Seaweed cultivation and processing industries could contribute to sustainable blue growth and the European bioeconomy. This article contributes a case study evaluation of environmental sustainability of preserved brown seaweed Saccharina latissima by means of environmental life cycle assessment of a pilot facility in Sweden. The study accounts for nutrient bioremediation and carbon capture and includes two alternative hatchery processes, a 2-ha longline cultivation, and four alternative preservation methods (hang-drying outdoors, heated air-cabinet drying, ensiling, and freezing). The study found that as a result of carbon capture and nitrogen and phosphorus uptake (bioremediation) by seaweed, more CO2 and PO4 equivalents are (temporarily) absorbed than emitted by the supply chain. The extent of emissions is most affected by preservation methods undertaken. Impact profiles of the supply chain show that the greatest impact shares result from freezing and air-cabinet drying, both the two most energy-intensive processes, followed by the cultivation infrastructure, highlighting strategic optimization opportunities. Hatchery processes, harvesting, and the low-energy ensilage and hang-drying outdoors were found to have relatively small impact shares. These findings presage the environmentally friendliness of seaweed-based products by documenting their potential to mitigate eutrophication and climate change, even when taking a life cycle perspective.

Um procedimento simples e de baixo custo, baseado na elevada diferença de solubilidade de cloreto de sódio em etanol e em água, é proposto para a estimativa do teor de água em etanol combustível. A concentração iônica de soluções saturadas com o sal é monitorada por medidas de condutividade com resposta linear até 16% de água em meio alcoólico e limite de detecção de 0,05% (v/v). O procedimento é preciso (coeficiente de variação de 0,6%, n = 10) e exato (resultados concordantes com os obtidos por titulação amperométrica de Karl Fischer com 95% de confiança). Um dispositivo eletrônico que explora o mesmo princípio foi proposto para monitoramento in situ de etanol combustível visando à detecção rápida de não conformidades. O dispositivo pode ser operado por não especialistas, gerando uma resposta binária indicada por LEDs coloridos e foi usado com sucesso na classificação de amostras comerciais adulteradas com diferentes quantidades de água.A simple and inexpensive procedure, based on the high difference in solubility of sodium chloride in ethanol and water, is proposed to estimate the water content in ethanol fuel. The ionic concentration of solutions saturated with the salt is monitored by conductometric measurements with a linear response up to 16% water in an alcoholic medium and a limit of detection of 0.05% (v/v). The procedure is precise (coefficient of variation of 0.6%, n = 10) and accurate (results in agreement with those obtained by Karl Fischer amperometric titration at the 95% confidence level). An indicating electronic device exploiting the same principle was proposed for in situ monitoring of ethanol fuel samples aiming at the fast detection of unconformities. The device can be operated by nonexperts, generating a binary response indicated by coloured LEDs, and it successfully classified commercial samples spiked with different amounts of water.Keywords: ethanol fuel, water, in situ analysis, conductivity IntroductionThe search for renewable and less polluting sources of energy is one of the major global challenges and, in this context, the replacement of fossil fuels is essential. Ethanol, obtained by the fermentation of sugar from vegetable sources such as sugar cane, is a real alternative because it can be obtained from renewable sources and its production and consumption as a fuel are less polluting than petroleum derivatives. The annual world production of ethanol reached ca. 85 billion litres in 2011 and 2012, 1 being estimated that ca. 70% of which is consumed as fuel. Brazil produces ca. 27 billion litres per year, 2 being the pioneer country in the production and use of ethanol fuel.Despite the use of hydrated ethanol fuel being restricted to Brazil, anhydrous ethanol is used in mixtures with gasoline in Europe and other countries such as the USA, Mexico, India, Argentina and Japan. The consumption of ethanol has increased with the use of flexible fuel vehicles that can work on gasoline and ethanol, as well as the increase in costs of petroleum derivatives and general political and environm...

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A new approach to process Saccharina latissima algal biomass was developed using sodium citrate and a polyvalent cation-specific resin to sequentially extract the alginate into several usable fractions. The fractionation was performed in a cyclic manner, utilizing a stepwise removal of the native polyvalent ions present in the algae to isolate fractions of alginate with different solubility in the presence of these ions. Sodium citrate was used in different concentrations in the extraction solution to remove polyvalent cations to adjust the alginate liberation while AMBERLITE IRC718 resin was added to further remove these ions and regenerate the extraction solution. Alginate was recovered by acid precipitation and analyzed for its uronic acid composition and molecular weight, and the carbohydrate compositions of the insoluble and soluble parts of the algal biomass residue were determined. Finally, the fractionation method was assessed with a life cycle analysis to determine the energy and water efficiency as well as the greenhouse gas emissions and the results were compared to conventional alkaline extraction. The results indicate that the energy and water use as well as the emissions are considerably lower for the cyclic extraction in comparison with the conventional methods.Electronic supplementary materialThe online version of this article (doi:10.1007/s10811-017-1176-5) contains supplementary material, which is available to authorized users.

Biodiesel can be obtained from renewable sources by catalytic transesterification of vegetable oils or animal fats, yielding alkyl esters of fatty acids and glycerol as a by-product. Glycerol needs to be removed before commercialization of the biofuel because high concentrations can damage motors and produce highly toxic gases during combustion. The aim of this work was to develop a procedure for in situ analysis of free glycerol in biodiesel samples exploiting a single-phase system. The time-consuming analyte extraction and phase separation, usually employed in previously proposed procedures, were both avoided. Anhydrous ethanol was used to simultaneously dissolve the biodiesel and the chromogenic reagents and the final solution should contain at least 85% ethanol to ensure the formation of a single phase before the spectrophotometric measurements. A linear response was observed from 20.0 to 400.0 mg kg − 1 glycerol, described by the equation: A = 0.0018 C + 0.0204, r = 0.999, in which C is the concentration of glycerol in mg kg − 1 . The detection limit was estimated at 2.0 mg kg − 1 (99.7% confidence level) and the coefficient of variation was 2.1% (n = 10). The proposed procedure was successfully applied to biodiesel samples from different fat sources and the results agreed with the reference procedure at the 95% confidence level.