US 4,741,868 A · Production of sulfonated asphalt

Abstract

Sulfonated asphalt is produced by heating an asphaltic material, preferably having a softening point between about 315.degree. F. and 350.degree. F., by mixing the asphalt with a solvent, such as hexane, sulfonating the asphalt with a liquid sulfonating agent, such as liquid sulfur trioxide, neutralizing the sulfonic acids with a basic neutralizing agent, such as sodium hydroxide, separating solvent from the sulfonated asphalt, preferably by passing the same through a wiped film evaporator, recovering the evaporated solvent for reuse, preferably by passing the same in indirect heat exchange with a closed cycle refrigerant, recovering solvent from vapors from the sulfonation and neutralization steps by either scrubbing with neutalizing agent or sulfuric acid or by passing the same through fiber-type filter means and, thereafter, passing the same to the refrigeration step and drying the separated, sulfonated asphalt, preferably by passage through a drum dryer, and separating particle-form sulfonated asphalt from the vapors from the drum dryer, preferably by passing the same through a cyclone separator. Preferably the process is a batch-type process in which the rates of flow of the solvent, the asphaltic material, the sulfonating agent and the neutralizing agent and the periods of time prior to withdrawal of the sulfonic acids and the sulfonated asphalt are coordinated in accordance with a predetermined time cycle.

Claims21

Dependent claims

A process for producing sulfonated asphalt comprising:

(a) adding a normally liquid, inert, low boiling solvent to an asphaltic material;
(b) contacting the thus formed mixture of asphaltic material and solvent with a liquid sulfonating agent under sulfonation conditions;
(c) neutralizing the thus produced sulfonic acids with a basic neutralizing agent under neutralizing conditions;
(d) separating said solvent from the thus produced sulfonated asphalt by forming a moving film of said sulfonated asphalt on a heated surface under conditions adapted to simultaneously evaporate said solvent;
(e) recovering the thus evaporated solvent;
and
(f) drying the thus separated sulfonated asphalt as a product of the process, wherein vapor phases containing significant amounts of solvent are withdrawn from at least one of the sulfonation step and the neutralization step and solvent is recovered therefrom by one of (1) countercurrently scrubbing said vapor phase with a portion of the neutralizing agent, (2) countercurrently scrubbing said vapor phase with an aqueous solution of sulfuric acid and (3) passing said vapor phase through a fiber-type filter means to purify the same.

4 more elements

A process for producing sulfonated asphalt, comprising:

(a) adding a normally liquid, inert, low boiling solvent to an asphaltic material;
(b) contacting the thus formed mixture of asphaltic material and solvent with a liquid sulfonating agent under sulfonation conditions;
(c) neutralizing the thus produced sulfonic acids with a basic neutralizing agent under neutralizing conditions;
(d) separating at least part of said solvent, in a vapor phase, from the thus produced sulfonated asphalt;
(e) subjecting a refrigerant to alternate compression and expansion in a closed cycle refrigeration system;
(f) passing the thus separated solvent in indirect heat exchange with the refrigerant at a temperature sufficient to purify, condense and recover essentially all of said solvent for reuse;
and
(g) drying the thus separated sulfonated asphalt as a product of the process.

5 more elements

A batch-type process for producing sulfonated asphalt comprising:

(a) adding a normally liquid, inert, low boiling solvent, at a predetermined flow rate, to a stream of asphaltic material, flowing at a predetermined flow rate;
(b) adding a liquid sulfonating agent at a predetermined flow rate to the thus formed mixture of asphaltic material and solvent and contacting the same under sulfonation conditions in a sulfonation zone;
(c) withdrawing the thus produced sulfonic acids from said sulfonation zone at the end of a predetermined period of time;
(d) adding a basic neutralizing agent at a predetermined flow rate to the thus produced sulfonic acid and contacting the same under neutralizing conditions in a neutralization zone;
(e) withdrawing the thus produced sulfonated asphalt from said neutralization zone at the end of a predetermined period of time;
(f) separating said solvent from said sulfonated asphalt;
and
(g) drying the thus separated sulfonated asphalt as a product of the process;
(h) said rates of flow of said solvent, said asphaltic material, said sulfonating agent and said neutralizing agent and said periods of time prior to said withdrawal of said sulfonic acids and said said sulfonated asphalt being selected to maintain essentially continuous flow of said solvent, said asphaltic material, said sulfonating agent and said neutralizing agent.

6 more elements

Dependencies are inferred from the claim text.

Production of sulfonated asphalt

Life of this patent

Production of sulfonated asphalt

Life of this patent

Abstract

Claims21