Fractionation of heavy metals in sewage sludge and their removal using low-molecular-weight organic acids

The total concentration and the concentrations of individual chemical species of selected heavy metals were estimated in primary and anaerobically digested sewage sludge. The concentration of Zn (1503 mg/kg) was highest and was followed by Cu (201 mg/kg), Cr (196 mg/kg), Pb (56 mg/kg), Ni (44 mg/kg) and Cd (3.6 mg/kg). The metal was divided into 5 fractions (exchangeable (F1), adsorbed (F2), organically bound (F3), bound to carbonates (F4), and residual (F5)) via sequential extraction. The sludge treatment procedure had no significant effect on the fractionation results. In both the primary and anaerobically digested sewage sludge, the heavy metals were ranked according to their mobilities (fractions F1 and F2) in the following order: Ni > Zn > Cu > Cd > Pb > >Cr. Metal stability in the environment was evaluated by the sulphide and residual fraction F5, and the following ranking order was identified: Cr > >Pb≈Ni > Cd > Zn≈Cu. A leaching experiment with low-molecular-weight organic acids (oxalic, acetic and citric acid) revealed that the metal-removal efficiency varied depending on the number of carboxyl groups in the extracting agent, the chemical speciation of the metal (Ni, Zn or Cu) in the sludge and the concentration and pH change of the extracting solution. Acid solutions with a 0.5 M concentration, ranked according to their Zn-removal efficiency, are ranked as follows: citric acid (100%) > acetic acid (78%) > oxalic acid (71%). In all of the cases, citric acid showed the best capacity for the removal of metal from the sludge, with an extraction efficiency ranging from 30–100%, while the Ni and Cu removal efficiencies with the acetic and oxalic acid were less than 40%. First published online: 11 Oct 201

Exhaust emissions from the engine running on multi-component fuel

Possible alternative raw materials for producing biodiesel fuel are as follows: Camelina sativa oil, fibre linseed oil and waste animal fat. The aim of this work was to analyse the emissions of the engine running on multi-component fuels containing fossil diesel fuel (D), linseed or Camelina sativa oil fatty acid methyl esters (LSME and CME respectively) and beef tallow (TME) fatty acid methyl esters. The concentration of fatty acid methyl esters (FAME) in the mixtures with fossil diesel fuel varied from 10% to 30%. The mass proportion of LSME (or CME) and TME in the mixtures was 1:4. The lowest NOxconcentration in exhaust gases was observed when the mixtures contained 10% of biofuel. For the mixtures containing CME and LSME, NOx concentrations reached 290 and 295 ppm respectively when the engine rotation speed was 1200 min−1 and 370 and 375 ppm respectively when rotation speed was 2000 min−1. CO concentration was the lowest when fuel contained 30% of the FAME mixture. HC concentration was slightly higher when the mixtures containing LSME were used relative to the mixtures containing CME. The amount of HC did not fluctuate considerably (195÷254 ppm) at rotation speeds between 1200 and 2000 min−1. Lower HC concentration was found in exhaust gas when the fuels containing 10% and 20% of biofuel were used. The lowest concentration of polycyclic aromatic hydrocarbons (PAHs) was found when the mixtures contained 30% of biofuel made of LSME or CME corresponding to 30 µg/m3 and 38 µg/m3 at a rotation speed of 1200 min−1 and 640 µg/m3 and 670 µg/m3 at a rotation speed of 2000 min−1 respectively. The greatest amount of smokiness at a high rotation speed of 2000 min−1 was observed when the mixture contained 30% of multi-component biodiesel fuel. It was found that the fuel containing a mixture of 30% of LSME biofuel and 20% of CME biofuel had a small advantage

Possibilities of using Camelina sativa oil for producing biodiesel fuel

Biofuels for diesel engines are produced mainly from rapeseed oil in Lithuania and the Member States of the European Union. In order to minimise an adverse impact of biodiesel fuel on the food sector, it is necessary to look for alternative feedstocks for producing biodiesel fuel including the potential utilisation of the new kinds of oilseed crops and various fatty waste. Camelina (Camelina sativa) could be one of the kinds of such oilseed crops, and therefore the physical and chemical parameters of Camelina sativa oil and biodiesel fuel produced from this oil were determined and the conformity of quality parameters with the requirements of biofuel standard was evaluated. It was found that fatty acid methyl esters made from Camelina sativa oil had a high iodine value (164.6÷169.6 g I2 / 100 g oil), and therefore could be used as fuel for diesel engines only in the mixtures with methyl esters produced from animal fat or used for frying oil. It has been established that similar mixtures can contain 50÷60% of Camelina sativa oil methyl esters. The possibilities of increasing oxidation stability as well as improving the cold flow properties of ester mixtures were investigated. The most effective antioxidant – Ionol (optimal dosage of 500 ppm) and the most efficient depressants Wintron XC-30 (optimal dosage – 1500 ppm) and Infineum R-442 (optimal dosage – 1200 ppm) were selected

Application of dolomite as a heterogeneous catalyst of biodiesel synthesis

Some of the more recent methods of obtaining biodiesel are based on heterogeneous catalysis, which has the advantage of multiple uses of a catalyst. Natural minerals, such as dolomite, opoca and serpentinites, could be promising for use in biodiesel synthesis. The purpose of this study was to optimise the reaction conditions for biodiesel synthesis from sunflower oil and methanol using dolomite as a catalyst. Optimum reaction conditions for the transesterification of sunflower oil with methanol, using dolomite calcined at the temperature of 850 °C, have been identified: the amount of the catalyst – 6%, the molar ratio of methanol to oil – 8:1, the reaction duration – 5 hours and the reaction temperature – 60 °C. The amount of Fatty Acid Methyl Esters (FAME) of the sunflower oil obtained – 97.6%. FAME is in conformity with the EN 14214:2003 standard, when 500 ppm of antioxidant Ionol and 500 ppm of depressant Infineum R-442 are added. The Cold Filter Plugging Point (CFPP) of FAME is reduced to7 °C by adding 500 ppm of Infineum R-442. This product can be used in summer in the countries that are placed in Class E, including Lithuania. It has been established that dolomite without regeneration can be used for the transesterification of sunflower oil 2 times

The mixture of biobutanol and petrol for Otto engines

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 CO2decreases 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. When the engine works using the mixture of 30% butanol and petrol, the amount of hydrocarbons HC decreases by 26% on average, and if it works with the mixture of 50% butanol and petrol, the amount increases by some 4% if compared to the HC amount of the engine working using petrol. To generalize the results of the performed experiment, it is possible to state that the optimal mixture would consist of 70% petrol and 30% biobutanol. First published online: 27 Oct 201

Usage of Fatty Wastes of Agricultural Origin for the Production of Biodiesel

For the first time it has been conducted an integrated research of possibilities to apply different kinds of fatty wastes for biodiesel fuel production. For this reason esterification process of oil an fat rich of free fatty acids by using acid catalysts and further transesterification of the obtained product until standard requirements for biodiesel fuel have been fulfilled. Intersolubility of different components of multi-component biofuel systems, and limits of stability were investigated. Emissions of the biodiesel fuel were analyzed and fuel biological decomposition in the environment was studied. Life cycle parameters of the suggested biodiesel fuel production process were determined.Žemės ūkio akademijaVytauto Didžiojo universiteta

Biodegalų vystymosi perspektyvos: antrosios kartos biodegalai

Vytauto Didžiojo universitetasŽemės ūkio akademij

Biodiesel fuel synthesis using dolomite as a catalyst

Some of the more recent methods of obtaining biodiesel fuel are based on heterogeneous catalysis, which has th of multiple uses of a catalyst. Natural minerals, such as dolomite, opoca, and serpentinites, could be promisin biodiesel synthesis. The purpose of this study was to optimize the reaction conditions for biodiesel synthesis fron oil and methanol using dolomite as a catalyst. Optimum reaction conditions for the transesterification of sunflo methanol, using dolomite calcined at the temperature of 850°C, have been identified: the amount of the catab molar ratio of methanol to oil-8:l, the reaction duration-5 hours and the reaction temperature-60°C. The amo acid methyl esters (FAME) of the sunflower oil obtained-97.6%. FAME is in conformity with the requirements o standard when 500 ppm of antioxidant Ionol and 500 ppm of depressant Infineum R-442 are added. The cold filt point of FAME is reduced to 7°C by adding 500 ppm of Infineum R-442. This product can be used in summer in tl that are placed in Class E, including Lithuania. It has been established that dolomite without regeneration can be I transesterification of sunflower oil by 2 timesVytauto Didžiojo universitetasŽemės ūkio akademij

Antrosios kartos biodegalai

Vytauto Didžiojo universitetasŽemės ūkio akademij

The use of different alcohols in lipase catalyzed in-situ transesterification processes to produce biodiesel

Joint Event on 13th World Congress on Biofuels and Bioenergy & 14th Global Summit and Expo on Biomass and Bioenergy, August 26-27, 2019, Vienna, Austria: scientific tracks abstractsRapeseed with high oil acidity is called low quality rapeseed and it is cheap raw material used for biodiesel production. The use of low quality rapeseed oil and biocatalyst is a green approach. The production of biodiesel were done by the lipase catalysed in situ by transesterification process with using a mineral diesel (as an extraction solvent), methanol or ethanol and biocatalyst- lipase. The conversion of rapeseed oil to biodiesel fuel was evaluated in the presence of a lipase from lipozyme TL IM (Thermomyces lanuginosus). The reaction conditions were optimized and conversions of rapeseed oil to fatty acid methyl ester or fatty acid ethyl ester was evaluated. The optimization temperature of the reaction, the duration of reaction and concentration of lipase were performed. The optimal reaction conditions when methanol to oil molar ratio was 5:1 were found to be a duration reaction of 5 h, a temperature reaction of 25�C and a lipase concentration of 7% (based on oil weight). Results showed 99.90% yield of rapeseed oil and rapeseed methyl esters in reaction product. The degree of transesterification acquired was 98.99%. The optimal reaction conditions when ethanol to oil molar ratio was 5:1 were found to be a duration reaction of 7 h, a temperature reaction of 30�C and a lipase concentration of 5% (based on oil weight). Results showed 99.92% yield of rapeseed oil and rapeseed ethyl esters in reaction product. The degree of transesterification acquired was 99.89%Miškų ir ekologijos fakultetasVytauto Didžiojo universiteta