Violeta Makareviciene

Biodiesel fuel from microalgae-promising alternative fuel for the future: a review

The use of organic matter such as vegetable oil to produce biodiesel fuel has been a practical technology for a number of years. However, the search for new technologies and raw materials for biodiesel fuel production has gained increased attention recently because of financial and environmental concerns. Of particular interest are raw materials that are not food-related. Microalgae have gained a great deal of attention as a potential biodiesel raw material because of their high growth rates and ability to accumulate oil, bind carbon dioxide, and remove contaminants from wastewater. This article is a literature review of technologies for biodiesel production from microalgae. The technologies relate to microalgal cultivation, microalgal growth enhancement to simultaneously increase biomass and reduce pollution, the preparation of microalgal biomass for biodiesel production, and biodiesel production itself.

The optimization of biodiesel fuel production from microalgae oil using response surface methodology.

Biodiesel fuel was produced by the transesterification of microalgae oil using sodium hydroxide as a catalyst. The oil was extracted from heterotrophic cultivated algae biomass. The transesterification process was optimized using response surface methodologyto increase the yield of methyl esters. The Box–Behnken design and fractional factorial design 24-1 points were used to investigate the interaction of process variables, such as the methanol/oil molar ratio, the percentage of sodium hydroxide, the temperature, and the reaction time in the production of biodiesel fuel, and to predict the optimum process conditions for the FAME yield. Based on the results, the optimal conditions for the synthesis of biodiesel fuel were as follows: methanol/oil molar ratio, 7:1; catalyst concentration, 1.0% (by weight of algae oil); temperature, 67°C, and reaction time, 51 minutes. The yield of FAME was confirmed by gas chromatography analysis.

The mixture of biobutanol and petrol for Otto engines

Abstract The expansion of production and the use of biofuels are determined by the legal acts of the European Commission and National legal acts encouraging such production and usage. It would be meaningful to use the mixtures of butanol and petrol in Otto engines. It was determined the possibility of producing biobutanol as a biofuel of the second generation from lignocellulose hydrolyzed to C5/C6 carbohydrates. If the 20–30% potential of lignocellulose biomass in Lithuania is used, it would be possible to produce 200–300 thousand t of biobutanol per year. The amount of carbon monoxide CO decreases by more than 80% when the engine works using the mixtures of petrol and butanol if compared to the CO amount of the engine working with petrol. When the engine works using the mixture of 30% butanol and petrol, the amount of carbon dioxide CO2 decreases by 4% on average, and in case it works with the mixture of 50% butanol and petrol ‐ by 14% if compared to the CO2 amount of the engine working using petrol. Wh...

Research into operational parameters of diesel engines running on RME biodiesel

Abstract The results of motor experimental researches on operational parameters of diesel engines F2L511 and A41 are presented in the publication. Change of harmful emission of exhaust gases was determined and evaluated, fuel economy and thrust characteristics of diesel engines running on RME biodiesel compared to diesel fuel. The influence of technical condition of fuel injection aggregates was evaluated for parameters of harmful emission of diesel engines running on biodiesel by simulation of setback of fuel injection in alowable range of technical conditions ‐ the coking of nozzles of fuel injector. The complex improvement of all ecological parameters was evaluated by optimisation of fuel injection phase of diesel engines running on RME biodiesel. Objectives and aspects of further researches on indicator process of diesel engines were determined.

The exploitation and environmental characteristics of diesel fuel containing rapeseed butyl esters

In an effort to consume fewer non-renewable resources and use primarily raw materials of biological origin in the production of biofuel, biomass-derived biobutanol can be used for transesterification of rapeseed oil. The study investigates the physical and chemical characteristics of rapeseed oil butyl esters (RBE) and 10%, 20% and 30% RBE-diesel composites. Characteristics of RBE and their composites with conventional diesel (D) are a little different from rapeseed oil methyl esters (RME) and their composites with D, while their basic characteristics comply with the requirements of European Standard EN 14214. Comparative tests in 4-stroke 4-cylinder 1Z type diesel engine of Audi-80 using 10-30% RBE and 10-30% RME compounds as fuels have been performed, and the results indicate that the biologically derived additives improved the energy characteristics of the engine but increased the fuel consumption compared to pure diesel. Increasing the bio-component concentration up to 30% in diesel and biodiesel fuel (RME and RBE) mixtures leads to complex improvements in the environmental impact compared to pure diesel; however, in the case of mixtures with RBE, slightly higher concentrations of carbon dioxide (CO2), hydrocarbons (HC) and nitrogen oxides (NOx) were observed in engine exhaust gases compared to RME and D mixtures of analogical composition.

Technological assumptions for biogas purification

Biogas can be used in the engines of transport vehicles and blended into natural gas networks, but it also requires the removal of carbon dioxide, hydrogen sulphide, and moisture. Biogas purification process flow diagrams have been developed for a process enabling the use of a dolomite suspension, as well as for solutions obtained by the filtration of the suspension, to obtain biogas free of hydrogen sulphide and with a carbon dioxide content that does not exceed 2%. The cost of biogas purification was evaluated on the basis of data on biogas production capacity and biogas production cost obtained from local water treatment facilities. It has been found that, with the use of dolomite suspension, the cost of biogas purification is approximately six times lower than that in the case of using a chemical sorbent such as monoethanolamine. The results showed travelling costs using biogas purified by dolomite suspension are nearly 1.5 time lower than travelling costs using gasoline and slightly lower than travelling costs using mineral diesel fuel.

Biodiesel fuel production by enzymatic microalgae oil transesterification with ethanol

This paper discusses the application of the enzymatic transesterification of algae oil with ethanol for the production of biodiesel fuel. Seven commercial lipases were tested, and the most effective lipase preparation—Lipolase 100L—was selected. The transesterification process was optimised by applying response surface methodology. The interaction of the molar ratio of ethanol to oil, the process duration, the lipase concentration, and the temperature was evaluated. Transesterification experiments were performed under different conditions, and the transesterification yield was measured. On the basis of the transesterification yield, a quadratic model was built, and the optimal conditions were determined: a temperature of 30 °C, a lipase amount of 10%, and an ethanol to oil molar ratio of 3:1. After 26 h, the transesterification yield was increased to 96.9%, and the requirements of the European standard for biodiesel fuel (EN 14214) were met.

Optimisation of enzymatic transesterification of linseed oil and pork lard mixture with ethanol using response surface methodology

Transesterification of linseed oil and pork lard mixture with ethanol was studied by applying a biotechnological method. The effectiveness of 16 lipases was evaluated, and the most effective lipase, Lipolase 100 L (EX), was selected for reaction condition optimisation by response surface methodology based on a Box-Behnken design. The influence of the main process parameters was evaluated, including the reaction temperature, ethanol to triglyceride molar ratio, lipase amount, and reaction time on transesterification yield. The optimal reaction conditions were found as follows: reaction temperature of 32.79 °C, ethanol to oil molar ratio of 5.99, lipase concentration of 6.39%, and reaction time of 7.95 h, with an expected transesterification yield of 52.2%. Optimised enzymatic pork fat and linseed oil mixture transesterification with ethanol was less effective compared with the chemical transesterifications described elsewhere; therefore, the step-wise transesterification procedure should be applied by addi...

Enzymatic microalgae oil transesterification with ethanol in mineral diesel fuel media

This article examines opportunities of enzyme application during the production of biodiesel from microalgae oil by its transesterification in the mixture with mineral diesel fuel. The oil and mineral diesel fuel ratio in the reaction mixture enabled a yield of 7% ester content in the mixture. Effectiveness tests were conducted on seven industrial lipases, and Lipozyme TL IM was selected as the most effective lipase for further optimization. The process of algae oil transesterification with ethanol was optimized by applying response surface methodology. The interactions and impacts of the following independent variables on the transesterification yield were evaluated: ethanol and oil molar ratio, process duration, lipase content, and temperature. Optimum conditions were determined: a temperature of 30 °C, 13.26% biocatalyst (from the oil content), an ethanol and oil molar ratio of 4.54:1, and a process duration of 13 h. The transesterification yield of the product under the above conditions reached 98%.