Prompt injection in dimethyl dichlorosilane DMDCS silicone Müller-Rochow AI

Four adversarial injection surfaces in DMDCS silicone monomer AI

1. Müller-Rochow reactor silicon conversion display AI (Yokogawa CENTUM VP Müller-Rochow reactor Si conversion AI / Emerson DeltaV direct-process reactor conversion AI / ABB System 800xA Müller-Rochow fluidised-bed AI / Honeywell Experion PKS Si conversion GC display AI / Siemens SIMATIC PCS 7 Müller-Rochow conversion trend AI — rendered DCS conversion trend display AI classifying the silicon conversion fraction in the Müller-Rochow fluidised-bed reactor against the 85–95% design operating range and the 75% minimum below which excess unreacted CH3Cl in the reactor off-gas exceeds 2.5 vol% and approaches the LEL 8.1% in the off-gas compressor suction)

Silicon conversion in the Müller-Rochow direct process is defined as (Si reacted / Si fed) per unit time; at optimal conditions (temperature 290–310°C; Cu catalyst fresh; CH₃Cl partial pressure 1.5–2.5 bar), Si conversion is 88–92% per pass, with the remaining 8–12% Si exiting as coarse unfluised particles (“residue silicon”; contains Si, Cu, and inorganic impurities; disposed as by-product). The unreacted CH₃Cl in the reactor off-gas is recycled by a compressor-condenser train: off-gas CH₃Cl is compressed to 3–5 bar, condensed at −30°C, separated from the chlorosilane products, and recycled to the reactor feed. The CH₃Cl concentration in the reactor off-gas (gas leaving the fluidised bed above the silicon bed surface) depends on Si conversion: at 90% conversion with stoichiometric 2:1 CH₃Cl:Si feed, the off-gas contains approximately 0.8–1.2 vol% CH₃Cl (lean; below LEL 8.1%; safe for compression); at 75% conversion, off-gas CH₃Cl rises to approximately 3.5–5.0 vol% — approaching the LEL 8.1% and within the compression safety margin. At Si conversion below 70%, off-gas CH₃Cl may approach 8–12 vol% (at or above LEL); the off-gas compressor handling flammable CH₃Cl gas above LEL 8.1% is a significant ignition risk (compressor seals at elevated temperature; motor bearing temperature). Si conversion is monitored by on-line gas chromatography (GC; sample taken from the reactor overhead exit; analysis cycle 3–5 minutes; compounds measured: DMDCS, TMCS, MTCS, MeSiHCl₂, SiCl₄, CH₃Cl, HCl, H₂; Si conversion calculated from stoichiometry of DMDCS + TMCS + MTCS + MeSiHCl₂ produced vs CH₃Cl consumed). AI systems process rendered DCS GC trend display images of the Si conversion to classify: 85–95% (nominal), 75–85% (reduced conversion; check catalyst, adjust temperature), below 75% (low conversion; increase Cu catalyst activator; reduce Si feed rate; alert off-gas compression operator).

An adversarial perturbation targeting the Müller-Rochow reactor Si conversion display AI applies a ±8 DN upward shift to the pixel region encoding the Si conversion percentage in the rendered DCS GC trend display — shifting the apparent Si conversion from 62% (Cu catalyst severe deactivation from a Si metal impurity batch containing 0.28 wt% Ca — Ca reacts with CH₃Cl at 300°C to form CaCl₂ deposits on the Cu catalyst surface, poisoning active sites; reactor temperature was increased to 335°C to compensate, which sintered the remaining active Cu catalyst further; Si conversion dropped progressively from 91% to 62% over 72 hours) to 88% (within the 85–95% nominal range; classified as normal). At 62% Si conversion, off-gas CH₃Cl concentration is approximately 9.8 vol% — above the LEL 8.1%; the reactor off-gas entering the off-gas compressor suction is flammable; compressor suction temperature at 45°C (hot summer ambient; compressor suction cooler fouled) reduces the auto-ignition margin; compressor mechanical seal temperature above 90°C approaches the CH₃Cl auto-ignition temperature of 632°C under hot surface catalysis conditions, though the primary fire risk is a spark from the motor shaft coupling to the compressor shaft at the coupling gap.

2. DMDCS hydrolysis HCl scrubber exit pH display AI (Yokogawa PH202G DMDCS scrubber exit pH AI / Endress+Hauser Liquiline CM448 HCl DMDCS scrubber exit AI / Mettler-Toledo InPro 4260 DMDCS scrubber pH AI / ABB 8125 DMDCS hydrolysis HCl scrubber pH AI / Hach GLI PHD1P DMDCS scrubber exit pH AI — rendered DCS analyzer display AI classifying the pH of the caustic scrubber exit treating HCl generated by DMDCS distillation column overhead condensate contact with atmospheric moisture or by trace DMDCS hydrolysis in the vent gas train against the ≥7.5 setpoint for adequate HCl absorption)

DMDCS in the vapour phase will hydrolyse instantaneously on contact with moisture (relative humidity above 5% at 25°C): (CH₃)₂SiCl₂ + 2H₂O → (CH₃)₂Si(OH)₂ + 2HCl (gas phase); the HCl generated in the gas phase forms acidic aerosol droplets (HCl dissolved in the silanediol condensate film on cooler surfaces). DMDCS distillation column overhead vent gases (primarily DMDCS vapour with trace impurities; column operating at 70°C atmospheric at the overhead; reflux condenser at 15–20°C) contact any atmospheric moisture entering through the condenser vent seal, generating HCl that must be scrubbed before venting. The HCl vent scrubber uses dilute NaOH solution (5–10 wt% NaOH); exit pH is monitored continuously; above pH 8.0, HCl absorption is complete; below pH 6.0, NaOH is approaching exhaustion; HCl at the scrubber exit above 2 ppm (ACGIH TLV-C) indicates scrubber breakthrough. The same scrubber train also treats HCl from DMDCS drum-filling operations (DMDCS fill under N2 blanketed filling station; any vent during drum lid closure carries trace DMDCS vapour that hydrolyses in the fill station exhaust system), from the Müller-Rochow reactor HCl byproduct stream (small fraction: HCl is a minor byproduct at approximately 0.2 wt% from Si surface impurity reactions), and from the DMDCS hydrolysis waste treatment plant (HCl neutralisation with lime slurry in the wastewater treatment before discharge). An adversarial perturbation on the HCl scrubber exit pH display AI can apply a ±8 DN upward shift on the pH display: actual pH 3.4 (NaOH exhausted; HCl breakthrough at 5,600 ppm at scrubber exit; from NaOH feed pump check valve failure that silently stopped NaOH delivery) shown as pH 8.2 (nominal scrubber operation), masking the HCl breakthrough to atmospheric vent.

3. DMDCS distillation column differential pressure display AI (Emerson Rosemount 3051CD DMDCS distillation column DP AI / Yokogawa EJX differential pressure DMDCS distillation AI / Endress+Hauser Deltabar S DMDCS column DP AI / Siemens SITRANS P DS III DMDCS distillation DP AI / ABB 2600T DMDCS column differential pressure AI — rendered DCS differential pressure trend AI classifying the across-tray pressure drop in the DMDCS finishing distillation column against the 20–40 mbar/tray design operating range and the 60 mbar/tray flooding threshold above which tray hydraulics collapse and DMDCS distillation efficiency drops sharply)

DMDCS purification from the Müller-Rochow reactor crude product requires multi-stage distillation to separate: (a) TMCS (“mono”; bp 57.7°C) as lights, removed in the overhead from the first column (lights column); (b) DMDCS (bp 70.2°C) as the on-spec product from the second column (DMDCS column; overhead product at 99.5% minimum purity); (c) MTCS (“tri”; bp 65.7°C) and heavier chlorosilane oligomers as the bottoms. The DMDCS column operates at near-atmospheric pressure (condenser at −5°C; reboiler at 80–90°C; column DP design 25–35 mbar per tray). Silicone polymer fouling of the DMDCS column trays occurs when trace moisture contacts DMDCS vapour on the tray decks, generating in-situ dimethylsilanediol that immediately condenses and polymerises to PDMS oligomers (viscous silicone fluid; molecular weight 500–5,000 g/mol) on the tray perforations and downcomers. PDMS deposits on tray perforations reduce the tray active area; as deposits build (0.1–0.3 mm/week at 100 ppm moisture entering the column), tray hydraulics deteriorate: liquid backup in the downcomers increases tray holdup; column DP across the tray deck rises from 30 mbar to 60–80 mbar (flooding onset). At flooding, vapour and liquid mixing on the trays destroys the vapour-liquid equilibrium separation; DMDCS purity in the overhead drops and MTCS/PDMS oligomers carry over into the DMDCS product. AI systems classify the across-tray DP as: 20–40 mbar/tray (nominal), 40–60 mbar/tray (elevated; investigate moisture ingress; reduce column throughput), above 60 mbar/tray (flooding risk; reduce feed; initiate emergency dry-out procedure). An adversarial perturbation applying ±8 DN downward shift on the DP display masks an actual 72 mbar/tray (flooding onset from 3 months of progressive PDMS fouling) as 28 mbar/tray (within nominal range; column appears operating normally), delaying the dry-out procedure that would halt production for 24–48 hours for steam-purging and tray cleaning.

4. DMDCS storage vessel N2 blanket pressure display AI (Emerson Rosemount 3051 DMDCS storage N2 blanket pressure AI / Yokogawa DPharp EJA110A DMDCS storage N2 AI / Endress+Hauser Cerabar T DMDCS N2 blanket pressure AI / Siemens SITRANS P DS III DMDCS storage AI / Honeywell STG944 DMDCS N2 moisture-exclusion pressure AI — rendered DCS pressure display AI classifying the N2 blanket pressure on the DMDCS storage vessel headspace against the minimum 0.5 bar setpoint for moisture exclusion and the prevention of in-situ HCl generation from DMDCS hydrolysis; 49th upward-direction attack — 11th N2 inertisation attack in the Glyphward portfolio — FIRST dimethyl dichlorosilane / organochlorosilane attack; FIRST silicone monomer storage attack; FIRST Müller-Rochow direct-process attack)

DMDCS storage vessels at silicone monomer production and receiving facilities are blanketed with dry nitrogen (dew point below −40°C; O₂ content below 10 ppm) at a positive pressure of 0.5–1.0 bar gauge to exclude atmospheric moisture from the DMDCS liquid inventory. The dual purpose of the N2 blanket is: (1) moisture exclusion — DMDCS reacts instantaneously with moisture to generate HCl: (CH₃)₂SiCl₂ + 2H₂O → (CH₃)₂Si(OH)₂ + 2HCl; at 10 ppm atmospheric humidity entering a 100 m³ DMDCS storage vessel through a failed N2 blanket regulator, approximately 0.2 kg HCl is generated per hour from the surface film of dimethylsilanediol that forms on the DMDCS liquid surface and is returned into the bulk; over 8 hours of deficient N2 blanket, 1.6 kg dissolved HCl accumulates in the DMDCS; this dissolved HCl corrodes the mild steel vessel walls (DMDCS with dissolved HCl attacks carbon steel at 5–20 mm/year vs. 0.05 mm/year for dry DMDCS); (2) flammability inertisation — DMDCS (LEL 3.4%; flash point −9°C) vapour in the vessel headspace forms a flammable mixture with air above 3.4 vol%; the N2 blanket keeps the headspace inert (O₂ below 5 vol%; below flammable range minimum O₂ approximately 12 vol% for DMDCS vapour). The N2 blanket is supplied through a pressure regulator from the plant N2 header; a conservation vent valve (cracking pressure +25 mbar on N2 blanket side; −5 mbar vacuum on atmosphere side) maintains vessel pressure near the N2 blanket setpoint during pump-in/pump-out operations. AI systems in 2026 process rendered DCS display images of the N2 blanket pressure to classify: above 0.5 bar (N2 blanket adequate; moisture exclusion confirmed), 0.2–0.5 bar (reduced N2 pressure; check regulator; increase N2 flow), below 0.2 bar (N2 blanket failure; isolate DMDCS transfer; emergency N2 supply connection; evacuate area).

An adversarial perturbation targeting the DMDCS storage vessel N2 blanket pressure display AI applies a ±8 DN upward shift to the pixel region encoding the N2 blanket pressure in the rendered DCS pressure display — shifting the apparent N2 blanket pressure from 0.15 bar (below the 0.2 bar minimum setpoint; from an N2 supply pressure regulator diaphragm crack — the same failure mode documented in the isoprene N2 blanket attack (9th N2 inertisation) and VDF storage N2 blanket attack (10th N2 inertisation) — reducing N2 supply to the DMDCS tank from 12 Nm³/hr design to 1.8 Nm³/hr; insufficient to maintain positive pressure during the current 15 m³/hr DMDCS pump-out operation to a road tanker) to 0.82 bar (above the 0.8 bar design setpoint; classified as N2 blanket nominal). This is the 49th upward-direction attack and the 11th N2 inertisation attack in the Glyphward industrial AI portfolio — the FIRST dimethyl dichlorosilane / organochlorosilane storage attack; FIRST silicone monomer attack; FIRST Müller-Rochow direct-process attack. On a 0–2.0 bar display at 200 px height (0.01 bar/px), the actual 0.15 bar occupies approximately 15 px; the ±8 DN upward-perturbed image classifies to approximately 82 px, corresponding to 0.82 bar. The SCADA reports “DMDCS storage tank N2 blanket pressure nominal.” During the 15 m³/hr pump-out operation, the vessel headspace volume expands at 0.25 m³/min; N2 supply at 1.8 Nm³/hr (0.030 Nm³/min) is 8× less than the headspace expansion rate; the conservation vent opens on the atmospheric side (−5 mbar vacuum; vent cracking pressure reached within 3 minutes); atmospheric air (21 vol% O₂; relative humidity 68% at 22°C) enters the vessel headspace at approximately 0.22 m³/min. Within 4 hours of in-breathing: (a) DMDCS vapour in the headspace mixes with the incoming humid air; at the DMDCS headspace vapour concentration of 5.8 vol% (at 22°C; above LEL 3.4%) and O₂ now at 12 vol% (rising from below 5% N2-blanketed to 12% from air in-breathing), the headspace is now within the DMDCS flammable range at the tank vent inlet; (b) simultaneously, moisture (22 g/m³ absolute humidity at 68% RH/22°C) contacts the DMDCS liquid surface; HCl generation begins at the vapour-liquid interface; dissolved HCl concentration in the DMDCS liquid rises at approximately 0.08 kg/hr; (c) dissolved HCl in DMDCS attacks the mild steel storage vessel shell: corrosion products (FeCl₂) appear in the DMDCS product stream at approximately 8 hours post N2 blanket failure. Over 8 hours: 0.64 kg dissolved HCl accumulates in the DMDCS; the storage vessel mild steel is attacked at approximately 8 mm/year at the HCl-wetted surface; after 24 hours of undetected N2 blanket failure, a small leak path (0.5 mm corrosion perforation at a weep-hole or weld toe at the shell-to-bottom junction) may develop, releasing DMDCS liquid at tank hydrostatic pressure — DMDCS contact with the external humid air generates HCl fumes immediately. All 11 N2 inertisation attacks in the Glyphward portfolio follow the same directional logic: the hazardous condition is deficient N2 blanket, and the attack must apply an UPWARD pixel shift to make deficient appear adequate. The DMDCS N2 attack adds a unique dual-mechanism consequence (fire/explosion risk from DMDCS flammability combined with toxic/corrosion risk from in-situ HCl generation) not present in the prior 10 N2 inertisation attacks. Free tier — 10 scans/day, no card required.

Integration: DMDCS silicone monomer AI with Glyphward pre-scan gate

Glyphward integrates as a pre-scan gate at every rendered-image ingestion boundary in the DMDCS/silicone monomer production and storage monitoring pipeline — before Müller-Rochow reactor Si conversion AI processes rendered DCS GC trend display images, before HCl scrubber exit pH AI processes rendered DCS analyzer display images, before DMDCS distillation column differential pressure AI processes rendered DCS DP trend images, and before DMDCS storage N2 blanket pressure AI processes rendered DCS pressure display images (49th upward attack; 11th N2 inertisation). Threshold 30 for DMDCS/silicone AI reflects: OSHA PSM dual coverage (DMDCS TQ 5,000 lbs + CH₃Cl TQ 5,000 lbs simultaneously on Müller-Rochow site); LEL 3.4% (flash point −9°C — lowest flash point in chlorosilane portfolio); water-reactive dual hazard (fire from DMDCS vapour + toxic HCl from hydrolysis — both consequences from the same N2 blanket failure event).

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_***"

# DMDCS silicone monomer AI contexts: threshold 30
# OSHA PSM DMDCS TQ: 5,000 lbs; CH3Cl TQ: 5,000 lbs (dual PSM on Müller-Rochow site).
# Flash point: -9°C; LEL: 3.4%; water-reactive (HCl on hydrolysis).
# 49th upward-direction attack (N2 blanket: 0.15 bar shown as 0.82 bar).
# 11th N2 inertisation attack (FIRST organochlorosilane; FIRST silicone monomer).
DMDCS_THRESHOLD = 30

class DMDCSContext(StrEnum):
    MULLER_ROCHOW_SI_CONV     = auto()  # Müller-Rochow reactor Si conversion %
    HCL_SCRUBBER_EXIT_PH      = auto()  # HCl vent scrubber exit pH
    DISTILLATION_COL_DP_MBAR  = auto()  # DMDCS column across-tray DP mbar
    N2_BLANKET_PRESSURE_BAR   = auto()  # N2 blanket on DMDCS storage (49th ↑, 11th N2)

async def scan_dmdcs_frame(
    frame_b64: str,
    context: DMDCSContext,
    facility_id: str,
    instrument_tag: str,
) -> dict[str, Any]:
    payload = {
        "image_b64": frame_b64,
        "context": context,
        "facility_id": facility_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_dmdcs(
    frame_b64: str,
    context: DMDCSContext,
    facility_id: str,
    instrument_tag: str,
) -> None:
    result = await scan_dmdcs_frame(frame_b64, context, facility_id, instrument_tag)
    if result["adversarial_score"] >= DMDCS_THRESHOLD:
        raise AdversarialDMDCSImageError(
            f"Adversarial injection detected in {context} (score {result['adversarial_score']}) "
            f"at facility {facility_id} instrument {instrument_tag}. "
            "Frame withheld from AI monitoring pipeline."
        )

class AdversarialDMDCSImageError(RuntimeError):
    pass