David Bolonio

Fatty acid methyl and ethyl esters obtained from rare seeds from Tunisia: Ammi visnaga, Citrullus colocynthis, Datura stramonium, Ecballium elaterium, and Silybum marianum

ABSTRACT This work aims to study the properties of fatty acid methyl and ethyl esters from Tunisian oils in order to assess their potential use as biofuel sources. The oils chosen for this study have been scarcely researched by other authors and are very interesting for a possible exploitation as fuels. Most of them are nonedible sources and all of them can be grown in arid places with no need of supplementary water: the bishop’s weed Ammi visnaga, the bitter apple Citrullus colocynthis, the stramonium Datura stramonium, the devil pickle Ecballium elaterium, and the milk thistle Silybum marianum.

Geographical variability of the composition and properties of fatty acid methyl esters from Citrullus colocynthis in Tunisia

ABSTRACT Biofuels are a promising alternative to substitute petroleum-based transportation fuels and could contribute to sustainable development. This work studies the composition and properties of the fatty acid methyl esters (FAMEs) obtained from Citrullus colocynthis, a plant that grows in arid and dry conditions. Samples from seven locations in Tunisia were collected to study the possible variability in their composition and properties to assess the performance in a combustion engine. Results show suitable properties and future studies are encouraged to assess the potential productivity at a large scale, regarding that domestication of the plant could contribute to improving its quality and productivity.

Leaching of polycyclic aromatic hydrocarbons (PAHs) from coal dumps reclaimed with apple trees: a mechanistic insight

Polycyclic aromatic hydrocarbons (PAHs) have been identified as compounds that can be incorporated to run-off waters or to aquifers becoming a real threat not only to aquatic organisms but also to humans due to its carcinogenic and mutagenic activity. This work studies the presence of PAHs in a coal dump pile located in the north of Spain (Asturias), downhill a spoil pile of a cinabrium mine. This unique site gives the opportunity to assess whether acid waters have more potential to leach PAHs than normal rainwater (acidified when it gets in contact with coal spoil). The distribution of PAHs and methyl PAHs has shown that their abundance is higher in the path of acid waters which could be caused by the ability of acid water to break bonds of coal macromolecules. This chemical reaction liberates PAHs of less molecular weight that can be detected by GC–MS. Moreover, less soluble PAHs are concentrated on the acid water circulation area and more soluble PAHs more leached by acid water that rainwater, which indicates that PAHs dissolve more in acid waters than in normal rainwater. In addition, this coal spoil pile has been reclaimed with apple trees to make cider for human consumption. Up to 152 different compounds were identified in the tree samples, but neither PAHs nor methyl PAHs were found, pointing to a possible retention of the PAHs in the roots zone. Apple trees in the acid waters path show more concentration in waxes and flavour compounds, indicating a more mature apple.Graphical Abstract

Fatty acid methyl esters (FAME) from oleaginous seeds grown in arid lands. Part II: Ibicella lutea, Onopordum nervosum, Peganum harmala, Smyrnium olusatrum and Solanum elaeagnifolium

ABSTRACT The properties of fatty acid methyl esters (FAMEs) obtained from Tunisian oleaginous seeds, grown in arid places with no need of supplementary water, are studied to assess their potential use as biodiesel: devil horn Ibicella lutea, cotton thistle Onopordum nervosum arabicum, Sirian rue Peganum harmala, horse celery Smyrnium olusatrum and silverleaf nightshade Solanum elaeagnifolium. Some key properties such as cloud point, pour point, cold filter plugging point, oxidation stability, cetane number, density, kinematic viscosity, heating value and oxygen extended sooting index have been predicted using equations that correlate the above properties with their ester profiles.

Green-filamentous macroalgae Chaetomorpha cf. gracilis from Cuban wetlands as a feedstock to produce alternative fuel: A physicochemical characterization

ABSTRACT The excessive blooming of green filamentous macroalgae is a global problem due to their unwanted presence in freshwater, lakes, nursery garden and stagnant waters. An attractive solution is to use macroalgae as a biofuel feedstock. In this work, the macroalgae studied was the Chaetomorpha cf. gracilis. The macroalgae oil extraction was accomplished using Soxhlet method obtaining a yield of 1.85%. The gas chromatography analysis showed higher unsaturated fatty acids (56.14%) compared to saturated fatty acids (35.18%), highlighting the content of oleic acid, 27.89%. The kinematic viscosity and density were 0.826 mm2/s and 699.6 kg/m3, respectively. The heating value, crystallization temperature and elemental composition showed higher values than other algae oils. Nevertheless, the nitrogen content was similar to L.digitata macroalgae. The analysis conducted on the net energy ratio for the oil extraction process showed that the Chaetomorpha macroalgae oil might represent an attractive alternative for liquid biofuel production.