Method for reducing foam in a primary fractionator
AssigneeDorf Ketal Chemicals (India) Pvt. Ltd.
InventorsPerumangode Neelakantan Ramaswamy, Mahesh Subramaniyam
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Abstract
The present invention includes methods for improving the operational parameters in primary fractionators which are experiencing diminished operation efficiencies due to deposits of polymerized hydrocarbon species. The invention comprises the step of adding a foam reducing amount of a foam reducing composition at the primary fractionator. A reduction in foaming is achieved whereby the operational efficiency of the process is improved based upon operation parameters including, but not limited to, liquid-gas contact ratio, product top temperature, pressure differentials, gasoline end point or combinations thereof.
Claims24
A method to extend run-length of a primary fractionator in an ethylene plant by reducing fouling and froth/foam formation and by reducing its column pressure drop, comprising the steps of:
- (a) feeding cracked gas to the primary fractionator, wherein:
- (i) the primary fractionator is experiencing severe fouling in a rectification section thereof;
- (ii) wherein severe fouling is a result of very rapid deposition of one or more fouling compounds selected from the group consisting of polymers of styrene, indene, di-vinylbenzene, alpha-methylstyrene, indenes, naphthalene, higher ring compounds and combinations thereof;
- (iii) wherein the severe fouling has been caused not only on upper tray surfaces, but also beneath tray surfaces resulting in increased column pressure drop along with its diminished operational efficiencies;
- and
- (iv) wherein the severe fouling due to very rapid deposition of fouling species also results in increased and excessive froth/foam formation, which in-turn results in further and very rapid increase in column pressure drop and thereby further reduced fractional efficiencies of the column as indicated by at least one of liquid-gas contact ratio, feed rate, reflux rate, product top temperature, gasoline end point or pressure differential;
- wherein, the process is characterized by:
- (b) essentially adding, continuously or periodically, an antifoulant-antifoaming agent to the primary fractionator reflux in an amount effective to reduce the deposits of fouling compounds and to reduce the froth/foam formation in the rectification section of the primary fractionators by injecting antifoulant-antifoaming agent along with reflux stream, wherein:
- (i) the antifoulant-antifoaming agent is polysiloxane;
- and
- (ii) the addition of antifoulant-antifoaming agent in above manner results in reduction of fouling by reducing deposits of fouling compounds and in reduction of froth/foam formation, and in reduction of column pressure drop as observed by change of colour of gasoline from brownish colour to its normal yellowish green colour and by improved operational efficiencies as indicated by at least one of liquid-gas contact ratio, feed rate, reflux rate, product top temperature, gasoline end point or pressure differential;
- and thereby
- (iii) results in extension of the run-length of the primary fractionator.
A method to extend run-length of a primary fractionator in an ethylene plant by reducing fouling, comprising the steps of:
- (a) feeding cracked gas to the primary fractionator experiencing fouling, wherein the severe and continuous fouling and increased and excessive froth/foam formation result in very rapid increase in column pressure drop along with diminished operational efficiencies as indicated by at least one of liquid-gas contact ratio, feed rate, reflux rate, product top temperature, gasoline end point or pressure differential;
- wherein the process is characterized by:
- (b) essentially adding, continuously or periodically, an antifoulant-antifoaming agent to the primary fractionator reflux by injecting it along with reflux stream in an amount effective to reduce the deposits of fouling compounds in the rectification section of the primary fractionator, wherein:
- (i) the antifoulant-antifoaming agent is polysiloxane;
- and
- (ii) the addition of antifoulant-antifoaming agent in above manner results in reduction of fouling as observed by reduced column pressure drop and improved operational efficiencies;
- and thereby
- (iii) results in extended run-length of the primary fractionator.
A method of using an antifoulant-antifoaming agent in extending run-length of a primary fractionator in an ethylene plant by reducing fouling and froth/foam formation and by reducing column pressure drop therein, wherein the antifouling-antifoaming agent is added in a process comprising the steps of:
- (a) feeding cracked gas to the primary fractionator, wherein:
- (i) the primary fractionator is experiencing severe fouling in a rectification section thereof;
- (ii) wherein severe fouling is a result of very rapid deposition of one or more fouling compounds selected from the group consisting of polymers of styrene, indene, di-vinylbenzene, alpha-methylstyrene, indenes, naphthalene, higher ring compounds and combinations thereof;
- and
- (iii) wherein the severe fouling has been caused not only on upper tray surfaces, but also beneath tray surfaces resulting in increased column pressure drop along with its diminished operational efficiencies;
- (iv) wherein the severe fouling due to very rapid deposition of fouling species also results in increased and excessive froth/foam formation, which in-turn results in further and very rapid increase in column pressure drop and thereby further reduced fractional efficiencies of the column as indicated by at least one of liquid-gas contact ratio, feed rate, reflux rate, product top temperature, gasoline end point or pressure differential;
- characterized by:
- (b) essentially adding, continuously or periodically, an antifoulant-antifoaming agent to the primary fractionator reflux in an amount effective to reduce the deposits of fouling compounds and to reduce the froth/foam formation in the rectification section of the primary fractionator by injecting antifoulant-antifoaming agent along with reflux stream, wherein:
- (i) the antifoulant-antifoaming agent is polysiloxane;
- and
- (ii) the addition of antifoulant-antifoaming agent in above manner results in reduction of fouling and froth/foam formation, and column pressure drop as observed by change of colour of gasoline from brownish colour to its normal yellowish green colour and by improved operational efficiencies as indicated by at least one of liquid-gas contact ratio, feed rate, reflux rate, product top temperature, gasoline end point or pressure differential;
- and thereby
- (iii) results in extension of the run-length of the primary fractionator.
Dependencies are inferred from the claim text.