Much H 2 SO 4 is used in petroleum refining, for example as a catalyst for the reaction of isobutane with isobutylene to give isooctane , a compound that raises the octane rating of gasoline petrol. Sulfuric acid is also important in the manufacture of dyestuffs , pigments such as titanium dioxide , solutions, and is the "acid" in lead-acid car batteries.
Sulfuric acid is also used as a general dehydrating agent in its concentrated form see Reaction with water. The sulfur-iodine cycle is a series of thermo-chemical processes used to obtain hydrogen. It consists of three chemical reactions whose net reactant is water and whose net products are hydrogen and oxygen. The sulfur and iodine compounds are recovered and reused, hence the consideration of the process as a cycle.
This process is endothermic and must occur at high temperatures, so energy in the form of heat has to be supplied. The sulfur-iodine cycle has been proposed as a way to supply hydrogen for a hydrogen-based economy. It does not require hydrocarbons like current methods of steam reforming. The sulfur-iodine cycle is currently being researched as a feasible method of obtaining hydrogen, but the concentrated, corrosive acid at high temperatures poses currently insurmountable safety hazards if the process were built on large-scale.
The discovery of sulfuric acid is credited to the 8th century Arabian chemist and alchemist , Jabir ibn Hayyan Geber. When heated, these compounds decompose to iron II oxide and copper II oxide , respectively, giving off water and sulfur trioxide , which combine to produce a dilute solution of sulfuric acid.
This method was popularized in Europe through translations of Arabic and Persian treatises, as well as books by European alchemists, such as the 13th-century German Albertus Magnus. Sulfuric acid was known to medieval European alchemists as oil of vitriol , spirit of vitriol , or simply vitriol , among other names.
The word vitriol derives from the Latin vitreus, 'glass', referring to the glassy appearance of the sulfate salts, which also carried the name vitriol. Salts called by this name included copper II sulfate blue vitriol, or rarely Roman vitriol , zinc sulfate white vitriol , iron II sulfate green vitriol , iron III sulfate vitriol of Mars , and cobalt II sulfate red vitriol.
Vitriol was widely considered the most important alchemical substance, intended to be used as a philosopher's stone. Highly purified vitriol was used as a medium for reacting other substances. This was largely because the acid does not react with gold , production of which was often the final goal of alchemical processes.
The importance of vitriol to alchemy is highlighted in the alchemical motto, Visita Interiora Terrae Rectificando Invenies Occultum Lapidem which is a backronym meaning 'Visit the interior of the earth and rectifying i.
In the 17th century, the German-Dutch chemist Johann Glauber prepared sulfuric acid by burning sulfur together with saltpeter potassium nitrate , KNO 3 , in the presence of steam. As saltpeter decomposes, it oxidizes the sulfur to SO 3 , which combines with water to produce sulfuric acid. In , Joshua Ward, a London pharmacist, used this method to begin the first large-scale production of sulfuric acid. In in Birmingham , John Roebuck adapted this method to produce sulfuric acid in lead -lined chambers, which were stronger, less expensive, and could be made larger than the previously used glass containers.
This lead chamber process allowed the effective industrialization of sulfuric acid production. After several refinements, this method remained the standard for sulfuric acid production for almost two centuries. However, the manufacture of some dyes and other chemical processes require a more concentrated product.
Throughout the 18th century, this could only be made by dry distilling minerals in a technique similar to the original alchemical processes. However, the expense of this process prevented the large-scale use of concentrated sulfuric acid. In , British vinegar merchant Peregrine Phillips patented the contact process , which was a far more economical process for producing sulfur trioxide and concentrated sulfuric acid. Today, nearly all of the world's sulfuric acid is produced using this method.
The corrosive properties of sulfuric acid are accentuated by its highly exothermic reaction with water. Hence burns from sulfuric acid are potentially more serious than those of comparable strong acids e.
The danger is obviously greater with more concentrated preparations of sulfuric acid, but it should be remembered that even the normal laboratory "dilute" grade approx. Solutions equal to or stronger than 1. Fuming sulfuric acid oleum is not recommended for use in schools due to it being quite hazardous. The standard first aid treatment for acid spills on the skin is, as for other corrosive agents, irrigation with large quantities of water. However, the acid should be neutralised first by rinsing with a base e.
Washing should be continued for at least ten to fifteen minutes in order to cool the tissue surrounding the acid burn and to prevent secondary damage. Contaminated clothing must be removed immediately and the underlying skin washed thoroughly.
Preparation of the diluted acid can also be dangerous due to the heat released in the dilution process. It is essential that the concentrated acid is added to water and not the other way round, to take advantage of the relatively high heat capacity of water. Addition of water to concentrated sulfuric acid leads at best to the dispersal of a sulfuric acid aerosol , at worst to an explosion.
Although sulfuric acid is non-flammable, contact with metals in the event of a spillage can lead to the liberation of hydrogen gas.
The dispersal of acid aerosols and gaseous sulfur dioxide is an additional hazard of fires involving sulfuric acid. Sulfuric acid is not considered toxic besides its obvious corrosive hazard, and the main occupational risks are skin contact leading to burns see above and the inhalation of aerosols. At lower concentrations, the most commonly reported symptom of chronic exposure to sulfuric acid aerosols is erosion of the teeth, found in virtually all studies: indications of possible chronic damage to the respiratory tract are inconclusive as of Interestingly there have been reports of sulfuric acid ingestion leading to vitamin B12 deficiency with subacute combined degeneration.
The spinal cord is most often affected in such cases, but the optic nerves may show demyelination , loss of axons and gliosis. International commerce of sulfuric acid is controlled under the United Nations Convention Against Illicit Traffic in Narcotic Drugs and Psychotropic Substances, , which lists sulfuric acid under Table II of the convention as a chemical frequently used in the illicit manufacture of narcotic drugs or psychotropic substances.
In the United States of America , sulfuric acid is included in List II of the list of essential or precursor chemicals established pursuant to the Chemical Diversion and Trafficking Act. Accordingly, transactions of sulfuric acid—such as sales, transfers, exports from and imports to the United States—are subject to regulation and monitoring by the Drug Enforcement Administration.
In several films, cartoons and TV shows, especially Science-Fiction shows and films, sulfuric acid is sometimes depicted as a bubbling green steaming liquid, sometimes capable of dissolving almost anything in an instant. This is purely for visual appeal, since boiling green acid is more dangerous-looking than the actual clear and syrupy form of sulfuric acid. As Liebig showed in , this could be achieved with sulphuric acid. This produces acidic calcium phosphate CaHPO 4 , which is soluble in water and can therefore be taken up by plants.
The large demand for super phosphate in European farming resulted in a large demand for sulphuric acid. Today more than half of the global production of sulphuric acid is used to produce super phosphate and other nutrients.
Read More: Little valley — a giant battery? The original sulphuric acid industry was largely based on recipes developed by craftsmen themselves, but by the end of the 19th century chemical research played an important role. By then, the once dominant lead-chamber process was competing against a new method known as the contact process. By the end of the First World War, the contact process had taken over world markets and most sulphuric acid today is produced in this way.
The new method produced a purer form of sulphuric acid--up to 98 per cent--which was required by new markets for alizarin, indigo, and other synthetic pigments used by the textile industry.
Read More: EU disagreements delay regulation of harmful chemicals. There was one technical hurdle that threatened to sink the profits of a new textile pigment industry. The problem was solved by a comprehensive research program implemented by the large German industry group BASF Badische Anilin und Soda Fabrikation and led by the industrial chemist Rudolf Knietsch to in the s.
Under normal circumstances, the combustion products of sulphuric acid, sulphur dioxide SO 2 , does not bind with oxygen in the air. But the German chemist showed that it can be achieved by contact with a suitable catalyst, such as platinum or vanadium oxide V 2 O 5.
BASF and another German manufacturer, Hoechst, established the first industrial plant based using the contact process in the mid s. Sulphuric acid is probably not a common household product. It is probably best known as battery acid, which together with distilled water is used in car batteries. But this does not change the fact that our society depends on it. Sulphuric acid is an immeasurably important chemical, but it is not a good idea to come too close.
We can be glad that we do not live on Venus, where not only is the surface temperature a searing degrees centigrade, but the atmosphere is formed of carbon dioxide and sulphuric acid. Read this article in English on ForskerZonen, part of Videnskab.
Helge Kragh. Large volcanic eruptions have cooled the global climate many times in the last 2, years and coincided with devastating famine across Europe, new research shows. Bacteria within the Greenland ice sheet are adapting to cope with pollutants deposited in the ice. These same bacteria may be key to removing some of this contamination before it enters the local food chain.
Ocean temperatures were cooling for almost two millennia but then human industrialisation came along. They utilize the first sulfuric acid chamber in the United States. However, the manufacture of some dyes and other chemical processes require a more concentrated product, and throughout the 18th century, this could only be made by dry distilling minerals in a technique similar to the original alchemical processes.
The expense of this process prevented the large-scale use of concentrated sulfuric acid. In , the British merchant Peregrine Phillips patented a far more economical process for producing sulfur trioxide and concentrated sulfuric acid. In this process sulfur dioxide, SO 2 , produced by roasting either sulfur or pyrite in air, is combined with additional air and passed over a platinum catalyst at high temperatures, where it combines with oxygen from the air to produce nearly pure SO 3.
Even so, there was little demand for highly concentrated sulfuric acid at the time, and the first sulfuric acid plant using this contact process was not built until in Freiburg, Germany.
The development of the less expensive and less easily contaminated vanadium pentoxide V 2 O 5 catalyst by BASF in Gemany in , combined with increasing demand for concentrated sulfuric acid by the chemical industry, has led to the gradual replacement of the lead-chamber process by the contact process.
Sulfuric acid makers in the United States did not immediately switch to the catalytic contact technique. Until the s, in fact, they had not adopted the Glover—Gay-Lussac towersor shifted to pyrites, in part because domestic sources were not available at a reasonable price.
After the Civil War, though, consumption of sulfuric acid grew, especially for making superphosphate fertilizers and refining petroleum. Output of the acid expanded from 60, tons in to about , tons in The first U. Other, similar facilities quickly followed. By the start of World War I, the annual U. With improvements in design and engineering, production from contact-process plants gradually eclipsed that from lead-chamber plants where the units were no longer necessarily built as boxlike chambers but as towers.
Probably no new chamber-process plants have been built since the s. Meanwhile, an increasing share of the sulfur dioxide used in contact-process plants has come from the off-gases of smelters, waste spent sulfuric acid, and other environmentally harmful wastes. These sources have largely replaced pyrites.
0コメント