Hydrochloric Acid

Molecular Structure

Molecular Details

Molecular Formula	HCl
Molecular Weight	36.46 g/mol
State	Gas (typically aqueous solution)

Olefinverbund Integration

Chemistry & Engineering

Reaction Equation	H₂ + Cl₂ → 2HCl
Thermodynamics	Highly exothermic combustion
Catalyst System	None (Burner)
Reactor Class	Graphite or brick-lined combustion chamber
Process Considerations	Often recovered as byproduct from chlorination reactions (e.g. isocyanates).

Extraterrestrial Production Pattern

1. Byproduct of chlor-alkali electrolysis
2. Reaction of NaCl + H₂SO₄ (Mannheim process)
3. Direct synthesis: H₂ + Cl₂ combustion
4. Absorption in water for aqueous HCl

Applications

• Metal pickling and cleaning
• pH control and neutralization
• PVC production (via VCM)
• Ore processing and extraction

Reaction Diagram

Overall Reaction: H2 + Cl2 -> 2HCl

Unit Operations

Process steps following chemical engineering unit operation principles:

Step	Operation	Description
1	H₂/Cl₂ Feed	Meter H₂ and Cl₂ to burner
2	Combustion	Burn H₂ + Cl₂ in graphite burner
3	Absorption	Absorb HCl gas in water (falling film)
4	Concentration	Absorb to 30-37% concentration
5	Cooling	Cool acid to storage temperature
6	Storage	Store in rubber-lined or plastic tanks

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 Hydrochloric Acid -->
<!-- Educational schema - simplified for demonstration -->
<BatchML xmlns="http://www.wbf.org/xml/B2MML-V0600">
  
  <ProcessCell ID="HCL_SYNTHESIS_CELL">
    <Description>Process cell for Hydrochloric Acid production</Description>
    
    <Unit ID="HCL_SYNTHESIS">
      <Description>Main synthesis unit</Description>
      
      <!-- Equipment Modules -->
      <EquipmentModule ID="FLOW_METERS">
        <Description>Flow Meters</Description>
      </EquipmentModule>
      <EquipmentModule ID="BURNER">
        <Description>Burner</Description>
      </EquipmentModule>
      <EquipmentModule ID="ABSORBER">
        <Description>Absorber</Description>
      </EquipmentModule>
      <EquipmentModule ID="COOLER">
        <Description>Cooler</Description>
      </EquipmentModule>
      <EquipmentModule ID="COOLER_2">
        <Description>Cooler 2</Description>
      </EquipmentModule>
      <EquipmentModule ID="STORAGE">
        <Description>Storage</Description>
      </EquipmentModule>
    </Unit>
  </ProcessCell>
  
  <MasterRecipe ID="HCL_SYNTHESIS_RECIPE">
    <Description>Master recipe for Hydrochloric Acid</Description>
    <ProductID>HYDROCHLORIC_ACID</ProductID>
    
    <UnitProcedure ID="HCL_SYNTHESIS_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="COMBUST">
          <Description>Combust 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="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_04">
        <Description>Operation 4</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>
      
      <Operation ID="OP_05">
        <Description>Operation 5</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_06">
        <Description>Operation 6</Description>
        <Phase ID="STORE">
          <Description>Store 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.