Pollutions

Very important  is that the pellets will be produced from clean wood coming from the forest. No recycling wood is allowed. Pellets should not have any chemical or mechanical pollution.

In this connection very important seems to be presence of toxic chemicals  and content of heavy metals such as Pb, Hg, Sn, Zn, Co, etc. Contamination of the pellets may occur in the pellet plant in a case of using  not pure raw material  (recycling wood, espeially demolition wood, residue  from the furniture factories containing glue, paint etc). In a case pellet plant equipment is old  or not getting good service, metal parts of the machinery ,like  small metal pieces, screws  may get into the pellet cargo. Second source of impurities can be storages of the pellets   in the pellet plant or   a  port storage. Also very important seems to be   the transport (  lorries) and   the holds of the vessels,   in a case they are not cleaned enough from the previous cargo. Big issue for the   shipping is the Certificate of the Cleanness of the Holds, which is issued by the Control Organization before loading. Very important is the monitoring of loading by the Neutral Control Organization. It can avoid a lot of problems already in the loading port.

SGS Baltic States implimented a metal detection in the pellet cargoes  with Industrial Metal Detector AF-350 produced by White’s Electronic Ltd, UK. Any metal intensity when using this instrument is not less than 40 cm deep  from the ground surface. The surface of the stock is inspected on all physically accessible points. In a case some metal pieces are  found  a calculation of the quantity of the metal  in the whole  cargo in grams per 1.000 mt is done. Metal detection  has helped  to find even very small pieces of metal. Method  can be used  when there is a smallest suspect of metal contamination.

 

In a case there is a suspect of radioactive contamination  of the pellets  portable radiometers are used.  As per our investigation the maximum   gamma radiation   expressed as a dose equivalent rate  which was measured  from accessible points of the material was found to be 0,012 micro Sieverts per hour. The ambient background gamma radiation expressed as dose equivalent in the immediate area  was found to be  0,004 and 0,016 micro Sieverts per hour. It means that maximum recorded radiation of the goods   was within the range of the  ambient  background radiation. According our tests  of  the samples of wood pellets  radioactive isotopes Cs 134+ Cs 137 with gamma radiometry  were found to be   24 Bq/kg and radioactive isotopes Cs 90 with  beta radiometry were not over than  1Bq/kg. Radioactivity level  was not exceeding permitted 600 Becquerel per kg.Contaminated pellets can be refused by the end user after unloading of the vessel. Refusal of the pellets creates a huge problem for the supplier as for the first    it is a breach of the contract  and for the second it is practically impossible to sell the cargo of refused pellets for a good price. Pellets contaminated with metal, stones etc may create a fire in the hammer mills of the power plant and in this case the seller will be reliable for the damages created to the plant.

Lack of control over the production process, quality of the raw material and negligence at the loading on the vessel may create big problems as it can bring to the pollution of the pellets and may end up with the refusal of the cargo in the unloading port.