An Air Emission Inventory is a structured study that identifies and quantifies air pollutants released from a facility, project site, industrial area or defined region over a specific period. It helps facility owners understand what pollutants are emitted, where they come from and how much is released into the atmosphere. For industrial facilities, an Air Emission Inventory is an important technical basis for environmental permitting, air quality management, air dispersion modelling, emission reduction planning, ESG reporting and regulatory compliance.
iFluids Engineering & Consultancy WLL provides reliable Air Emission Inventory Study services for oil and gas facilities, refineries, petrochemical plants, power plants, ports, utilities, manufacturing units and infrastructure projects. Our approach combines engineering data review, process understanding and approved calculation methods to deliver clear, traceable and compliance-ready emission reports.
What is an Air Emission Inventory?
An Air Emission Inventory is a source-wise and pollutant-wise record of emissions from all relevant sources within a defined study boundary. It may be prepared for an existing plant, new project, expansion facility, industrial estate or regional air quality assessment.
The inventory typically covers:
- Point sources such as stacks, boilers, heaters, diesel generators, turbines, incinerators, vents and process exhausts.
- Area and fugitive sources such as storage tanks, loading areas, wastewater units, solvent use, material handling, construction activities and fugitive VOC sources.
- Line and mobile sources such as plant vehicles, trucks, buses, construction equipment, forklifts, marine vessels and other mobile equipment.
The final output is a clear emission database that helps the facility owner understand the actual emission profile and identify sources that may require monitoring, control or further evaluation.
Air Emission Inventory of Criteria Pollutants
An Air Emission Inventory of Criteria Pollutants focuses on pollutants that are commonly evaluated for air quality impact, environmental approval and public health protection.
Depending on the project scope, the study may include:
- Particulate Matter, including TSP, PM10 and PM2.5
- Nitrogen Oxides, including NOx, NO and NO2
- Sulphur Oxides, including SO2 and SOx
- Carbon Monoxide
- Volatile Organic Compounds and Non-Methane VOCs
- Hydrocarbons, where applicable
- Ammonia, metals or toxic pollutants, where relevant
- Greenhouse gases such as CO2, CH4 and N2O, when required
The pollutant list is finalized based on the process type, fuel usage, raw materials, emission sources, control systems, local regulatory requirements and the purpose of the study.
Why Air Emission Inventory is Important for Industrial Facilities
A well-prepared Air Emission Inventory helps owners and operators understand their emission sources in a structured and auditable format. It supports compliance, modelling, reporting and practical emission reduction planning.
| Importance Area | How Air Emission Inventory Supports Industrial Facilities |
| Environmental Approval and Permitting | Provides source-wise emission rates required for EIA studies, environmental permits, consent applications and authority submissions. |
| Air Dispersion Modelling | Supplies emission data from stacks, vents, fugitive sources and mobile sources for air quality impact assessment and dispersion modelling. |
| Emission Reduction Planning | Identifies major emission contributors and helps prioritize controls such as fuel improvement, combustion optimization, vapour recovery, filtration, scrubbers and dust suppression. |
| Regulatory and Corporate Reporting | Supports environmental audits, compliance reports, ESG disclosure, sustainability reporting and internal emission tracking. |
| Baseline and Future Planning | Establishes a reliable emission baseline to compare future expansions, production changes, plant modifications or new emission control systems. |
Our Air Emission Inventory Methodology
1. Study Objective, Boundary and Pollutant Scope
The study begins by defining the purpose, boundary, inventory period and pollutants to be assessed. iFluids confirms the source categories, operating cases and reporting units such as g/s, kg/hr, kg/day or tonnes/year to ensure the inventory is aligned with project and regulatory requirements.
2. Data Collection and Source Information Review
Relevant engineering, process and operating data are reviewed to develop a reliable emission basis. This may include stack details, fuel consumption, operating hours, production rates, storage tank data, VOC material usage, control equipment details, vehicle movements and available monitoring records.
Where information is incomplete, data gaps are clearly identified and suitable engineering assumptions are documented.
3. Source Identification and Classification
All emission sources are identified and classified as point sources, area/fugitive sources or line/mobile sources. This ensures that major sources such as stacks, vents, tanks, loading areas, vehicles and construction equipment are properly captured without omission or double counting.
4. Selection of Calculation Method
The most suitable calculation method is selected based on the source type and data availability. iFluids uses direct monitoring or stack test data where available. For other sources, emissions are estimated using emission factors, mass balance, mass loading, fuel-based calculations or engineering methods.
General calculation basis:
Emission = Activity Data × Emission Factor × Control Efficiency Adjustment
5. Emission Factor Selection and Justification
Emission factors are selected from recognized references, vendor data, stack test results, local studies or authority-accepted sources. Each factor is reviewed against the source type, fuel type, process condition, control system, pollutant type and unit consistency before being applied.
6. Emission Calculation and Unit Conversion
Source-wise emissions are calculated for each pollutant and converted into the required reporting units. Results may be presented as g/s for dispersion modelling, kg/hr for operational review, kg/day for daily estimates or tonnes/year for annual reporting.
Control efficiencies are applied where abatement systems such as scrubbers, filters, ESPs, catalytic systems or vapour recovery units are installed.
7. Spatial and Temporal Allocation
Emissions are assigned to the correct location and operating period. This may include stack coordinates, area source boundaries, road routes, plant zones, operating hours, seasonal variations, batch operations and intermittent activities where required for modelling or source contribution assessment.
8. Quality Assurance, Gap Review and Uncertainty Check
The inventory is reviewed for completeness, calculation accuracy and consistency. iFluids checks source coverage, unit conversions, emission factor suitability, control efficiency, fuel data and production data. Assumptions, limitations and uncertainty areas are clearly documented to make the final inventory traceable and suitable for technical review.
9. Source Ranking and Emission Reduction Planning
Final results are evaluated to identify the major contributing sources for each pollutant. Based on the findings, iFluids recommends practical improvement measures such as combustion optimization, fuel quality improvement, fugitive emission control, vapour recovery, dust suppression, improved maintenance, stack monitoring or additional emission control systems.
Key Deliverables
A typical Air Emission Inventory Study includes:
- Air Emission Inventory report
- Source-wise emission register
- Pollutant-wise emission summary
- Point, area and mobile source classification
- Emission calculation workbook
- Emission factor reference table
- Activity data and assumption register
- Annual, daily or seasonal emission estimates
- Source contribution and ranking summary
- GIS or layout-based emission source mapping, if required
- Data gap and uncertainty summary
- Recommendations for monitoring and emission reduction
- Input emission rates for air dispersion modelling, if included in the scope
Industries We Support
iFluids provides Air Emission Inventory services for:
- Oil and gas facilities
- Refineries and petrochemical plants
- LNG and gas processing facilities
- Power generation plants
- Chemical and manufacturing industries
- Ports and marine terminals
- Industrial estates
- Waste treatment facilities
- Utilities and captive power units
- Storage terminals and loading facilities
- Infrastructure and construction projects
Conclusion
A well-prepared Air Emission Inventory Study helps industrial facilities understand their emission sources, quantify pollutant releases and support environmental approval, compliance reporting, air dispersion modelling and future emission reduction planning.iFluids Engineering & Consultancy WLL provides technically structured and compliance-ready Air Emission Inventory services for industrial and infrastructure projects. Our approach combines source-wise emission calculations, pollutant-wise reporting, transparent assumptions and practical recommendations to help clients make informed environmental decisions