Raivauspuuston korjuuvaihtoehdot ja puubiomassan puskurivarastointi

HaBu

Alkamispäivä

01.01.2018

Päättymispäivä

31.12.2020

Tiivistelmä

Overgrowth forest vegetation along roads is considered a traffic safety risk, and may undermine or even jam the forest roads if the vegetation growing is not cleared on regular basis. Similarly, in power line corridors, along railway lines and edge zones along fields, brushwood is routinely cut and often left to decompose. Clearcutting is also used to construct forestland for farming or peat production. The cost of such management is considerable and is still done partly motor-manually. Currently very little of the brushwood regrowth or land clearing wood is being utilised for energy or biorefining. The basic economic advantages would be the fact that the cost of harvesting could be offset by the existing management costs. In addition it could decrease e.g. the forest road maintenance costs and improve both the availability and accessibility of forest biomass.

Buffer storage of comminuted wood material origin from forest harvesting operations or wood industries or is required to manage seasonal feedstock availability and ensure a continuous flow of biomass. It is also used as a means to direct a homogenous flow of material into the biomass plant. If this is not done properly, there can be excessive loss of biomass through biological and chemical degradation, as well as the very real potential of fire. Comminution of forest residues to chips is an expensive process, partly because of the low machine utilisation caused by the seasonal nature of the activity. One way to reduce costs is to utilise the machines for longer period and buffer store the chips. The demand for bark and sawdust is often diachronic in energy production and a need for buffer storing at a sawmill yard is often unavoidable during warm seasons.

The project develops cost effective means for harvesting land clearing wood and improving storing properties of comminuted wood material by evaluating various storing logistical solutions and machinery involving logging, comminuting, screening, compacting and transportation.

Tavoitteet, vaikuttavuus ja hyödyt

Projektissa haetaan kustannustehokkaita keinoja hyödyntää eri tyyppistä raivauspuustoa ja etsitään tehokkaita menetelmiä infraa (metsäautotiet, sähkölinjat tms.) haittaavan puuston korjuuseen ja raivaukseen. Toisena päätavoitteena on on tutkia haketetun puubiomassan (metsähake, sahanpuru, kuori) puskurivarastointia varastoaumoissa ja selvittää em. varastointitavan aiheuttamat muutokset materiaalin laadussa ja ominaisuuksissa sekä mitata em. varastointitavan aiheuttamat päästöt.

Hankkeessa koottujen tuottavuus- ja kustannustietojen perusteella voidaan arvioida, milloin raivuspuusto kannattaa korjata talteen ja minkä tyyppisellä kohteella kustannustehokkain vaihtoehto on jättää puusto korjaamatta ja raivata se pelkästään maahan. Puskurivarastointikokeissa selvitetään varastoitavassa materiaalissa tapahtuivat laadun ja määrän muutokset ajan funktiona ja etsitään keinoja parantaa haketetun puubiomassan varastoitavuutta puskurivarastointiaumoissa.