Chemical Plant Engineering

We deliver multi-discipline engineering for greenfield and brownfield chemical, petrochemical and specialty chemical plants — from concept and FEED through detailed engineering, construction support and startup.

Engineering Challenges

Chemical facilities demand rigorous process safety management, corrosive-environment material selection, complex piping, and close coordination between process, mechanical, structural and I&C disciplines — all while operating facilities safely.

Key Technical Requirements

Process Safety Management (PSM)

• Hazard and Operability (HAZOP) analysis per API RP 750
• Layer of Protection Analysis (LOPA) and Safety Integrity Level (SIL) determination
• Management of Change (MOC) procedures and documentation
• Process Safety Information (PSI) database and P&IDs
• Compliance with OSHA PSM 29 CFR 1910.119

Piping & Pressure Systems

• Pressure piping design per ASME B31.3 (process) or B31.8 (gas) — see the Pressure Vessel Design guide for equipment-side rules
• Stress analysis for thermal expansion, vibration and equipment reactions
• Corrosion allowance and material selection (CS, SS, Duplex, Hastelloy, etc.)
• Pressure relief device sizing and overpressure protection per API 520/521
• Flare system design and tail gas disposal
• Valve selection for process isolation and control — see the Valve Types and Applications guide

Equipment & Structures

• Distillation columns, reactors, heat exchangers, storage tanks (size with the Pressure Vessel Volume Calculator and Steel Weight Calculator)
• Positive displacement and centrifugal process pumps (PD pump guide)
• Pipe racks with equipment supports and cantilever loads
• Structural design for future expansion (e.g., module addition)
• Foundation design for heavy rotating equipment
• Equipment isolation, vibration damping

Instrumentation & Control

• DCS/PLC systems with redundancy for critical loops
• Safety Instrumented Systems (SIS) for high-consequence functions
• Field instrumentation (temperature, pressure, flow, level)
• Human-Machine Interface (HMI) for operator situational awareness

Environmental & Utilities

• Wastewater treatment and disposal per local regulations
• Air emissions control (scrubbers, thermal oxidizers, etc.)
• Utility demand (power, steam, cooling water, nitrogen, etc.)
• Waste handling and disposal procedures

Our Engineering Approach

We integrate process simulation, 3D plant modeling and safety reviews from project inception. Every chemical project is delivered with complete HAZOP documentation, overpressure protection per API standards, and constructible piping/structural designs coordinated across disciplines.

Detailed Design Services

Phase 1: Front-End Engineering Design (FEED)

• Preliminary process simulation and material balances
• Equipment sizing and cost estimation
• 3D conceptual plant layout
• Risk screening (initial HAZOP)
• Utility and infrastructure requirements

Phase 2: Detailed Engineering

• Finalized P&IDs and process data sheets
• Complete HAZOP/LOPA with SIL determination
• Piping 3D models with stress analysis
• Structural calculations and drawings
• Electrical one-line diagrams and load flow
• DCS/SIS logic specifications and loop diagrams

Phase 3: Construction Support

• Construction document review and RFIs
• Site inspection and quality control
• Equipment vendor coordination
• Pre-commissioning checklists and pressure testing
• Training documentation for operations

Phase 4: Commissioning & Startup

• Pre-startup safety review (PSSR)
• Operator and technician training
• Performance testing and troubleshooting
• Performance guarantees verification

Technology Stack

• Process Simulation: Aspen Plus, Hysys for steady-state and dynamic models
• BIM/Plant Modeling: AutoCAD Plant 3D, Intergraph SmartPlant for 3D P&ID + isometrics
• Structural Analysis: STAAD Pro, SAP2000 for pipe racks and equipment supports
• Piping Stress: Caesar II for pressure piping stress analysis
• Safety Analysis: HAZOP facilitation, LOPA calculations, SIL verification
• Electrical: ETAP for power systems, SIS logic design tools

Typical Project Scope

Plant Types:

• Commodity chemicals (ammonia, chlor-alkali, etc.)
• Specialty chemicals (pharma intermediates, fine chemicals)
• Petrochemicals (ethylene, propylene, BTX)
• Refinery units (hydroprocessing, reforming, visbreaking)
• Environmental processing (wastewater, emissions control)

Facility Size: 10,000–200,000 m²

Typical Investments: $50M–$500M+

Timeline: 6–18 months design + 12–24 months construction

Unit Conversion Reference

Chemical plant engineering data crosses SI and US customary units daily. Common conversions used in process and piping work:

Example: a 200 m³/h process line = 200 × 4.403 ≈ 881 gpm. A 10 bar design pressure = 145 psi. Always convert P&ID and data sheet values to one consistent unit system before sizing.

Design Standards & Compliance

Design Codes:

• ASME B31.3: Process piping design
• ASME B31.8: Gas transmission and distribution piping
• ASME Boiler & Pressure Vessel Code: Pressure equipment
• API 650: Large welded low-pressure storage tanks
• API 620: Design and construction of large, welded, low-pressure storage tanks

Safety Standards:

• API RP 750: Management of Process Hazards
• OSHA PSM (29 CFR 1910.119)
• ASME RTP-1: Recommended Practice for Reinforced Thermoplastic Pipe
• IEC 61508/61511: Functional Safety (SIL determination)

Environmental Compliance:

• EPA Clean Air Act: VOC/HAP emissions limits
• EPA Clean Water Act: Wastewater discharge permits
• RCRA: Hazardous waste handling and disposal
• Local permitting: City/state environmental review

Common Applications

Petrochemical Crackers

• Ethylene and propylene production from naphtha/ethane
• Polyethylene and polypropylene feed supply
• By-product recovery (fuel gas, BTX)

Specialty Chemical Plants

• Pharmaceutical intermediates synthesis
• Fine chemical batch processing
• Agrochemical production

Refinery Processing Units

• Hydroprocessing (hydrotreating, hydrocracking)
• Catalytic reforming
• Alkylation and polymerization

Environmental Processing

• Wastewater treatment (biological, chemical)
• Air emission control (thermal oxidation, scrubbing)
• Waste incineration and recovery

Risk Management & Safety

Our HAZOP facilitation identifies potential failure modes across:

• Equipment malfunction or failure
• Instrumentation and control failures
• Human factors and operational errors
• External events (utilities loss, extreme weather)
• Domino effects and cascade failures

For each identified hazard, we determine:

• Severity (consequence rating)
• Likelihood (occurrence frequency)
• Existing safeguards and their effectiveness
• Recommended additional layers of protection (SIL levels)

Related Engineering Services

Structural Engineering: Pipe racks, equipment foundations, equipment supports Industrial Building Design: Control rooms, maintenance facilities, storage buildings HVAC & Utilities: Air supply, cooling systems, waste gas handling

Quick Calculations

Use our tools to size critical piping and equipment:

• Pump power for fluid transfer: Pump Power Calculator
• Pressure drop across pipe runs: Pressure Drop Calculator
• Thermal duty calculations: Heat Transfer Calculator
• Storage tank volume: Tank Volume Calculator
• Vessel and head volume: Pressure Vessel Volume Calculator
• Line flow and velocity: Flow Rate Calculator and Pipe Velocity Calculator
• Pump head and NPSH: Pump Head Calculator
• P&ID reading and symbols: Understanding P&ID Diagrams
• Corrosion-resistant material selection: Corrosion Prevention Guide
• Steam and condensate systems: Steam System Fundamentals
• Pump selection: Pump Selection Guide

Project Examples

We have engineered greenfield and brownfield projects for petrochemical majors, independent refiners, specialty chemical producers and toll manufacturers. Our portfolio spans commodity chemicals, bulk pharmaceuticals, and environmental processing facilities across multiple continents.

Frequently Asked Questions

What does chemical plant engineering cover? Chemical plant engineering covers the full lifecycle of process facilities: process design and simulation, piping and pressure system design (ASME B31.3), equipment specification, pressure relief and flare systems, structural design, instrumentation and control, process safety management (PSM), and environmental compliance. Delivery spans FEED through detailed engineering, construction support, commissioning and startup.

How often should HAZOP be performed? HAZOP is performed at defined stages of a project — typically at conceptual/FEED stage and again at detailed design before construction — and periodically during operation (often every 3-5 years or after significant modifications). OSHA PSM and IEC 61882 require systematic revalidation of process hazard analyses.

What is the difference between ASME B31.3 and B31.8? ASME B31.3 covers process piping in chemical, refinery and industrial plants, including fluids with high consequence of release. B31.8 covers gas transmission and distribution piping systems. A chemical plant's in-plant process lines are B31.3; long-distance gas transmission lines to and from the facility are B31.8.

What is FEED in chemical plant projects? Front-End Engineering Design (FEED) is the engineering phase between conceptual design and detailed engineering. It develops process simulation, preliminary P&IDs, equipment sizing, plot plan, cost estimate (±20-30%) and initial HAZOP so the owner can make a final investment decision before committing to detailed engineering.

What are the main process safety requirements for a chemical plant? Under OSHA PSM (29 CFR 1910.119) and equivalent regulations, plants handling hazardous chemicals need process safety information, P&IDs, mechanical integrity programs, management of change, pre-startup safety reviews, operating procedures, training, incident investigation, emergency planning, and compliance audits — with HAZOP/LOPA used to establish safeguards and SIL requirements.

How long does it take to build a chemical plant? A typical $50M-$500M chemical plant takes 6-18 months of design plus 12-24 months of construction. Specialty chemical plants are often faster, large petrochemical crackers slower. Overall project duration is driven by permitting, long-lead equipment, and contractor availability.

Next Steps

Have a chemical or petrochemical project in scope? Our team has deep expertise in process safety, compliance and risk management, combined with 20+ years of successful project delivery.