Opportunities for small-scale anaerobic digesters for hotels and restaurants in Kathmandu, Nepal

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Journal ISSN

Volume Title

Insinööritieteiden korkeakoulu | Master's thesis

Authors

Dhital, Avinash

Date

2018-06-11

Department

Major/Subject

Nordic Master Programme in Innovative and Sustainable Energy Engineering (ISEE)

Mcode

ENG215

Degree programme

Master's Programme in Energy Engineering and HVAC

Language

en

Pages

42+15

Series

Abstract

Approximately 83% of total energy consumed in Nepal comes directly from the solid fuels. The import of Liquified Petroleum Gas (LPG) is also growing at an exponential rate. The hospitality sub-sector (hotels and restaurants), one of the key economic sub-sectors in the country, consumes most of the energy within the commercial sector primarily for cooking purposes. The bio-waste generated from growing hospitality subsector and other sectors in Kathmandu is poorly managed. On the other hand, Nepal has an extensive knowledge and experience of manure based anaerobic household biogas systems mainly in rural areas. Based upon this situation, this thesis investigates the opportunities for anaerobic biogas production for cooking at hotels and restaurants by utilizing their own organic waste. Currently available biogas technologies, important parameters affecting the biogas yield, policy and financial supports and case studies of various stakeholders employing the biogas technologies in the hotels and restaurants in Nepal were considered. The most applicable technology for the purpose was then chosen. The organic waste sampling study from randomly selected 4-star hotel (Yatri Spa and Suites), tourist standard hotel (Hotel Bliss International) and restaurant (Fren’s Kitchen) in Thamel, the tourist zone of Kathmandu was conducted. Similarly, various data especially focusing on the current cooking energy need, demand, supply, cost, organic waste management of the hotels and the restaurant was collected through questionnaires and series of interviews. The average amount of daily organic waste and organic waste fraction for Yatri, Bliss and Fren’s was found to be 61.3 kg and 63.0%, 18.4 kg and 82.7%, and 16.3 kg and 81.8% respectively. Similarly, the variations in weekly organic wastes and waste generated per guest was also determined. Based upon the amount and characteristics of organic waste from the sampling survey, the theoretical biogas potential of the organic waste at digester output rate of 0.27 kWh/kg/day for JUAS digesters, the technology selected for the biogas conversion, was found to be 16.6 kWh/day, 5.0 kWh/day and 4.4 kWh/day equivalent to 4.4%, 2.7% and 4.8% of the current daily energy need for Yatri, Bliss and Fren’s respectively. Similarly, the economic implications of the small-scale biogas technology if employed in the hotels and the restaurant was scoped out. It was found that the recommended Polyvinyl Chloride (PVC) based 3000 l sized JUAS bio-digesters had positive Net Present Value (NPV), Internal Rate of Return (IRR) and payback time for all the eateries under study. The monthly life cycle cost of the integrated LPG-JUAS system is found be cheaper for all eateries as compared to the current LPG system. Levelized Cost of Energy (LCoE) of the JUAS digesters is competitive as compared to energy from other renewables in the country. There is, however, need to improve the digester conditions to get higher biogas yields. For the wider adoption of the digesters across urban sectors, the subsidies amount should also be increased together with information dissemination regarding biogas uses and its potential among the stakeholders. The digesters at restaurants could also function as local communal waste centres thereby locally managing the bio-waste. However, further study into the matter is required to tackle the challenges and concretely scope out its feasibility.

Description

Supervisor

Järvinen, Mika

Thesis advisor

N/A, N/A

Keywords

anaerobic digestion, bio-waste, biogas, hotels and restaurants, cooking, Nepal

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https://urn.fi/URN:NBN:fi:aalto-201806293789

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[dipl] Insinööritieteiden korkeakoulu / ENG