"Fire, as the agent for , was a favorite tool of the alchemist. Although the general prevalence... of pyrolysis has long been recognized... in the last six decades... the subject has assumed a scientific basis. Since many... data on have been incidental observations... the information is widely scattered... [T]hat ...records of many melting-point determinations are accompanied by ..."It melts with decomposition" is ...evidence ...the subject ...has ...an unorganized past."
Pyrolysis is a process involving the separation of covalent bonds in organic matter by thermal decomposition within an inert environment without oxygen.
"Occasionally... it will be helpful to note the effect of catalysts... Frequently in s, it is difficult to distinguish between the catalytic and the non-catalytic. ...Glass, or surfaces are the ones which are most used in laboratory pyrolyses. Their catalytic action is, at the best, very slight."
Pyrolysis"The groups from [wood distillation] are 1. s; formic to caproic, especially . Also, furoic, angelic, s, and valerolactone. For different woods, the total acid, calculated as acetic acid, varies between 4.3 and 6.8[%]... In vacuum distillation... formic acid may be... as high as 35[%] of the acetic acid, but in ordinary distillation at atmospheric pressure, it varies from 10-20[%] of the acetic acid. Only these two acids appear to be formed in appreciable amounts. 2. Alcohols; especially and , but also isoamyl and isobutyl alcohols, and buten-3-ol-2. The content is usually... 1.3-2[%]. 3. Esters; formed by interaction of the above acids and alcohols. 4. Ketones; ... and... its homologs... [plus] small quantities of , methyl cyclopentanone, and . The acetone is not a primary [distillation] product... but is formed secondarily from the acetic acid... homologs of acetone have a similar history. 5. Aldehydes; , , methylal and dimethyl acetal, valeric aldehyde, and methyl furfural. The pentosans are... the source of the furfural and other... homologs of furan... 6. Phenols and phenol methyl ethers [only about 1 percent of the wood distilled], mostly s of di- and tris. ...These substances come largely from the . 7. ["
Pyrolysis"[P]roducts can be classified into two groups relative to the temperature dependence of the yields. , water and evolve at lower temperatures with ultimate yields that are essentially independent of temperature above 700°C. The second group... of gaseous hydrocarbons, and evolve at higher temperatures. The ultimate yield of these... continues increasing... up to 1,000°C or higher."
Pyrolysis"We are... concerned with the evolution of tar and gases during the plastic state of coal. In this... consists of two processes in series: diffusion through the molten coal to some internal surface, that of a bubble or a pore; and transport with the bubble or through the pore to the surface of the particle. The role of preexisting pores is not well understood. ...[A] certain fraction of preexisting pores ("
Pyrolysis"Fast pyrolysis is a high temperature process in which biomass is rapidly heated in the absence of oxygen. ...[I]t decomposes to generate mostly vapours... s and some . After cooling and condensation, a... liquid is formed which has a heating value about half... conventional . ...Fast pyrolysis ...is carefully controlled to give high yields ..."
Pyrolysis"The pyrolysis of and is often the process of choice for the production of . ...Marketing of the products of from ethane pyrolysis is greatly simplified by the low yield of by-products. ...Pyrolysis of ethane and propane produces the lowest yield of byproducts, which... minimizes the size of downstream units... as the depropanizer, debutanizer, and compressors."
Pyrolysis