J.A.Rodríguez Añón

Calorific values and flammability of forest species in Galicia. Coastal and hillside zones

Abstract Changes in heat values and in flammability with the seasons of the year for the different species which make up the woodland map of two zones, Sada (coastal area) and Santiago (hillside and plateau area), situated in La Coruna (Galicia, Spain), are reported. These data were evaluated as a help for fighting forest fires, which have been very frequent in this region during the last decade. The species studied are the most abundant in the areas: Eucalyptus globulus Labill., Pinus pinaster Aiton, Ulex europaeus L., Rubus fructicosus L., Pteridium aquilinum L., Sarothamnus scoparius (L.) Link, Quercus robur L., Castanea sativa Miller and Acer pseudoplatanus L. The calorific values were measured by static bomb calorimetry. These data were complemented with flammability determinations and completed with chemical analyses of the different species.

Calorific values and flammability of forest species in Galicia. Continental high mountainous and humid Atlantic zones

Abstract Calorific value, flammability and chemical composition during the seasons of the year for the different forest species which make up the woodland map of two zones, Devesa da Rogueira (continental high mountainous zone) and As Neves (humid atlantic zone), situated in Galicia (Spain), are reported. The species characteristic of the zones are: Sorbus aucuparia L., Acer pseudoplatanus L., Taxus baccata L., Fagus sylvatica L., Quercus robur L. and Castanea sativa Miller. in Devesa da Rogueira (Orense), and: Alnus glutinosa (L.) Gaertner., Betula celtiberica L., Prunus avium (L.) L., Fraxinus excelsior L., Laurus nobilis L. and Salix Atrocinera L. , in As Neves (La Coruāna). The calorific values were measured by static bomb calorimetry and the flammability using a method proposed by Valette.

Calorific values and flammability for forest wastes during the seasons of the year

Abstract In this paper are reported changes in heat values (HV) with the seasons of the year for the different species which make up most of the undergrowth in Galicia (Spain). Knowledge of these values is essential when evaluating the possibility of exploiting the energy content of the bushes in energy-recovery plants. The calorific values of combustion at 25°C were measured by static-bomb calorimetry for forest residues originated in activities related to afforestation, fire-breaks, forest clearing, etc. From combustion experiments, the mean calorific value was found to be close to 19000 kJ kg −1 , similar to the calorific values of municipal solid waste (MSW). For this reason, these forest residues can be used as an additional fuel to be added to MSW in energy recovery plants and this will also minimize the risk of forest fires.

The influence of some physicochemical parameters on the microbial growth in soils

Abstiact Microcalorimetric techniques have been used to study the influence of different physicochemical parameters on microbial growth in different soils in Galicia (NW Spain). The study was carried out using a 4 channels Thermal Activity Monitor (Thermometric, Sweden). Two types of soil, humic cambisol and umbric regosol, with different uses, vineyard, orchard, maize field, and scrubland, were investigated. Microbial activity in all the soils studied was stimulated by the addition of 1.25 mg of glucose g - 1 soil. The power-time curves recorded from every experiment were analysed and from these analyses characteristic parameters such as peak time, peak height and microbial growth rate constants were determined. The influence of different environmental parameters, temperature (ambience and soil), moisture content (sample and residual), pH in water, and C/N ratio, were considered.

Activation energies and rate constants for an epoxy/cure agent reaction

From the peak reaction temperatures as a function of heating rate, the activation energies were obtained for a system consisting of an epoxy resin (Badgen=0) and a curing agent (isophorone diamine), using a Perkin Elmer DSC7 operated in the dynamic mode. At the same time, the Arrhenius law was used to calculate rate constants.

Design of risk index maps as a tool to prevent forest fires.: Continental high mountainous zone of Galicia (NW Spain)

Risk indices for the different forest species existing in a high mountainous zone situated in Galicia (NW Spain) as well as their seasonal evolution were studied. Calculation of these risk indices was based on the previous elaboration of energy maps from mean calorific values, flammabilities and chemical analyses of forest species. A combined study of energy maps, bioclimatic characteristics of the zone and main biological properties of the different species led to the determination of the seasonal risk indices. Knowledge of risk indices of the species allows the design of maps to be used to prevent and/or fight forest fires.

Design of risk index maps as a tool to prevent forest fires in the northern coast of Galicia (N.W. Spain)

The thermochemical parameters: calorific values and flammability, elementary chemical composition and heavy metal contents during the seasons of the year for the different forest species which make up the woodland map of the northern coast of Galicia (Spain) are reported. These data, together with bioclimatic conditions of the zone, were used to elaborate energy maps of forest biomass. The different forest species were classified in terms of energy contents, resistance to wildfires, and forest fire risk indices. The resulting energy maps can be very useful to prevent and fight forest fires effectively. The main equipment used to carry out this research was a static bomb calorimeter, a standard epiradiator nominal constant power 500 W, an atomic absorption spectrophotometer and apparatus for elementary analyses.

FOREST WASTE AS A POTENTIAL ALTERNATIVE ENERGY SOURCE

Following a method based on the procedure given by Hubbardet al. [1] the calorific values of combustion in oxygen at 298.15 K were measured by static-bomb calorimetry for forest residues. This waste mainly coming from mount reforestation, construction of firebreaks, etc., constitutes an important risk to originate forest fire. From combustion experiments the mean calorific value of all species studied was found close to 19 000 kJ·kg−1, similar to calorific values of Municipal Waste. It can be concluded that this forest residues can be used as an additional fuel to be added to Municipal Solid Waste in energy recovery plants. By doing this, energy, in this moment lost as abandoned residues, can be recovered. At the same time the elimination of this waste minimizes the risk of forest fires. Our results reasonably agree with literature values.ZusammenfassungNach einer auf der von Hubbardet al. [1] empfohlenen Vorgehensweise beruhenden Methode wurden die Heizwerte für die Verbrennung von Forstrückständen in einer Festkalorimeterbombe in Sauerstoff bei 298.15 K gemessen. Dieser Abfall entstammt hauptsächlich der Wiederaufforstung, dem Schlagen von Feuerschneisen usw. und stellt einen wichtigen Risikofaktor bei der Entstehung von Waldbränden dar. Anhand der Verbrennungsversuche fand man für alle untersuchten Arten einen mittleren Heizwert in der Nähe von 19 000 kJ·kg−1, ähnlich dem Heizwert von Kommunalmüll. Man kann annehmen, daß diese Forstrückstände neben Kommunalmüll als zusätzlicher Brennstoff in Energie-Rückgewinnungsanlagen verwendet werden können. Hierdurch kann brach zurückgelassene Energie rückgewonnen werden. Gleichzeitig reduziert die Beseitigung dieser Forstrückstände das Risiko von Waldbränden. Unsere Resultate stimmen gut mit Literaturangaben überein.