Nitric Acid

Molecular Structure

Molecular Details

Molecular Formula	HNO₃
Molecular Weight	63.01 g/mol
State	Liquid at standard conditions

Olefinverbund Integration

Chemistry & Engineering

Reaction Equation	NH₃ + O₂ → NO; NO + O₂ → NO₂; NO₂ + H₂O → HNO₃
Thermodynamics	Exothermic oxidation
Catalyst System	Platinum-Rhodium gauze
Reactor Class	Burner at 900°C followed by absorption columns
Process Considerations	Ostwald process. Noble metal catalyst loss is a key operating cost.

Extraterrestrial Production Pattern

1. Ammonia oxidation over Pt-Rh gauze catalyst at 850-950°C
2. Cooling and oxidation of NO to NO₂
3. Absorption in water to form nitric acid
4. Concentration by distillation or extractive methods

Applications

• Ammonium nitrate fertilizer
• Explosives manufacturing
• Metal etching and pickling
• Nitration reactions for organics

Reaction Diagram

Overall Reaction: 4NH3 + 5O2 -> 4NO + 6H2O; 2NO + O2 -> 2NO2; 3NO2 + H2O -> 2HNO3 + NO

Unit Operations

Process steps following chemical engineering unit operation principles:

Step	Operation	Description
1	Ammonia/Air Mixing	Mix NH₃ with filtered air (10-12% NH₃)
2	Catalytic Oxidation	Pt-Rh gauze at 850-950°C, 1-10 bar
3	Gas Cooling	Cool NO gas and oxidize to NO₂
4	Absorption	Absorb NO₂ in water in absorption tower
5	Tail Gas Treatment	Catalytic reduction of residual NOx
6	Concentration	Concentrate to 60-68% HNO₃ by distillation

S88 Batch Control Model

This module follows the ISA-88 (S88) batch control standard. Below is a simplified BatchML schema for educational purposes:

<?xml version="1.0" encoding="UTF-8"?>
<!-- ISA-88 Batch Control Model for Nitric Acid -->
<!-- Educational schema - simplified for demonstration -->
<BatchML xmlns="http://www.wbf.org/xml/B2MML-V0600">
  
  <ProcessCell ID="NITRIC_ACID_PLANT_CELL">
    <Description>Process cell for Nitric Acid production</Description>
    
    <Unit ID="NITRIC_ACID_PLANT">
      <Description>Main synthesis unit</Description>
      
      <!-- Equipment Modules -->
      <EquipmentModule ID="MIXER">
        <Description>Mixer</Description>
      </EquipmentModule>
      <EquipmentModule ID="BURNER">
        <Description>Burner</Description>
      </EquipmentModule>
      <EquipmentModule ID="COOLER">
        <Description>Cooler</Description>
      </EquipmentModule>
      <EquipmentModule ID="ABSORBER">
        <Description>Absorber</Description>
      </EquipmentModule>
      <EquipmentModule ID="SCR_REACTOR">
        <Description>Scr Reactor</Description>
      </EquipmentModule>
      <EquipmentModule ID="CONCENTRATOR">
        <Description>Concentrator</Description>
      </EquipmentModule>
    </Unit>
  </ProcessCell>
  
  <MasterRecipe ID="NITRIC_ACID_PLANT_RECIPE">
    <Description>Master recipe for Nitric Acid</Description>
    <ProductID>NITRIC_ACID</ProductID>
    
    <UnitProcedure ID="NITRIC_ACID_PLANT_UP">
      <Description>Unit procedure for synthesis</Description>
      
      <Operation ID="OP_01">
        <Description>Operation 1</Description>
        <Phase ID="MIX">
          <Description>Mix phase</Description>
          <PhaseLogic>
            <Step ID="STEP_1"><Action>Initialize</Action></Step>
            <Step ID="STEP_2"><Action>Execute</Action></Step>
            <Step ID="STEP_3"><Action>Complete</Action></Step>
          </PhaseLogic>
        </Phase>
      </Operation>
      
      <Operation ID="OP_02">
        <Description>Operation 2</Description>
        <Phase ID="OXIDIZE_NH3">
          <Description>Oxidize Nh3 phase</Description>
          <PhaseLogic>
            <Step ID="STEP_1"><Action>Initialize</Action></Step>
            <Step ID="STEP_2"><Action>Execute</Action></Step>
            <Step ID="STEP_3"><Action>Complete</Action></Step>
          </PhaseLogic>
        </Phase>
      </Operation>
      
      <Operation ID="OP_03">
        <Description>Operation 3</Description>
        <Phase ID="COOL">
          <Description>Cool phase</Description>
          <PhaseLogic>
            <Step ID="STEP_1"><Action>Initialize</Action></Step>
            <Step ID="STEP_2"><Action>Execute</Action></Step>
            <Step ID="STEP_3"><Action>Complete</Action></Step>
          </PhaseLogic>
        </Phase>
      </Operation>
      
      <Operation ID="OP_04">
        <Description>Operation 4</Description>
        <Phase ID="ABSORB">
          <Description>Absorb phase</Description>
          <PhaseLogic>
            <Step ID="STEP_1"><Action>Initialize</Action></Step>
            <Step ID="STEP_2"><Action>Execute</Action></Step>
            <Step ID="STEP_3"><Action>Complete</Action></Step>
          </PhaseLogic>
        </Phase>
      </Operation>
      
      <Operation ID="OP_05">
        <Description>Operation 5</Description>
        <Phase ID="TREAT_TAILGAS">
          <Description>Treat Tailgas phase</Description>
          <PhaseLogic>
            <Step ID="STEP_1"><Action>Initialize</Action></Step>
            <Step ID="STEP_2"><Action>Execute</Action></Step>
            <Step ID="STEP_3"><Action>Complete</Action></Step>
          </PhaseLogic>
        </Phase>
      </Operation>
      
      <Operation ID="OP_06">
        <Description>Operation 6</Description>
        <Phase ID="CONCENTRATE">
          <Description>Concentrate phase</Description>
          <PhaseLogic>
            <Step ID="STEP_1"><Action>Initialize</Action></Step>
            <Step ID="STEP_2"><Action>Execute</Action></Step>
            <Step ID="STEP_3"><Action>Complete</Action></Step>
          </PhaseLogic>
        </Phase>
      </Operation>
    </UnitProcedure>
  </MasterRecipe>
  
</BatchML>

**Key S88 Concepts:**
- **Process Cell**: The physical grouping containing all equipment for this process
- **Unit**: The major equipment that performs the synthesis
- **Equipment Modules**: Individual pieces of equipment (reactors, columns, etc.)
- **Unit Procedure**: The sequence of operations to produce the product
- **Phases**: The lowest level of procedural control (e.g., REACT, SEPARATE, PURIFY)

Key S88 Concepts:
• Process Cell: Physical grouping containing all equipment
• Unit: Major equipment performing synthesis
• Equipment Modules: Individual pieces (reactors, columns, etc.)
• Phases: Lowest level of procedural control (REACT, SEPARATE, etc.)

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This Synthesis Module is part of the 100chemicals Olefinverbund — an integrated chemical production network designed for extraterrestrial civilization on Moon and Mars.