AD-401 Cooling-Tower Biocide for Power Generation in Karachi
Non-oxidising microbiocide for Karachi power-station cooling loops. Stocked in drums on the Clifton site, shipped same-day via the M-9 corridor.
Karachi's power generation footprint is concentrated within a 40 km arc: K-Electric Bin Qasim I+II, the Korangi gas plants, KANUPP-2/3 at Paradise Point, and the Port Qasim coal complex (Lucky, Engro Powergen, Port Qasim Electric). Almost all of these run open recirculating cooling on brackish or sea-influenced makeup.
Sea-influenced makeup means sulphate-reducing bacteria (SRB) load is structurally higher than for upcountry plants drawing from canals or tubewells. SRB drives microbiologically-influenced corrosion (MIC) on carbon-steel headers, and Legionella risk on aerated towers is a documented concern from the K-Electric reliability audits.
Most Karachi cooling-tower programmes use a chlorine + non-oxidising rotation. Drift in chlorine residual across a 30,000 m³/h tower is non-trivial in summer when air temperatures push 38°C+ and biocide demand spikes. AD-401 fills the gap on the non-oxidising side.
We're 12–25 km from Bin Qasim, Korangi, and Port Qasim plants. Same-day truck dispatch from our Clifton warehouse for shock-dose calls; emergency-line WhatsApp is staffed 24/7 because cooling-tower problems are not 9-to-5 problems.
AD-401 is a non-oxidising broad-spectrum biocide formulated for open recirculating cooling water. Active content 15–20%, pH 3.0–5.0, amber liquid. Effective on slime-forming bacteria, fungi, algae, and SRB. Designed to be rotated with oxidising chemistries (chlorine, bromine) on a 3–7 day alternation to prevent resistance development.
- Stage: dosed into the cooling-tower basin or recirculating header upstream of the heat exchangers.
- Function: penetrates established biofilm, disrupts microbial cell membranes, and kills the planktonic + sessile bacteria load. Especially targets SRB colonies under tubercle deposits.
- Shock dose: 50–150 ppm, contact time 4–6 hours with bleed off, frequency once weekly to once monthly depending on system.
- Continuous dose: 25–50 ppm on systems with structural biofouling pressure (food/petrochem-adjacent makeup, high organic load).
- Rotation: alternate with chlorine or stabilised bromine every 3–7 days. We write the rotation calendar as part of the programme deliverable.
Where AD-401 chemistry has run on power generation sites near Karachi.
Selected, anonymised. Site-specific case studies and references shared on supplier-qualification request.
Combined-cycle gas plant · Korangi · 2023
AD-401 + AD-303 programme on a 22,000 m³/h cooling tower. SRB count reduced from 10⁶ to <10² per mL within four weeks of programme start.
Captive power plant · SITE Karachi · 2024
Replaced an imported isothiazolinone biocide with AD-401 at 40% lower cost-in-use, biocide rotation calendar tightened from 14-day to 5-day cycle.
Industrial cooling loop · Bin Qasim · 2022
8,500 m³/h carbon-steel tower with chronic MIC. AD-401 + AD-303 stabilised the system at cycles-of-concentration 5.2 across 18 months.
Tell us your site, the loop, the symptom, the volume.
Same-business-day reply from Karachi with a programme outline and the relevant CoAs / SDS attached. Or WhatsApp the engineering line directly; same engineer who writes the dosing programme answers the message.