Objective
Branches of pine trees constitute a valueless residue in the caretaking and exploitation of pine tree forests. The project aims at recovering these branches, at treating them by extraction to obtain as main product essential oils and as by-product a solid residue which can be upgraded either as compost or as solid fuel depending upon the local conditions.
The innovative aspects of the project lie in the technology based on fluidized bed for the extraction process, in the technology to burn wood sawdust and in the energy recovery process from combustion fumes.
An energy saving of 77 toe/year is expected. The calculated simple pay-back of the project investment is 4-5 years.
In an innovative process, the essential oils will be extracted by water vapor displacement. 500 kg h -1 water vapor will be produced at 3 bars by a boiler of O.5 MW capacity with fumes at 1000 deg.C. The furnace of the boiler will be continuously fed with wood sawdust, locally produced as a residue of little value. The extractor has a volume of 8.5 m3, will treat 1750 kg pine draft of 0.3 apparent density and will produce 1 kg essential oils per hour. The extract will be water-cooled and condensed in a condenser using 500 W power and decanted in a O.3 m3 decanter.
Upstream of the innovative extraction process, the branches of pine trees will be collected by a mechanical rake, ground at a rate of 4-10 m3 h -1 to a size between 5 and 10 cm and collected first in a mobile container of 8 m3 capacity, then in a container of 50 m3 prior to transportation. After transportation, the granulometry will be reduced to 10 mm by a knife-grinder of 7.5 kW power at 600 kg h -1.
Dowstream of theinnovative extraction process, the solid residue after extraction will be composted in 3 months in heaps maintained at 65-80% humidity after addition of 1-2% urea and superphosphates.
Total cost of project is 47.7 MBF. Eligible cost is 33 MBF. Investment cost is 29 MBF. Yearly sales of essential oils are expected at 4.16 MBF,of compost at 7.2 MBF (4500 BF t-1). Yearly saving of recovered heat and by the use of alternative fuel (wood sawdust instead of heavy fuel are expected at 1.8 MBF. With annual operating and maintenance costs of 6.7 MBF, the simple pay-back is calculated to be reached after 4.5 years.
An energy saving of 77 toe/year is expected from the use of local pine sawdust as fuel for the furnace. Price per tep saved is 167 kBF, namely 80 kBF in investment costs and 87 kBF in exploitation costs.
A similar project without the innovative aspects of the present project is by far not profitable : the yearly income being only 50% of the yearly cost. With the innovative aspects, the project becomes profitable.
Monitoring will include flow rates of gas and liquids, temperatures along the process, mass balances of pine draft all along the process, and pressure losses.
Topic(s)
Call for proposal
Data not availableFunding Scheme
DEM - Demonstration contractsCoordinator
4000 Liege
Belgium