Phosphoric Acid

Molecular Structure

Molecular Details

Molecular Formula	H₃PO₄
Molecular Weight	98.00 g/mol
State	Liquid (concentrated) or solid

Olefinverbund Integration

Chemistry & Engineering

Reaction Equation	Ca₅(PO₄)₃F + 5H₂SO₄ → 3H₃PO₄ + 5CaSO₄ + HF
Thermodynamics	Exothermic acidulation
Catalyst System	None
Reactor Class	Digester tanks (Wet Process)
Process Considerations	Gypsum (CaSO₄) byproduct is massive; HF must be captured.

Extraterrestrial Production Pattern

1. Wet process: phosphate rock + sulfuric acid
2. Filtration to remove calcium sulfate (gypsum)
3. Concentration by evaporation
4. Thermal process: P₄ combustion + hydration for pure acid

Applications

• Phosphate fertilizers (DAP, MAP, TSP)
• Food and beverage acidulant
• Metal surface treatment
• Semiconductor etching

Reaction Diagram

Overall Reaction: Ca3(PO4)2 + 3H2SO4 -> 2H3PO4 + 3CaSO4

Unit Operations

Process steps following chemical engineering unit operation principles:

Step	Operation	Description
1	Phosphate Rock Prep	Grind phosphate rock to 100 mesh
2	Digestion	React with H₂SO₄ at 70-80°C
3	Filtration	Filter gypsum (CaSO₄) on belt/tilting pan
4	Concentration	Multi-stage evaporation to 52-54% P₂O₅
5	Clarification	Settle/filter to remove sludge
6	Storage	Store in rubber-lined 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 Phosphoric Acid -->
<!-- Educational schema - simplified for demonstration -->
<BatchML xmlns="http://www.wbf.org/xml/B2MML-V0600">
  
  <ProcessCell ID="WET_PHOSPHORIC_ACID_CELL">
    <Description>Process cell for Phosphoric Acid production</Description>
    
    <Unit ID="WET_PHOSPHORIC_ACID">
      <Description>Main synthesis unit</Description>
      
      <!-- Equipment Modules -->
      <EquipmentModule ID="MILL">
        <Description>Mill</Description>
      </EquipmentModule>
      <EquipmentModule ID="DIGESTER">
        <Description>Digester</Description>
      </EquipmentModule>
      <EquipmentModule ID="BELT_FILTER">
        <Description>Belt Filter</Description>
      </EquipmentModule>
      <EquipmentModule ID="EVAPORATORS">
        <Description>Evaporators</Description>
      </EquipmentModule>
      <EquipmentModule ID="CLARIFIER">
        <Description>Clarifier</Description>
      </EquipmentModule>
      <EquipmentModule ID="STORAGE">
        <Description>Storage</Description>
      </EquipmentModule>
    </Unit>
  </ProcessCell>
  
  <MasterRecipe ID="WET_PHOSPHORIC_ACID_RECIPE">
    <Description>Master recipe for Phosphoric Acid</Description>
    <ProductID>PHOSPHORIC_ACID</ProductID>
    
    <UnitProcedure ID="WET_PHOSPHORIC_ACID_UP">
      <Description>Unit procedure for synthesis</Description>
      
      <Operation ID="OP_01">
        <Description>Operation 1</Description>
        <Phase ID="PREP_ROCK">
          <Description>Prep Rock 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="DIGEST">
          <Description>Digest 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="FILTER">
          <Description>Filter 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="EVAPORATE">
          <Description>Evaporate 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="CLARIFY">
          <Description>Clarify 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.