Lead chamber process

The lead chamber process was an industrial method used to produce sulfuric acid in large quantities. It has been largely supplanted by the contact process.

In 1746 in Birmingham, England, John Roebuck began producing sulfuric acid in lead-lined chambers, which were stronger and less expensive, and could be made much larger, than the glass containers which had been used previously. This allowed the effective industrialization of sulfuric acid production and, with several refinements, this process remained the standard method of production for almost two centuries. So robust was the process that as late as 1946, the chamber process still accounted for 25% of sulfuric acid manufactured.[1]


Sulfur dioxide is introduced with steam and nitrogen dioxide into large chambers lined with sheet lead where the gases are sprayed down with water and chamber acid (62–70% Sulfuric acid). The sulfur dioxide and nitrogen dioxide dissolve and over a period of approximately 30 minutes the sulfur dioxide is oxidized to sulfuric acid. The presence of nitrogen dioxide is necessary for the reaction to proceed at a reasonable rate. The process is highly exothermic, and a major consideration of the design of the chambers was to provide a way to dissipate the heat formed in the reactions.

Early plants used very large lead-lined wooden rectangular chambers (Faulding box chambers) that were cooled by ambient air. The internal lead sheathing served to contain the corrosive sulfuric acid and to render the wooden chambers waterproof. Around the turn of the nineteenth century, such plants required about half a cubic meter of volume to process the sulfur dioxide equivalent of a kilogram of burned sulfur. In the mid-19th century, French chemist Gay-Lussac redesigned the chambers as stoneware packed masonry cylinders. In the 20th century, plants using Mills-Packard chambers supplanted the earlier designs. These chambers were tall tapered cylinders that were externally cooled by water flowing down the outside surface of the chamber.

Sulfur dioxide for the process was provided by burning elemental sulfur or by the roasting of sulfur-containing metal ores in a stream of air in a furnace. During the early period of manufacture, nitrogen oxides were produced by the decomposition of niter at high temperature in the presence of acid, but this process was gradually supplanted by the air oxidation of ammonia to nitric oxide in the presence of a catalyst. The recovery and reuse of oxides of nitrogen was an important economic consideration in the operation of a chamber process plant.

In the reaction chambers, nitric oxide reacts with oxygen to produce nitrogen dioxide. Liquid from the bottom of the chambers is diluted and pumped to the top of the chamber and sprayed downwards in a fine mist. Sulfur dioxide and nitrogen dioxide are absorbed in the liquid and react to form sulfuric acid and nitric oxide. The liberated nitric oxide is sparingly soluble in water and returns to the gas in the chamber where it reacts with oxygen in the air to reform nitrogen dioxide. Some percentage of the nitrogen oxides are sequestered in the reaction liquor as nitrosylsulfuric acid and as nitric acid, so fresh nitric oxide must be added as the process proceeds. Later versions of chamber plants included a high-temperature Glover tower to recover the nitrogen oxides from the chamber liquor, while concentrating the chamber acid to as much as 78% H2SO4. Exhaust gases from the chambers are scrubbed by passing into a tower through which some of the Glover acid flows over broken tile. Nitrogen oxides are absorbed to form nitrosylsulfuric acid, which is then returned to the Glover tower to reclaim the oxides of nitrogen.

Sulfuric acid produced in the reaction chambers is limited to about 35% concentration. At higher concentrations, nitrosylsulfuric acid precipitates on the lead walls as chamber crystals and is no longer able to catalyze the oxidation reactions.[2]


Sulfur dioxide is generated by burning elemental sulfur or by roasting pyritic ore in a current of air:

S8 + 8 O2 → 8 SO2
4 FeS2 + 11 O2 → 2 Fe2O3 + 8 SO2

Nitrogen oxides are produced by decomposition of niter in the presence of sulfuric acid or hydrolysis of nitrosylsulfuric acid:

2 NaNO3 + H2SO4 → Na2SO4 + H2O + NO + NO2 + O2
2 NOHSO4 + H2O → 2 H2SO4 + NO + NO2

In the reaction chambers, sulfur dioxide and nitrogen dioxide dissolve in the reaction liquor. Nitrogen dioxide is hydrated to produce nitrous acid which then oxidizes the sulfur dioxide to sulfuric acid and nitric oxide. The reactions are not well characterized but it is known that nitrosylsulfuric acid is an intermediate in at least one pathway. The major overall reactions are:

2 NO2 + H2O → HNO2 + HNO3
SO2 (aq) + HNO3 → NOHSO4
NOHSO4 + HNO2 → H2SO4 + NO2 + NO
SO2 (aq) + 2 HNO2 → H2SO4 + 2 NO

Nitric oxide escapes from the reaction liquor and is subsequently reoxidized by molecular oxygen to nitrogen dioxide. This is the overall rate determining step in the process:[3]

2 NO + O2 → 2 NO2

Nitrogen oxides are absorbed and regenerated in the process, and thus serve as a catalyst for the overall reaction:

2 SO2 + 2 H2O + O2 → 2 H2SO4


  1. ^ Edward M. Jones, "Chamber Process Manufacture of Sulfuric Acid", Industrial and Engineering Chemistry, Nov 1950, Vol 42, No. 11, pp 2208–10.
  2. ^ F. A. Gooch and C. F. Walker, Outlines of Inorganic Chemistry, MacMillan, London, 1905, pp 274.
  3. ^ Jones, pp 2209.

Further reading

  • Derry, Thomas Kingston; Williams, Trevor I. (1993). A Short History of Technology: From the Earliest Times to A.D. 1900. New York: Dover.
  • Kiefer, David M. (2001). "Sulfuric Acid: Pumping Up the Volume". American Chemical Society. Retrieved 2008-04-21.

External links

1746 in science

The year 1746 in science and technology involved some significant events.


BASF SE is a German chemical company and the largest chemical producer in the world. The BASF Group comprises subsidiaries and joint ventures in more than 80 countries and operates six integrated production sites and 390 other production sites in Europe, Asia, Australia, the Americas and Africa. Its headquarters is located in Ludwigshafen, Germany. BASF has customers in over 190 countries and supplies products to a wide variety of industries. Despite its size and global presence, BASF has received relatively little public attention since it abandoned manufacturing and selling BASF-branded consumer electronics products in the 1990s.

At the end of 2017, the company employed around 115,490 people, with over 52,000 in Germany alone. In 2015, BASF posted sales of €70.4 billion and income from operations before special items of about €6.7 billion. The company is currently expanding its international activities with a particular focus on Asia. Between 1990 and 2005, the company invested €5.6 billion in Asia, for example in sites near Nanjing and Shanghai, China and Mangalore, India.

BASF is listed on the Frankfurt Stock Exchange, London Stock Exchange, and Zurich Stock Exchange. The company delisted its ADR from the New York Stock Exchange in September 2007. The company is a component of the Euro Stoxx 50 stock market index.


Birmingham ( (listen), locally also: ) is the second-most populous city in the United Kingdom, after London, and the most populous city in the English Midlands. With an estimated population of 1,137,100 as of 2017, Birmingham is the cultural, social, financial and commercial centre of the Midlands. It is the main centre of the West Midlands conurbation, which is the third most populated urban area in the United Kingdom, with a population in 2011 of 2,440,986. The wider Birmingham metropolitan area is the second largest in the United Kingdom with a population of over 3.7 million. Birmingham is frequently referred to as the United Kingdom's "second city".A market town in the medieval period, Birmingham grew in the 18th-century Midlands Enlightenment and subsequent Industrial Revolution, which saw advances in science, technology, and economic development, producing a series of innovations that laid many of the foundations of modern industrial society. By 1791 it was being hailed as "the first manufacturing town in the world". Birmingham's distinctive economic profile, with thousands of small workshops practising a wide variety of specialised and highly skilled trades, encouraged exceptional levels of creativity and innovation and provided an economic base for prosperity that was to last into the final quarter of the 20th century. The Watt steam engine was invented in Birmingham.The resulting high level of social mobility also fostered a culture of political radicalism which, under leaders from Thomas Attwood to Joseph Chamberlain, was to give it a political influence unparalleled in Britain outside London, and a pivotal role in the development of British democracy. From the summer of 1940 to the spring of 1943, Birmingham was bombed heavily by the German Luftwaffe in what is known as the Birmingham Blitz. The damage done to the city's infrastructure, in addition to a deliberate policy of demolition and new building by planners, led to extensive urban regeneration in subsequent decades.

Birmingham's economy is now dominated by the service sector. The city is a major international commercial centre, ranked as a beta- world city by the Globalization and World Cities Research Network; and an important transport, retail, events and conference hub. Its metropolitan economy is the second largest in the United Kingdom with a GDP of $121.1bn (2014), and its six universities make it the largest centre of higher education in the country outside London. Birmingham's major cultural institutions – the City of Birmingham Symphony Orchestra, the Birmingham Royal Ballet, the Birmingham Repertory Theatre, the Library of Birmingham and the Barber Institute of Fine Arts – enjoy international reputations, and the city has vibrant and influential grassroots art, music, literary and culinary scenes. Birmingham is the fourth-most visited city in the UK by foreign visitors.People from Birmingham are called Brummies, a term derived from the city's nickname of "Brum", which originates from the city's old name, Brummagem, which in turn is thought to have derived from "Bromwich-ham". The Brummie accent and dialect are particularly distinctive.

Chemical reaction

A chemical reaction is a process that leads to the chemical transformation of one set of chemical substances to another. Classically, chemical reactions encompass changes that only involve the positions of electrons in the forming and breaking of chemical bonds between atoms, with no change to the nuclei (no change to the elements present), and can often be described by a chemical equation. Nuclear chemistry is a sub-discipline of chemistry that involves the chemical reactions of unstable and radioactive elements where both electronic and nuclear changes can occur.

The substance (or substances) initially involved in a chemical reaction are called reactants or reagents. Chemical reactions are usually characterized by a chemical change, and they yield one or more products, which usually have properties different from the reactants. Reactions often consist of a sequence of individual sub-steps, the so-called elementary reactions, and the information on the precise course of action is part of the reaction mechanism. Chemical reactions are described with chemical equations, which symbolically present the starting materials, end products, and sometimes intermediate products and reaction conditions.

Chemical reactions happen at a characteristic reaction rate at a given temperature and chemical concentration. Typically, reaction rates increase with increasing temperature because there is more thermal energy available to reach the activation energy necessary for breaking bonds between atoms.

Reactions may proceed in the forward or reverse direction until they go to completion or reach equilibrium. Reactions that proceed in the forward direction to approach equilibrium are often described as spontaneous, requiring no input of free energy to go forward. Non-spontaneous reactions require input of free energy to go forward (examples include charging a battery by applying an external electrical power source, or photosynthesis driven by absorption of electromagnetic radiation in the form of sunlight).

Different chemical reactions are used in combinations during chemical synthesis in order to obtain a desired product. In biochemistry, a consecutive series of chemical reactions (where the product of one reaction is the reactant of the next reaction) form metabolic pathways. These reactions are often catalyzed by protein enzymes. Enzymes increase the rates of biochemical reactions, so that metabolic syntheses and decompositions impossible under ordinary conditions can occur at the temperatures and concentrations present within a cell.

The general concept of a chemical reaction has been extended to reactions between entities smaller than atoms, including nuclear reactions, radioactive decays, and reactions between elementary particles, as described by quantum field theory.

Contact process

The contact process is the current method of producing sulfuric acid in the high concentrations needed for industrial processes. Platinum used to be the catalyst for this reaction; however, as it is susceptible to reacting with arsenic impurities in the sulphur feedstock, vanadium(V) oxide (V2O5) is now preferred.This process was patented in 1831 by British vinegar merchant Peregrine Phillips. In addition to being a far more economical process for producing concentrated sulfuric acid than the previous lead chamber process, the contact process also produces sulfur trioxide and oleum.

History of Birmingham

Birmingham has seen 1400 years of growth, during which time it has evolved from a small 7th century Anglo Saxon hamlet on the edge of the Forest of Arden at the fringe of early Mercia to become a major city through a combination of immigration, innovation and civic pride that helped to bring about major social and economic reforms and to create the Industrial Revolution, inspiring the growth of similar cities across the world.

The last 200 years have seen Birmingham rise from market town into the fastest-growing city of the 19th century, spurred on by a combination of civic investment, scientific achievement, commercial innovation and by a steady influx of migrant workers into its suburbs. By the 20th century Birmingham had become the metropolitan hub of the United Kingdom's manufacturing and automotive industries, having earned itself a reputation first as a city of canals, then of cars, and most recently as a major European convention and shopping destination.

By the beginning of the 21st century, Birmingham lay at the heart of a major post-industrial metropolis surrounded by significant educational, manufacturing, shopping, sporting and conferencing facilities.

Industrial Revolution

The Industrial Revolution was the transition to new manufacturing processes in Europe and the US, in the period from about 1760 to sometime between 1820 and 1840. This transition included going from hand production methods to machines, new chemical manufacturing and iron production processes, the increasing use of steam power and water power, the development of machine tools and the rise of the mechanized factory system. The Industrial Revolution also led to an unprecedented rise in the rate of population growth.

Textiles were the dominant industry of the Industrial Revolution in terms of employment, value of output and capital invested. The textile industry was also the first to use modern production methods.The Industrial Revolution began in Great Britain, and many of the technological innovations were of British origin. By the mid-18th century Britain was the world's leading commercial nation, controlling a global trading empire with colonies in North America and the Caribbean, and with some political influence on the Indian subcontinent, through the activities of the East India Company. The development of trade and the rise of business were major causes of the Industrial Revolution.The Industrial Revolution marks a major turning point in history; almost every aspect of daily life was influenced in some way. In particular, average income and population began to exhibit unprecedented sustained growth. Some economists say that the major impact of the Industrial Revolution was that the standard of living for the general population began to increase consistently for the first time in history, although others have said that it did not begin to meaningfully improve until the late 19th and 20th centuries.GDP per capita was broadly stable before the Industrial Revolution and the emergence of the modern capitalist economy, while the Industrial Revolution began an era of per-capita economic growth in capitalist economies. Economic historians are in agreement that the onset of the Industrial Revolution is the most important event in the history of humanity since the domestication of animals and plants.Although the structural change from agriculture to industry is widely associated with the Industrial Revolution, in the United Kingdom it was already almost complete by 1760.The precise start and end of the Industrial Revolution is still debated among historians, as is the pace of economic and social changes. Eric Hobsbawm held that the Industrial Revolution began in Britain in the 1780s and was not fully felt until the 1830s or 1840s, while T.S. Ashton held that it occurred roughly between 1760 and 1830. Rapid industrialization first began in Britain, starting with mechanized spinning in the 1780s, with high rates of growth in steam power and iron production occurring after 1800. Mechanized textile production spread from Great Britain to continental Europe and the United States in the early 19th century, with important centres of textiles, iron and coal emerging in Belgium and the United States and later textiles in France.An economic recession occurred from the late 1830s to the early 1840s when the adoption of the original innovations of the Industrial Revolution, such as mechanized spinning and weaving, slowed and their markets matured. Innovations developed late in the period, such as the increasing adoption of locomotives, steamboats and steamships, hot blast iron smelting and new technologies, such as the electrical telegraph, widely introduced in the 1840s and 1850s, were not powerful enough to drive high rates of growth. Rapid economic growth began to occur after 1870, springing from a new group of innovations in what has been called the Second Industrial Revolution. These new innovations included new steel making processes, mass-production, assembly lines, electrical grid systems, the large-scale manufacture of machine tools and the use of increasingly advanced machinery in steam-powered factories.

Industrial processes

Industrial processes are procedures involving chemical, physical, electrical or mechanical steps to aid in the manufacturing of an item or items, usually carried out on a very large scale. Industrial processes are the key components of heavy industry.

John Roebuck

John Roebuck of Kinneil FRS FRSE (1718 – 17 July 1794) was an English inventor and industrialist who played an important role in the Industrial Revolution and who is known for developing the industrial-scale manufacture of sulphuric acid.

List of British innovations and discoveries

The following is a list and timeline of innovations as well as inventions and discoveries that involved British people or the United Kingdom including predecessor states in the history of the formation of the United Kingdom. This list covers innovation and invention in the mechanical, electronic, and industrial fields, as well as medicine, military devices and theory, artistic and scientific discovery and innovation, and ideas in religion and ethics.

The scientific revolution in 17th century Europe stimulated innovation and discovery in Britain. Experimentation was considered central to innovation by groups such as the Royal Society, which was founded in 1660. The English patent system evolved from its medieval origins into a system that recognised intellectual property; this encouraged invention and spurred on the Industrial Revolution from the late 18th century. During the 19th century, innovation in Britain led to revolutionary changes in manufacturing, the development of factory systems, and growth of transportation by railway and steam ship that spread around the world. In the 20th century, Britain's rate of innovation, measured by patents registered, slowed in comparison to other leading economies. Nonetheless, science and technology in Britain continued to develop rapidly in absolute terms.

List of English inventions and discoveries

English inventions and discoveries are objects, processes or techniques invented, innovated or discovered, partially or entirely, in England by a person from England (that is, someone born in England – including to non-English parents – or born abroad with at least one English parent and who had the majority of their education or career in England). Often, things discovered for the first time are also called inventions and in many cases, there is no clear line between the two.

The following is a list of inventions, innovations or discoveries known or generally recognised to be English.

List of inventors

This is a list of notable inventors.

Nitrosylsulfuric acid

Nitrosylsulfuric acid is the chemical compound with the formula NOHSO4. It is a colourless solid that is used industrially in the production of caprolactam, and was formerly part of the lead chamber process for producing sulfuric acid. The compound is the mixed anhydride of sulfuric acid and nitrous acid.

In organic chemistry, it is used as a reagent for nitrosating, as a diazotizing agent, and as an oxidizing agent.


Oleum (Latin oleum, meaning oil), or fuming sulfuric acid, is a solution of various compositions of sulfur trioxide in sulfuric acid, or sometimes more specifically to disulfuric acid (also known as pyrosulfuric acid). Oleum is identified by the CAS number 8014-95-7 (EC/List number: 616-954-1 ; ECHA InfoCard: 100.116.872).

Oleums can be described by the formula ySO3.H2O where y is the total molar sulfur trioxide content. The value of y can be varied, to include different oleums. They can also be described by the formula H2SO4.xSO3 where x is now defined as the molar free sulfur trioxide content. Oleum is generally assessed according to the free SO3 content by mass. It can also be expressed as a percentage of sulfuric acid strength; for oleum concentrations, that would be over 100%. For example, 10% oleum can also be expressed as H2SO4.0.13611SO3, 1.0225SO3.H2O or 102.25% sulfuric acid. The conversion between % acid and % oleum is: % acid = 100 + 18/80 × % oleum

A value for x of 1 gives the empirical formula H2S2O7 for disulfuric (pyrosulfuric) acid. Pure disulfuric acid is a solid at room temperature, melting at 36 °C and rarely used either in the laboratory or industrial processes.

Science and invention in Birmingham

Birmingham is one of England's principal industrial centres and has a history of industrial and scientific innovation. It was once known as 'city of a thousand trades' and in 1791, Arthur Young (the writer and commentator on British economic life) described Birmingham as "the first manufacturing town in the world". Right up until the mid-19th century Birmingham was regarded as the prime industrial urban town in Britain and perhaps the world, the town's rivals were more specific in their trade bases. Mills and foundries across the world were helped along by the advances in steam power and engineering that were taking place in the city. The town offered a vast array of industries and was the world's leading manufacturer of metal ware, although this was by no means the only trade flourishing in the town.By the year 2000, of the 4,000 inventions copyrighted in the UK, 2,800 came from within a 35-mile radius of Birmingham. Peter Colegate of the Patent Office stated that "Every year, Birmingham amazes us by coming up with thousands of inventions. It is impossible to explain but people in the area seem to have a remarkable ability to come up with, and have the dedication to produce, ideas."While the time line of industry and innovation listed below is extensive, it is by no means a comprehensive list of Birmingham's industrial and scientific achievements, more a guide to highlight the great diversity in the city's industrial might, which can still be seen today.


Selenium is a chemical element with symbol Se and atomic number 34. It is a nonmetal (more rarely considered a metalloid) with properties that are intermediate between the elements above and below in the periodic table, sulfur and tellurium, and also has similarities to arsenic. It rarely occurs in its elemental state or as pure ore compounds in the Earth's crust. Selenium (from Ancient Greek σελήνη (selḗnē) "Moon") was discovered in 1817 by Jöns Jacob Berzelius, who noted the similarity of the new element to the previously discovered tellurium (named for the Earth).

Selenium is found in metal sulfide ores, where it partially replaces the sulfur. Commercially, selenium is produced as a byproduct in the refining of these ores, most often during production. Minerals that are pure selenide or selenate compounds are known but rare. The chief commercial uses for selenium today are glassmaking and pigments. Selenium is a semiconductor and is used in photocells. Applications in electronics, once important, have been mostly replaced with silicon semiconductor devices. Selenium is still used in a few types of DC power surge protectors and one type of fluorescent quantum dot.

Selenium salts are toxic in large amounts, but trace amounts are necessary for cellular function in many organisms, including all animals. Selenium is an ingredient in many multivitamins and other dietary supplements, including infant formula. It is a component of the antioxidant enzymes glutathione peroxidase and thioredoxin reductase (which indirectly reduce certain oxidized molecules in animals and some plants). It is also found in three deiodinase enzymes, which convert one thyroid hormone to another. Selenium requirements in plants differ by species, with some plants requiring relatively large amounts and others apparently requiring none.

Sulfuric acid

Sulfuric acid (alternative spelling sulphuric acid), also known as vitriol, is a mineral acid composed of the elements sulfur, oxygen and hydrogen, with molecular formula H2SO4. It is a colorless, odorless, and syrupy liquid that is soluble in water, in a reaction that is highly exothermic.Its corrosiveness can be mainly ascribed to its strong acidic nature, and, if at a high concentration, its dehydrating and oxidizing properties. It is also hygroscopic, readily absorbing water vapor from the air. Upon contact, sulfuric acid can cause severe chemical burns and even secondary thermal burns; it is very dangerous even at moderate concentrations.Sulfuric acid is a very important commodity chemical, and a nation's sulfuric acid production is a good indicator of its industrial strength. It is widely produced with different methods, such as contact process, wet sulfuric acid process, lead chamber process and some other methods.Sulfuric acid is also a key substance in the chemical industry. It is most commonly used in fertilizer manufacture, but is also important in mineral processing, oil refining, wastewater processing, and chemical synthesis. It has a wide range of end applications including in domestic acidic drain cleaners, as an electrolyte in lead-acid batteries, and in various cleaning agents.

Timeline of Birmingham history

This article is intended to show a timeline of events in the History of Birmingham, England, with a particular focus on the events, people or places that are covered in Wikipedia articles.

Timeline of historic inventions

The timeline of historic inventions is a chronological list of particularly important or significant technological inventions and the people who created the inventions.

Note: Dates for inventions are often controversial. Inventions are often invented by several inventors around the same time, or may be invented in an impractical form many years before another inventor improves the invention into a more practical form. Where there is ambiguity, the date of the first known working version of the invention is used here.

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