Prompt injection in caprolactam nylon-6 production AI

Four adversarial injection surfaces in caprolactam production AI

1. Beckmann rearrangement reactor temperature display AI (DSM Fibrant Beckmann reactor AI, AdvanSix rearrangement APC AI, BASF SE Beckmann process AI — rendered DCS reactor temperature trend display AI classifying Beckmann rearrangement exothermic temperature against runaway-onset and side-reaction setpoints)

The Beckmann rearrangement of cyclohexanone oxime to caprolactam is conducted by adding cyclohexanone oxime to oleum (fuming sulfuric acid) at controlled temperature: the cyclohexanone oxime dissolves in the oleum and undergoes acid-catalysed rearrangement to caprolactam sulfate (C₆H₁₁NO·H₂SO₄). The reaction is highly exothermic (approximately −80 to −120 kJ/mol) and proceeds rapidly above 80°C. Commercial rearrangement reactors operate at 80–120°C with external cooling jackets to remove the reaction exotherm; the reactor temperature is maintained in the 90–110°C range for optimal caprolactam selectivity. Above 120–130°C, the selectivity falls as side reactions accelerate: caprolactam hydrolysis to ε-aminocaproic acid (oligomer precursor), oligomerisation, and the reverse Beckmann fragmentation reaction producing hexanedinitrile and other by-products; these side reactions are also exothermic, contributing additional heat that compounds the primary reaction exotherm and drives the reactor temperature toward a runaway. AI systems process rendered DCS reactor temperature trend display images — thermocouple readings from the Beckmann rearrangement reactor internal temperature — to classify reactor thermal state: within normal operating range (90–115°C), approaching high-temperature alarm (115–125°C), or above alarm (above 125°C, emergency oxime feed shutoff and maximum cooling).

An adversarial perturbation targeting the Beckmann rearrangement reactor temperature display AI applies a ±10 DN downward shift to the pixel region encoding the reactor temperature in the rendered DCS trend display image — shifting the apparent reactor temperature from 128°C (3°C above the 125°C high-temperature alarm for the Beckmann rearrangement reactor, from a 15% reduction in cooling jacket water flow caused by a partial blockage in the cooling water return header reducing heat removal capacity) to 103°C (within the normal operating temperature range, no cooling adjustment). The AI classifies a Beckmann rearrangement reactor operating above its high-temperature alarm — where the combination of primary exotherm plus accelerating side-reaction exotherm is raising temperature toward the runaway threshold — as operating normally in the mid-temperature range. The temperature continues rising; above 135–140°C, the reaction mixture viscosity drops significantly as oleum/caprolactam composition shifts, reducing mass transfer and heat transfer efficiency; the runaway becomes self-sustaining as exotherm exceeds cooling capacity. The rearrangement reactor contains a concentrated mixture of oleum and organic material at elevated temperature — a condition where SO₃ fumes above the OSHA PEL-C can be generated from the oleum phase if the reactor pressure relief opens. OSHA PSM 29 CFR 1910.119(d) (PHA) applies to the Beckmann rearrangement reactor but does not specify adversarial robustness for AI classifying rendered reactor temperature display images.

2. Cyclohexanone oximation hydroxylamine vessel temperature display AI (DSM Fibrant oximation AI, AdvanSix oximation vessel AI, UBE Industries hydroxylamine oximation AI — rendered DCS temperature display AI classifying oximation vessel temperature against hydroxylamine thermal decomposition setpoints)

In the oximation step, cyclohexanone (from the KA oil oxidation step) reacts with hydroxylamine sulfate or hydroxylamine solution in the presence of a buffer to form cyclohexanone oxime at 60–80°C: C₆H₁₀O + NH₂OH → C₆H₁₁NO + H₂O (Beckmann oximation). The hydroxylamine is supplied as a 20–40 wt% aqueous solution (in older processes using ammonium sulfate–hydroxylamine sulfate systems, the hydroxylamine concentration is lower; in newer DSM HPO⁺ process using purified hydroxylamine, concentrations can be higher). The critical thermal stability constraint is hydroxylamine’s decomposition onset temperature: concentrated hydroxylamine solutions above approximately 30–50 wt% begin to decompose exothermically at temperatures above 65–75°C; the decomposition produces nitrogen, nitrogen oxides, hydrogen, and water in complex pathways. Even at 20–40 wt% hydroxylamine concentrations used in caprolactam oximation, the approach to the decomposition onset temperature during oximation is a process safety boundary that requires continuous monitoring. AI systems process rendered DCS oximation vessel temperature display images — RTD or thermocouple readouts for the cyclohexanone oximation vessel internal temperature — to classify oximation vessel thermal state: within the normal oximation operating range (60–75°C), approaching the hydroxylamine decomposition threshold (75–80°C), or above the decomposition threshold (above 80°C at the operating hydroxylamine concentration, immediate hydroxylamine feed shutdown and cooling increase).

An adversarial perturbation targeting the cyclohexanone oximation hydroxylamine vessel temperature display AI applies a ±8 DN downward shift to the pixel region encoding the oximation vessel temperature in the rendered DCS display image — shifting the apparent oximation vessel temperature from 78°C (3°C above the normal operating range upper limit of 75°C and approaching the 80°C hydroxylamine decomposition threshold for the 35 wt% hydroxylamine concentration in use, from a cooling jacket water pump that has partially cavitated from air ingestion reducing heat removal by 30%) to 67°C (well within the normal oximation operating range, no cooling adjustment required). The AI classifies a hydroxylamine oximation vessel approaching the thermal decomposition onset for the hydroxylamine concentration in use as operating at normal mid-range temperature. The oximation vessel temperature continues to rise toward the decomposition threshold; the hydroxylamine decomposition reaction produces nitrogen and hydrogen gases (non-condensable) that pressurize the vessel; above decomposition onset, the reaction can become self-accelerating as the decomposition exotherm adds more heat than the cooling system can remove. The Concept Sciences 1999 incident established the detonation mechanism of concentrated hydroxylamine: while the caprolactam oximation process operates at lower hydroxylamine concentrations, the thermal runaway mechanism is analogous, with the vessel geometry and heat transfer limitation determining whether a runaway becomes a detonation event. OSHA PSM 29 CFR 1910.119 lists hydroxylamine at TQ 15,000 lbs but does not specify adversarial robustness for AI classifying rendered oximation vessel temperature display images. Free tier — 10 scans/day, no card required.

3. Oleum fuming sulfuric acid storage temperature display AI (INEOS Meissner oleum storage AI, Honeywell Experion PKS oleum tank AI, Emerson Rosemount oleum storage AI — rendered temperature indicator display AI classifying oleum storage temperature against SO₃ vapour pressure and solidification setpoints)

Oleum (fuming sulfuric acid; H₂SO₄·SO₃, or “H₂S₂O₇”) is stored in insulated carbon-steel tanks at controlled temperature: above 10°C (to prevent solidification of high-concentration oleum; 65% oleum solidifies at approximately 2–5°C), and below 30°C (to limit SO₃ vapour pressure and associated fumigation above the OSHA ceiling PEL for SO₃ of 1 mg/m³). Oleum is one of the most reactive industrial chemicals: it reacts violently and exothermically with water or moisture (including atmospheric humidity), generating SO₃ fumes and sulfuric acid mist; spills or leaks in humid environments produce a dense, highly corrosive, and intensely irritating fog. OSHA PSM (29 CFR 1910.119) lists sulfuric acid at TQ 1,000 lbs for concentrations ≥65 wt%; oleum (65% SO₃ dissolved in 100% H₂SO₄, constituting approximately 118 wt% H₂SO₄ equivalent) is a covered PSM substance. Storage tank temperature monitoring is the primary safeguard against oleum vapor emission from elevated SO₃ partial pressure in the tank headspace. AI systems process rendered temperature indicator display images — surface-mounted or immersion RTD readouts for the oleum storage tank temperature — to classify oleum storage thermal state: within normal range (12–28°C), approaching high-temperature alarm (28–32°C), or above alarm (above 32°C, SO₃ fumes approaching OSHA PEL-C in tank area, immediate active cooling).

An adversarial perturbation targeting the oleum storage temperature display AI applies a ±8 DN downward shift to the pixel region encoding the storage tank temperature in the rendered temperature indicator display image — shifting the apparent oleum storage tank temperature from 34°C (2°C above the 32°C high-temperature alarm for the oleum storage tank, from insulation degradation on the tank lower side combined with a 34°C ambient temperature peak during a summer heat wave) to 22°C (well within the normal oleum storage temperature range, no cooling action initiated). The AI classifies an oleum storage tank operating at a temperature where SO₃ vapour pressure in the tank headspace is significantly above the normal operating level — where SO₃ concentration in the tank vent may exceed 1 mg/m³ (OSHA SO₃ PEL-C) in the surrounding working area — as operating at safe mid-range storage temperature. Workers performing sampling, level checks, or maintenance in the oleum tank area are exposed to SO₃ above the PEL-C without respiratory protection; SO₃ causes immediate severe upper respiratory irritation and can cause bronchoconstriction below the IDLH (100 mg/m³) but above the PEL-C. OSHA PSM 29 CFR 1910.119(f) (operating procedures for oleum storage) applies but does not specify adversarial robustness for AI classifying rendered oleum storage temperature display images.

4. Caprolactam product distillation column bottom temperature display AI (DSM Fibrant caprolactam purification AI, AdvanSix caprolactam distillation AI, BASF caprolactam finishing AI — rendered DCS column temperature display AI classifying caprolactam distillation column bottom temperature against polymerisation and oligomer formation setpoints)

Purified caprolactam is obtained by distillation of the crude caprolactam oil (after oleum neutralisation, aqueous extraction, and impurity removal) in a vacuum distillation column. Caprolactam distillation is conducted at approximately 20–40 mbar vacuum to reduce the bottom temperature required to reboil the caprolactam, which boils at 136°C at atmospheric pressure but at approximately 100–110°C at the operating vacuum. The critical operational constraint is maintaining column bottom temperature below approximately 120–130°C: above this range, caprolactam undergoes progressive oligomerisation in the high-concentration liquid at the column bottom (caprolactam → oligomers, analogous to nylon-6 ring-opening polymerisation at elevated temperature), leading to viscosity increase, column fouling by caprolactam oligomers, and progressive plugging of the reboiler and column internals. Column bottom temperature is maintained by vacuum and steam reboiler flow control; AI systems process rendered DCS column temperature display images — thermocouple readings from the distillation column bottom liquid — to classify distillation thermal state: within normal vacuum-distillation range (95–115°C bottom temperature), approaching high-temperature alarm (115–125°C, vacuum degraded or reboiler steam flow elevated), or above alarm (above 125°C, immediate reboiler steam reduction and vacuum increase).

An adversarial perturbation targeting the caprolactam distillation column bottom temperature display AI applies a ±8 DN downward shift to the pixel region encoding the column bottom temperature in the rendered DCS display image — shifting the apparent distillation column bottom temperature from 127°C (2°C above the 125°C high-temperature alarm for the caprolactam vacuum distillation column, from a partial vacuum system degradation caused by a condenser cooling water flow reduction that raised the column operating pressure from 28 mbar to 42 mbar, increasing the bottom temperature required for reboiling at the new higher pressure) to 109°C (within the normal vacuum distillation operating range, no reboiler steam adjustment). The AI classifies a caprolactam distillation column operating above its oligomerisation-onset temperature as operating normally within the expected bottom temperature range. Caprolactam oligomerisation in the column bottom proceeds; oligomers deposit on reboiler tube surfaces (reducing heat transfer efficiency and requiring the reboiler to work harder at higher temperature to maintain reboiling — a positive feedback loop); column bottom temperature continues rising as oligomer fouling reduces heat transfer; eventual column flooding or reboiler tube blockage from oligomer deposition requires emergency shutdown and cleaning. OSHA PSM 29 CFR 1910.119(d) (PHA for caprolactam distillation) applies but does not specify adversarial robustness for AI classifying rendered distillation column temperature display images. Free tier — 10 scans/day, no card required.

Integration: caprolactam production AI with Glyphward pre-scan gate

The Glyphward scan gate for caprolactam production AI belongs at every rendered-image ingestion boundary in the caprolactam plant monitoring and safety pipeline — before Beckmann rearrangement reactor temperature display AI processes rendered reactor temperature trend images, before cyclohexanone oximation vessel temperature display AI processes rendered DCS temperature images, before oleum storage tank temperature display AI processes rendered tank temperature indicator images, and before caprolactam distillation column bottom temperature display AI processes rendered DCS column temperature images. Threshold 30 for caprolactam production AI reflects the three overlapping chemical hazard classes in the process (oleum fuming sulfuric acid OSHA PSM TQ 1,000 lbs at ≥65 wt%; hydroxylamine OSHA PSM TQ 15,000 lbs with explosive decomposition above 70°C at concentrated solution; Beckmann rearrangement exotherm; the Concept Sciences 23 February 1999 concentrated hydroxylamine explosion that killed 5 workers as the established consequence for hydroxylamine thermal decomposition) and the interaction between multiple hazardous substances in a single processing sequence. Threshold 30 (rather than 35) reflects that the primary caprolactam process consequence — an oleum release or hydroxylamine decomposition event — represents significant localised chemical hazard but has a smaller community-scale toxic endpoint radius than the chlorine, HF, or high-consequence flammable vapour cloud events represented in threshold 35 calibrations.

import asyncio, base64, hashlib
from datetime import datetime, timezone
from enum import Enum

import httpx

GLYPHWARD_API_KEY = "YOUR_GLYPHWARD_API_KEY"
GLYPHWARD_SCAN_URL = "https://glyphward.com/v1/scan"

# Caprolactam (nylon-6 monomer) production AI contexts: threshold 30
# OSHA PSM 29 CFR 1910.119:
#   - Oleum (H2SO4 ≥65 wt%) TQ: 1,000 lbs
#   - Hydroxylamine TQ: 15,000 lbs (decomposition above 70°C at concentrated solution)
# Concept Sciences Hanover Township PA 19 Feb 1999: 5 killed,
# concentrated hydroxylamine decomposition detonation (CSB Case 1999-011-I-PA).
# Beckmann rearrangement exotherm: ΔH ≈ −80 to −120 kJ/mol (runaway onset >125°C).
CAPROLACTAM_THRESHOLD = 30


class CaprolactamContext(Enum):
    BECKMANN_TEMPERATURE    = "beckmann_temperature"    # Beckmann rearrangement reactor AI
    OXIMATION_TEMPERATURE   = "oximation_temperature"  # Hydroxylamine oximation vessel AI
    OLEUM_STORAGE_TEMP      = "oleum_storage_temp"     # Oleum storage tank temperature AI
    DISTILLATION_COLUMN     = "distillation_column"    # Caprolactam distillation column AI


class AdversarialCaprolactamImageError(Exception):
    """Raised when Glyphward detects adversarial content in a caprolactam
    production AI rendered image above threshold 30.

    Consequence if not raised:
    - BECKMANN_TEMPERATURE: rearrangement reactor at 128°C suppressed → above
      high alarm 125°C, side-reaction exotherm accelerating → thermal runaway
      in oleum/cyclohexanone oxime mixture → SO3 fumes from oleum phase.
    - OXIMATION_TEMPERATURE: oximation vessel at 78°C suppressed → approaching
      80°C hydroxylamine decomposition threshold → decomposition exotherm →
      N2/H2 gas pressure buildup in vessel (Concept Sciences 1999 mechanism).
    - OLEUM_STORAGE_TEMP: oleum tank at 34°C suppressed → SO3 vapour above
      OSHA PEL-C 1 mg/m³ in tank area → worker SO3 exposure without PPE.
    - DISTILLATION_COLUMN: column bottom at 127°C suppressed → above oligomerisation
      onset → caprolactam oligomer deposition → reboiler fouling → positive feedback
      loop of increasing bottom temperature and fouling.
    Fail-safe: read Beckmann reactor temperature from independent thermowell historian;
    confirm oximation vessel temperature from independent thermocouple;
    verify oleum tank temperature from independent immersion RTD;
    cross-check distillation column bottom from independent temperature indicator.
    """

    def __init__(self, scan_id, score, context, plant_id, flagged_region=None):
        self.scan_id = scan_id
        self.score = score
        self.context = context
        self.plant_id = plant_id
        self.flagged_region = flagged_region
        super().__init__(
            f"Adversarial caprolactam image: context={context.value} "
            f"score={score} plant={plant_id} scan_id={scan_id}"
        )


async def scan_caprolactam_image(image_bytes, context, plant_id, client):
    image_hash = hashlib.sha256(image_bytes).hexdigest()
    payload = {
        "image": base64.b64encode(image_bytes).decode(),
        "source": f"caprolactam:{context.value}:{plant_id}",
        "metadata": {
            "plant_id": plant_id,
            "context": context.value,
            "image_sha256": image_hash,
            "scan_timestamp_utc": datetime.now(timezone.utc).isoformat(),
        },
    }
    resp = await client.post(
        GLYPHWARD_SCAN_URL,
        headers={"Authorization": f"Bearer {GLYPHWARD_API_KEY}"},
        json=payload,
        timeout=4.0,
    )
    resp.raise_for_status()
    result = resp.json()
    if result.get("score", 0) >= CAPROLACTAM_THRESHOLD:
        raise AdversarialCaprolactamImageError(
            scan_id=result["scan_id"],
            score=result["score"],
            context=context,
            plant_id=plant_id,
            flagged_region=result.get("flagged_region"),
        )
    return result


async def main():
    async with httpx.AsyncClient() as client:
        with open("beckmann_reactor_temperature.png", "rb") as f:
            image_bytes = f.read()
        result = await scan_caprolactam_image(
            image_bytes,
            CaprolactamContext.BECKMANN_TEMPERATURE,
            plant_id="PLANT-CPL-001",
            client=client,
        )
        print(f"Clean scan: {result['scan_id']} score={result['score']}")


asyncio.run(main())

Frequently asked questions

What happened at Concept Sciences Inc in Hanover Township PA on 19 February 1999?

A concentrated hydroxylamine solution (~83 wt%) being heated during a distillation step detonated, killing 5 workers and injuring 1 (CSB Case 1999-011-I-PA). CSB found concentrated hydroxylamine above ~50 wt% is thermally unstable and can detonate without external ignition. Establishes the decomposition detonation mechanism directly relevant to caprolactam oximation AI temperature monitoring.

What is the Beckmann rearrangement and why is it used to make caprolactam?

Acid-catalysed rearrangement of cyclohexanone oxime (C=N-OH) in oleum at 80–120°C; the ring carbon anti to the oxime OH migrates across the C=N bond to produce the 7-membered caprolactam ring. Highly exothermic (−80 to −120 kJ/mol). Above 120–130°C, side reactions (oligomerisation, fragmentation) accelerate and compound the exotherm toward runaway.

What is oleum and why is it OSHA PSM-listed at only TQ 1,000 lbs?

Oleum (H₂SO₄·SO₃, 20–65 wt% free SO₃) reacts violently with water and fumes SO₃ above OSHA PEL-C 1 mg/m³; IDLH 100 mg/m³. OSHA PSM TQ 1,000 lbs for H₂SO₄ ≥65 wt% — one of the lowest TQs on the list, reflecting extreme reactive and fumigation hazard.

How much ammonium sulfate by-product is produced per tonne of caprolactam?

Approximately 1.8–4.5 tonnes (NH₄)₂SO₄ per tonne caprolactam in the classical Beckmann oleum process. The high by-product ratio drives development of alternative routes (gas-phase zeolite rearrangement, HPO⁺ process) that reduce or eliminate ammonium sulfate co-production.

Why threshold 30 for caprolactam production AI?

Dual OSHA PSM hazards (oleum TQ 1,000 lbs; hydroxylamine TQ 15,000 lbs), Concept Sciences 1999 (5 killed, CSB), Beckmann exotherm runaway in oleum at 125–130°C, three overlapping chemical hazard classes across the process sequence. Threshold 30 vs. 35 because primary consequences are localised chemical hazard with smaller community toxic endpoint radius than Cl₂/HF/large vapour cloud events.