Remarks about the use of cremation cellulose coffins
By the Decree issued on April 12th, 2007, in conformity with the article 115, paragraph 1, letter b of the decree No 112 of 1998, the Ministry of Health authorizes the use of wooden-edged cellulose coffins, instead of wooden coffins to bury, carry and/or cremate corpses in our country. The Decree was issued in conformity with the article 31 of the Decree N° 285/90 and with the article 75 paragraph 3 of the Decree N° 287/90. This opportunity has greatly improved the coffin combustion cycle during cremation. Actually, a cellulose coffin weighs 17 kg. on average, wood weighs 5-6 kg., cellulose the remainder. The frame is made of wood, so as to carry corpses more easily during funeral services.
Combustion is helped, firstly because the mass to burn is much smaller. Indeed hard wood coffins are heavier and more time is required to burn coffin and corpse.Generally, according to the coffin size, the weight varies from 40 to 80 kg. for fir, larch, walnut, mahogany, and density rises from about 0.44 kg/cubic dm. to about 1 ( commercial densities with 15% moisture ). We must take into account that now almost all Crematoriums work by methane, the most suitable fuel, because of its heating power, as well as its fairly short emissions and no solid combustion products.
Besides, methane has a much higher flame temperature ( 1,949 °C adiabatic and about 1,200 °C real average) compared to wood (max 800°C ) which has a higher C/H index. Economy practised in using cellulose coffins must also be taken into account, cremation being destructive.
The hypothesis advanced by someone to use hard wood coffins in order to stoke combustion is absolutely illogical and against good technique for many reasons. First of all, as already said, the cremation mass is increased, cremation takes more time, emissions are higher.
For instance, if an average corpse to be cremated weighs 65 kg. and a wooden coffin 50 kg., the cremation mass is increased from 82 to 115 kg., that is a 40% increase in comparison with the 17 kg. cellulose coffin.
Then, a fuel ( that is wood ) with a weight heating power about three-four times lower ( according to moisture with about averag 3,250 kcal/kg with 20% ) than methane and a much more unfavourable C/H ratio would be used.
Moreover, wood produces cinders ( 1% ), thus increasing the powder rate in emissions, which must be definitely avoided as far as possible, since emissions during cremation are the most important environmental problem. Besides, wood must be initially heated up (at about 210° C) to burn and to produce heat, so that those degradation complicated reactions producing combustible gases can take place in order to get a positive heat balance. It must also be borne in mind that methane, which burns instantaneously, sends forth fewer emissions, heat being equal, and it’s environmentally friendly, while wood combustion comes from different and complicated volatile substances ( 85%) and from coal ( 14%). It must finally be borne in mind that cremation initial stage, ending with the coffin breakdown, must be as quick as possible, so that corpse cremation starts with the most difficult stage, that is water evaporation from the body (about 76%). As everybody knows, evaporation keeps the body “ fairly “ cold until its removal ( evaporation heat about 540 Kcal/Kg plus sensitive heat ). The cellulose coffin, burning very quickly, with little cinder production, makes this operation easier, in consideration of its nature. The Methane Burners of Crematorium Primary Chambers offer the required heat potential under the most favourable cremation conditions, as above said.
Cellulose coffin considerably favours the best possible cremation, which would be by a simple linen sheet covering the body.
Ing. Alessandro Salvi - Noli, 06 Jul 2007
Italy has 15,384 graveyards of different sizes, subdivided into about 8,000 towns, and about 60 million inhabitants, with a 9.5% death-rate: every year 550,000 people die in Italy. Deceases are subdivided as follows : 310,000 burials in grave, 190,000 inhumations, 50,000 cremations. To bury 550,000 deceased, subdivided this way, we need every year:
- not less than 500,000 hundred kg of cut and machined timber, the most common timber ( and also the cheapest one on average ) is larch, a conifer growing in the Alpine climate; it takes it not less than 15 years to reach 40 m. in height and 60 cm in diameter. Not more than 20 coffins can be manufactured with a larch; so, to provide for yearly needs, at least 37,000 larches are required, a 50 sq km forest area, nearly half as big as the whole territory of Rosignano town;
- the wood renewal cycle being estimated at 15 years, a 750 sq km total area is needed for that purpose;
- 6 times Rosignano territory - at least 600,000 long-trunked trees;
- to provide for the zinc coffin needs to bury 310,000 deceased, not less then 6,000 zinc tons are drawn out of the planet exhaustible resources;
- not less than 6,000 paint tons are required, only for the aesthetic treating of 550,000 coffins;
- 400 kg of toxic solvents to man and environment, also containing cancerous substances evaporate from each paint ton;
- 310,000 burial niches and graves occupy not less than 700,000 cubic m;
- which correspond to 2,500 flats;
- for their construction 390,000 tons of building material, cement, scaffolding, sand are needed;
- and in addition finish marble, not less than 70,000 tons, in about 2 cm slabs, covering 1 hect. surface ;
- in order to bury 190,000 deceased, not less than 1,520,000 cubic m of ground are dug, occupying about 600,000 sq m, that is the area required to build 6,000 flats, enough for a 20,000 inhabitant community;
by Donatella Mariani