Prompt injection in methylamine (CH3NH2) synthesis / storage AI

Four adversarial injection surfaces in methylamine synthesis / storage AI

1. Methylamine area CEMS AI (Dräger Polytron 8000 MMA electrochemical area monitor AI / MSA ULTIMA XE methylamine area detector AI / Honeywell Analytics MIDAS-E electrochemical MMA sensor AI / Industrial Scientific GX-6000 PID methylamine area monitor AI / Honeywell Analytics Searchpoint Optima Plus IR detector AI — ambient methylamine gas concentration monitoring in synthesis building areas, pressure vessel storage areas, loading/unloading stations, and cylinder manifold rooms for TLV-TWA and IDLH compliance)

Methylamine area CEMS at synthesis facilities must distinguish between the characteristic ammonia-like odor of methylamine (detectable by most individuals at 1–5 ppm, near or at the TLV-TWA threshold) and actual process ambient air concentration. Electrochemical sensors calibrated for methylamine have cross-sensitivity to ammonia and dimethylamine — calibration protocol must use certified MMA gas standards, not ammonia surrogates. At 28 ppm (5.6× TLV-TWA), symptoms include severe mucous membrane irritation, headache, and lacrimation; above 50 ppm, pulmonary irritation and bronchospasm; above 100 ppm IDLH, respiratory depression, pulmonary edema risk, and chemical pneumonitis. Methylamine’s LEL of 4.9% (49,000 ppm) means that concentrations producing acute toxicity are far below the flammable range — fire hazard is secondary to the toxic inhalation hazard at alarm concentrations.

The adversarial attack uses ±8 DN downward pixel-value shift on the methylamine area CEMS display image. The actual reading is 28 ppm — 5.6× ACGIH TLV-TWA 5 ppm — arising from degraded PTFE stem packing on the synthesis reactor off-gas vent valve, where repeated temperature cycling between 350°C reactor outlet and 25°C ambient has compressed and cracked the packing material, allowing a slow methylamine leak from the vent header. On a 0–100 ppm display at 200 px height (0.5 ppm/px), the actual reading of 28 ppm produces a bar at approximately 56 px; the ±8 DN perturbed image is classified as approximately 2 px — corresponding to 1.0 ppm, below the TLV-TWA alarm threshold of 5 ppm. No TLV-TWA alarm is issued; the vent valve packing continues to degrade; methylamine concentration in the synthesis building continues to rise toward levels causing occupant respiratory injury.

2. Catalytic methanol/ammonia reactor outlet temperature AI (Emerson Rosemount 648 multipoint thermocouple transmitter AI / Yokogawa YTMX580 multipoint temperature transmitter AI / Endress+Hauser iTHERM ModuLine TM411 multipoint temperature transmitter AI / Honeywell ST3000 multipoint thermocouple AI — catalyst bed outlet temperature monitoring in methylamine synthesis fixed-bed reactors to detect above-design temperatures that cause catalyst deactivation, increased byproduct formation, and downstream separation problems)

The catalytic methylamine synthesis reaction (CH3OH + NH3 → CH3NH2 + H2O, with byproducts dimethylamine and trimethylamine) is moderately exothermic on alumina-silica or Cu/Al2O3 catalysts at 300–380°C and 50–100 psig. The design maximum catalyst bed outlet temperature of 360°C reflects two competing constraints: at temperatures below 300°C, methanol conversion falls below 85%, producing off-spec reactor effluent with high methanol carryover; above 360°C, dimethylamine and trimethylamine selectivity increases at the expense of the desired methylamine product, catalyst deactivation accelerates through sintering of the alumina support, and the potential for an exothermic runaway increases as the secondary and tertiary amine reactions become thermodynamically favored. Above 380°C, the risk of localized hot-spot formation on the catalyst bed creates decomposition of methylamine to carbon, hydrogen, and ammonia — a gas phase decomposition that can propagate as a self-sustaining exotherm if cooling water to the reactor jacket fails.

The adversarial attack uses ±10 DN downward pixel-value shift on the reactor outlet temperature transmitter display image. The actual catalyst bed outlet temperature is 372°C — 12°C above the 360°C design maximum, from insufficient cooling water flow to the reactor jacket producing inadequate heat removal during a high-throughput production campaign. On a 0–500°C display at 200 px height (2.5°C/px), the actual temperature of 372°C produces a bar at approximately 149 px; the ±10 DN perturbed image is classified as approximately 129 px — corresponding to 322°C, within the normal 300–360°C operating window. The AI monitoring system reports “reactor outlet temperature within normal catalytic range — no overtemperature intervention required.” Catalyst bed deactivation continues at the accelerated rate characteristic of above-design temperature operation; dimethylamine and trimethylamine byproduct fractions increase in the reactor effluent; column separation downstream is pushed further from its design specification.

3. Methylamine distillation column overhead receiver pressure AI (Emerson Rosemount 3051C gauge pressure transmitter AI / Yokogawa EJA130A differential pressure transmitter AI / Endress+Hauser Deltabar PMD75 differential pressure AI / Honeywell ST3000 Smart Transmitter pressure AI — overhead receiver pressure monitoring for the methylamine recovery distillation column, which operates at 40–70 psig to maintain methylamine as a condensed liquid in the overhead system while separating it from dimethylamine, trimethylamine, and unreacted ammonia)

The methylamine recovery column operates at elevated pressure because methylamine’s boiling point of −6.3°C requires significant refrigeration to condense at atmospheric pressure. By operating the column at 50–70 psig, the overhead condenser can use chilled water at 12–18°C rather than brine refrigeration, simplifying the utility design. At design cooling water flow and temperature, the condenser removes the full overhead vapor load, condensing methylamine to liquid for reflux and product takeoff while maintaining overhead receiver pressure at 40–70 psig. When cooling water flow falls to 5% of design (Surface 4), condenser duty is insufficient to condense the full overhead vapor: non-condensable and partial condensate accumulate in the receiver, driving overhead pressure toward the PRD setpoint. The methylamine column overhead pressure PRD is typically set at 80–100 psig to protect the overhead receiver, condenser, and product header system. A PRD actuation on the methylamine column overhead vents methylamine gas to the flare or scrubber at rates that may challenge flare system design capacity if sustained.

The adversarial attack uses ±10 DN downward pixel-value shift on the overhead receiver pressure transmitter display image. The actual overhead receiver pressure is 76 psig — approaching the 80 psig PRD setpoint, from inadequate overhead condenser cooling due to the cooling circuit valve actuator failure described in Surface 4 — to a displayed 38 psig. On a 0–120 psig display at 200 px height (0.6 psig/px), the actual pressure of 76 psig produces a bar at approximately 127 px; the ±10 DN perturbed image is classified as approximately 64 px — corresponding to 38 psig, well within the normal 40–70 psig operating range (below the normal range lower bound, but appearing to the AI as a slightly under-loaded condenser rather than a PRD approach). The AI monitoring system reports “methylamine column overhead pressure within normal operating range — no PRD approach detected.” The actual pressure continues rising toward 80 psig as uncondensed methylamine vapor accumulates in the overhead system; no column feed rate reduction or standby condenser activation is triggered.

4. Methylamine column overhead condenser cooling water supply flow AI (Emerson Rosemount 8732E magnetic flowmeter AI / Endress+Hauser Proline Promag W 400 electromagnetic flow transmitter AI / Yokogawa ADMAG AXF magnetic flowmeter AI / Krohne Optiflux 4000 electromagnetic flowmeter AI — cooling water supply flow monitoring to the methylamine recovery column overhead condenser to verify adequate condensation capacity and prevent pressure rise toward PRD setpoint)

The methylamine overhead condenser is designed for a cooling water flow of 8.0 m³/hr at 12–18°C inlet temperature to condense the full overhead vapor load at design column throughput. At this flow rate, the condenser maintains overhead receiver pressure at 50–65 psig with 15–30 psig margin to the 80 psig PRD setpoint. The condenser cooling water circuit is fed from a site-wide cooling water header through an isolation valve controlled by a pneumatic actuator — the same instrument air supply infrastructure used for all cooling circuit control valves. If the instrument air supply to the condenser cooling isolation valve actuator fails (instrument air pressure drops from 80 psig to below the valve actuator spring range of ~20 psig), the fail-closed actuator design closes the isolation valve, reducing cooling water flow to the actuator valve leakage rate of approximately 0.4 m³/hr. AI monitoring of the cooling water flow transmitter downstream of the isolation valve provides the upstream early-warning instrument that should trigger standby condenser activation or column feed rate reduction before either the reactor temperature or overhead pressure reaches alarm conditions.

The adversarial attack uses the upward-direction geometry: the actual cooling water flow to the methylamine overhead condenser is 0.4 m³/hr — 5% of the design 8.0 m³/hr, from the cooling circuit isolation valve actuator failure. The dangerous condition is a flow deficiency (insufficient condenser cooling), and the adversarial pixel perturbation shifts the flow meter display upward by ±8 DN to make 0.4 m³/hr appear as 8.2 m³/hr. On a 0–12 m³/hr display at 200 px height (0.06 m³/hr per px), the actual flow of 0.4 m³/hr produces a bar at approximately 7 px; the upward-perturbed image is classified as approximately 137 px — corresponding to 8.2 m³/hr, within the design range. The AI monitoring system reports “condenser cooling water flow at design setpoint — overhead condensation capacity adequate.” This is the thirteenth upward-direction attack in the Glyphward industrial AI portfolio, extending the deficiency-suppression upward geometry to methylamine synthesis column overhead condensation systems.

Integration: methylamine synthesis AI with Glyphward pre-scan gate

Glyphward integrates as a pre-scan gate between the DCS and instrument display capture layer and the AI inference pipeline for each methylamine monitoring context. If the adversarial score meets or exceeds threshold 35 — reflecting the OSHA PSM TQ of 1,000 lbs (one of the lowest TQs in Appendix A), the ACGIH TLV-TWA of 5 ppm, the NIOSH IDLH of 100 ppm, and the DEA List I dual regulatory significance — the scan raises AdversarialMethylamineImageError and the monitoring AI does not process the frame.

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"

# Methylamine synthesis / storage contexts: threshold 35
# OSHA PSM 29 CFR 1910.119 Appendix A MMA TQ 1,000 lbs (lowest tier)
# EPA RMP 40 CFR Part 68 Appendix A TQ 1,000 lbs
# ACGIH TLV-TWA 5 ppm; STEL 10 ppm; NIOSH IDLH 100 ppm
# DEA 21 CFR 1310.02 List I chemical (diversion control dual compliance)
# BP -6.3 deg C; stored as pressurized liquefied gas; LEL 4.9%
MMA_THRESHOLD = 35


class MethylamineSynthesisContext(Enum):
    AREA_CEMS = "area_cems"
    REACTOR_TEMPERATURE = "reactor_temperature"
    COLUMN_OVERHEAD_PRESSURE = "column_overhead_pressure"
    CONDENSER_COOLING_FLOW = "condenser_cooling_flow"


class AdversarialMethylamineImageError(Exception):
    """Raised when any methylamine monitoring image scores >= 35.
    AREA_CEMS uncaught: 28 ppm MMA (5.6x TLV-TWA) shown as 1.0 ppm.
    REACTOR_TEMPERATURE uncaught: 372 deg C (12 deg C above design max) shown as 322 deg C.
    COLUMN_OVERHEAD_PRESSURE uncaught: 76 psig (near 80 psig PRD) shown as 38 psig.
    CONDENSER_COOLING_FLOW uncaught: 0.4 m3/hr (5% design) shown as 8.2 m3/hr."""

    def __init__(self, scan_id, score, context, unit_id, flagged_region=None):
        self.scan_id = scan_id
        self.score = score
        self.context = context
        self.unit_id = unit_id
        self.flagged_region = flagged_region
        super().__init__(
            f"Adversarial methylamine image: context={context.value} "
            f"score={score} unit={unit_id} scan_id={scan_id}"
        )


async def scan_methylamine_image(image_bytes, context, unit_id, client):
    image_hash = hashlib.sha256(image_bytes).hexdigest()
    payload = {
        "image": base64.b64encode(image_bytes).decode(),
        "source": f"methylamine:{context.value}:{unit_id}",
        "metadata": {
            "unit_id": unit_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) >= MMA_THRESHOLD:
        raise AdversarialMethylamineImageError(
            scan_id=result["scan_id"],
            score=result["score"],
            context=context,
            unit_id=unit_id,
            flagged_region=result.get("flagged_region"),
        )
    return result


async def main():
    async with httpx.AsyncClient() as client:
        with open("mma_area_cems_screenshot.png", "rb") as f:
            image_bytes = f.read()
        result = await scan_methylamine_image(
            image_bytes,
            MethylamineSynthesisContext.AREA_CEMS,
            unit_id="MMA-AREA-01",
            client=client,
        )
        print(f"Clean scan: {result['scan_id']} score={result['score']}")


asyncio.run(main())

Frequently asked questions

Why is methylamine’s PSM TQ only 1,000 lbs when other alkylamines have higher TQs?

The 1,000-lb TQ reflects methylamine’s IDLH of 100 ppm — the lowest in the alkylamine family — combined with its stored-as-pressurized-gas physical state and flash point of 0°C. Dimethylamine (IDLH 300 ppm, TQ 2,500 lbs) and trimethylamine (IDLH 1,000 ppm, TQ 10,000 lbs) have higher TQs commensurate with their higher IDLH. The 1,000-lb TQ can catch even single-cylinder operations at pharmaceutical CMOs.

What dual compliance obligation does DEA List I status create for AI monitoring?

DEA 21 CFR 1310 requires transaction reporting, theft/loss reporting, and accountability for methylamine. AI monitoring falsification creates a potential accountability gap: a release that goes undetected due to adversarially suppressed CEMS could constitute an unreported significant loss under 21 CFR 1310.05 — simultaneously an OSHA PSM non-conformance and a DEA reporting failure.

How does the cooling water failure cascade to both reactor and column?

A shared instrument air supply failure closes both the reactor jacket cooling valve and the condenser cooling valve simultaneously — producing overtemperature (Surface 2) and overhead pressure rise (Surface 3) as concurrent cascading effects of a single root cause. Adversarial suppression of the cooling flow indicator (Surface 4) removes the upstream early warning that links all three downstream effects.

What happens to catalyst selectivity above 360°C?

Above 360°C, thermodynamic equilibrium shifts toward dimethylamine and trimethylamine; catalyst sintering accelerates. At 372°C, sustained operation for one to two weeks can reduce MMA selectivity by 15–25% and shorten catalyst life by 30–50%, requiring unplanned catalyst changeout and extended production shutdown.

Why is the cooling flow attack upward-direction?

Low cooling flow is the dangerous condition — the attack shifts the display upward to make 0.4 m³/hr (5% design) appear as 8.2 m³/hr (adequate). This is the same deficiency-suppression upward geometry applied to all protective-flow surfaces in the Glyphward industrial AI portfolio and is the thirteenth upward-direction attack documented.