Regular recycling of wood ash to prevent waste production (RecAsh)

Transcription

1 TASK 3 REPORT PRO2/2064/05 28/6/2005 Regular recycling of wood ash to prevent waste production (RecAsh) PROMOTION OF THE RECULATING PROCESS FOR USING OF FINNISH BIOENERGY PLANT ASH AS A FOREST FERTILIZER Authors Tuulikki Lindh, Saara Isännäinen, Samuli Rinne VTT Processes, PO Box 1603 FIN Jyväskylä, Finland Public VTT PROCESSES

2 ABSTRACT The goal of RecAsh project is to promote the recycling of wood and possibly peat ashes from bioenergy heat and power plants to forests. One target is to support the regulating process for ashes, in order to ensure the good quality and harmlessness of ashes for forest fertilizing. Authorities have presented existing recommendations in RecAsh project meetings. The stakeholders in ash usage chain have pointed the need of regulating and especially getting a product status instead of waste status for ash. VTT has discussed with different parties in order to promote the regulating process. The regulation subject will be discussed in the next reference group meeting in

3 PREFACE This short report is a part of Task 3 or Ash Classification Study. The work is a part of Life EU-project. The aim of project is to promote the recycling of wood ashes to forests. Authors are Tuulikki Lindh, Saara Isännäinen and Samuli Rinne. They all are from VTT Processes, Finland. In Jyväskylä Authors 3

4 CONTENTS PREFACE THE AIM OF THE WORK THE WORK UNTILL NOW FOLLOW UP ACTIONS SOURCES...7 4

5 1 THE AIM OF THE WORK The goal of RecAsh project is to promote the recycling of wood and possibly peat ashes from bioenergy heat and power plants to forests. One target is to support the regulating process for ashes, in order to ensure the good quality and harmlessness of ashes for forest fertilizing. RecAsh project supports the process by bringing out the matter of regulating especially at reference group meetings and it also encourages the discussion about view points. 2 THE WORK UNTILL NOW VTT has compared some Finnish ash qualities with Swedish recommendations of heavy metal residues and nutrient contents. A very preliminary conclusion was that the Swedish recommendations are suitable for many nutrients and heavy metals which exist in Finnish ashes (Lindh et al. 2005). VTT presented these recommendations and the comparison at reference group meeting of RecAsh project in The comparison is based on already existing knowledge of ashes and analyses studied by VTT in heat and power plants which participate in the RecAsh project. Conclusion is that power plants must ensure that wood and peat fuels don t contain any polluted parts, such as waste wood from the demolished houses. It must be ensured that even small amounts of contaminated fuel fractions will not be burned. Wood ash is more suitable for forest fertilizing than peat ash, because peat ash contains nutrients less than wood ash. More nutrients would be got from wood ash or biotite. Biotite is a side product of the apatite concentration process. Containing lot of potassium, biotite supplements low-potassium peat ash to an acceptable forest fertilizer. Even though the mixture of biotite and peat ash do not qualify all the Swedish requirements for fertilizer, it has been demonstrated that the biotite peat ash-mixture improves tree growth in peatland forests, according to a study made by the Finnish Forest Research Institute. In the same reference group meeting the Environment Centre of Central Finland presented existing orders for ashes as a forest fertilizer. In Finland, ash is always classified as a waste and a environment licence is always needed. Licences are admitted by environmental protection committee or regional environment centre. Licence concerns both the usage of ash (spreading) and the area where the ash would be spread. The quality of ash must be analysed and it must have a statement from a research institute (or accredited analyse laboratory). Ash must also be stabilised to prevent dust formation. There are also some restrictions for spreading concerning safety zones and distances near lakes and streams, forest ditches and ground water area. Restrictions for safety zones and also spreading time are recommendations and the authority checks the situation case by case. 5

6 Both in the reference group meeting of the RecAsh and in ash demonstration-info afternoon of the RecAsh at the regulation for ashes was an important conversation topic. Current and potential stake holders of ash usage chain were present at both meetings. The special aim was to get the product status for ash instead of the waste status. If ash had a product status, the waste law would not anymore concern ash as a forest fertilizer. Within RecAsh VTT has discussed about present orders for ash and regulating of ash with different parties. Contacts have been made to the Environmental Centre of Central Finland, the Environmental Centre of Finland and the Regional Forestry Centre of Central Finland. For the base of conversations, VTT has also made preliminary proposal for recommendations of limits of heavy metal residues of ash for Finnish conditions. In conversations it has been put out that Finnish industry (pulp and paper industry, ash producers) sets great store by the ash regulating. If ash had a product status instead of waste status, ash handling and spreading wouldn t need environment licence anymore. This would help ash recycling and also ease the work of authorities. In conversations it has also brought out that ash can be used in Finland for health fertilizing of forests, but ash is in the weaker situation in comparison to artificial fertilizers because the state subsidies are based on the costs of the artificial fertilization. In addition the forest owners must be very active and have knowledge about the usage of ash as forest fertilizer. There is not yet sufficiently information about ash for instance in present forestry recommendations. 3 FOLLOW UP ACTIONS In the following there are some objects which are important for ash usage as a forest fertilizer. The status of ash should be changed from waste to product since the regulation for waste disposal restricts the usage of waste-status ash Quality classes must be created for ashes, which are used as forest fertilizers (compare classification of wood and peat fuels) Limits in classes should be well-studied, also for mixtures of wood and peat ashes, to prevent excessive and expensive sample taking with fluctuating fuel mixtures, and not to prevent the sensible use of ashes for forest fertilizing The subject would be promoted in following ways in RecAsh project: Knowledge about ashes as forest fertilizer will be spread and the need to get regulations and product status to ashes as a forest fertilizer will be brought out. The fact that only pure, incontaminated wood ashes and mixtures of wood and peat ashes can be spread into forests will especially be pointed. 6

7 The regulation subject will be discussed in the next reference group meeting in SOURCES Lindh, T., Rinne, S. and Järvelä E Proposal for modification of Swedish recommendations. VTT Processes. Reports number PRO2/2063/