FORESTRY BIOMASS DEMONSTRATION PROJECT

Ziel

The objective of the project is to demonstrate the feasibility of energy production from renewable forestry biomass according to the concept of "short rotation forestry" developed as aim of contract SE/00100/79/IR, first phase of this project. The originality of this project lies in the continuation of the demonstration of the technical feasibility and the profitability of the concept.
In 1982, soils were prepared by incorporation of 25 tons lime and 30 kg of CuSO4 per ha.
The following plantations were made :
a) 24 ha Salix aquatica gigantea and 10 ha Pinus contorta
b) 2.75 ha of the same Salix, 6 ha Alnus and 1.25 ha Populus, in mineral clay soil, and
c) 1 ha of the same Salix for fertilisation trials.
Because of project failure, no further plantations were made.
The project was abandoned since growth has been a failure. A first reason for this is the lack of available nutrient such as P which strongly reduced the growth of mycorhyzal fungi necessarily associated with vigorous root growth. Addition of external fertilizer such as 350 kg phosphate, 250 kg potash and 250 kg calcium ammonium nitrate did not cure the problem. In the best 10% of the cases, the yield was half the expected yield : 7.5 instead of 12 tons dry matter per year.
The second reason is the lack of suitable depth of improved top soil, here only 12 cm. Preparation of soil by pre-cultivating itas a grassland improved soil quality.
A third reason is the lack of adequate drainage which resulted in too low an acidity of the soil.
A fourth reason is the need for 20 to 40 tons lime per ha which has to be plowed into a depth of 40 cm. However, lime does not move in peat soils and destroys existing locally plantations where incorporated.
It must be added that separate research plots had shown promising growth and yields of Salix coppices. Furthermore, 200 ha gley soil, treated with 1 250 kg phosphate and 150 kg potash per ha, showed elsewhere good growth of lodgepole pines.
As a conclusion, positive results obtained on research plots, cannot be automatically transferred to other demonstration plots, due in particular, to minor but important variations in the soil status of these cutover peat lands. Improvements could be defined but proved completely uneconomic even through an elementary analysis.
The harvesting prototype able to produce "chuncks" 15-20 cm long proved not suitable because it was not adapted to the nature and the growth habits of the biomass material.
The boiler of the electrical power plant could successfully be adapted to alternative peat-woody biomass material burning with little changes. The furnace requires wood chips of less than 55%, better 40% humidity, a state which could be attained after a 2 month period drying.
The project entails first planting 240 ha of hardwood coppice and 120 ha of single-stem forestry, mainly conifers in lands of low fertility. Together with project nr SE/100/79/IR, over a five-year period, it was foreseen to have planted 400 ha of coppice and 200 ha of single-stem forestry.
An important part of the project, secondly, is the optimization of the mechanical, whenever necessary complete-tree harvesting and of the transportation of biomass presumably with unit trains and/or tractor trailers.
A 4 to 8 year cycle was expected to yield from 7.5 to 12 tons dry matter per ha, that is, for the whole plantation, a yearly yield in woody biomass of 15 ktons dry weight including 3.75 ktons forest residue.
An existing 5 MW electrical power station was foreseen to be modified to accept woody biomass to produce steam at a pressure of 4.75 kg cm-2 and a temperature of 463 deg.C.

Programm/Programme

ENG-ENALT 1C - Programme (EEC) of financial support for projects to exploit alternative energy sources, 1979-1984

Thema/Themen

3.7 - ENERGY CROPS

Aufforderung zur Vorschlagseinreichung

Data not available

Finanzierungsplan

DEM - Demonstration contracts

Koordinator

BORD NA MONA

EU-Beitrag

Keine Daten

Adresse

LOWER BAGGOT STREET
2 Dublin
Irland

Gesamtkosten