Bedömning av gasproduktion i returfiber : En studie för att utvärdera alternativ för att inhibera gasproduktionen inom pappersmassaindustrin

Sammanfattning: In the pulp production industry one potential problem is the production of gas from microbial activity in the storage tank. If left unchecked such gas production can in extreme cases lead to an explosion. To prevent any such event the current method of maintaining microbial activity in pulp plants is to use hazardous biocides. Such biocides can be expensive and dangerous to handle – therefore a safer and cheaper alternative would be preferred. This study aims to examine and evaluate two potential alternatives: Tannins extracted from trees with natural antibacterial properties and introduction of Lactobacillus plantarum to see if a more manageable bacteria can out-compete the bacteria already in the pulp. The results were measured by observing gas production in different trials where pulp from a nearby plant was mixed with different concentrations of tannins or Lactobacillus. The results showed that this strand of Lactobacillus plantarum had no effect on gas volume production while the pulp mixed with tannins did have some effect by lowering the amount of gas volume produced. However, the experiments with tannins and pulp showed no clear dose-response relationship which most likely is caused by varying quality and handling of the pulp used in the experiments. In summary this study shows that tannins can have an effect on the volume of gas produced by recycled paper pulp by lowering it – although not completely inhibiting it.