Mechanism of formation of oil by the hot aqueous alkaline digestion of cellulose

The overall mechanism of cellulose converson in hot aqueous alkali appears to be one of degradation through glucose to low molecular weight saccharinic acids, dihydroxybutyric acid, glycolic acid, and carbonyl products such as acetone, acetaldehyde, formaldehyde, and similar compounds. Although the products identified in the present report were fairly complex furans, carbocyclic ketones, unsaturated hydrocarbons, and aromatic compounds, nevertheless, in most cases, they could have been formed from simple carbonyl compounds through a series of condensations involving carbanion intermediates. It is conceivable that residual alkali in the oil during acetone extraction could have given rise to diacetone alcohol as an artifact. This is refuted by examination of an aqueous residue which was extracted with diethyl ether and which was never exposed to any acetone: Compounds derived from diacetone alcohol (such as mesityl oxide or 4-methyl-3-penten-2-one) were also identified in the diethyl ether extract of the aqueous phase. Other compounds were identified in the oil acetone extract which could not have been derived from acetone or diacetone alcohol, but which could have been formed from other carbonyl compounds by the same mechanism. Hence, diacetone alcohol is a genuine product of cellulose conversion although apparently not an intermediate in further synthesis of other products. The further reaction of the postulated cyclic intermediates, and the route to formation of unsaturated hydrocarbons of high molecular weight is intended to be the next subject of investigation in the current work. The fundamental difference in the mechanism of cellulose conversion to oil by pyrolysis and by aqueous alkaline digestion predicted by theory is therefore confirmed. Pyrolysis products may be explained generally by carbonium ion and free radical reactions (in fact, cellulose decomposition is acid-catalyzed), while in aqueous alkali, nucleophilic carbanion reactions are favored

Radiochemistry for the rupture of a Zircaloy-2 clad uranium fuel element in KER-2

During the 1600--2400 shift on August 7, 1960, the delayed neutron monitor on KER Loop 2 indicated a high coolant activity level. Sympathetic responses were also observed on the Loop 1, 3 and 4 monitors. This indicated a possible fuel element failure in Loop 2 and the KE Reactor began shutdown operations immediately. The purpose of this report is to summarize the events pertinent to this reactor outage and to discuss the results obtained from coolant and coupon samples taken from Loop 2 after shutdown

Radiochemistry for the rupture of a Zircaloy-2 clad uranium fuel element in KER-1

During the 0800--1600 shift on July 7, 1960, the delayed neutron monitor on KER Loop 1 indicated a high coolant activity level. Sympathetic responses were also recorded on the Loop 3 and Loop 4 instruments indicating a possible fuel element failure in Loop 1. The KE Reactor began shutdown operations immediately thereafter. The purpose of this report is to summarize the events pertinent to this reactor outage and to discuss the results obtained from coolant samples and a thermocouple wire sample taken from Loop 1

Crud deposition in KER loops at pH 10 LiOH

One of the problems which may be encountered in the operation of NPR, or of any similar pressurized-water reactor, is the deposition of crud in the reactor core, particularly on the surfaces of the fuel elements. This crud consists primarily of iron oxides resulting from the corrosion of the piping. It has generally been found to deposit preferentially in a radiation field such as is present in the reactor core. Such deposition is undesirable for two reasons. First, the crud will become activated, and on subsequent release may create radioactivity levels in the ex-reactor components of the primary loop high enough to be a hazard to maintenance and operating personnel. Secondly, the crud deposit is a poor conductor of heat, and even a rather thin film can raise the cladding temperature by 100 -- 200{degree}C and result in accelerated corrosion of the cladding

Low molecular weight products from the aqueous alkaline degradation of cellulose

Low molecular weight products from the degradation of pure cellulose in 0.6 to 1.3 N alkali at 300/sup 0/C were identified by gas chromatography/mass spectrometry (GC/MS). Both the aqueous residual phase and the floating oil product phase were examined, and found to contain essentially the same compounds. Derivatization by trifluoroacetic anhydride was used as an ancillary method to aid identification of these compounds, which consisted primarily of unsaturated aliphatic and alicyclic hydrocarbons, aldehydes, ketones, alcohols, and furans. Many isomers were present. Specific compounds identified with a high level of confidence were cyclopentanone, cyclohexanone, phenol, cresols, 2-ethylcyclopentanone, 2- or 3-methylcyclopentanone, 2,5-dimethyl-2-cylopentenone, acrolein, 2,5-dimethyl-2,4-hexadiene, and octene. Compounds identified with a lower level of confidence include 2,4-dimethylfuran, 2,5-diethylfuran, ethylmethylfuran, 4-octyne, and decyne. The formation of these compounds from cellulose under alkaline conditions demonstrates not only the degradation of cellulose, but the resynthesis of molecules with carbon chain lengths greater than 6 atoms (the chain length of glucose). Such resynthesis must occur to a great extent in the formation of insoluble high molecular weight oils from cellulose by heating in aqueous alkali

Investigation of chemical cleaning and startup operations proposed for N-reactor /

"March 1963."Includes bibliographical references.Work performed between the Atomic Energy Commission and General Electric CompanyMode of access: Internet

Decontamination studies for HAPO water-cooled reactor systems : progress report January 1, 1960 through September 1, 1960 /

"December 27, 1960."Bibliographical references: p. 156.Work performed between the Atomic Energy Commission and General Electric CompanyMode of access: Internet