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.

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.

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.

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.