Sampling, Characterization, and BMP Assessment of Municipal Solid Waste from Rajkot and Ahmedabad City Municipal Corporations for CBG Plant Installation

Project Overview: Waste Characterization and Biomethanation Potential of MSW in Ahmedabad and Rajkot

Adani Total Gas Limited (ATGL) partnered with The Energy and Resources Institute (TERI) to conduct a comprehensive analysis of Municipal Solid Waste (MSW). The study focused on the physical and chemical characterization of waste, alongside the evaluation of its biomethanation potential.

The analysis involved MSW samples collected from critical hubs in Gujarat:

• Ahmedabad Municipal Corporation (AMC): Nine Refuse Transfer Stations (RTS)—Rakhial, Khadia, Shayona, Vastral, Vatva, Vasna, Naroda, Vadaj, and Sola.
• Rajkot Municipal Corporation (RMC): Three Refuse Transfer Stations (RTS)—Raiya, KSD, and Kothariya.

These insights empowered ATGL to assess waste composition accurately and identify viable opportunities for converting MSW into clean energy resources, such as Bio-CNG. This initiative was a significant step toward ATGL’s vision of supporting India’s sustainable energy transition and environmental stewardship.

Methodology and Sample Collection

The study was designed to span 12 months, divided into four quarters. This longitudinal approach was essential to account for seasonal variations in waste composition, which can significantly impact energy yield.

Quarter-1 Sampling: Ahmedabad (AMC)

The first phase of sampling in Ahmedabad was executed over six days (December 13–15 and December 17–19, 2024).

• Scope: Nine RTS sites were covered via 18 site visits.
• Scale: 21 samples were collected daily, totaling 126 samples.
• Rigour: To ensure a comprehensive and representative dataset, a two-day gap was maintained between consecutive collections at each site. The process followed TERI’s standardized methodology to guarantee precision, reliability, and technical accuracy.

Quarter-1 Sampling: Rajkot (RMC)

In Rajkot, sampling was conducted over four days (January 11–13 and January 15, 2025).

• Scope: Three RTS sites were monitored through 12 site visits.
• Scale: 21 samples were collected daily, totaling 84 samples.
• Rigour: Adhering to the same stringent TERI protocols, the team ensured that the waste characterization reflected the specific urban waste profile of Rajkot.

Analytical Findings

1. Physical Characterization

The study analyzed the organic fraction of the waste (comprising kitchen and green waste) across all RTS locations. The data revealed varying levels of organic content at each site, which is a critical factor in determining the feedstock quality for biomethanation plants.

2. Chemical Characterization

A deep-dive chemical analysis was performed to establish baseline values for:

• Core Metrics: Total Solids (TS), Volatile Solids (VS), and Moisture Content.
• Chemical Stability: pH levels and Alkalinity.
• Nutrient & Energy Profile: C:N Ratios, Nitrogen Content, Ash Content, and Calorific Value.

In Ahmedabad, the analysis highlighted distinct trends across Phase 1 and Phase 2. Similarly, in Rajkot, the chemical profile was tracked across four distinct phases to map the waste’s evolving chemical signature.

3. Proximate Analysis and BMP Testing

To determine the actual energy potential, samples were transported to TERI’s specialized laboratories for:

• Proximate Analysis: Quantifying Total Solids and Volatile Solids to understand the combustible and biodegradable portions of the waste.
• Biomethanation Potential (BMP) Testing: This crucial test measured the total biogas yield relative to raw waste, dry matter, and volatile solids.

Conclusion

The preliminary results provide a clear roadmap for waste-to-energy conversion. By establishing the specific biogas generation capacity of MSW in these two major cities, the study provides the scientific foundation necessary for ATGL to implement scalable, sustainable Bio-CNG solutions, furthering the circular economy in India.