♻️ Determination of carbon, hydrogen, nitrogen and sulphur in solid recovered fuels (PN-EN ISO 21663)

Petrochemistry and fuels PN-EN ISO 21663

Overview

WHAT THE STANDARD COVERS — ACCORDING TO THE CATALOGUE CARD. The scope quoted from the PKN card (reading of 22.09.2026): "Niniejszy dokument określa oznaczanie całkowitej zawartości węgla, wodoru, azotu i siarki w stałych paliwach wtórnych za pomocą metod instrumentalnych. W zależności od ilości użytej porcji testowej stosowane są aparaty mikro i makro instrumentalne. Niniejszą metodę stosuje się do stężeń w suchej masie C> 0,1%, N> 0,1%, H> 0,1% i S> 0,05%." [This document specifies the determination of the total content of carbon, hydrogen, nitrogen and sulphur in solid recovered fuels by instrumental methods. Depending on the amount of test portion used, micro and macro instruments are applied. This method is applicable to concentrations in the dry matter of C > 0.1 %, N > 0.1 %, H > 0.1 % and S > 0.05 %.]

THE SUCCESSOR ADDED AN ELEMENT — AND THAT IS THE MOST IMPORTANT THING IN THIS ENTRY. The predecessor, PN-EN 15407:2011, bore the title "Stałe paliwa wtórne — Metody oznaczania zawartości węgla (C), wodoru (H) i azotu (N)" [Solid recovered fuels — Methods for the determination of carbon (C), hydrogen (H) and nitrogen (N) content]. The current standard ALSO has SULPHUR (S) in its title. The change of the document number was therefore not just a change of number: THE SCOPE OF THE TEST WAS WIDENED. A laboratory citing the old standard DID NOT HAVE sulphur within it — and when comparing two accreditation scopes, one of which cites 15407 and the other 21663, the reader is comparing documents of DIFFERENT CONTENT, not two editions of the same one. The chain of succession is confirmed by both cards: the new one gives "Zastępuje PN-EN 15407:2011" [Replaces], the old one has the header "Wycofana i zastąpiona przez PN-EN ISO 21663:2021-06" [Withdrawn and replaced by] and the row "Data wycofania: 07-06-2021" [withdrawal date].

THE APPLICABILITY THRESHOLD IS PART OF THE METHOD, NOT ITS TECHNICAL LIMITATION. The card states the concentration range directly: C > 0.1 %, N > 0.1 %, H > 0.1 %, S > 0.05 % in the dry matter. Below these values the method does not apply — and this is information for the client, not for the laboratory: a result "below 0.05 % sulphur" is not a result of this method.

TRANSITIONAL CITATIONS — SIX ENTRIES, ONE LABORATORY. Measurement (22-09-2026): PN-EN ISO 21663 appears in 65 entries at 18 laboratories; the withdrawn PN-EN 15407 — in 6 entries at one, and ALL SIX cite the new standard at the same time. There is not a single entry citing only the withdrawn document. The transition is therefore practically complete, and what remains of it takes the form of a joint citation — a different phenomenon from a backlog.

EIGHTEEN LABORATORIES FOR SIXTY-FIVE ENTRIES — THE OTHER POLE OF THE SAME PHENOMENON. A separate entry of the Knowledge Base concerns PN-EN ISO 16968: that standard has 135 entries at EIGHT laboratories, of which 123 at one. NOTE ON THE ORIGIN OF THIS NUMBER (added 22-09-2026): the number 135 comes FROM ANOTHER ENTRY and from one of the two copies of the scope database on which we count. In the second, independent copy the same standard has 55 entries at the same EIGHT laboratories, of which 43 at one — because in that copy laboratory AB 053 has 438 entries instead of 886. The number of laboratories agrees in both copies, the numbers of entries do not. The comparison "135 versus 65" reads "55 versus 65" in that copy and leads to the OPPOSITE conclusion: the dispersion would be similar, not opposite. We therefore base the conclusion about two poles on the NUMBER OF LABORATORIES (eight versus eighteen), which agrees on both sides, and not on the number of entries. Here the distribution is the reverse: the test is performed by many bodies, each with a few entries. These two numbers — "135 entries" and "65 entries" — compared without the number of laboratories would lead to a conclusion opposite to the true one.

FORM OF NOTATION. Forty-nine entries give "PN-EN ISO 21663:2021-06", sixteen — "PN-EN ISO 21663" without a year. The laboratories tab for this entry searches with the prefix "PN-EN ISO 21663" and covers both forms.

WHAT WE DO NOT GIVE. We did not have the text of the standard (26 pages, English-language version, Mining Sector, KT 144 Coke and Processed Solid Fuels, ICS 75.160.10). WE DO NOT GIVE: the combustion conditions, temperatures, type of carrier gas, method of calibration, requirements for the mass of the test portion or repeatability requirements. The card distinguishes "mikro i makro" [micro and macro] instruments depending on the amount of test portion — what exactly this boundary consists of is not on the card, and we do not add it. Nor have we established whether and which legal acts concerning fuels from waste indicate this standard by name.

Method principle

A weighed portion of the recovered fuel is burned in the analyser, and the resulting combustion products are measured by detectors assigned to the individual elements. The result concerns the TOTAL content of carbon, hydrogen, nitrogen and sulphur in the dry matter. We do not quote the combustion and measurement conditions — they are the content of the standard, whose text we did not have.

Applications

• Testing of solid recovered fuel (SRF) before sending it for co-incineration
• Assessment of waste processed into alternative fuel — the most numerous matrix with this standard in the scopes
• Checking whether an older report citing PN-EN 15407 could have covered sulphur at all
• Reading a C, H, N, S result given in the dry matter together with the applicability threshold of the method

Key parameters

Standard

Standard number

PN-EN ISO 21663:2021-06 (wersja angielska; wprowadza EN ISO 21663:2020 [IDT] oraz ISO 21663:2020 [IDT])

Title (PL)

Stałe paliwa wtórne — Metody instrumentalne oznaczania zawartości węgla (C), wodoru (H), azotu (N) i siarki (S)

Title (EN)

Solid recovered fuels — Instrumental methods for the determination of carbon (C), hydrogen (H), nitrogen (N) and sulfur (S)

Step-by-step procedure

1. Checking whether the expected content falls within the range of the method

   The method applies at C > 0.1 %, N > 0.1 %, H > 0.1 % and S > 0.05 % in the dry matter. At a lower content, the result is not a result of this method, and this must be established BEFORE the test, not after it.

2. Preparation of the analysis sample

   The result concerns the portion actually burned. WE DO NOT GIVE the method of preparing the analysis sample — we did not have the text of the standard.

3. Determination of moisture content

   The result is given in the dry matter, so it requires knowledge of the moisture content; the method of its determination HAS NOT BEEN ESTABLISHED. An error in this step enters the final result, which looks correct.

4. Combustion of the test portion and measurement

   We do not quote the combustion conditions, temperatures, gases and detection method — they are the content of the standard. The choice of a micro or macro instrument is linked to the size of the test portion.

5. Recording the result with the basis of reference stated

   State that the result refers to the dry matter and which element was determined. When comparing with a report citing PN-EN 15407, remember that that document did not cover sulphur.

Required equipment and apparatus

Reagents, media and consumables

Health and safety (OHS)

• The analyser operates at high temperature — risk of burns and fire with incompletely burned residues
• Compressed gas cylinders secured against falling over, lines checked for leaks
• Recovered fuel from waste may contain components of unknown origin, including sharp and contaminated ones — puncture-resistant gloves during size reduction
• Recovered fuel dusts are combustible — use extraction when pouring and crushing

Frequently asked questions