By-product utilization in integrated steel plants: which fertilizer is commonly manufactured in the by-products (coke ovens) plant using ammoniacal liquor from coke oven gas?

Introduction / Context:
Integrated steel plants generate coke oven gas (COG) containing ammonia, among other components. Recovering ammonia from COG and converting it into marketable fertilizer improves resource efficiency and reduces emissions. The question asks which fertilizer is typically produced from this by-product stream.

Given Data / Assumptions:

• Coke oven gas contains ammoniacal liquor (NH3 dissolved in water).
• By-product plants scrub and recover ammonia.
• On-site neutralization options exist for fertilizer manufacture.

Concept / Approach:
The recovered ammonia is commonly neutralized with sulfuric acid to form ammonium sulfate crystals. The process is well-established at steelworks due to available sulfuric acid logistics and straightforward crystallization. Urea and CAN require different feedstocks and process trains; phosphate fertilizers are not made directly from COG ammonia without separate phosphoric acid routes.

Step-by-Step Solution:

Verification / Alternative check:
Process descriptions of steel by-product plants consistently list ammonium sulfate production via ammonia recovery and sulfuric acid neutralization.

Why Other Options Are Wrong:

• Urea: requires CO2 and NH3 synthesis loop; not a direct COG by-product route.
• CAN: made by mixing ammonium nitrate with limestone; not typical to COG.
• SSP/TSP: phosphate fertilizers requiring phosphate rock and acids; unrelated to COG ammonia alone.

Common Pitfalls:
Assuming all nitrogen fertilizers can be made from any ammonia source without considering the specific process chains.

Final Answer:
Ammonium sulfate ((NH4)2SO4).