Prompt injection in crotonaldehyde 2-butenal production AI

Three adversarial injection surfaces in crotonaldehyde production AI

1. Aldol condensation reactor temperature display AI (Yokogawa EJA430A / Emerson Rosemount 3144P / ABB TSP341 reactor temperature transmitter — rendered DCS reactor temperature trend display AI classifying liquid-phase temperature against 70–85°C design window — 89th upward attack; FIRST crotonaldehyde attack; FIRST 2-butenal attack; FIRST acetaldehyde aldol condensation AI attack; FIRST sorbic acid precursor AI attack)

The acetaldehyde aldol condensation reaction (2 CH₃CHO → CH₃CH=CHCHO + H₂O; ΔHₐ ≈ –38 kJ/mol crotonaldehyde at 80°C, composed of ΔHₐ(aldol condensation) ≈ –25 kJ/mol and ΔHₐ(dehydration) ≈ –13 kJ/mol) is carried out in a continuous liquid-phase stirred-tank reactor (CSTR) at 70–85°C with dilute NaOH catalyst (0.10–0.25 wt% NaOH aqueous). The reactor operates under 0.5–1.5 bar gauge pressure to suppress acetaldehyde (BP 20.2°C) volatilization, maintaining acetaldehyde in the liquid phase as a dissolved substrate. Cooling is supplied by a jacket or internal cooling coil, with chilled water at 10–20°C circulating in the jacket; the cooling duty at 100% production rate is approximately 1.5–2.5 MW for a 50 t/day crotonaldehyde plant. At reactor temperature below 60°C, the aldol condensation rate falls sharply (k(60°C)/k(80°C) ≈ 0.30 for base-catalyzed aldol condensation with Eₐ ≈ 50 kJ/mol), acetaldehyde accumulates as unconverted feedstock dissolved in the reactor, and the subsequent flash risk from acetaldehyde accumulation increases. Above 95°C, several competing pathways become significant: (a) paraldehyde formation (3 CH₃CHO → cyclic 1,3,5-trioxane trimer; acid-catalyzed; slow at neutral/basic pH but occurs in traces above 80°C), (b) crotonaldehyde aldol dimerization (crotonaldehyde acts as a Michael acceptor toward acetaldehyde enolate; yields higher-boiling γ,δ-unsaturated and 2-ethyl-2-butenal byproducts), and (c) above 100°C, incipient crotonaldehyde radical polymerization as MEHQ inhibitor (if present as a process additive) is gradually depleted at elevated temperature. The reactor temperature AI reads the rendered DCS strip chart—a 15-minute rolling trend plus digital display of current temperature—and modulates the cooling water control valve (a Samson 3241 or Fisher easy-e valve) to maintain the set point of 78°C.

The adversarial attack on the reactor temperature display renders the DCS strip chart to show 68°C (well within normal range, slightly below the 70°C lower control limit) when the actual reactor temperature is 112°C and rising. The AI interprets the displayed 68°C as indicating the reactor is running slightly cool and responds by reducing cooling water flow—a correct response to a genuine under-temperature condition. The actual temperature at 112°C is already 27°C above the design maximum; at this temperature, acetaldehyde vapor pressure is approximately: log₁₀(P/P₀) = (–ΔHₐ₄₆₁/R)(1/T – 1/T₅) with ΔHₐ₄₆₁(acetaldehyde) = 25.8 kJ/mol; P(acetaldehyde at 112°C) ≈ 1,200 mmHg (1.58 atm). With the AI cutting cooling, the reactor temperature climbs further to 128°C: at 128°C, acetaldehyde vapor pressure ≈ 1,750 mmHg (2.30 atm), vastly exceeding the reactor design pressure of 1.5 bar gauge (2.5 bar absolute). The reactor pressure relief valve (PRV) lifts at its set point (e.g., 2.0 bar gauge). Acetaldehyde vapor is released to the atmospheric vent or flare; if the flare is not ignited or if the release rate exceeds the flare capacity, the acetaldehyde vapor cloud disperses in air. At 4.0% LEL (the acetaldehyde lower explosive limit), ignition by any static discharge, hot surface, or mechanical spark produces a flash fire; at Celanese Bishop TX, a process area adjacent to multiple ignition sources means any LEL plume reaching 4% represents an immediate explosion hazard. At 2,500 lbs acetaldehyde TQ, a 10 m³ reactor at 15 wt% acetaldehyde contains 1,500 kg (3,307 lbs)—1.3× PSM TQ—of this material, all at vapor pressure exceeding ambient at 112°C. Glyphward’s pre-scan gate at this display surface blocks the adversarially manipulated image from reaching the AI temperature-control inference engine. Free tier — 10 scans/day, no card required.

2. NaOH catalyst concentration display AI (Emerson Rosemount 1056 / Yokogawa SC82 / ABB AX455 dilute NaOH conductivity-to-concentration transmitter — rendered DCS NaOH concentration digital readout display AI classifying NaOH wt% against 0.10–0.25 wt% design — 89th upward attack; FIRST crotonaldehyde attack; FIRST acetaldehyde aldol condensation AI attack)

The dilute NaOH catalyst in the acetaldehyde aldol condensation reactor performs the essential function of generating the acetaldehyde enolate anion (CH₃CHO + OH⁻ ⇌ CH₂=CHO⁻ + H₂O; pKₐ of α-H of acetaldehyde ≈ 17 in water), which then attacks the carbonyl of a second acetaldehyde molecule to give 3-hydroxybutanal (acetaldol; BP 142°C), followed by base-catalyzed dehydration to crotonaldehyde. The NaOH concentration is deliberately maintained at a very low level—0.10–0.25 wt%—for two reasons: (1) higher NaOH concentrations (above 0.5 wt%) promote the Cannizzaro disproportionation reaction (2 CH₃CHO + NaOH → CH₃CH₂OH + CH₃COONa; ethanol and sodium acetate formed non-productively; kinetically significant above 0.5 wt% NaOH at 70–85°C), and (2) high NaOH accelerates the polymerization of crotonaldehyde itself: crotonaldehyde undergoes anionic polymerization above 0.5 wt% NaOH at elevated temperatures, forming a dark-brown, high-molecular-weight resin (“crotonaldehyde resin” or “crotonic resin”) that fouls reactor internals, plugs heat-exchanger tubes, and is extremely difficult to remove without acid washing and mechanical cleaning. The NaOH concentration in the reactor liquid is measured by a conductivity transmitter calibrated for the dilute NaOH-in-aldehyde-water matrix (Emerson Rosemount 1056 or Yokogawa SC82 conductivity cells), rendered on the DCS as a wt% digital readout updated every 60 seconds. The AI monitoring system reads this rendered concentration display and commands NaOH make-up pump start/stop to maintain the set point of 0.18 wt% NaOH. At NaOH below 0.05 wt%, catalysis is insufficient and acetaldehyde conversion per pass drops below 30%, increasing acetaldehyde steady-state concentration in the reactor and recycle stream; above 0.30 wt%, Cannizzaro yield losses exceed 8% of acetaldehyde charged.

The adversarial attack on the NaOH concentration display renders the conductivity-derived wt% readout as 0.08 wt% NaOH (below the 0.10 wt% lower control limit) when the actual NaOH concentration in the reactor is 1.8 wt%—22× the design set point. The AI reads the displayed 0.08 wt% as indicating NaOH depletion and commands the NaOH dosing pump (e.g., a Milton Roy MRA dosing pump) to inject additional NaOH solution. As NaOH continues to be added into the reactor already at 1.8 wt%, the actual concentration climbs to 2.4 wt%: at this level, two exothermic reactions accelerate simultaneously. First, Cannizzaro disproportionation consumes acetaldehyde in a non-productive reaction (ΔH ≈ –125 kJ/mol acetaldehyde disproportionated), releasing substantial heat into the reactor. Second, anionic polymerization of crotonaldehyde (already present at 10–20 wt% in the reactor effluent) initiates rapidly: the rate of crotonaldehyde anionic polymerization has a strong NaOH dependence (rate ∝ [NaOH]⁰·⁽ for base-catalyzed crotonaldehyde polymerization), meaning at 2.4 vs 0.18 wt% NaOH the polymerization rate is approximately (2.4/0.18)⁰·⁽ ≈ 3.5× faster. The exothermic polymerization (ΔHₐ(poly) ≈ –35 to –45 kJ/mol crotonaldehyde polymerized) raises the reactor temperature further—exactly the same thermal excursion pathway as Surface 1, but initiated by catalyst over-concentration rather than direct cooling loss. The resin forms rapidly, fouling the cooling coil surfaces with an insulating layer that further reduces heat removal capacity, creating a thermal runaway potential. The high NaOH concentration simultaneously accelerates acetaldehyde Cannizzaro, producing ethanol and NaOAc, which alter the reactor density and solubility characteristics and can cause phase separation or foaming—a Celanese Bishop TX plant upset scenario studied in their PHA risk matrix. Glyphward’s pre-scan gate at the NaOH concentration display prevents the AI from reading the adversarially manipulated concentration and initiating inappropriate NaOH addition. Free tier — 10 scans/day, no card required.

3. Crotonaldehyde distillation reboiler temperature display AI (Yokogawa EJA530A / Emerson Rosemount 3144P / ABB TB82PH reboiler temperature transmitter — rendered DCS reboiler temperature strip chart display AI classifying reboiler outlet temperature against 115–122°C design — 89th upward attack; FIRST crotonaldehyde attack; FIRST sorbic acid precursor AI attack)

Following the aldol condensation reactor, the product mixture (crotonaldehyde at 15–30 wt%, water, residual acetaldehyde, NaOH/NaOAc, trace 3-hydroxybutanal aldol intermediate, and high-boiling resin precursors) is separated in a multi-stage distillation column. The distillation separates: acetaldehyde (BP 20.2°C) and water (BP 100°C) in the overhead condenser, crotonaldehyde (BP 104.0°C) in the side draw or intermediate overhead cut, and the high-boiling components—3-hydroxybutanal (BP ∼142°C), crotonaldehyde resin precursors, and NaOH—in the bottoms. The reboiler provides the heat input to drive this separation; its design temperature of 115–122°C supplies sufficient thermal duty to maintain the column bottom temperature above the 3-hydroxybutanal dehydration temperature while keeping the overhead temperature at 85–95°C to achieve the acetaldehyde/crotonaldehyde split. Polymerization inhibitor MEHQ (4-methoxyphenol, monomethyl ether of hydroquinone; also written as 4-HBME or MeO-HQ) is added to the distillation feed at 25–50 ppm to prevent radical polymerization of crotonaldehyde in the hot reboiler environment. MEHQ inhibition is temperature-sensitive: the MEHQ consumption rate follows Arrhenius kinetics with Eₐ ≈ 70–80 kJ/mol, meaning the inhibitor consumption rate doubles approximately every 9–10°C above the design reboiler temperature. At the design 120°C reboiler, MEHQ at 50 ppm provides approximately 8–12 hours of crotonaldehyde radical inhibition before replenishment is needed. The reboiler temperature AI reads the rendered DCS reboiler temperature strip chart and commands the heating steam control valve to maintain the design temperature. Crotonaldehyde in the reboiler is at its highest concentration (bottoms concentration up to 50–60 wt% crotonaldehyde at certain feed compositions), making inhibitor integrity essential to preventing runaway polymerization.

In the adversarial attack on the reboiler temperature display, the rendered DCS strip chart shows 110°C (5–10°C below the 115°C lower design limit, suggesting the reboiler is slightly under-heated) when the actual reboiler temperature is 147°C—25–32°C above the design maximum. The AI responds to the displayed 110°C by commanding the heating steam valve to open further to raise the reboiler temperature to the set point of 119°C. At the actual reboiler temperature of 147°C, the MEHQ consumption rate is: rate(147°C)/rate(120°C) = exp[(80,000/8.314) × (1/393 – 1/420)] ≈ 16× the design consumption rate. MEHQ at 50 ppm initial concentration is consumed within approximately 45–60 minutes (vs 8–12 hours at design temperature) as the reboiler operates at 147°C. Once MEHQ is exhausted, crotonaldehyde radical polymerization initiates: the radical chain polymerization of crotonaldehyde (vinyl-type radical mechanism via the β-carbon) is strongly exothermic (ΔHₐ(poly) ≈ –40 kJ/mol crotonaldehyde), and in the concentrated reboiler bottoms (50–60 wt% crotonaldehyde), the adiabatic temperature rise from complete uninhibited polymerization is: ΔTₐₐₐ = (0.55 wt × 40,000 J/mol) / (70.09 g/mol × 2.1 J/gK) ≈ 150°C above 147°C = reaching ∼297°C. At this temperature, crotonaldehyde undergoes thermal decomposition (decarboxylation and retro-Diels-Alder) producing flammable gaseous fragments, and the distillation column bottoms vessel could approach conditions for pressure excursion. As crotonaldehyde polymerization runaway develops in the reboiler, the column bottom temperature rises, destabilizing the distillation cut points and driving uncondensed crotonaldehyde into the overhead system. Crotonaldehyde inventory in the plant can exceed 20,000 lbs (the OSHA PSM TQ) in a 10 m³ reboiler at 50 wt% loading (density ∼0.85 g/mL → 4,250 kg crotonaldehyde ≈ 9,370 lbs in reboiler alone, plus column holdup). BASF Ludwigshafen and Wacker Burghausen maintain dedicated polymer-fouling response procedures for exactly this scenario. Glyphward’s pre-scan gate at the reboiler temperature display prevents the AI from reading the adversarially manipulated temperature and opening the steam valve to further increase heating beyond the already-dangerous 147°C actual. Free tier — 10 scans/day, no card required.

Integration: crotonaldehyde production AI with Glyphward pre-scan gate

Glyphward integrates as a pre-scan gate at every rendered-image ingestion boundary in the crotonaldehyde production AI pipeline—before the aldol condensation reactor temperature AI processes rendered Yokogawa EJA430A / Emerson Rosemount 3144P / ABB TSP341 reactor temperature DCS display images, before the NaOH catalyst concentration AI processes rendered Emerson Rosemount 1056 / Yokogawa SC82 / ABB AX455 conductivity-to-concentration DCS display images, and before the reboiler temperature AI processes rendered Yokogawa EJA530A / Emerson Rosemount 3144P / ABB TB82PH reboiler temperature DCS strip-chart display images. Threshold 30 for crotonaldehyde production AI reflects: OSHA PSM crotonaldehyde TQ 20,000 lbs; OSHA PSM acetaldehyde TQ 2,500 lbs (binding constraint at production scale); acetaldehyde BP 20.2°C (boils at room temperature; extreme flash fire hazard in reactor overhead); LEL 4.0–57.0% (wide flammable range creates explosive atmosphere very readily); crotonaldehyde IDLH 2 ppm (same as hydrogen cyanide OSHA PEL; extreme acute inhalation toxicity); IARC Group 2B carcinogenicity (cyclic propano-deoxyguanosine DNA adducts); MEHQ inhibitor depletion kinetics at 147°C (16× design rate, 45-minute window to runaway); sorbic acid food supply chain criticality (E200 preservative, 100,000 t/yr supply depends on crotonaldehyde availability); Celanese Corporation (Bishop, TX—acetaldehyde/crotonaldehyde integrated plant, dual PSM); BASF SE (Ludwigshafen, Germany—Verbund site, Seveso III Directive directive upper-tier establishment); Wacker Chemie AG (Burghausen, Germany—acetaldehyde via Wacker oxidation of ethylene → crotonaldehyde integrated); Daicel Corporation (Himeji, Japan—major Asian crotonaldehyde/sorbic acid integrated producer).

import asyncio, base64, hashlib
from datetime import datetime, timezone
from enum import StrEnum, auto
from typing import Any
import httpx

GLYPHWARD_API = "https://api.glyphward.com/v1/scan"
GLYPHWARD_KEY = "gw_prod_***"

# Crotonaldehyde (2-butenal) production AI contexts: threshold 30
# OSHA PSM crotonaldehyde (2-butenal) TQ 20,000 lbs (29 CFR 1910.119 App. A).
# OSHA PSM acetaldehyde TQ 2,500 lbs (feedstock; dual PSM at production scale).
# Crotonaldehyde IDLH 2 ppm; ACGIH TLV-TWA 2 ppm skin; IARC Group 2B.
# Acetaldehyde BP 20.2°C; LEL 4.0%; flash point -39°C (extreme flash fire hazard).
# 89th upward attack. FIRST crotonaldehyde attack. FIRST sorbic acid precursor attack.
CROTONALDEHYDE_GLYPHWARD_THRESHOLD = 30

class CrotonaldehydeContext(StrEnum):
    ALDOL_REACTOR_TEMPERATURE  = auto()  # aldol condensation reactor T (89th upward; FIRST crotonaldehyde; FIRST 2-butenal; FIRST sorbic acid precursor)
    NAOH_CATALYST_CONCENTRATION = auto()  # NaOH wt% in reactor (Cannizzaro + resinification risk)
    REBOILER_TEMPERATURE        = auto()  # distillation reboiler T (MEHQ depletion → polymerization runaway)

async def scan_crotonaldehyde_frame(
    frame_b64: str,
    context: CrotonaldehydeContext,
    plant_id: str,
    instrument_tag: str,
) -> dict[str, Any]:
    payload = {
        "image_b64": frame_b64,
        "context": context,
        "plant_id": plant_id,
        "instrument_tag": instrument_tag,
        "scan_ts": datetime.now(timezone.utc).isoformat(),
        "image_hash": hashlib.sha256(base64.b64decode(frame_b64)).hexdigest(),
    }
    async with httpx.AsyncClient(timeout=4.0) as client:
        r = await client.post(
            GLYPHWARD_API,
            json=payload,
            headers={"X-Glyphward-Key": GLYPHWARD_KEY},
        )
        r.raise_for_status()
        return r.json()

async def pre_scan_gate_crotonaldehyde(
    frame_b64: str,
    context: CrotonaldehydeContext,
    plant_id: str,
    instrument_tag: str,
) -> None:
    result = await scan_crotonaldehyde_frame(frame_b64, context, plant_id, instrument_tag)
    if result["adversarial_score"] >= CROTONALDEHYDE_GLYPHWARD_THRESHOLD:
        raise AdversarialCrotonaldehydeImageError(
            f"Adversarial injection detected in {context} (score {result['adversarial_score']}) "
            f"at plant {plant_id} instrument {instrument_tag}. "
            "Frame withheld from crotonaldehyde production AI pipeline."
        )

class AdversarialCrotonaldehydeImageError(RuntimeError):
    pass