ISO 21404 pdf free download
ISO 21404-2020 pdf free download.Solid biofuels – Determination of ash melting behaviour.
5 Reagents
5.1 Ethanol, with a purity 95 %.
5.2 Gold wire, of diameter 0,5 mm or larger, or gold plate, of thickness 0,5 mm to 1,0 mm with a purity of 99,99% or a certified melting point (e.g. 1 064 °C).
5.3 Nickel wire, of diameter 0,5 mm or larger, or nickel plate, of thickness 0,5 mm to 1,0 mm, with a purity of 99,9% or a certified melting point (e.g. 1 455 °C).
NOTE Nickel Is used for calibration in reducing atmosphere only.
5.4 Palladium wire, of diameter 0,5 mm or larger, or palladium plate, of thickness 0,5 mm to 1,0 mm with a purity of 99,9 % or a certified melting point (e.g. 1 554 °C).
5.5 Carbon dioxide, carbon monoxide, hydrogen or ready mixture of carbon dioxide and carbon monoxide with 55 % (V/li) to 65 % (V/V) carbon monoxide and 35 % (V/li) to 45 % (V/li) carbon dioxide or ready mixture of hydrogen and carbon dioxide with 45 % (V/li) to 55 % (V/V) hydrogen and 45 % (V/V) to 55 % (V/li) carbon dioxide.
6 Apparatus
6.1 DIshes for ashing made of inert material, such as platinum or graphite and of such size that the test portion loading does not exceed 1 g/cm2 of bottom area can be used for all biomass material. Before the first use, the dish shall be heated to ashing temperature for 60 mm and shall cool down to ambient temperature before use. The material of the dish shall not react with the sample or ash of the sample. When using dishes of other materials (e.g. porcelain) it shall be checked that no reaction with the ashes/ biomass material occurs during ashing process, i.e. the ash should be a loose powder (no smntering or melt) and the surface of the dishes shall be intact after the ashing.
6.2 Furnace for ashing, which shall be capable of providing a zone of uniform heat at the temperatures required and reaching these temperatures within the specified times. The air exchange in the furnace shall be sufficient to remove the flue gasses SO2 and CO2 formed during decomposition of the biofuel before these gases react with the ash components during the heating procedure.
NOTE For preparation of coal ashes according to ISO 1171,5 to 10 air changes/mm are necessary to eliminate reaction of SO2 and CO2 with the ash, For hioniass there is currently no scientific proof for the influence of air exchange in the ashing furnace on the ash melting results although an influence is expected. Biomass usually has a lower ash content and ash is of light weight in comparison to coal ash. This property can cause the ash to be blown from the ashing crucible which can limit air exchange possibilities. A sensitivity analysis of variation of these parameters on the result of ash melting behavior can be valuable fora certain set-up.
6.3 Sample containers or bags, airtight, suitable for holding (1 to 10) g of ashed sample leaving minimum free air space e.g. LDPE zip -lip bags or max. 50 ml wide-mouth HDPE bottles.
6.4 Furnace for ash melting behaviour, electrically heated, which satisfies the following conditions:
a) it shall be capable of reaching the maximum temperature of at least 1 500 °C);
b) it shall provide an adequate zone of uniform temperature in which to heat the test piece(s);
c) it shall provide means of heating the test piece(s) at a uniform rate from 550 °C upwards;
d) it shall be capable of maintaining the required test atmosphere (see Clause 7) around the test piece(s);
e) it shall provide means of observing the change of shape of the test piece(s) during heating. The requirements for the operation/design of the furnace shall be such that a provision for observing the test in low light conditions is stipulated, be that provision one of illumination or camera sensitivity.
6.5 Pyrometer, comprised of a platinum/platinum-rhodium thermocouple.
6.6 Mould, of brass, stainless steel or other suitable material for preparing an upright cylinder of height 3 mm to 4 mm and with diameter equal to the height.
6.7 Hand press with spring pressure compression, to produce the test piece.
NOTE Manufacturers of ash fusion moulds (f) generally provide a hand press designed to be used with the mould. Manufacturer provided hand presses are considered suitable.
6.8 Support for the test piece, of such a material that it becomes neither distorted, not reacts with nor absorbs the ash during the determination.
Zirconium dioxide supports are suitable or a non-absorbent interface such as platinum foil can be used between the original support and the test piece. Supports of sintered alumina or fine textured mullite have shown to influence the result especially for FT due to reaction or absorption of liquid ash and should be avoided.
6.9 Flowmeters, for measuring the components of the reducing gases (see Clause 7) and/or for measuring the flow rate of the oxidizing gas.
6.10 Mortar and pestle made of agate or zirconium oxide or other adequate grinding instruments like ball mill made of abrasion resistant material.ISO 21404 pdf download.
