We are looking for an experienced Lead / Principal Process Engineer to join our team in Kolkata, West Bengal
Experience: 12+ years in Process Engineering / Biochemical Engineering / Mechanical / Piping / in Water-Wastewater / Oil & Gas or related industry
Bio-CNG / CBG Experience: Minimum 5 years
Location: Kolkata | In office / Hybrid
Employment: Full-Time

Key Expertise:
Process Design & Engineering
· Lead the conceptual design, FEED (Front-End Engineering Design), and detailed process engineering of Bio-CNG plants.
· Optimize anaerobic digestion (AD) systems specifically for tough, fibrous local feedstocks like Napier grass and paddy/rice straw.
· Design efficient feedstock pre-treatment, milling etc systems tailored to handle high-silica and high-lignin materials.
· Develop Mass & Energy Balances, Process Flow Diagrams (PFDs), and Piping & Instrumentation Diagrams (P&IDs;)
Technology Selection & Biogas Upgrading
· Should have knowledge about technologies for biogas purification and upgrading (e.g., membrane separation/ Water Scrubbing/ PSA)



to meet IS 16087:2016 standards for commercial Bio-CNG.
· Design and integrate digestate management, solid-liquid separation, and organic fertilizer (FOM/LFOM) production systems.
· Establish process safety frameworks, including leading HAZOP (Hazard and Operability) studies and adhering to PESO (Petroleum and Explosives Safety Organization) guidelines.
Project Leadership & Lifecycle Management
· Collaborate closely with mechanical, electrical, instrumentation, and civil engineering teams.
· Support plant commissioning, performance testing, troubleshooting, and continuous process optimization
Technical & Feedstock Expertise
· Lignocellulosic Biomass Expertise: Having working experience with agricultural residues; specific experience with Napier grass and Rice Straw is highly preferred.
· Solid understanding of anaerobic digestion chemistry, including C:N ratio balancing, volatile fatty acids (VFA) tracking, and enzymatic or hydro

📌 Lead / Principal Process Engineer (Bio-CNG) (India)
🏢 Rigel BioEnviron Solutions
📍 India