Adipic Acid

HOOC(CH₂)₄COOH

Monomer for nylon 6,6 and polyurethanes

Molecular Structure

Adipic Acid molecular structure
2D structure of Adipic Acid

Molecular Details

Molecular FormulaHOOC(CH₂)₄COOH
Molecular Weight146.14 g/mol
StateSolid at standard conditions

Olefinverbund Integration

⬅️ Inputs (Starting Materials): Cyclohexanone, Cyclohexanol, Nitric Acid

➡️ Outputs (Products): Nylon 6,6

Chemistry & Engineering

Reaction EquationKA Oil + HNO₃ → Adipic Acid + NOx
ThermodynamicsStrongly exothermic oxidation
Catalyst SystemCopper/Vanadium
Reactor ClassStirred tank oxidation reactors
Process ConsiderationsProduces N₂O (greenhouse gas) which must be abated or recycled.

Extraterrestrial Production Pattern

  1. Cyclohexane oxidation → KA oil (cyclohexanol/cyclohexanone)
  2. Nitric acid oxidation of KA oil → adipic acid
  3. Operating at 60-80°C with Cu-V catalyst
  4. Crystallization and purification

Applications

  • Nylon 6,6 production
  • Polyurethane polyols
  • Plasticizers
  • Food acidulant (E355)

Reaction Diagram

Reaction diagram
Synthesis reaction pathway

Overall Reaction: C6H10O + HNO3 -> HOOC(CH2)4COOH + NO + H2O

Unit Operations

Process steps following chemical engineering unit operation principles:

StepOperationDescription
1Cyclohexanone FeedPump cyclohexanone to oxidation reactor
2Nitric Acid OxidationOxidize with 50-60% HNO₃ at 60-80°C
3NOx RecoveryAbsorb and recover NOx for nitric acid
4CrystallizationCrystallize adipic acid from solution
5CentrifugationSeparate crystals from mother liquor
6DryingDry crystals to <0.1% moisture

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 Adipic Acid -->
<!-- Educational schema - simplified for demonstration -->
<BatchML xmlns="http://www.wbf.org/xml/B2MML-V0600">
  
  <ProcessCell ID="ADIPIC_ACID_PLANT_CELL">
    <Description>Process cell for Adipic Acid production</Description>
    
    <Unit ID="ADIPIC_ACID_PLANT">
      <Description>Main synthesis unit</Description>
      
      <!-- Equipment Modules -->
      <EquipmentModule ID="PUMP">
        <Description>Pump</Description>
      </EquipmentModule>
      <EquipmentModule ID="OXIDIZER">
        <Description>Oxidizer</Description>
      </EquipmentModule>
      <EquipmentModule ID="NOX_ABSORBER">
        <Description>Nox Absorber</Description>
      </EquipmentModule>
      <EquipmentModule ID="CRYSTALLIZER">
        <Description>Crystallizer</Description>
      </EquipmentModule>
      <EquipmentModule ID="CENTRIFUGE">
        <Description>Centrifuge</Description>
      </EquipmentModule>
      <EquipmentModule ID="DRYER">
        <Description>Dryer</Description>
      </EquipmentModule>
    </Unit>
  </ProcessCell>
  
  <MasterRecipe ID="ADIPIC_ACID_PLANT_RECIPE">
    <Description>Master recipe for Adipic Acid</Description>
    <ProductID>ADIPIC_ACID</ProductID>
    
    <UnitProcedure ID="ADIPIC_ACID_PLANT_UP">
      <Description>Unit procedure for synthesis</Description>
      
      <Operation ID="OP_01">
        <Description>Operation 1</Description>
        <Phase ID="FEED">
          <Description>Feed 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">
          <Description>Oxidize 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="RECOVER_NOX">
          <Description>Recover Nox 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="CRYSTALLIZE">
          <Description>Crystallize 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="CENTRIFUGE">
          <Description>Centrifuge 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="DRY">
          <Description>Dry 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.)


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