MétaCan
Menu
Back to cohort

Ammonia

2000· other· en· W4239594782 on OpenAlexaff
T. A. Czuppon, S. A. Knez, J. M. Rovner

Bibliographic record

VenueKirk-Othmer Encyclopedia of Chemical Technology · 2000
Typeother
Languageen
FieldChemical Engineering
TopicAmmonia Synthesis and Nitrogen Reduction
Canadian institutionsKellogg's (Canada)
Fundersnot available
KeywordsAmmoniaChemistryInorganic chemistryNitrogenAmmoniumAmmonia productionOdorHydrogenOrganic chemistry

Abstract

fetched live from OpenAlex

Abstract Ammonia, NH 3 , a colorless alkaline gas, is lighter than air and possesses a unique, penetrating odor. The synthesis of ammonia directly from hydrogen and nitrogen on a commercial scale was pioneered by Haber and Bosch. Further developments in economical, large‐scale ammonia production for fertilizers have made a significant impact on increases in the world's food supply. The flammable limits of ammonia in air are 16 to 25% by volume; in oxygen the range is 15 to 79%. Such mixtures can explode, although ammonia–air mixtures are quite difficult to ignite. Ammonia is readily absorbed in water to make ammonia liquor. Additional thermodynamic properties may be found in the literature. Considerable heat is evolved during the solution of ammonia in water. Ammonia is an excellent solvent for salts, and has an exceptional capacity to ionize electrolytes. Many organic compounds such as amines, nitro compounds, and aromatic sulfonic acids also dissolve in liquid ammonia. Ammonia is comparatively stable at ordinary temperatures, but decomposes into hydrogen and nitrogen at elevated temperatures. Ammonia reacts readily with a large variety of substances. Oxidation at a high temperature is one of the more important reactions, giving nitrogen and water. The reaction of ammonia and carbon dioxide, giving ammonium carbamate, CH 6 N 2 O 2 , which then decomposes to urea and water, is of major industrial importance. Ammonia is synthesized by the reversible reaction of hydrogen and nitrogen. The energy‐intensive nature of ammonia production and the worldwide energy crisis in the 1970s led to the proposal of new concepts for synthesis gas generation that do not require hydrocarbon feedstock. In the 1980s, however, the prices of oil and natural gas reversed their upward trends. Natural gas discoveries and oil discoveries contributed more feedstock potential for ammonia production. Based on these developments, the foreseeable future sources of ammonia synthesis gas are expected to be mainly from steam‐reforming of natural gas. At the start of the 1990s, almost 70% of the world's ammonia production was based on this source. Ammonia production per se is relatively clean compared to other chemical process industries. Synthesis gas generation is the principal area requiring environmental controls. Coal feedstocks present the most serious environmental problems. Reforming of natural gas or naphtha, respectively, constitutes the cleanest synthesis gas generation operations. All fired equipment, whether it be a process furnace or a utility boiler, is also subject to regulation, usually in the form of sulfur and nitrous oxide limitations. Anhydrous ammonia is ordinarily stored in refrigerated tanks at the plant site at \documentclass{article}\usepackage{amssymb}\pagestyle{empty}\begin{document}${-33.3{^\circ}{\rm{C}}}$\end{document} and atmospheric pressure. Distribution of anhydrous ammonia in the United States is facilitated by pipeline, by water, by rail, and by truck. Ammonia production has worldwide significance; about 85% of the ammonia produced is used for nitrogen fertilizers. As the primary source of fertilizer nitrogen, it is key to solving world food production requirements. The remaining 15% goes into various industrial products such as fibers, animal feeds, explosives, refrigerant, etc. Ammonia is a strong local irritant which also has a corrosive effect on the eyes and the membranes of the pulmonary system. Respiratory protection should be provided for workers exposed to ammonia. Protective clothing such as rubber aprons, boots, gloves, and goggles should be worn when handling ammonia. The search for a high yield alternative energy route to ammonia, in an effort to meet fertilizer demands and conserve natural gas reserve, is a continuing one. Alternate energy sources are being explored in the laboratory for fixing nitrogen as ammonia.

Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.

How this classification was reachedexpand

Full frame distilled prediction

Teacher imitation

Not calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.

metaresearch head score (Codex)0.000
metaresearch head score (Gemma)0.000
Version: codex-gemma-dda1882f352aValidation status: machine_predicted_unvalidated
Candidate categoriesMeta-epidemiology (narrow), Research integrity, Insufficient payload (model declined to judge)
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Not applicable · Consensus signal: Not applicable
GenreCandidate signal: Other · Consensus signal: Other
Teacher disagreement score0.221
Threshold uncertainty score1.000

Codex and Gemma teacher scores by category

CategoryCodexGemma
Metaresearch0.0000.000
Meta-epidemiology (narrow)0.0010.001
Meta-epidemiology (broad)0.0010.000
Bibliometrics0.0010.001
Science and technology studies0.0000.000
Scholarly communication0.0000.000
Open science0.0010.000
Research integrity0.0020.001
Insufficient payload (model declined to judge)0.0040.000

Machine scores (provisional)

The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.

Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.

Opus teacher head0.005
GPT teacher head0.212
Teacher spread0.207 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it

Classification

machine, unvalidated

Machine predicted; a candidate call from one teacher head, not a consensus.

Study designNot applicable
Domainnot available
GenreOther

How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".

Quick stats

Citations1
Published2000
Admission routes1
Has abstractyes

Explore more

Same venueKirk-Othmer Encyclopedia of Chemical TechnologySame topicAmmonia Synthesis and Nitrogen ReductionFrench-language works237,207