The Silica Gel Process: Small Scale Studies. Part 1. Comparison of Catalysts and Labelling Experiments
Abstract
Small scale experiments using silica gel, ammonium nitrate and urea show that formation of guanidine nitrate becomes erratic if insolubles build up on the catalyst surface. The rate of production of insolubles increases rapidly with temperature, so that a trade-off between low conversions at lower temperatures and insoluble formation at higher temperatures is possible. The yield/temperature relationship is a property of the silica gel used. Yields of guanidine nitrate can be higher than predicted, possibly because by-product water is removed in the form of ammonium silicates rather than ammonium carbamate. Experiments with N15 and 018 suggest that guanidine nitrate does not result from the direct combination of cyanamide and urea: oxygen (or hydroxyl groups) of the silica gel plays an important role. The rate of formation of guanidine nitrate is second order (first order in both urea and ammonium nitrate). The phase diagram for the ternary system has been investigated.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 1972
- Accession Number
- AD0908525
Entities
People
- F. A. Armstrong
- R. T. Fraser