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This review paper summarizes the current state-of-the-art of the chemical transformation of oils/fats (i.e., triacylglycerols) to the use of biofuels or bio-lubricants in the means of transport, which is a novelty. The chemical transformation is necessary to obtain products that are more usable with properties corresponding to fuels synthesized from crude oil. Two types of fuels are described-biodiesel (the mixture of methyl esters produced by transesterification) and green diesel (paraffins produced by hydrogenation of oils). Moreover, three bio-lubricant synthesis methods are described. The transformation, which is usually catalysed, depends on: (i) the type and composition of the raw material, including alcohols for biodiesel production and hydrogen for green diesel; (ii) the type of the catalyst in the case of catalysed reactions; (iii) the reaction conditions; and (iv) types of final products. The most important catalysts, especially heterogeneous and including reaction conditions, for each product are described. The properties of biodiesel and green diesel and a comparison with diesel from crude oil are also discussed. Review sumarizuje současný stav výzkumu chemické transformace olejů a tuků na bionaftu a biolubrikanty s využitím katalyzovaných procesů. Různé typy výchozích materiálů, katalyzátorů, reakčních podmínek a finálních produktů jsou popsány.

Safe disposal of sewage sludge is one of the most pressing issues in the wastewater treatment cycle: at the European Union level, sludge production is expected to reach 13 Mt by year 2020. Sludge disposal costs may constitute up to, and sometimes above, 50% of the total cost of operation of a WWTP, and contribute to over 40% of its GHGs emissions. The most common disposal options at the moment are landfilling, disposal in agriculture (about 40% EU-wide), incineration or co-incineration, and use in the industrial production of bricks, asphalts and concrete. Sewage sludge, however, still contains beneficial resources such as nutrients, that can be recovered through specific processes (e.g. precipitation as struvite) and energy, recoverable through a variety of approaches. Microwave-assisted pyrolysis of urban waste sludge was applied for the production of oil, (Syn)gas, and biochar that were afterwards characterized and compared to mainstream alternative fuels (biodiesels) and other material recovery options. Sustainability issues related to the production of biodiesel/biochars from urban wastewater treatment sludge are also discussed. The paper shows that waste urban sludge can indeed be a full component of the urban circular economy by allowing, if properly processed, recovery of energy resources at multiple levels: bio-oils (biodiesel), syngas and bio-char, all having definite advantages for final residues use and disposal. Biodiesel, in particular, allowing energy recovery as liquid fuel, offers a much more flexible and efficient utilization. Resumo A eliminação segura das lamas de esgoto é uma das questões mais urgentes no ciclo de tratamento de águas residuais: a nível da União Européia, espera-se que a produção de lamas atinja 13 Mt até o ano 2020. Os custos de disposição das lamas podem constituir-se e às vezes acima de 50% Custo total de operação de uma ETAR e contribui para mais de 40% das emissões de GEEs. As opções de eliminação mais comuns no momento são: aterro, eliminação na agricultura (cerca de 40% em toda a escala), incineração ou co-incineração, uso na produção industrial de tijolos, asfaltos, concreto. As lamas de esgoto, no entanto, ainda contêm recursos benéficos, como nutrientes, que podem ser recuperados através de processos específicos (por exemplo, precipitação como estruvita) e energia, recuperável através de uma variedade de abordagens. A pirólise assistida por microondas de lama de lixo urbano foi aplicada para a produção de petróleo, gás (Syn) e biochar que posteriormente foram caracterizados e comparados aos principais combustíveis alternativos (biodiesels) e outras opções de recuperação de materiais. São discutidos os problemas de sustentabilidade relacionados à produção de biodiesel / biochars de lamas de tratamento de águas residuais urbanas. O documento mostra que o lodo urbano residual pode de fato ser um componente completo da economia circular urbana, permitindo, se devidamente processado, a recuperação de recursos energéticos em vários níveis: bio-óleos (biodiesel), gás de síntese e bio-carbon, todos com vantagens definidas para o uso e eliminação de resíduos finais. O biodiesel, em particular, que permite a recuperação de energia como combustível líquido, oferece uma utilização muito mais flexível (e eficiente).

Bibliographic entry Filip, O. (2015): "Food vs. Fuel: The Role of Bioenergy." (Unpublished master's thesis). Charles University in Prague. Supervisor: prof. Ing. Karel Janda M.A., Dr., Ph. D. Length: 121,976 characters Abstract This thesis studies the relationship between the first generation biofuels and selected commodities and assets in the USA, Europe, and Brazil. It is the first attempt to combine the taxonomy and wavelet analyses in a single research application. Our unique dataset comprises 32 weekly price series covering the 2003-2015 time period. First, we employ a method of minimum spanning trees and hierarchical trees to model a biofuel-related price network. We demonstrate a development phase shift between Brazilian and the US/EU biofuel industries. We reveal a strong and stable connection between Brazilian ethanol and its main production factor, local sugarcane. We further find that US ethanol is closely linked to corn. In the contrary, European biodiesel exhibits only moderate ties to its production factors. Subsequent wavelet analysis scrutinizes the identified price connections both in time and frequency domains. Both Brazilian and US ethanols are found to be positively related to their respective feedstock commodities. In particular, feedstock proves to lead the price of the biofuel and not...

The methanolysis of rape seed oil catalyzed by KOH has been studied from the standpoint of the dependences of the acid value (neutralisation number) and concentration of unreacted oil (as sum of glycerides) in the final mixture of methyl esters of fatty acids on the oil (biodiesel) on the initial KOH concentration in methanol and on the acid value and water content of the used oil.

Waste oils and fats can be used as renewable fuel resources. Conversion of waste oils and fats to biodiesel fuel is one possibility but poses some difficulties such as in the use of toxic or caustic materials and by product disposal. Conversion to biodiesel may also decrease the economic attractiveness of using waste oils as fuels. An alternative to the use of biodiesel is the use of vegetable oils or rendered animal fats as a fuel. Using relatively unmodified oils or fats eliminates the problem associated with toxic and caustic precursor chemicals and residual biodiesel alkalinity as the oil is used without altering its chemical properties. This paper discusses the use of waste vegetable and animal oils and fats as unmodified fuels in compression ignition engines.