T11 · Sustainability / LCALife Cycle Assessment (LCA)GATE 2027 Syllabus (XE5)Shop-Floor Standard

Global Warming Potential (GWP) Carbon Footprint per kg Resin

Computes cradle-to-gate Global Warming Potential (GWP in kg CO2e / kg polymer) according to ISO 14040/14044 methodology by summing raw material emissions and plant electrical grid consumption.

Mathematical Canonical Relation

\text{GWP} = \sum_{i} (m_i \cdot EF_i) + (E_{elec} \cdot EF_{grid})

Plain Formula: GWP = Sum(m_i * EF_i) + (E_elec * EF_grid)

Live Engineering Parameter Solver

Input your production or test values below for instant, verified output.

Verified Engine

Feedstock Embodied Carbon (kg CO2e/kg) (kg CO2e/kg)

feed_ef

Range: 0.1 – 5 kg CO2e/kg

Plant Energy Usage (kWh/kg) (kWh/kg)

elec_kwh

Range: 0.1 – 2.5 kWh/kg

Grid Factor (kg CO2e/kWh) (kg CO2e/kWh)

grid_ef

Range: 0.2 – 1.1 kg CO2e/kWh

Calculated Engineering Result:

2.07 kg CO2e / kg resin

Engineering Verification:Electricity accounts for 18% of total carbon footprint.

When & Where to Apply

Use when preparing Environmental Product Declarations (EPD), corporate ESG greenhouse gas reports, and comparing virgin vs recycled resin environmental offsets.

Common Engineering Pitfalls

Comparing cradle-to-gate figures with cradle-to-grave figures (which include end-of-life incineration)
Using European grid electricity factors (0.25–0.40) for manufacturing plants located in India (0.82)

Physical Assumptions & Validity Limits

Cradle-to-gate boundary (feedstock extraction, cracking, polymerization, and granulation)
Indian regional electrical grid emission factor EF_grid approx 0.82 kg CO2e / kWh
Standard 100-year GWP horizon factors from IPCC AR6

Variable Symbols, SI Units & Dimensional Specifications

Symbol	Variable Meaning	SI Unit	Typical Industrial Range
\text{GWP}	Global Warming Potential	kg CO2e / kg polymer	—
m_i \cdot EF_i	Feedstock embodied carbon emissions	kg CO2e / kg	1.80
E_{elec}	Plant electrical energy consumption	kWh / kg	0.45
EF_{grid}	Electrical grid carbon intensity factor	kg CO2e / kWh	0.82

Worked Industrial Numerical Example: Virgin HDPE vs 100% Recycled rHDPE Carbon Footprint Comparison

Problem Statement:

Virgin HDPE has cradle-to-gate monomer carbon 1.70 kg CO2e/kg and polymerization energy 0.40 kWh/kg. Recycled rHDPE wash/extrusion requires zero virgin monomer (0.15 kg CO2e/kg transport/chemicals) and 0.50 kWh/kg electrical energy. Compute GWP for both at EF_grid = 0.82 kg CO2e/kWh.

Step-by-Step Numerical Solution:

Virgin GWP = 1.70 + (0.40 * 0.82) = 1.70 + 0.328 = 2.03 kg CO2e / kg
Recycled GWP = 0.15 + (0.50 * 0.82) = 0.15 + 0.410 = 0.56 kg CO2e / kg
Calculate carbon reduction: (2.03 - 0.56) / 2.03 * 100 = 72.4%

Final Answer: Virgin: 2.03 kg CO2e/kg | Recycled: 0.56 kg CO2e/kg (72.4% Reduction)

💡 Engineering Interpretation: Switching 1,000 Tonnes of virgin HDPE to rHDPE saves 1,470 Tonnes of net CO2 equivalent emissions, unlocking substantial EPR environmental benefit credits.

Authoritative Technical Reference & Source Provenance

Environmental management — Life cycle assessment — Requirements and guidelines by ISO TC 207 (International Organization for Standardization, 2006), ISO 14044:2006, Page 1-46.

Connected Curriculum Lesson

Life Cycle Assessment: ISO 14040, Carbon Footprint & Circularity Metrics

Study Full Lesson