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Abstract Increasing interest in microalgal research calls for simple and automated tools to identify algal species' taxonomic level, examine their quality, monitor their growth, determine their size and shape, and enumerate them. We demonstrate the applicability of micro-flow imaging as an innovative tool to count algal cells and determine their shape and size, toward a future systematic species database, and biofuel applications. Ozonation was used to introduce changes in cell morphology such as cell oxidation, lysis and agglomeration, which were characterized by micro-flow imaging. Two ozone system configurations were used—batch and semi-batch—to oxidize four different Spirulina platensis samples, each presenting a different initial morphology correlated to culture growth stage, environmental conditions and hydration–dehydration of the cells. The ozone dose acted differently in each system: with the batch system (ozone dose of 5–15 mg L−1), the dominant action was breakage of spirulina filaments into smaller ones; with the semi-batch system (ozone dose up to ∼510 mg L−1), the dominant action was perforation of the cell walls and an increase in filament transparency (measured by mean intensity). The study also showed the influence of culture growth stage on ozonated spirulina count and shape analysis.

Abstract Bioenergy is recognized as the most important renewable energy source in Poland in several national policy documents. This has spurred an in increasing interest in energy crops, particularly willow, due to the large areas of arable land in Poland. However, in order for willow to be adopted by farmers, this crop must be perceived to be at least as profitable as cereal crops, such as wheat and barley, which compete for the same land. The objective of this study was to calculate the economics of growing willow on relatively large farms from a farmer's perspective in Poland. An additional objective was to relate the viability of growing willow to that of growing wheat and barley. Our calculations show that growing willow can indeed be an economically viable alternative to wheat and barley. At the current Polish price of wood chips (about 33 PLN/MWh or 7.5 €/MWh), the viability of willow is similar to that of barley given our assumptions on yields, etc. Wheat is the most viable crop of the three crops studied. Willow, however, is more profitable than both wheat and barley assuming a wood chip price of 50 PLN/MWh (11 €/MWh), which better represents the price in Europe as a whole. Despite good viability, willow is unlikely to be adopted by a great number of farmers without active support mechanisms and long-term stability of the status of energy crops in the Polish and the EU common agricultural policy.

Abstract Located in the tropics, with the sun shining all year round, and with its vast territory, Brazil may be regarded as having all the basic conditions to develop a modern Biomass for Electricity industry. Those characteristics together with: (a) the necessity of developing new energy resources for electricity production, in the northeast of the country; (b) the results of studies made by various entities, including CHESF; (c) the progress achieved by the BIG-GT technology; (d) the organisation of the Global Environment Facility (GEF); (e) and the support of the Brazilian government, through the Ministry of Science and Technology (MCT), provided the unique opportunity for the implementation of a commercial demonstration of that technology in Brazil. This paper describes the idea, scope, challenges, lessons, and actual status of development of the WBP/SIGAME project. It also highlights some institutional issues, budget figures, and energy prices.

Abstract To improve the efficiency of anaerobic digestion, we examined the effects of C2–C6 volatile fatty acids (VFAs) on methane fermentation, as well as the behavior of VFAs in anaerobic digestion. The VFA concentrations and methane production in anaerobic digestion were increased by pretreatment of waste activated sludge (WAS), such as ultrasonic disintegration, thermal and freezing treatments. The major intermediate products of anaerobic digestion for untreated and pretreated WAS, such as acetate, propionate, isobutyrate, butyrate, isovalerate, valerate, isocaproate and caproate, were used as substrates and the anaerobic degradation of these was carried out under the same conditions. It was found that decomposition rates of the VFAs (C2–C6) with a straight chain (normal form) were greater than those of their respective isomers with a branched chain (iso form). It was shown that the decomposition rates of the iso and normal forms of butyrate were greater than those of valerate and caproate. This was caused by the isomerization between butyrate and isobutyrate which occurred during the digestion process. Anaerobic bacteria in digested sludge converted butyrate to isobutyrate and vice versa by migration of the carboxyl group to the adjacent carbon atom. In addition, inhibition of degradation of the VFAs by acetate in a digester was also examined.

Renewable energy sources are expected to represent a growing proportion of the primary energy sources for the production of electricity. Environmental and social reasons support this tendency. European and Spanish energy plans assign a role of primary importance to biomass in general and, especially, to forest biomass for the period up to 2010. This paper reviews, organises and quantifies the potentials and values of this renewable resource in the foremost Spanish Region in terms of silviculture. The non-market externalities (environmental, economic and social) are classified, and some of them are quantified to present a synthesis of the benefits of a partial substitution of fossil fuels by forest biomass for electricity generation.

Forests are significant stores of carbon (C). This has been recognised by the United Nations Framework Convention on Climate Change and forests are one of the sectors which are included in national greenhouse gas (GHG) inventories. Some of this C pool remains in wood after harvest and can remain in use for long periods of time. Accounting for the C stored in harvested wood products (HWP) can potentially contribute to GHG mitigation. A model was developed for this research to estimate C stocks and flows in HWP in Ireland for the years 1961e2009. The change in carbon stocks in HWP were estimated on an annual basis and shown to increase between 1961 and 2009. This increase in annual net additions to C stocks is the result of an increase in domestic harvest (and the resulting inflow into HWP pool) and an increase in HWP going to end uses with longer half-lives. This model (using a Tier II method) is an improvement to previous national estimates (using the Tier I method). Uncertainty was reduced by utilizing national data. This work shows that HWP has considerable potential to support GHG mitigation in Ireland. Inclusion of HWP in Ireland’s National Inventory Report (NIR) would give a more comprehensive picture of how the Irish forest sector is mitigating GHG emissions. This model will be incorporated into CARBWARE (Black 2008), the model used to estimate C stored in each of the 5 forest pools, of current and future Irish forests.

When a new crop is being promoted as a pro-poor, like in the case of Jatropha curcas (J. curcas) in Zambian rural communities, it is pertinent to explore factors that might affect its adoption, on not only homogenous groups but also heterogeneous wealth categories. This is because poorer farmers may be reluctant to invest in any untried innovations mainly due to their limited factors of production. Evidence from a household survey of 249 randomly selected farmers in eastern Zambia indicates that some factors that affect the farmers in embracing J. curcas seed production and exchange activities differ according to wealth. While factors related to household labour availability were crucial to involvement in J. curcas collection and exchange activities among poorest farmers, it was gender of the household heads and access to off-farm income that significantly influenced these activities among the well endowed farmers. Results further indicate that the farmers who are relatively well endowed are the ones most likely to benefit more from J. curcas collection and selling activities. Well endowed households harvested more seed from hedges because they have more labour and currently harvesting of seed is not restricted to private hedges. Further evidence show that even with fewer household members, the poorly endowed could be involved in planting of hedges. This is an avenue that can help the poorest farmers especially when property rights over J. curcas hedges are secured.