
Use crucibles from porcelain with an diameter of aprox. 30 - 50 mm. Coal is grinded to partikles below 0,2 mm.
· Weight at least two, I recommend three, dry stored crucibles with 0,0001 g precision
· Fill about 1 g sample into each crucible and weight it with 0,0001 g precision
· Run the following temperature program with the crucibles inside the oven:
o Start with cold oven (below 100 °C)
o Heat up to 500 °C with constant heating rate within 60 minutes
o Heat up at full power to 815 °C (for coal) and to 710 °C (for char coal)
o Maintain the temperature for 60 minutes
· Take the crucibles from the oven and put them for 5 to 10 minute on a fire resistant plate to cool down before putting them into an exsikkator (or something that fullfills the purpose of keeping dry and letting exhaust warm air)
· weight the crucibles with 0,0001 g precision
· If the sample is not fully burned, put the crucibles back into the oven and heat up tot he former maximum temperature and maintain it for 30 minutes.
Ash content on wet basis (A_an, like analysed):
A_an / % = (m_3 – m_1)/(m_2 – m_1) x 100 with: m_1 = initial weight of the empty crucible m_2 = gross initial weight of crucible with sample m_3 = gross final weight of crucible with sample
Ash content on dry basis (A_wf, water free):
A_wf / % = A_an x 100/(100 – W_an) with: W_an = analytical moisture of the sample (FA in DIN 51718, W in DIN EN 14774-3)
Differences betwen two measurements schould be below 0,2 %, if ash content is less than 10 %, and below 2 % relative tot he ash content, if it is above 10 %
DIN EN 14775 – Biomass as energy source
Bestimmung des Aschegehaltes von Analysenproben (Determination of the ash)
Use crucibles from porcelain with an diameter of aprox. 30 - 50 mm. Make at least two, I recommend three, simultane analysis for each sample. Biomass is grinded to particles below 0,5 mm.
· Heat the crucibles to 550 °C for at least 60 minutes
· Take the crucibles from the oven and put them for 5 to 10 minute on a fire resistant plate to cool down before putting them into an exsikkator (or something that fullfills the purpose of keeping dry and letting exhaust warm air)
· Weight the cold crucibles with 0,0001 g precision
· Fill about 1 g sample into each crucible and weight it with 0,0001 g precision
· Run the following temperature program with the crucibles inside the oven:
o Start with cold oven
o Heat up to 250 °C with constant heating rate around 6 K/min (+/- 1,5 K/min)
o Maintain 250 °C for 60 minutes
o Heat up to 550 °C with constant heating rate of 10 K/min
o Maintain the temperature for 120 minutes
· Take the crucibles from the oven and put them for 5 to 10 minute on a fire resistant plate to cool down before putting them into an exsikkator (or something that fullfills the purpose of keeping dry and letting exhaust warm air)
· weight the crucibles with 0,0001 g precision
· If the sample is not fully burned, put the crucibles back into the oven at 550 °C maintain temperature for 30 minutes.
Ash content on dry basis (A_wf, water free):
A_wf / % = (m_3 – m_1)/(m_2 – m_1) x 100 x 100/(100 – W_an) with: m_1 = initial weight of the empty crucible m_2 = gross initial weight of crucible with sample m_3 = gross final weight of crucible with sample W_an = analytical moisture of the sample (W in DIN EN 14774-3, FA in DIN 51718)
Differences betwen two measurements schould be below 0,2 %, if ash content is less than 10 %, and below 2 % relative to the ash content, if it is above 10 %
VOLATILE MATTER:
DIN 51720 - Bestimmung des Anteils der Flüchtigen Bestandteile (Determination of the content of volatile matter)
Use crucibles from quarz with an outer diameter of aprox. 25 mm and a height of aprox. 40 mm with lid. Use a rack from heat resistant wire steel to handle the number of crucibles. Coal is grinded to particles below 0,2 mm. Make at least two simultane analysis for each sample.
· Heat the empty oven to 900 °C
· Put the crucibles and lids into the rack
· Put the rack with the crucibles for 7 minutes into the oven. USE HEAT RESISTENT GLOVES! Radiation from the oven would burn your skin!
· Take the crucibles from the oven and put them on a fire resistant plate to cool down
· Weight the cold crucibles with 0,0001 g precision
· Fill about 1 g sample into each crucible and weight it with 0,0001 g precision
· Put the crucibles with lid laying on top to close them and let volatiles emerge into the rack
· Put the rack with the crucibles for 7 minutes into the oven. USE HEAT RESISTENT GLOVES! Radiation from the oven would burn your skin!
· Take the crucibles from the oven and put them on a fire resistant plate to cool down
· weight the crucibles with 0,0001 g precision
Content of volatile matter on wet basis (VM_an, like analysed):
VM_an / % = (m_2 – m_3)/(m_2 – m_1) x 100 – W_an with: m_1 = initial weight of the empty crucible with lid m_2 = gross initial weight of crucible with sample and lid m_3 = gross final weight of crucible with sample and lid W_an = analytical moisture of the sample (W in DIN EN 14774-3, FA in DIN 51718)
Differences betwen two measurements schould be below 0,3 %, if volatile matter is less than 10 %, and below 3 % relative to the content of volatile matter, if it is above 10 %
ULTIMATE/ELEMENTAL ANALYSIS
Well, there are quite expensiv elemental analysers, that would do the job determining c, h, n, s and cl on a single run by burning a sample with pure oxygen. Oxygen may be analysed seperately with a pyrolysis unit, but there are possibilities to analyse the elemental composition the classical way, say without any very expensive equipment.
At least you need to determine the analysis moisture and ash content for the same sample, that you use for determining the ultimate analysis.
CONTENT of CARBON and HYDROGEN:
DIN 51721 - Bestimmung des Gehaltes an Kohlenstoff und Wasserstoff [Verfahren nach Radmacher-Hoverath]
(Determination of the carbon and hydrogen content of a sample)
You need a apparatus from quarz like in picture ch-app.png
Ledgend tot he picture:
1: quarz wool, 2: silicone oil, 3: lead dioxide, 4: thermal insulation, 5: baffle with kapillary, 6: oxygen supply pipe, 7: adsorption chamber, 8: combustion chamber, 9: pyrolysis chamber, 10: gound joint with supply pipe, 11: temperature measurement, 12: gas outlet pipe
Chemicals you need: Please, to your own safty, read the safty data sheets carefully! - magnesium perchlorate: grain size 0,8 – 2,5 mm (You must not regenerate used perchlorate!) (perchlorates are pretty dangerous if they get into contact with anything that might burn! Look at: https://doi.org/10.1016/S1074-9098(02)00294-0) - sodium hydroxide: grain size 0,8 – 1,6 mm and 1,6 – 3 mm - lead dioxide: mix lead dioxide powder with water to obtain a sticky sludge, apply it 10 mm thick to a 2 mm metal grid, dry it for 12 hours at 250 °C, grind i carefully, dry it again at 200 °C and finally sieve it with a 1,6 mm mesh
But up the apparatus as shown in the picture. Further you‘ll need two gas burners. Further you need two flasks (shematic: picture ch-flask.png) for the adsorbtion of gases. Legend:
1: Glass wool, 2: potsherd, 3: sodium hydroxide 1,6 – 3 mm, 4: sodium hydroxide 0,8 – 1,6 mm, 5: magnesium perchlorate 0,8 – 2,5 mm
· Flask A gets a plug of glass wool (1) at either side and is filled with magnesium perchlorate (5)
· Flask B also gets a plug of glass wool (1) at either side and a layer of potsherdon the bottom above the glass wool. Further it is filled with sodium hydroxide 1,6 – 3 mm (3) in the bottom half and (you may put a layer of glass wool there as well) sodium hydroxide 0,8 – 1,6 mm (4) above most of the upper half. On top there is another small layer of magnesium perchlorate (5) between two layers of glass wool (1)
· Prepare the reactor tube with quarz glass wool, fill the adsorption chamber (7) with the prepared lead dioxide, and again with quarz glass wool
· Connect the top inlet of Flask A to the outlet of the reactor tube at (1)
· Apply a 3-way valve to a ground joint and connect it with a oxygen supply of 25 ml/min on one side and a nitrogen supply of 25 ml/min on the other side in a way, that you can either supply oxygen or nitrogen through the ground joint to the pyrolysis chamber
· To test the performance and correct size of the absorption flasks you should run a experiment for each flask:
o For Flask A put two identical flasks in row and run the experiment described below with a test sample. The standard suggests 0,2 g of a hydrogen ritch coal, but I would recommend dried hardwood or nut shells, as it would put you on the safe side.
o For Flask B put two identical flasks in row and run the experiment described below with a test sample. The standard suggests 0,2 g of coal.
o If the second flask in each case shows now gain in weight, then the flask performes correct. You schould not run an experiment for Flask B without Flask A, just to be sure water won’t effect your experiment.
Prepare and conduct an analysis as follows:
· Apply a 3-way valve to a ground joint and connect it with a oxygen supply of 25 ml/min on one side and a nitrogen supply of 25 ml/min on the other side in a way, that you can either supply oxygen or nitrogen through the ground joint to the pyrolysis chamber
· Weight a porcelain combustion boat with 0,0001 g precision
· Fill the combustion boat with approx. 0,2 g sample and weight it with 0,0001 g precision
· Weight the absorption Flask A with 0,0001 g precision and connect them to the reactor at the gas outlet (1)
· Fill the chamber coaxial around the adsorption chamber (7) with silicone oil and apply a thermometer, that works in a range of 150 to 250 °C
· Heat the cumbustion chamber (8) with gas burners in a matter that there is a temperature of 200 °C +/- 5 °C adsorption chamber (7)
· Preheat the pyrolysis chamber (9) (well, there is no temperature given, but I would suggest 200 °C for biomass and peat and 300 °C for coal)
· Apply 120 ml/min oxygen to the combustion chamber (8) through the oxygen supply pipe (6)
· Prepare a flow of 25 ml/min Nitrogen to the pyrolysis chamber (9) through a ground joint
· Insert the combustion boat with the sample into the pyrolysis chamber (9) and close it with the ground joint applying the nitrogen
· Pyrolyse the sample slowly, that there is complete combustion in the combustion chamber (8) where the oxygen is applied. No black smoke should be seen! If pyrolysis is nearly completed, switch the 3-way valve from nitrogen to oxygen for complete combustion
· When combustion in the pyrolysis chamber (9) is completed maintain the oxygen flow for 5 minutes, afterwards switch back to nitrogen
· Switch of the oxygen supply (6) and turn of the burners
· After cool down do the weighting:
o Flask A for determining hydrogen from the gain of weight from water
o Flask B for determining carbon from the gain of weight from carbondioxide
· Calculations:
o C_ges,an / % = 27,29 x m_2/m_1
o H_ges / % = 11,19 x m_3/m_1
o H_an / % = H_ges – 0,1119 x W_an
with: C_ges,an = total carbon content of the sample as analysed H_ges = total hydrogen per mass of the sample including hydrogen from moisture H_an = total hydrogen content of the sample as analysed m_1 = initial net weight of the sample m_2 = gain in weight of Flask B m_3 = gain in weight of Flask A W_an = analytical moisture of the sample
For further details you have to cunsult the standard DIN 51721.
Ultimate (elemental) analysis of biomass can be measured using ASTM D5373 (for carbon, hydrogen, oxygen, and nitrogen) and ASTM D4239 (for sulfur). The analysis can be performed using an Elemental Analyzer. During the analysis, a tiny amount (about 2-3 mg) of a biomass sample is put in the instrument. Then the sample is exposed to an excess oxygen and it undergoes a combustion reaction. The combustion products (e.g. CO2, H2O, NO, NO2, etc.) are collected and then measured using gas chromatography technique. By obtaining the composition of the combustion products and using a mass balance equation, the composition of the sample or ultimate analysis (CHONS) can be obtained.
Hello again,
shure, if you've got an elemental analyzer or aproximatly 50000 US$, go ahead with DIN 51732 or ASTM D5373 etc., if not, and if there is no laboratory at hand that might do the job, you can use chemical analysis.
So, for those of you who'd like to spent 50000 US$ on other things - sorry, just joking - I proceed with nitrogen analysis.
You need some more glas equipment, like shown in 'https://www.neubert-glas.de/laborglas/onlineshop/katalog_php/1_995727484085_1030342896125_997508551870_1248783281843/1007470445699/Parnas-Wagner-App-10-teilig.html' [reference for the numbers of glass apparatus in bracetts] or 'http://www.lederpedia.de/_detail/lederpruefung_lederbeurteilung/bestimmung_des_ammoniumgehaltes_zur_berechnung_der_hautsubstanz/abb_102_kjeldahlapparatur_nach_parnas-wagner.jpg?id=lederpruefung_lederbeurteilung%3Abestimmung_des_ammoniumgehaltes_zur_berechnung_der_hautsubstanz_sowie_des_gehaltes_an_ammoniumsalzen' or you search for "Parnas Wagner".
Determining nitrogen is done from the ashes of the sample. Next to the Parnas Wagner apparatus you need to do titration, we usually use a burette with a 0,02 ml scale. Further you need cemicals. For analyzing 100 mg ash you need: a katalyst containing 1684 mg K2SO4, 52 mg pulverized Se, 264 mg HgSO4 (all ingedients are grinded in a porcelain mortar and mixed, please watch for proper dispose after usage! You might like to produce more for more samples, you need 2 g catalyst for 100 mg ash); saccharose (C12H22O11); sulphuric acid with a density of 1,84 g/ml; a boric acid solution from 60 g H3BO3 and 1 L hot water (it has to be filtered when it is cold); a sodium sulphide solution from 20 g Na2S (9-12)H2O [any with chrystal water ranging between 9 and 12] mixed with a little water and water added up to 50 ml and than mixed with a solution from 240 g NaOH and 600 ml water; sulphuric acid solution with a molarity of 0,01 mol/L. Further you need an indicator mixed from two components with equal parts (mix it before usage, it will be usable for a week): Component A: 0,125 g methyl red with 60 ml C2H5OH (pure) with water added to a sum of 100 ml, Component B: 0,083 g methylene blue in 100 ml C2H5OH (pure). Cooling water for the condendors.
Procedure:
1. chemical extraction: Weight 100 mg ash (sample) if possible to 0,1 mg precission (m) and mix it with 2 g of the catalyst in the Kjehldal flask of 50 ml (70), add 4 ml of sulphuric acid (1,84 g/ml) and mix again. The sample has to be througly wettened. Put a condenser (e.g. like 72) on top of the Kjehldal flask and heat up slowly slightly inclined until bioling starts. Keep it boiling until first there are no dark particles anymore (approxametly 20 - 25 minutes) and second maintain it at boiling temperature for another 30 minutes. At this stage only the Kjehldal flask and a cooler are needed. Keep the inlets of the Kjehldal flask through the tube closed!
2. Destillation: After cooling down to ambient temperature add carefully 10 ml of water. A Erlenmeyer flask (77) of at least 100 ml is filled with 10 ml of the boric acid solution and 20 ml water and 4 drops of the mixed indicator solution. Fit a Condeser (72) (e.g. a Liebig cooler) and a destillation bridge (71) between the Kjehldal flask and the Erlenmeyer flask and adjust it, that the tubing of the cooler reaches down below the surface of the solution in the Erlenmeyer flask. Add 20 ml of the sodium sulphide solution to the solution with the sample inside the Kjehldal flask (through the top inlet and close it, for 73 a simple glas plug with a fastener should do) and start adding water vapour through the tube of the Kjehldal flask (all the apparatus 73, 74, 75, 76, 78, but I think, a round bottom flask (75) of sufficient size to boil water to apply steam to the sample, and a proper connection to the down pointing inlet of the Kjehldal flask is sufficient) to white out ammonia from the sample and dissolve it in the boric acid solution. During this the Erlemeyer flask (77) has to be kept cool!
To chek for completeness you can change the Erlemeyer flask (77) prepared as before and continue adding water vapour (from 75) to the sample. If there is no change in the color of the indicator, whiting out was complete.
3. acidimetric titration: The cooler (72) is rinsed with water into the Erlenmeyer flask (77). After adding another few drops of mixed indicator start titration with the sulphuric acid solution (0,01 mol/L) until color is changing from green to purple. Determine the Volume of the sulphuric acid solution (V_s)
4. zero value: to obtain a zero value of the apparatus repeat the procedure 1. to 3. with 0,1 g saccharose in place of the sample ash. Determine the Volume of the sulphuric acid solution (V_0)
5. evaluation: nitrogen content N_wf (water free) in % is: N_wf = 0,00014 (V_s - V_0)*100/m * 100/(100-W_an) [For W_an look at an earlier one of my posts]
To be continued with a description for sulphur.
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