Tag Archives: biofuel

xxx S. Akhmedov, T. Ivanova, V. Krepl and A. Muntean
Research on solid biofuels from cotton waste biomass –alternative for Tajikistan’s energy sector development
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Research on solid biofuels from cotton waste biomass –alternative for Tajikistan’s energy sector development

S. Akhmedov, T. Ivanova*, V. Krepl and A. Muntean

Czech University of Life Sciences Prague, Faculty of Tropical AgriSciences, Department of Sustainable Technologies, Kamýcká 129, CZ165 21 Prague 6, Czech Republic
*Correspondence: ivanova@ftz.czu.cz

Abstract:

An increasing awareness of the negative environmental cost associated with the combustion of fossil fuels and concerns over the geopolitical instability of the main oil producing regions is driving the development of renewable energy sources and biofuels. Use of solid biofuels made of different types of biomass became perspective alternative to conventional fuels in many countries. Such positive indicators as low cost of the final product that meets the quality of standards, not capital intensive production, possibility of producing briquettes/pellets from almost any agricultural waste or combination of raw materials are undoubted advantages of biomass based fuels. The main challenges for Tajikistan’s energy sector, which is depended on energy imports, are: to increase energy supply through better exploitation of hydropower and other renewable energy sources such as wind, solar and primary biofuels. Within the agricultural sector of Tajikistan, which is highly agrarian country, cotton accounts for 60% of agricultural output. According to the Ministry of Agriculture of Tajikistan 199,400 hectares of lands have been allocated to cotton cultivation in the year of 2014. Plenty of unused cotton residual biomass could be effectively utilized for winter heating in rural areas. The main focus of the research was to investigate and assess physical, chemical and mechanical properties of pellets and briquettes produced form cotton waste biomass.

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897–904 M. Strods and L. Mezule
Alcohol recovery from fermentation broth with gas stripping: system experimental and optimisation
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Alcohol recovery from fermentation broth with gas stripping: system experimental and optimisation

M. Strods* and L. Mezule

Riga Technical University, Faculty of Civil Engineering, Research Centre for Civil Engineering, Water Research Laboratory, Kipsalas 6A–263, LV–1048 Riga, Latvia
*Correspondence: martins.strods_4@rtu.lv

Abstract:

Effective liquid biofuel production from various lignocellulosic waste resources is dependant not only on pre–treatment and hydrolysis but also on effective removal of alcohols from the fermentation media. Distillation and rectification is not suitable in low alcohol content systems (butanol production with clostridia) or in cases when the fermentation is performed in a continuous mode. One of the technologies offering continuous, in situ removal of alcohol is gas stripping. Despite the recognition of this technology, it is still under evaluation and adjustment. Thus, the aim of this study was to evaluate if gas stripping technology at rapid flow conditions is efficient enough to recover ethanol from the fermentation media. The results showed that 60 l min-1 flow rate was optimal to recover more than 45% of the available ethanol in 8 hours of stripping with nitrogen gas. The technology was efficient if the ethanol content in the fermentation broth was 10 wt%. At lower concentrations the recovery showed to be inefficient. Application of CO2 as the stripping gas was not suitable for ethanol recovery and should be tested prior use. In conclusion, the application of rapid N2 flow rate for gas stripping of ethanol from fermentation media showed to be an efficient technology and could replace long time, low flow rate stripping.

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830–847 L. Rocha–Meneses, M. Raud, K. Orupõld and T. Kikas,
Second-generation bioethanol production: A review of strategies for waste valorisation
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Second-generation bioethanol production: A review of strategies for waste valorisation

L. Rocha–Meneses¹, M. Raud¹, K. Orupõld² and T. Kikas¹,*

¹ Institute of Technology, Estonian University of Life Sciences, Kreutzwaldi 56,
EE51014 Tartu, Estonia
² Institute of Agricultural and Environmental Sciences, Estonian University of Life
Sciences, Kreutzwaldi 5, EE51014 Tartu, Estonia
*Correspondence: Timo.Kikas@emu.ee

Abstract:

This paper reviews second–generation biofuel production chain and focuses on its energetic, economic and environmental impacts. The biggest challenge in the production of bioethanol from lignocellulosic material refers to the biomass waste that is left over after the separation of bioethanol in the distillation process. This waste still has high energetic value and could be further utilised to add value to the production chain. Furthermore, the environmental impact of untreated waste from bioethanol production is very high, which also requires attention. Anaerobic digestion of bioethanol production waste has been proposed as a possible solution to utilise the energetic potential of this waste and lower its environmental impact.

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xxx M. Gailis, J. Rudzitis, J. Kreicbergs and G. Zalcmanis
Experimental analysis of hydrotreated vegetable oil (HVO) and commercial diesel fuel blend characteristics using modified CFR engine
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Experimental analysis of hydrotreated vegetable oil (HVO) and commercial diesel fuel blend characteristics using modified CFR engine

M. Gailis¹²*, J. Rudzitis¹, J. Kreicbergs¹ and G. Zalcmanis¹

¹Riga Technical University, Faculty of Mechanical Engineering, Transport and Aeronautics, Department of Automotive Engineering, Viskalu 36A, LV1006 Riga, Latvia
²Latvia University of Agriculture, Faculty of Engineering, Department of Mechanics, Liela street 2, LV 3001, Jelgava, Latvia
*Correspondence: maris.gailis@rtu.lv

Abstract:

Performance parameters of different commercial diesel fuels is a subject of interest for fuel consumers. Fuel retailer Neste recently introduced a new brand of WWFC 5th grade diesel fuel in Baltic market, consisting of diesel fuel and hydrotreated vegetable oil (HVO) blend. Fuel samples have been recently tested on chassis dynamometer, measuring wheel power and torque and in road conditions, measuring fuel consumption. Evaluation of fuel consumption and performance parameters in road or laboratory conditions may yield uncertain results due to complexity of modern automobile engine management and emission reduction systems. To better evaluate the combustion, fuel samples have been tested in modified CFR engine at various intake air pressure, temperature and compression ratio settings. Engine indicated performance parameters and combustion phasing of regular diesel fuel and diesel fuel-HVO blend are presented. Comparing to regular diesel fuel, fuel blend with HVO showed reduced apparent heat release rate (AHRR) during premixed combustion phase at low inlet air temperature and low compression ratio conditions, comparing to regular diesel fuel. Premixed combustion phase AHRR of diesel-HVO blend increased above AHRR of regular diesel fuel at higher inlet air temperature and higher compression ratio conditions. Diffusion controlled combustion phase AHRR of diesel-HVO blend increased above AHRR of regular diesel fuel at higher inlet air temperature, higher compression ratio conditions and supercharged air supply.

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406–416 V. Hönig,, Z. Linhart, P. Procházka and K. Pernica
Regulatives for biorefineries
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Regulatives for biorefineries

V. Hönig¹,*, Z. Linhart², P. Procházka³ and K. Pernica¹

¹ University of Economics, Faculty of Business Administration, Department of Strategy, W. Churchill Sq., CZ130 67 Prague 3, Czech Republic
² University of Economics and Management, Department of Marketing, Nárožní 2600/9A, Prague 5, Czech Republic
³ Czech University of Life Sciences Prague, Faculty of Economics and Management, Department of Economics, Kamýcka 129, CZ165 21 Prague 6, Czech Republic
*Correspondence: vladimir.honig@vse.cz

Abstract:

The relationship between uncertainty and risk–taking behaviour towards innovations and Common Market protection are investigated in this article. Therefore, the aim of this article is to assess points of control over market regulation protecting innovative products. It was found that risk of creative destruction due to implementation of innovations is increased by regulators due to antimonopoly metric they use. EU fiscal policy implementation in renewable fuels in Czech Republic of both EU and CZ calculations is compared. Historical data has shown that regulators have collapsed market of high condensed biofuels. Pattern of fine calculation has explained a market collapse. Comparison of excise duty of favoured biofuels was compared with subsidies for photovoltaics. Substitution of former fossil fuels taking into account excise duty and subsidies of alternative or renewable energies is less market distorting than recent tariffs of excise duty and fines to first generation biofuels.

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1232–1241 K. Sirviö, S. Niemi, S. Heikkilä and E. Hiltunen
Effects of sulphur on the storage stability of the bio and fossil fuel blends
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Effects of sulphur on the storage stability of the bio and fossil fuel blends

K. Sirviö*, S. Niemi, S. Heikkilä and E. Hiltunen

University of Vaasa, Faculty of Technology, PL 700, FIN-65101 Vaasa, Finland
*Correspondence: katriina.sirvio@uva.fi

Abstract:

In this study, the aim was to find out if mixing two common fuels together could be beneficial for both the environment and storage stability of fuel. It is obvious, that adding biodiesel to fossil fuel will decrease its sulphur content and reduce its carbon monoxide and hydrocarbon, sulphur dioxide and soot emissions. But will the high sulphur content enhance the storage stability of the biodiesel? Four B20 samples were produced, consisting of 20 vol% biodiesel and 80 vol% fossil diesel. The samples were prepared from rapeseed methyl ester (RME), low sulphuric fossil diesel fuel and high sulphuric diesel solvent. The blends had different sulphur contents of 6, 76, 149 and 226 mg kg-1. For these B20 fuel samples, the parameters were compared that correlate with the storage stability of the fuel blends. The studied parameters were the oxidation stability (OSI, according to EN 15751:2015), acid number (AN, according to EN 14104:2003) and kinematic viscosity (KV, by Stabinger SVM 3000 rotational viscometer). The measurements were carried out straight after mixing the blends, and again after 4, 8 and 12 weeks. According to the results, the fuel containing less sulphur slightly lost its oxidation stability within three months. Instead, the oxidation stability of high sulphuric samples improved within the same time frame. As a conclusion, the study gave a reason to assume that – in spite of its known drawbacks – the sulphur may be favourable to fuel blends’ storage stability but the phenomenon and chemistry should be studied in more detail.

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579–589 A. Zimelis, G. Spalva, G. Saule, M. Daugaviete, and A. Lazdinš
Productivity and cost of biofuel in ditch cleaning operations using tracked excavator based harvester
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Productivity and cost of biofuel in ditch cleaning operations using tracked excavator based harvester

A. Zimelis¹, G. Spalva¹, G. Saule¹, M. Daugaviete¹,² and A. Lazdinš¹*

¹Latvian State forest Research Institute 'Silava', RPgas street 111, LV-2169 Salaspils,
Latvia
²Forest Sector Competence Center, DzRrbenes street 27, LV-1006 RPga, Latvia
*Correspondence: andis.lazdins@silava.lv

Abstract:

Forest ditches is one of the poorly utilized sources of biomass for energy production and timber industry. Increase of productivity and reduction of cost of extraction of biomass from the ditches, retaining at the same time high quality standards, are the key issues of mechanization of harvesting operations in this area. The scope of the study was to evaluate productivity and cost of biomass delivered from forest ditches, when tracked excavator based harvester and different work methods are used. New Holland 215B excavator with Ponsse H7 felling head was used in trials. The machine was operated by experienced operators. The study was implemented in drainage systems managed by Joint stock company „Latvia state forests”. Total extracted area 12 ha, extracted biomass – 734 m3. Duration of the study including harvesting and forwarding – 4 months. Average cost of roundwood production including road transport to 50 km distance in the trials was 27 EUR m-3, average cost of biofuel – 11 EUR m-3 (4.5 EUR LV m-3). The study approved advantages of excavators in ditch cleaning operations; however, several improvements are possible. The machine should be equipped with smaller accumulating felling head, delimbing and bucking should be done in parallel to a ditch direction, number of assortments should be reduced, as well as extraction of trees with diameter below 6 cm should be avoided.

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327–336 A. Brunerová, J. Pecen, M. Brožek and T. Ivanova
Mechanical durability of briquettes from digestate in different storage conditions
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Mechanical durability of briquettes from digestate in different storage conditions

A. Brunerová¹*, J. Pecen², M. Brožek¹ and T. Ivanova²

¹Czech University of Life Sciences Prague, Faculty of Engineering, Department of
Material Science and Manufacturing Technology, Kamýcká 129, CZ 165 00 Prague,
Czech Republic
²Czech University of Life Sciences Prague, Faculty of Tropical AgriSciences,
Department of Sustainable Technologies, Kamýcká 129, CZ 165 00 Prague,
Czech Republic
*Correspondence: brunerova@tf.czu.cz

Abstract:

A present research was conducted to determine mechanical durability of digestate briquettes and potential influence of different storage condition. Experiments were performed on briquette samples produced from digestate feedstock with moisture content of 8.2%, ash content of 10.9% and gross calorific value of 17.15 MJ kg-1 by hydraulic piston press with working pressure of 18 MPa with external diameter 50 mm and length 40–60 mm. Briquette samples were divided into two groups and stored inside and outside building. Both groups were subjected to five experimental testing during specific time period from May until late November 2014. Mechanical durability of each briquette was measured after every testing, subsequently overall mechanical durability of specific groups was calculated. Results showed the lowest mechanical durability after first measurement: 98.85% for Group 1 and 98.95% for Group 2. The biggest change in mechanical durability was observed between first and second testing, values of following measurements were approximately equal. The highest mechanical durability was achieved after fifth testing: 99.65% for Group 1 and 99.63% for Group 2. It implied mechanical durability equal to 99.44% for Group 1 and 99.45% for Group 2 in average. Research proved very high mechanical durability which corresponds to the highest category of this quality indicator given by standard EN ISO 17225-1. Difference between mechanical durability of groups stored in different conditions was considered as minor. Thereby briquettes made from digestate are not only secondary product of proper waste management, effectively modified fertilizer but as was found by results of this research it is also suitable fuel with outstanding mechanical properties.

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297–302 K. Veselá, M. Pexa and J. Pavlů
The water content in the engine oil by using E85
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The water content in the engine oil by using E85

K. Veselá*, M. Pexa and J. Pavlů

Czech University of Life Sciences Prague, Faculty of Engineering, Department for
Quality and Dependability of Machines, Kamycka 129, CZ 16521, Prague 6,
Czech Republic
*Correspondence: katerina86@email.cz

Abstract:

The European Union adopted a decision to achieve by 2020 at least 20% reduction in greenhouse gas emissions. To fulfill this task, the EU proposed in 2020 binding targets – further improve energy efficiency by 20%, achieving a 20% share of renewable energy and a 10% share of biofuels in the fuel market. One of the most widely used biofuel in the automotive industry is bioethanol. Bioethanol can be used on low-percentage blending into petrol, which is governed by European Directive 2003/30/EC, and on high-blend bioethanol mixture, particularly E85 consists of 85% bioethanol and 15% petrol BA95. But in recent years, increasingly demonstrating opinions, that biofuels do not produce nearly as much effect as was propagated. This paper deals with the concentration of water in the engine oil with using biofuel E85. The water in the engineoil significantly affects its parameters (especially viscosity). How measurement results demonstrated the use of bioethanol in the fuel increases the concentration of water in the engine oil.

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405-412 M. Raud, M. Tutt, J. Olt and T. Kikas
Effect of lignin content of lignocellulosic material on hydrolysis efficiency
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Effect of lignin content of lignocellulosic material on hydrolysis efficiency

M. Raud, M. Tutt, J. Olt and T. Kikas*

Estonian University of Life Sciences, Institute of Technology, Kreutzwaldi 56, EE51014 Tartu, Estonia; *Correspondence: timo.kikas@emu.ee

Abstract:

Lignocellulosic material is the most promising feedstock for bioethanol production; however, due to the varying physicochemical characteristics of different biomasses, it is necessary to select a biomass with a composition suitable for bioethanol production. For this purpose several different alternative non-food energy crops were chosen to investigate their suitability for bioethanol production, considering their cellulose, hemicellulose and lignin content. The traditional three-step bioethanol production process was used, where dilute acid was applied for biomass pre-treatment. Glucose and ethanol concentrations were measured during the process. Glucose and ethanol yields and hydrolysis efficiency were used to evaluate the suitability of different energy crops for bioethanol production. The results show that, with most biomass types, the glucose yield increases as the cellulose content in the biomass rises. However, a sharp decrease in hydrolysis efficiency was noted in the lignin content range of 7 to 9 g 100 g-1. The lower hydrolysis efficiency also resulted in a lower ethanol yield in the next step of the bioethanol production process for these samples.

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