A comparison between the sulfate and sulfite pulping processes reveals that ______________ occurs in the latter ?
Show answer Hide answer
Answer: B. Both temperature & pressure in the former is more than that
Explanation
Sulfate pulping requires harsher chemical conditions to dissolve stubborn lignin bonding in wood chips. Consequently, sulfate digesters operate at significantly higher temperatures and pressures than sulfite digesters. These intense operating conditions allow the kraft process to break down almost any wood species efficiently. Pulping processes separate wood fibers by dissolving lignin using chemical cooking liquors in digester vessels. The sulfate process uses sodium hydroxide and sodium sulfide, whereas sulfite uses acid sulfite solutions. High temperatures and pressures accelerate the chemical delignification reactions inside commercial digesters.
Paper mills choose sulfate pulping when manufacturing high strength packaging papers and brown paper bags. Engineers design heavy pressure vessels to withstand the severe operating conditions of kraft digesters. Comparing pulping technologies helps paper manufacturers optimize chemical recovery and product strength. Reversing the comparison to claim the former has lower conditions contradicts actual chemical engineering data. Claiming temperature is higher while pressure is lower contradicts the coupled nature of digester conditions. Stating pressure is higher while temperature is lower is incorrect because both parameters are elevated.
- Subject
- Engineering
- Category
- Chemical Engineering
- Topic
- —
- Difficulty
- medium
Related questions
Q1. Vanaspati is produced on a commercial scale through the _______________ of edible vegetable oils ?
Show answer Hide answer
Answer: A. Hydrogenation
Hydrogenation adds hydrogen gas across unsaturated double bonds in liquid vegetable oil molecules. This chemical reaction saturates the fatty acid chains, raising their melting points significantly. Commercial processing...
Q2. Common salt is generally not extracted from brine via the ________________ method ?
Show answer Hide answer
Answer: A. Freeze drying
Freeze drying removes water through sublimation under vacuum, which is energetically impractical for bulk salt. Extracting sodium chloride from brine requires evaporating massive volumes of water economically. Freeze dry...
Q3. Coke oven gas is predominantly composed of ____________________?
Show answer Hide answer
Answer: A. H2, & CH4
Coke oven gas is generated by the destructive distillation of bituminous coal inside heated ovens. Hydrogen and methane gases comprise the vast majority of the combustible volume in coke oven gas. These light gases provi...
Q4. Hydrogen peroxide is concentrated by employing_____________________?
Show answer Hide answer
Answer: B. Vacuum crystallisation
Hydrogen peroxide solutions are concentrated using vacuum distillation or crystallization techniques to prevent thermal decomposition.
Q5. Diaphragm electrolytic cells produce a sodium hydroxide solution with a concentration of roughly _______________ percent?
Show answer Hide answer
Answer: A. 10
Diaphragm cells allow water and ions to pass through a porous barrier alongside the product solution. This bulk flow dilutes the resulting sodium hydroxide, keeping concentration levels at approximately ten percent. Evap...
Q6. Sulfide ores are typically concentrated through the method of____________________?
Show answer Hide answer
Answer: C. Froth floatation
Hydrophobic sulfide ore particles attach selectively to rising air bubbles in an agitated aqueous slurry. The rising froth carries the concentrated mineral particles to the surface for skimming and collection. This prefe...