Fertiliser, Chlor-alkali & Commodity Chemicals interview questions

1. A.carbonation of ammoniated brine to precipitate sodium bicarbonate, calcined to Na2CO3, with ammonia recovered by lime and calcium chloride as by-product
2. B.prilling sprays urea melt down a tower to form small prills; fluidised-bed granulation gives larger, harder granules preferred for bulk blending
3. C.pipe reactor or pre-neutraliser reacting phosphoric acid with ammonia to an 18-46-0 product with the N:P mole ratio held near 1.8–2.0
4. D.iron-catalysed reaction of syngas at 150–250 bar and 400–500 °C with about 15% single-pass conversion, chilling to condense product and recycling unreacted gas

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1. A.Prilling vs granulation
2. B.Double contact double absorption
3. C.Solvay soda ash
4. D.Ammonia synthesis loop

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1. A.Ammonia synthesis loop — carbonation of ammoniated brine to precipitate sodium bicarbonate, calcined to Na2CO3, with ammonia recovered by lime and calcium chloride as by-product
2. B.Ammonia synthesis loop — iron-catalysed reaction of syngas at 150–250 bar and 400–500 °C with about 15% single-pass conversion, chilling to condense product and recycling unreacted gas
3. C.Ammonia synthesis loop — pipe reactor or pre-neutraliser reacting phosphoric acid with ammonia to an 18-46-0 product with the N:P mole ratio held near 1.8–2.0
4. D.Ammonia synthesis loop — prilling sprays urea melt down a tower to form small prills; fluidised-bed granulation gives larger, harder granules preferred for bulk blending

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1. A.sulphuric acid process converting SO2 in two catalyst stages with intermediate absorption, reaching about 99.7% conversion and low stack SO2
2. B.chlor-alkali electrolyser with a perfluorinated cation-exchange membrane at about 3 V giving 32% NaOH, chlorine and hydrogen with lower energy than diaphragm cells
3. C.pipe reactor or pre-neutraliser reacting phosphoric acid with ammonia to an 18-46-0 product with the N:P mole ratio held near 1.8–2.0
4. D.CO2 or ammonia stripping (Stamicarbon or Snamprogetti) decomposes carbamate at synthesis pressure so recycle needs no gas compression

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1. A.Urea stripping process
2. B.Ammonia synthesis loop
3. C.DAP granulation
4. D.Chlorine handling

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1. A.Urea stripping process — CO2 or ammonia stripping (Stamicarbon or Snamprogetti) decomposes carbamate at synthesis pressure so recycle needs no gas compression
2. B.Urea stripping process — prilling sprays urea melt down a tower to form small prills; fluidised-bed granulation gives larger, harder granules preferred for bulk blending
3. C.Urea stripping process — iron-catalysed reaction of syngas at 150–250 bar and 400–500 °C with about 15% single-pass conversion, chilling to condense product and recycling unreacted gas
4. D.Urea stripping process — modern plant consumes about 7–8 Gcal per tonne, with reforming, CO2 removal and synthesis-gas compression the main energy sinks

Answer + AI explanation with Pro

1. A.prilling sprays urea melt down a tower to form small prills; fluidised-bed granulation gives larger, harder granules preferred for bulk blending
2. B.CO2 or ammonia stripping (Stamicarbon or Snamprogetti) decomposes carbamate at synthesis pressure so recycle needs no gas compression
3. C.liquefaction and storage under PESO-licensed pressure vessels and tonners, with caustic scrubbers for tail gas and detectors alarming near 1 ppm
4. D.iron-catalysed reaction of syngas at 150–250 bar and 400–500 °C with about 15% single-pass conversion, chilling to condense product and recycling unreacted gas

Answer + AI explanation with Pro

1. A.Prilling vs granulation
2. B.Solvay soda ash
3. C.Double contact double absorption
4. D.Ammonia synthesis loop

Answer + AI explanation with Pro

1. A.Prilling vs granulation — iron-catalysed reaction of syngas at 150–250 bar and 400–500 °C with about 15% single-pass conversion, chilling to condense product and recycling unreacted gas
2. B.Prilling vs granulation — chlor-alkali electrolyser with a perfluorinated cation-exchange membrane at about 3 V giving 32% NaOH, chlorine and hydrogen with lower energy than diaphragm cells
3. C.Prilling vs granulation — carbonation of ammoniated brine to precipitate sodium bicarbonate, calcined to Na2CO3, with ammonia recovered by lime and calcium chloride as by-product
4. D.Prilling vs granulation — prilling sprays urea melt down a tower to form small prills; fluidised-bed granulation gives larger, harder granules preferred for bulk blending

Answer + AI explanation with Pro

1. A.carbonation of ammoniated brine to precipitate sodium bicarbonate, calcined to Na2CO3, with ammonia recovered by lime and calcium chloride as by-product
2. B.modern plant consumes about 7–8 Gcal per tonne, with reforming, CO2 removal and synthesis-gas compression the main energy sinks
3. C.chlor-alkali electrolyser with a perfluorinated cation-exchange membrane at about 3 V giving 32% NaOH, chlorine and hydrogen with lower energy than diaphragm cells
4. D.CO2 or ammonia stripping (Stamicarbon or Snamprogetti) decomposes carbamate at synthesis pressure so recycle needs no gas compression

Answer + AI explanation with Pro

1. A.Urea stripping process
2. B.Chlorine handling
3. C.Double contact double absorption
4. D.Membrane cell

Answer + AI explanation with Pro

1. A.Membrane cell — prilling sprays urea melt down a tower to form small prills; fluidised-bed granulation gives larger, harder granules preferred for bulk blending
2. B.Membrane cell — modern plant consumes about 7–8 Gcal per tonne, with reforming, CO2 removal and synthesis-gas compression the main energy sinks
3. C.Membrane cell — carbonation of ammoniated brine to precipitate sodium bicarbonate, calcined to Na2CO3, with ammonia recovered by lime and calcium chloride as by-product
4. D.Membrane cell — chlor-alkali electrolyser with a perfluorinated cation-exchange membrane at about 3 V giving 32% NaOH, chlorine and hydrogen with lower energy than diaphragm cells

Answer + AI explanation with Pro

1. A.iron-catalysed reaction of syngas at 150–250 bar and 400–500 °C with about 15% single-pass conversion, chilling to condense product and recycling unreacted gas
2. B.sulphuric acid process converting SO2 in two catalyst stages with intermediate absorption, reaching about 99.7% conversion and low stack SO2
3. C.modern plant consumes about 7–8 Gcal per tonne, with reforming, CO2 removal and synthesis-gas compression the main energy sinks
4. D.pipe reactor or pre-neutraliser reacting phosphoric acid with ammonia to an 18-46-0 product with the N:P mole ratio held near 1.8–2.0

Answer + AI explanation with Pro

1. A.Double contact double absorption
2. B.Prilling vs granulation
3. C.DAP granulation
4. D.Membrane cell

Answer + AI explanation with Pro

1. A.Double contact double absorption — pipe reactor or pre-neutraliser reacting phosphoric acid with ammonia to an 18-46-0 product with the N:P mole ratio held near 1.8–2.0
2. B.Double contact double absorption — sulphuric acid process converting SO2 in two catalyst stages with intermediate absorption, reaching about 99.7% conversion and low stack SO2
3. C.Double contact double absorption — CO2 or ammonia stripping (Stamicarbon or Snamprogetti) decomposes carbamate at synthesis pressure so recycle needs no gas compression
4. D.Double contact double absorption — prilling sprays urea melt down a tower to form small prills; fluidised-bed granulation gives larger, harder granules preferred for bulk blending

Answer + AI explanation with Pro

1. A.pipe reactor or pre-neutraliser reacting phosphoric acid with ammonia to an 18-46-0 product with the N:P mole ratio held near 1.8–2.0
2. B.sulphuric acid process converting SO2 in two catalyst stages with intermediate absorption, reaching about 99.7% conversion and low stack SO2
3. C.iron-catalysed reaction of syngas at 150–250 bar and 400–500 °C with about 15% single-pass conversion, chilling to condense product and recycling unreacted gas
4. D.modern plant consumes about 7–8 Gcal per tonne, with reforming, CO2 removal and synthesis-gas compression the main energy sinks

Answer + AI explanation with Pro

1. A.Ammonia synthesis loop
2. B.DAP granulation
3. C.Urea stripping process
4. D.Prilling vs granulation

Answer + AI explanation with Pro

1. A.DAP granulation — chlor-alkali electrolyser with a perfluorinated cation-exchange membrane at about 3 V giving 32% NaOH, chlorine and hydrogen with lower energy than diaphragm cells
2. B.DAP granulation — liquefaction and storage under PESO-licensed pressure vessels and tonners, with caustic scrubbers for tail gas and detectors alarming near 1 ppm
3. C.DAP granulation — CO2 or ammonia stripping (Stamicarbon or Snamprogetti) decomposes carbamate at synthesis pressure so recycle needs no gas compression
4. D.DAP granulation — pipe reactor or pre-neutraliser reacting phosphoric acid with ammonia to an 18-46-0 product with the N:P mole ratio held near 1.8–2.0

Answer + AI explanation with Pro

1. A.modern plant consumes about 7–8 Gcal per tonne, with reforming, CO2 removal and synthesis-gas compression the main energy sinks
2. B.prilling sprays urea melt down a tower to form small prills; fluidised-bed granulation gives larger, harder granules preferred for bulk blending
3. C.carbonation of ammoniated brine to precipitate sodium bicarbonate, calcined to Na2CO3, with ammonia recovered by lime and calcium chloride as by-product
4. D.pipe reactor or pre-neutraliser reacting phosphoric acid with ammonia to an 18-46-0 product with the N:P mole ratio held near 1.8–2.0

Answer + AI explanation with Pro

1. A.Double contact double absorption
2. B.Urea stripping process
3. C.Prilling vs granulation
4. D.Solvay soda ash

Answer + AI explanation with Pro

1. A.Solvay soda ash — CO2 or ammonia stripping (Stamicarbon or Snamprogetti) decomposes carbamate at synthesis pressure so recycle needs no gas compression
2. B.Solvay soda ash — carbonation of ammoniated brine to precipitate sodium bicarbonate, calcined to Na2CO3, with ammonia recovered by lime and calcium chloride as by-product
3. C.Solvay soda ash — chlor-alkali electrolyser with a perfluorinated cation-exchange membrane at about 3 V giving 32% NaOH, chlorine and hydrogen with lower energy than diaphragm cells
4. D.Solvay soda ash — iron-catalysed reaction of syngas at 150–250 bar and 400–500 °C with about 15% single-pass conversion, chilling to condense product and recycling unreacted gas

Answer + AI explanation with Pro

1. A.chlor-alkali electrolyser with a perfluorinated cation-exchange membrane at about 3 V giving 32% NaOH, chlorine and hydrogen with lower energy than diaphragm cells
2. B.modern plant consumes about 7–8 Gcal per tonne, with reforming, CO2 removal and synthesis-gas compression the main energy sinks
3. C.iron-catalysed reaction of syngas at 150–250 bar and 400–500 °C with about 15% single-pass conversion, chilling to condense product and recycling unreacted gas
4. D.pipe reactor or pre-neutraliser reacting phosphoric acid with ammonia to an 18-46-0 product with the N:P mole ratio held near 1.8–2.0

Answer + AI explanation with Pro

1. A.Ammonia plant energy
2. B.Urea stripping process
3. C.Double contact double absorption
4. D.Solvay soda ash

Answer + AI explanation with Pro

1. A.Ammonia plant energy — carbonation of ammoniated brine to precipitate sodium bicarbonate, calcined to Na2CO3, with ammonia recovered by lime and calcium chloride as by-product
2. B.Ammonia plant energy — CO2 or ammonia stripping (Stamicarbon or Snamprogetti) decomposes carbamate at synthesis pressure so recycle needs no gas compression
3. C.Ammonia plant energy — liquefaction and storage under PESO-licensed pressure vessels and tonners, with caustic scrubbers for tail gas and detectors alarming near 1 ppm
4. D.Ammonia plant energy — modern plant consumes about 7–8 Gcal per tonne, with reforming, CO2 removal and synthesis-gas compression the main energy sinks

Answer + AI explanation with Pro

1. A.liquefaction and storage under PESO-licensed pressure vessels and tonners, with caustic scrubbers for tail gas and detectors alarming near 1 ppm
2. B.modern plant consumes about 7–8 Gcal per tonne, with reforming, CO2 removal and synthesis-gas compression the main energy sinks
3. C.pipe reactor or pre-neutraliser reacting phosphoric acid with ammonia to an 18-46-0 product with the N:P mole ratio held near 1.8–2.0
4. D.carbonation of ammoniated brine to precipitate sodium bicarbonate, calcined to Na2CO3, with ammonia recovered by lime and calcium chloride as by-product

Answer + AI explanation with Pro

1. A.Ammonia plant energy
2. B.Chlorine handling
3. C.Solvay soda ash
4. D.Ammonia synthesis loop

Answer + AI explanation with Pro

1. A.Chlorine handling — prilling sprays urea melt down a tower to form small prills; fluidised-bed granulation gives larger, harder granules preferred for bulk blending
2. B.Chlorine handling — carbonation of ammoniated brine to precipitate sodium bicarbonate, calcined to Na2CO3, with ammonia recovered by lime and calcium chloride as by-product
3. C.Chlorine handling — liquefaction and storage under PESO-licensed pressure vessels and tonners, with caustic scrubbers for tail gas and detectors alarming near 1 ppm
4. D.Chlorine handling — iron-catalysed reaction of syngas at 150–250 bar and 400–500 °C with about 15% single-pass conversion, chilling to condense product and recycling unreacted gas

Answer + AI explanation with Pro