Khaled Loubar

Eucalyptus Biodiesel as an Alternative to Diesel Fuel: Preparation and Tests on DI Diesel Engine

Nowadays, the increasing oil consumption throughout the world induces crucial economical, security, and environmental problems. As a result, intensive researches are undertaken to find appropriate substitution to fossil fuels. In view of the large amount of eucalyptus trees present in arid areas, we focus in this study on the investigation of using eucalyptus biodiesel as fuel in diesel engine. Eucalyptus oil is converted by transesterification into biodiesel. Eucalyptus biodiesel characterization shows that the physicochemical properties are comparable to those of diesel fuel. In the second phase, a single cylinder air-cooled, DI diesel engine was used to test neat eucalyptus biodiesel and its blends with diesel fuel in various ratios (75, 50, and 25 by v%) at several engine loads. The engine combustion parameters such as peak pressure, rate of pressure rise, and heat release rate are determined. Performances and exhaust emissions are also evaluated at all operating conditions. Results show that neat eucalyptus biodiesel and its blends present significant improvements of carbon monoxide, unburned hydrocarbon, and particulates emissions especially at high loads with equivalent performances to those of diesel fuel. However, the NOx emissions are slightly increased when the biodiesel content is increased in the blend.

Hydrothermal liquefaction of oil mill wastewater for bio-oil production in subcritical conditions.

The main purpose of this study is to investigate the direct hydrothermal liquefaction of oil mill wastewater (OMWW). Experiments were carried out at different temperatures (240-300°C), water contents (58-88wt.%) and reaction times (15-45min). Results show that the highest bio-oil yield was about 58wt.%, resulting in a higher heating value of 38MJ/kg. This was conducted at the following optimal conditions: water content 88wt.%, a temperature of 280°C, and 30min as reaction time. To put bio-oil into wide application, the various physical and chemical characteristics were determined. A detailed chemical composition analysis of bio-oil was performed by gas chromatography-mass spectrometry (GC-MS) coupled with a flame ionization detector (FID). The dominant compounds were identified by using NIST library. Analyses show that the bio-oil contains mainly oleic acid, hexadecanoic acid, fatty acid methyl ester, fatty acid ethyl ester, amino acid derived compounds and phenolic compounds.

Unsteady Heat Transfer Enhancement Around an Engine Cylinder in Order to Detect Knock

This paper deals with the transient thermal signal around an engine cylinder in order to propose a new and nonintrusive method of knock detection. Numerical simulations of unsteady heat transfer through the cylinder and inside the coolant flow are carried out to account for heat flux variations due to normal and knocking combustion. The effect of rib roughened surfaces on thermal signal amplification is investigated. The geometric parameters are fixed at Pi/h=70 and w/h=1 with a Reynolds number based on hydraulic diameter of 12,000. The results reveal that square ribs give better performance in term of thermal signal amplification within the fluid. An amplification of the temperature variation up to 20 times higher is found. Finally, flow analysis shows that amplification depends on the position where the thermal signal is collected.

Influence of impregnation method on metal retention of CCB-treated wood in slow pyrolysis process

In the present work, the effects of copper, chromium and boron on the pyrolysis of wood and their distribution in the pyrolysis products were investigated. For this, the wood has been impregnated with chromium-copper-boron (CCB). In addition, to describe the effects of impregnation method, vacuum-pressure and dipping methods were also conducted. Thermogravimetric analysis (TGA) results show that an increase in the final residue and decrease in degradation temperature on both methods of treated wood compared to untreated wood. Then, slow pyrolysis experiments were carried out in a laboratory reactor. The mass balance of pyrolysis products is confirmed by TGA. Furthermore, the concentration of metals in the final residue is measured by inductively coupled plasma mass spectroscopy (ICP-MS). The results show that the final residue contains more than 45% of the initial amount of metal present in the treated wood. The phenomenon is more pronounced with vacuum-pressure treated wood. The heating values of pyrolysis products were analyzed. The heating value of charcoal obtained from treated and untreated wood is approximately same. But the heating value of tar from untreated wood is higher than the heating value of the tar from treated wood.

Combination of pyrolysis and hydroliquefaction of CCB-treated wood for energy recovery: optimization and products characterization.

In this paper, pyrolysis and hydroliquefaction processes were successively used to convert CCB-treated wood into bio-oil with respect to environment. Pyrolysis temperature has been optimized to produce maximum yield of charcoal with a high metal content (Cu, Cr, and B). The results obtained indicate that the pyrolysis at 300 °C and 30 min are the optimal conditions giving high yield of charcoal about 45% which contains up to 94% of Cu, 100% of Cr and 88% of B. After pyrolysis process, the charcoal has been converted into bio-oil using hydroliquefaction process. The optimization approach for the yield of bio-oil using a complete factorial design with three parameters: charcoal/solvent, temperature and hydrogen pressure was discussed. It is observed that the temperature is the most significant parameter and the optimum yield of bio-oil is around 82%. The metal analysis shows that the metals present in the bio-oil is very negligible.

Numerical Investigation on DI Diesel Engine Running With Eucalyptus Biodiesel and its Blends

The aim of the present work is to investigate the possibility of using eucalyptus biodiesel and its blends with diesel fuel as an alternative fuel for diesel engines. Eucalyptus oil is converted to biodiesel with ethanol using sodium hydroxide as a catalyst. The characterization of the obtained biodiesel shows that the thermo-physical properties are in the range recommended by American Standard (ASTM D6751). Innovative biodiesel development tests on the diesel engine require a lot of time and efforts. Here, mathematical model, which is based on the thermodynamic single zone model, is developed to analyze the combustion characteristics such as cylinder pressure and the performance characteristics such as brake power, brake thermal efficiency and specific fuel consumption of a DI diesel engine.Copyright

Experimental evaluation of performance and emissions of DI diesel engine fuelled with eucalyptus biodiesel

Nowadays, the increasing oil consumption throughout the world induces crucial economical, security and environmental problems. As a result, intensive researches are undertaken to find appropriate substitution to fossil fuels. We focus in this study on the investigation of using eucalyptus biodiesel as fuel in diesel engine. A single cylinder air-cooled, DI diesel engine, was used to test eucalyptus biodiesel and its blends with diesel fuel in various ratios at several engine loads. Performance and exhaust emissions are evaluated for different operating conditions. Results show that neat eucalyptus biodiesel and its blends present significant reduction of exhaust emissions especially at high loads with equivalent performances to those of diesel fuel.

Biodiesel Production from Nonedible Oil Using Heterogeneous Solid Base Catalysts

Biodiesel is a clean-burning and renewable substitute for conventional diesel. It is produced particularly from vegetable oils. It’s nontoxic and biodegradable, and it can also be used in most diesel equipments with no or only minor modifications. In this study we focused our work on the elaboration of heterogeneous solid base catalysts (KF/MgO and KF/CaO). The catalysts are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and Brunauer-Emmett-Teller (BET) surface area. The heterogeneous base-catalyzed transesterification is applied for producing a biodiesel starting from a nonedible and abundant vegetable source in the Mediterranean Basin such as Pistacia lentiscus (PL). The catalysts are compared in terms of activities in the transesterification process under suitable conditions (reaction temperature of 50 °C, methanol to oil molar ratio of 12:1, catalyst loading of 1 wt.%, and reaction time of 2 h). For the two catalysts, a higher than 90% conversion was found.

Experimental study on the production of diesel-like fuel from waste high density polyethylene via non-catalytic pyrolysis

Plastics have become an indispensable part of our daily life. Due to its non biodegradable nature it cannot be easily disposed off. Pyrolysis is a tertiary recycling method which can convert plastics into valuable petroleum resources. In this work, pyrolysis of waste high density polyethylene (HDPE) plastic was carried out in a fixed bed reactor heated for a final temperature of 500°C under a heating rate of 10°C/min. Direct pyrolysis led to wax production while a two step pyrolysis (setup 1) led to the production of 32.7% liquid and 65.3% gas. Thus a setup with reflux (setup 2) was designed and the liquid yield increased to 78.2%. The liquid fractions obtained were analyzed for composition using a gas chromatograph coupled to a Mass spectrometer and a flame ionization detector (GC-MS-FID). Specific diesel-like fuel production, as reported to HDPE mass, with setup 2 was estimated to be 2.3 times higher than setup 1 The physical properties of the pyrolytic oil (viscosity, density) were found to be lower than that of diesel fuel due to the presence of light compounds.