Steam reforming of naphtha:\nWhat is the typical optimum reaction temperature range (°C) used in primary reformers?

Introduction / Context:
Steam reforming converts hydrocarbons (e.g., naphtha) into synthesis gas (H2, CO, CO2). The endothermic reforming reactions require high temperature to achieve practical equilibrium conversion and catalyst activity. This question asks for the customary temperature range employed in industrial primary reformers processing naphtha.

Given Data / Assumptions:

• Feed: light hydrocarbon/naphtha with steam.
• Catalyst: Ni-based reforming catalyst.
• Tubular fired furnace providing heat to reach outlet temperatures in the upper range.

Concept / Approach:
Industrial practice targets outlet temperatures roughly 780–900 °C, with furnace bridgewall temperatures higher to drive heat into tubes. The broader standard range cited in textbooks for reforming operation envelopes is approximately 700–1000 °C, encompassing inlet-to-outlet conditions and different feed severities. Lower ranges (300–450 °C) suit shift or methanation; extremely high ranges (1500–1700 °C) are for processes like partial oxidation flames, not catalytic reforming.

Step-by-Step Solution:

Verification / Alternative check:
Design manuals and licensor data show reformer outlet temperatures near 800–900 °C for naphtha feeds, confirming the chosen range.

Why Other Options Are Wrong:

• 300–450 °C, 100–200 °C, 450–550 °C: far too low for reforming; these correspond to other unit operations.
• 1500–1700 °C: flame temperatures of partial oxidation, not tubular catalytic reforming.

Common Pitfalls:
Confusing reforming with secondary reforming or POX; mixing up bed outlet temperature with furnace wall temperature.

Final Answer:
700 – 1000 °C