Development of indigenous household kitchen waste biogas digester

ABSTRACT

Large quantities of nutrition-rich food wastes reach dumpsites due to improper management. Anaerobic digestion (AD) has the potential to produce biogas from such wastes and reduce carbon footprint. The present study was aimed at developing an indigenous, user-friendly, compact digester to produce biogas from household kitchen waste (KW) in decentralized manner. A survey (1041 households) showed 0.5 kg/d KW generation per family. The mixed KW has average 0.08 g total solids (TS) and 0.048 g total volatile solids (VS). The study involved for the first time, a comparison of the efficacy of cow dung inoculum from rural/urban areas with different feeding bases. Ten each (30 L) rural (RCD)/urban (UCD) digesters (average 24kgVS/m³ feedstock concentration, FC; 0.8 kgVS/m³ organic loading rate, OLR) were run in AD cycle for 90d. RCD digesters produced 173–462 mL/gVS, while only four UCD digesters produced biogas (115–273 mL/gVS). Amongst various substrate-to-water ratios, 1:3 ratio gave the best biogas yield (352–384 mL/gVS). Scale-up parameters were calculated for designing 0.5/0.25 kg/d KW fed digester. The study is novel in reporting for the first time significant effect of inoculum source and developing compact indigenous biogas reactor for in situ management/utilization of KW to produce clean cooking fuel with scope for add-on controls.

KEYWORDS:

• Biogas digester
• design
• indigenous
• rural/urban cow dung
• kitchen waste

Acknowledgements

Financial assistance to one of the authors (BB) in the form of a Fellowship (STRF) from GGSIP University, Delhi, and infrastructural and technical assistance by M/S MACLEC Technical Project Laboratory, Delhi, under the Research and Development Initiative Program are gratefully acknowledged.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the GGSIP University.

Notes on contributors

BalRam Bhardwaj

BalRam Bhardwaj is reseach scholar in the University School of Environment Management, GGSIP University, New Delhi, India. His research interests include biogas and renewable energy.

Anubha Kaushik

Anubha Kaushik is Professor in the University School of Environment Management, GGSIP University, New Delhi, India. Her research interests include pollution management and energy from wastes.

Chandra Prakash Kaushik

Chandra Prakash Kaushik is Retired Professor and recognised research supervisor in the University School of Environment Management, GGSIP University, New Delhi, India. His research interests include pollution management and energy from wastes.

Narayan Bhardwaj

Narayan Bhardwaj is heading MACLEC Technical Project Laboratory (P) Ltd, New Delhi, India. His research interests include instrumentation and renewable energy.