Biodiesel is a renewable and reduced-emission alternative fuel produced mainly from the alcoholysis of vegetable oils and/or animal fats. It is mainly used in blends with diesel fuel to reduce emissions, enhance lubrication and lower sulfur content. Being able to accurately determine the physicochemical properties of blended fuel is important for optimal injection, combustion, and lubricating performance in diesel engines. Also, fuel properties vary as the ratio of biodiesel-diesel changes, affecting the final fuel quality. In this study, a wide range and narrow intervals of (0,2,4,6,8,10,12,15,18,20, 25, 35, 50, 75 and 100% by volume) off-quality canola-based biodiesel blends were prepared at ambient conditions and used to study the blended fuel properties (density, kinematic viscosity, flash point, cloud point and pour point). This is particularly important for examining the effect of a biodiesel content of more than 20%-the industry maximum blend content-on cold flow properties, fuel stability, energy value, and emissions. It was found that the kinematic viscosity and density increased linearly as the concentration of the biodiesel in the blend increases. The pour point and cloud point temperature showed a small increase up to 35% blending ratio and a rapid increase in temperature for biodiesel concentrations higher than 35%. Also, the flash point remained almost constant at an average value of 73 • C for blends less than 20%, above which the values for the flash point increased exponentially with biodiesel concentration. Furthermore, predictive correlations were developed for all tested fuel properties from regressing corresponding experimental data. All models exhibited excellent agreement with experimental data with an average absolute deviation of less than 5%.

Vapor diffusion was studied from volatile liquids of ethanol blend gasoline. The studying was conducted at two operating temperatures of 40 and 50 oC and blending of 0, 5, 10, 20, 30, 40, and 100 % by volume ethanol. The diffusion coefficients of the blend showed an increase in diffusion coefficient in air with increasing temperature and % of ethanol added. The diffusivity coefficient of gasoline-ethanol followed the following polynomial equations:

Petroleum refinery uses many catalysts such as hydroprocessing catalyst HPC, fluid catalytic cracking catalyst FCCC, reforming catalyst RC, etc. During the refining processes, the catalysts are deactivated; the spent catalysts are regarded as hazardous toxic materials due to heavy metals, coke, other poisonous compounds, and hydrocarbons. Huge amount of spent catalysts SC is generated which is expected to increase with expansion capacities of available refineries processes. This paper is reviewing the mechanisms of refining catalyst and the deactivation processes and focusing on spent catalysts management. Management of spent catalyst includes four main options; select the catalysts which reduce the generation of SC by switching to more environment friendly, longer lifetime and less toxic catalyst during the refining process; regenerate the SC; and precious metal recovery should be explored and reuse for other applications. The selection can be based on many factors such as safety, environment, mobility, etc.

Petroleum refinery uses many catalysts such as hydroprocessing catalyst HPC, fluid catalytic cracking catalyst FCCC, reforming catalyst RC, etc. During the refining processes, the catalysts are deactivated; the spent catalysts are regarded as hazardous toxic materials due to heavy metals, coke, other poisonous compounds, and hydrocarbons. Huge amount of spent catalysts SC is generated which is expected to increase with expansion capacities of available refineries processes. This paper is reviewing the mechanisms of refining catalyst and the deactivation processes and focusing on spent catalysts management. Management of spent catalyst includes four main options; select the catalysts which reduce the generation of SC by switching to more environment friendly, longer lifetime and less toxic catalyst during the refining process; regenerate the SC; and precious metal recovery should be explored and reuse for other applications. The selection can be based on many factors such as safety, environment, mobility, etc.