Fractional distillation is a process of separating a mixture of chemical compounds. This means that each part (called a "fraction") of the mixture can be kept apart from the other chemicals. Different chemicals have different boiling points. Fractional distillation is done by heating the mixture so that it evaporates and then each fraction condenses in its own separate compartment. The reason we don't use simple distillation is because for liquids that boil at less than 25°kelvin from each other, some of the other liquid(s) may evaporate and so part of the separated liquid may have part of the other liquid(s).
It is a special type of distillation. Generally, the component parts boil at less than 25°kelvin from each other under a pressure of one atmosphere (atm). If the difference in boiling points is greater than 25°kelvin, a simple distillation is used.
Fractionation is done by boiling a mixture in a fractionating column. The mixture evaporates at different times and is caught in a container as a pure compound.
Fractional distillation is the main activity of oil refineries, and is done in a large fractionating column known as a "fractionation tower".
Industrially, crude oil is heated and sent up along the fractionating column that has decreasing temperatures with height and several platforms at different levels to collect the condensate. Different components of crude oil have different boiling points. High molecular weight components have higher boiling points and condense at lower portions of the column while fractions with lower boiling points rise to the top of the column to condense.
The main fractions include refinery gases, gasoline (petrol), naphtha, kerosene, diesel oil, fuel oil, and a residue that contains bitumen. These fractions are mainly used as fuels, although they do have other uses too. Hydrocarbons with small molecules make better fuels than those with large molecules because they are volatile, flow easily and are easily ignited.
https://www.quora.com/Why-does-simple-distillation-not-give-pure-compounds
Monte Alto solar power plant
The Monte Alto photovoltaic power plant in Spain has a generating capacity of 9.55 megawatts peak (MWp) and will generate 14 million kilowatt-hours of electricity per year. It cost 65 million Euros [US$87 million].
The plant covers an area of 51 hectares on agricultural land near the locality of Milagro (Navarre) and contains 889 solar structures, of which 864 have automated solar tracking. The rest are fixed structures adapted to the terrain.
Odor
An odor or odour is a volatilized chemical compound, usually at a very low concentration, which humans and other animals perceive by the sense of olfaction.
Odors are also called smells, which can be used to describe both pleasant and unpleasant odors. The words fragrance, scent, or aroma are used mostly by the food and cosmetic industry to describe a pleasant odor, and is sometimes used to refer to perfumes. On the other hand, the words stench, reek, and stink are used specifically to describe unpleasant odors.
Odor is a sensation caused by molecules dissolved in air.
The widest range of odors are made up of organic compounds although some inorganic substances, such as hydrogen sulfide and ammonia, are also odorants.
The perception of an odor effect is a two step process.
First, there is the physiological part; the sense of the stimulus by receptors in the nose.
After that the psychological part follows. The stimuli are processed by the region of the human brain which is responsible for smelling.
Because of this, an objective and analytical measure of odor is impossible.
While odor feelings are very personal perceptions, individual reactions are related to gender, age, state of health and private affectations. Common odors that people are used to, such as their own body odor, are less noticeable to individuals than external or uncommon odors.
For most people, the process of smelling gives little information concerning the ingredients of a substance. It only offers information related to the emotional impact. However, experienced people, such as flavorists and perfumers can pick out individual chemicals in complex mixes through smell alone.
The concentrations of odorant in Germany are defined by the “Olfaktometrie” since the 1870s. In this connection it’s about the standard method to define the sense barrier of odors on basis the thinner of concentrated odor loaded assays. Following parameters are defined: odor substance concentration, intensity of odor and hedonism assessment.
Pheromones are odors that are deliberately used for communication. A female moth may release a pheromone that can entice a male moth that is several kilometers away. Honeybee queens constantly release pheromones that regulate the activity of the hive. Workers can release such smells to call other bees into an appropriate cavity when a swarm moves in or to "sound" an alarm when the hive is threatened.
In mammals, some pathway of pheromones identification are in the vomeronasal organ and some in olfactory receptors.
European ash
The European ash ("Fraxinus excelsior") is a kind of ash tree. It is found throughout Europe and not just Scandinavia. It is a deciduous tree that grows to a height of 20–35 metres.
Ash wood is very easy to bend. It is therefore the material of choice to make bows. Tennis rackets, and the long poles used for snooker are sometimes made from it.
In Norse mythology, the tree Yggdrasil was a European ash. The tree linked all the nine world, Niflheim and Asgard, amongst others. Below the tree resides Hel as well as the Well of Urd.
Solar power in Spain
Spain is the fourth largest manufacturer in the world of solar power technology and exports 80 percent of this output to Germany. Spain is one of the most attractive countries with regard to the development of solar energy, as it has the greatest amount of available sunshine of any country in Europe.
The Spanish government wants to produce 12 percent of primary energy from renewable energy by 2010. That would mean a solar generating capacity of 400 megawatts.
Through a ministerial ruling in March 2004, the Spanish government removed economic barriers to grid-connection of renewable energy. The widely applauded Royal Decree 436/2004 equalises conditions for large-scale thermal and photovoltaic plants and guarantees feed-in tariffs.
In March 2007, Europe's first commercial concentrating solar power tower plant was opened near the sunny southern Spanish city of Seville. The 11 megawatt plant, known as the PS10 solar power tower, produces electricity with 624 large heliostats. Each of these mirrors has a surface measuring 120 square meters (1,290 square feet) that concentrates the Sun's rays to the top of a 115-meter (377 foot) high tower where a solar receiver and a steam turbine are located. The turbine drives a generator, producing electricity. PS10 is the first of a set of solar electric power generation plants to be constructed in the same area that will total more than 300MW by 2013. This power generation will be accomplished using a variety of technologies.
Solar thermal power plants designed for solar-only generation are ideally matched to summer noon peak loads in prosperous areas with significant cooling demands, such as Spain. Using thermal energy storage systems, solar thermal operating periods can even be extended to meet base-load needs. For example, the 50-MWe AndaSol solar trough power plants are designed with six to twelve hours of thermal storage, which increases annual availability by some 1,000 to 2,500 hours.
Construction has started on a 20MW solar photovoltaics power system in Trujillo, Cáceres, in Spain. Costing €150m, the new plant will have double the output of the 10MW Bavaria Solar Park in Germany, the previous largest ever photovoltaic (PV) system. The project will use 200 100 kW units (120,000 PV modules in total), gaining the top feed-in tariff for this type of plant.