초록 ▼

A carbonaceous residue or char having novel properties is produced from particulate agricultural waste material, such as peanut shells, which upon heating exhibits an exothermic decomposition into an off gas component and a solid component in which the off gas component is more highly reactive to ox

A carbonaceous residue or char having novel properties is produced from particulate agricultural waste material, such as peanut shells, which upon heating exhibits an exothermic decomposition into an off gas component and a solid component in which the off gas component is more highly reactive to oxygen than is the solid component. By introducing air into the reaction zone whereat the decomposition is effected and controlling the amount of air so introduced such that not all of the off gas component may be oxidized, the preferential reaction of the air with the off gas component will protect the solid component from any significant oxidation while at the same time it will elevate the temperature in the reaction zone sufficiently to effect substantially complete decomposition of the material so that the recovered product is of very high carbon content. At the same time, a temperature gradient is established in the reaction zone which will allow some of the vapor component of the decomposition (i.e. heavier tars) to condense on the solid component at cooler regions for subsequent reintroduction into the high temperature regions so that the latent carbon content of these tars may also be recovered. The throughput or residence time of the material through the reaction zone and the amount of air introduced (to control the maximum reaction temperature as well as the temperature gradient) are controlled in related manner to recover more or less of the heavier tar residue.

대표청구항 ▼

In a process for the production of a high-carbon content carbonaceous residue product from a particulate cellulosic material, which material decomposes at elevated temperatures in an exothermic reaction, to produce a gaseous component containing a condensable fraction, and a less-readily oxidized so

In a process for the production of a high-carbon content carbonaceous residue product from a particulate cellulosic material, which material decomposes at elevated temperatures in an exothermic reaction, to produce a gaseous component containing a condensable fraction, and a less-readily oxidized solid component, the steps comprising: (a) introducing such cellulosic material into the upper end of a vertical reaction zone; (b) substantially continuously effecting the descent of said material, as a non-fluidIzed moving bed, within said zone and outwardly therefrom; (c) heating said material to effect its thermal decomposition, into said gaseous and solid components, in said zone; (d) introducing air at a flow rate in the order of 0.25 cu. ft. of air per pound of cellulosic material introduced in step (a) into the lower portion of said zone at a plurality of vertically-spaced locations partially to oxidize said gaseous component and raise the temperatures in said bed, and passing the resultant gas upwardly therethrough; and (e) controlling both the rate of descent of said bed through said zone and said flow rate of said air introduced thereinto, to: (1) sustain said thermal decomposition of said material, while avoiding complete oxidation of said gaseous component, (2) establish an upwardly decreasing vertical temperature gradient in said bed, (3) effect condensation of at least part of said condensable fraction upon said material near said upper end of said zone, and (4) effect substantially complete devolatilization of said solid component, so as to produce a substantially dry, devolatized carbonaceous residue product having an elemental carbon content in excess of about ninety percent by weight thereof and a surface area in excess of about 100 sq. meters per gram.