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This chapter presents the use of a commercial micro-sized TiO2 powder as an alternative to the traditional nano-powders as semiconductors in photocatalytic processes. Results of the photocatalytic efficiency towards the photodegradation of the traditional pollutant molecules both in gas phase (nitrogen oxides (NOx) and volatile organic compounds (VOCs)) and in water phase (phenol) are presented and compared to the results obtained with two nano-sized reference powders. Micro-sized TiO2 is also industrially coated at the surfaces of porcelain gres tiles (Active Clean Air and Antibacterial Ceramic™). The possibility to have a photocatalytic material, strongly stuck at the surface of a vitrified tile, increases the use of photocatalysis in real conditions: no problem of filtration of the semiconductor from the liquid medium after use and no risks of leakage of nanoparticles in the atmosphere. Tests were performed using reactors equipped with UV-A lamps and with suitable analytical systems, depending on the final purpose. Characterization data from both powders and coated tiles are put in correlation with the photocatalytic results to understand the semiconductor action during the photocatalytic process. Polluting molecules were chosen in order to cover all the common aspects of environmental pollution: NOx and some VOCs represent the model molecules to test the efficiency of the micro-sized TiO2 (degradation from the pristine molecule to CO2 or inorganic salts) in gas phase. As for the water pollution, phenol was chosen as common pollutant in worldwide rivers. Moreover, tests on self-cleaning and antibacterial properties are also reported. The positive results of micro-sized TiO2 both in powder and coated onto the surface of porcelain gres tiles open the way to new photocatalytic products that do not make use of nanoscale powders avoiding problems to human safety caused by the inherent toxicity of the nanoparticles.

Despite the intent of biofuels production as an alternative to fossil fuel sources, its sustaina‐ bility has been often criticized. In this context, land use change is a major issue. Indeed, con‐ sidering traditional energy crop yields, vast amounts of land and water would be needed to produce enough biomass to significantly reduce fossil fuel dependency. There is also a wide debate on increasing biomass demand for the energy market which could result in a danger‐ ous competition with the food requirements by humankind, as well as in increasing food prices. Second and third generation sources of feedstock, as well as improved sustainable production of biofuels of first generation such those from non-edible crop, are some of the fields or research handled to fight negative impact of biofuels production on land use.

In EU directive 2003/30/EC biodiesel is defined as “methyl ester produced from vegetable or animal oil, of diesel quality, to be used as biofuel”. The more recent EU directive 2009/28/EC has set the targets of achieving, by 2020, a 20% share of energy from renewable energy sources in the EU’s overall energy consumption and a 10% share of energy from renewable sources in each member State’s transport energy consumption. In this context special consideration is paid to the role played by the development of a sustainable and responsible biofuels production, with no impact on food chain. Nowadays most biodiesel is produced through triglycerides transesterification of edible oils with methanol, in the presence of an alkaline catalyst (Lotero et al., 2005). The so obtained product has low viscosity and is a biofuel (fatty methyl ester) that can replace petroleum-based diesel fuel with no need of engine modifications (Suwannakarn et al., 2005). Furthermore, if compared to fossil fuel, the formed ester fuels are non-toxic, safe to handle, and biodegradable (Krawczyk, 1996). Glycerine is also obtained as by-product as shown in Fig. 1.

According to the predictive studies of the World Energy Outlook 2009, the global demand of energy is expected to increase till 2030 of about 1.5 percentage points per year. Fossil fuels are expected to remain the main energy source in the world, but in the meantime renewable energy sources (wind, solar, geothermal, bioenergy) will be characterized by a rapid growing rate. Their use and development is strongly encouraged by most of the recent regulations. For instance, as reported by the European Environment Agency Transport (EEA), 2009, the European Union required in the same year to achieve by 2020 at least 10% of mixture of hydrocarbons from renewable and conventional sources for what concerns the energy employed for the transports. In addition, the increase in oil price and the growing interest in environmental issues have recently given a considerable impetus to the research for cleaner and renewable energy sources, in order to ensure a sustainable future. Biodiesel (BD) is a renewable energy source in liquid form that has many advantages over normal diesel, including lower emissions of gases harmful to humans and environment. The UE directive 2003/30/EC, defines the Biodiesel as “a methyl ester produced from vegetable or animal oil, of diesel quality, to be used as biofuel”. Moreover, the National Biodiesel Board (NBB), 1996, responsable for biodiesel ASTM standards, define biodiesel as “the mono alkyl esters of long chain fatty acids derived from renewable lipid feedstock’s, such as vegetable oils or animal fats, for use in compression ignition (diesel) engines.” The processes for BD production are well known. According to the NBB, 2007, there are three main routes to BD production from oils and fats: Basecatalyzed transesterification; Direct acidcatalyzed transesterification; Conversion of the oil into fatty acids and then into biodiesel. At the present BD is mainly produced through the base-catalyzed transesterification for many different reasons: Mild reaction conditions, i.e. low temperature and pressure may be adopted; High conversions (up to 98.5%) are usually achieved in short times with minimization of side reactions; The conversion into BD is direct and no intermediate steps are required