GB812832A - Method for continuous self-sustaining flameless oxidation of combustible materials - Google Patents

Abstract

A process for continuously oxidising combustible materials dispersed in liquid water comprises passing the dispersion and an oxygen-containing gas into a reaction zone under super-atmospheric pressure and maintaining conditions in the reaction zone such that the combustion products are produced at a rate which balances stoichiometrically the rate at which the combustible materials and oxygen-containing gas are fed to the reaction zone. A flameless oxidation reaction is established in the reaction zone and some of the water therein always remains in the liquid phase. Preferably heat is initially applied from an external source to establish the reaction, after which such heating is discontinued. Specification 706,686 is referred to, and two examples closely similar to those described therein are given. In another example, charcoal suspended in water is fed continuously at a rate of ten grams every thirty minutes together with air containing sufficient oxygen theoretically to convert ten grams of charcoal to carbon dioxide every thirty minutes, to a reactor containing 200 grams of charcoal and 1 litre of water, and maintained at 250 DEG C. and 800 lbs. per square inch pressure, the liquid level being maintained constant by heating or cooling. After one hour 20 grams of charcoal had been completely oxidised and vented from the reactor as carbon dioxide. In a further example the amount of combustible material maintained in the reactor is approximately forty times the amount of combustible material in the liquor fed per hour to the reactor. To illustrate the treatment of material containing both combustible and non-combustible substances, in another example a gallon of "semi-chemical" liquor containing 4,44 pounds of sodium lignin sulphonate, sodium acetate, sodium sulphite and carbohydrates and the like, is fed into a reactor maintained at 250 DEG C. and 800 lbs. per square inch, and further supplies are then introduced continuously together with air containing the oxygen theoretically required to oxidize completely all the combustible materials in the feed, so as to maintain within the reactor an amount of combustible material having the same oxygen demand as the original reactor charge after equilibrium conditions are established. Energy is generated by the reaction, and the reaction products are nitrogen, water vapour, carbon dioxide and sodium sulphate, the latter being removable as ash or solution.