Overview

A press-mud-based CBG plant was looking to improve the digestion efficiency of press mud and enhance CBG production from its anaerobic digestion process. To address this challenge, The Catalysts Group conducted a commercial trial of NutriBoost CPNS at PS Green CBG Plant in Uttar Pradesh. The trial demonstrated a significant improvement in press mud digestion and CBG yield following NutriBoost CPNS application. CBG yield increased from 30.80 kg/ton of press mud to 47.83 kg/ton, representing a 55.3% improvement. Digestion efficiency also increased from approximately 51% to 81%.

Plant Profile

Parameter Details
Industry Compressed Biogas (CBG) Production
Feedstock Sugar Mill Press Mud
Digester Type CSTR – Completely Mixed Anaerobic Digester
Number of Digesters 2
Working Volume 5,500–6,000 m³ per digester
Total CBG Capacity 5.5 TPD
Product Evaluated NutriBoost CPNS

The Challenge

  • The plant required improved digestion of press mud to maximize methane and CBG generation
  • The baseline CBG yield was approximately 30.80 kg per ton of press mud
  • Initial digestion efficiency was approximately 51%, indicating scope for improved degradation of the feedstock
  • The plant required better utilization of the organic matter present in press mud to improve overall CBG productivity
  • Variations in feedstock characteristics and microbial activity could impact digester performance and CBG generation

Catalysts Solution

The Catalysts Group implemented NutriBoost CPNS as a nutritional intervention to support digester performance, microbial activity, and improved degradation of press mud. During the trial, daily press mud input, NutriBoost CPNS dosing, and CBG dispatch were monitored. In addition, samples of press mud, inlet feed slurry, and outlet digestate slurry were collected and analyzed to evaluate changes in the physical and microbial characteristics of the digestion process. The trial data demonstrated a positive response in both CBG yield and digestion efficiency, supporting the use of NutriBoost CPNS for maintaining improved digester performance.

Performance Highlights

  • CBG yield increased by 55.3%, from 30.80 kg/ton to 47.83 kg/ton of press mud
  • Digestion efficiency increased from 51.02% to 81.09%, indicating substantially improved degradation of press mud
  • Estimated methanogenic bacterial count increased from 2.4 × 10⁵ to 3.65 × 10⁵ MPN/g dry weight, representing an increase of more than 50%
  • VS% of the outlet digestate decreased from approximately 4.61% to 4.15%, indicating improved degradation of organic matter
  • Feed slurry VS% increased from approximately 6.54% to 7.8% during the observed period
  • Average CBG yield improved despite a lower average press mud feed rate during the trial period

Before vs After Performance

Parameter Before NutriBoost CPNS After NutriBoost CPNS Improvement
CBG Yield 30.80 kg/ton press mud 47.83 kg/ton press mud ↑ 55.3%
Digestion Efficiency 51.02% 81.09% ↑ 58.9%*
Estimated Methanogenic Bacterial Count 2.4 × 10⁵ MPN/g dry weight 3.65 × 10⁵ MPN/g dry weight ↑ 52.1%
Outlet Digestate VS% ~4.61% ~4.15% ↓ ~10.0%
Feed Slurry VS% ~6.54% ~7.8% ↑ ~19.3%

Key Outcomes

  • Higher CBG Yield: Achieved a 55.3% increase in CBG yield, from 30.80 to 47.83 kg/ton of press mud, despite a lower average feed rate during the trial
  • Improved Digestion Efficiency: Increased overall digestion efficiency from 51.02% to 81.09%, with reduced VS% in the outlet digestate indicating better organic matter degradation
  • Enhanced Microbial Activity: Estimated methanogenic bacterial count increased by more than 50%, supporting improved microbial activity within the digester
  • Better Press Mud Utilization: Demonstrated improved utilization of press mud under commercial operating conditions, resulting in higher CBG productivity
  • Sustained Performance: NutriBoost CPNS demonstrated positive effects on digester performance, microbial activity and CBG yield, with continued dosing recommended to sustain the improvements

Conclusion

  • CBG Yield Improvement: Increased by 55.3%, from 30.80 to 47.83 kg/ton of press mud
  • Higher Digestion Efficiency: Improved from 51.02% to 81.09%, indicating better press mud degradation
  • Enhanced Microbial Activity: Increased estimated methanogenic bacterial count and reduced outlet digestate VS%, supporting improved digester performance
  • Sustained CBG Performance: NutriBoost CPNS enhanced microbial activity, press mud utilization and CBG generation; continued dosing at the recommended dosage is advised