AFREPREN/FWD - Energy, Environment and Development Network for Africa Website

Home l Site Map l Contact Us l

Working Paper 314



Home

About Us

Focal Areas

Projects

Publications

Members

Energy News

Energy Events

Opportunities

Related Links

Picture Gallery

Contact Us

No. of Website Visitors:

Potential for Electricity Generation from Land Filling in Eritrea

By

S. Habtetsion, B. Ghirmay and I. Tesfu


Executive Summary

This report presents an assessment of the current solid waste management regime in Asmara and an analysis of the potentials of energy generation from municipal solid waste of the city and other sound practices in municipal solid waste management. Initially, it was anticipated that the study would cover all urban centres of the country. However, it was decided that the present study should concentrate on Asmara, the capital city reasons being, the unavailability of data and lack of resources. Moreover, this type of research is being conducted for the first time in Eritrea. It is also important to note that more than half of the country’s urban solid waste is generated in Asmara. 

This project attempts to determine the potential of energy recovery from municipal waste. Data from the sanitary unit of the municipality of Asmara puts the total collected solid waste from Asmara at 50,281 tons, 61,998 tons and 87,000 tons for 1995, 1996 and 1997 respectively. The same office also reports that the refuse collected in 1995 and 1996 was 60% and 70% of the total generated solid waste. It is also claimed that solid waste collected in 1997/98 is approaching 90% due to increased efficiency and the national cleanliness campaign held once a year through out the country. 

Determinations by the sanitary unit of the quantity of Municipal Solid Waste (MSW) collected and landfilled are based on vehicle counts and then multiplied by the assumed weight of the vehicle contents judged from the nominal capacity of the vehicles. This is not satisfactory, a fairly accurate knowledge of the quantities generated and collected is necessary for the purposes of resource recovery and also to plan and provide optimum collection and disposal services. In this study, an investigation was made to determine both the type of solid waste generated and collected as well as their sources and composition. The results show that the figures issued by the sanitary unit are exaggerated by at least 10%. This study shows that the amount of combustible (organic) waste generated in the city is about 73% by weight and over 90% of the combustibles are of biological origin. 70% of the collected waste is from the household sector, 14.2% industrial, 4.8% institutional, 4.4% commercial (market places), 1.6% hospitals and 5% from street sweepings. 

Three different economic growth scenarios, base case, high and low, were considered in projecting the amount of solid waste generated and landfilled for 1998 to 2020. For the base case scenario, 102,600 tons will be generated in 1998 and thereafter will increase at 8% to 557,900 tons by 2020. Collection rate is assumed to be 80% for all these years and the 100,000-ton collection will be bypassed by the year 2001. 

The two important bacterial decomposition processes of organic waste in nature are aerobic and anaerobic. The outputs of aerobic decomposition are carbon dioxide and water, which are not expected to be higher than 10% in the Asmara landfill. In the course of anaerobic biological degradation, landfill gas or biogas is discharged this is appropriate for the 90% of degradable amount in the landfill. The gases are predominantly methane (CH4) and carbon dioxide (CO2) -99%, they are produced in equal amounts, the rest -1% being traces of organic and inorganic gases. The landfill gas diffuses within the landfill and eventually burns at the landfill surface or ends up in the atmosphere and adds to the green house effect syndrome. Linked with the production of CH4 and CO2 is the formation of acids, which dissolve metals from the landfill waste. Together with degraded products, a solution known as leachate is formed from the organic material. Leachate poses an enormous threat to the underground and downstream water resources, but assessing its impacts was beyond the scope of this study. In addition, municipal and industrial landfill sites cause air pollution through volatilisation of substances dumped there, odour problems are a manifestation of this. 

In Eritrea where energy costs are not only high but also scarce, it is prudent to consider utilisation of alternative renewable energy sources. Usage of municipal wastes as sources of energy has an additional advantage of reducing pollution. Incineration and landfill gas recovery, reuse and recycling of waste are among the alternative technologies for recovery of energy from MSW considered in detail here.


Return to top

This paper is available on an exchange basis. If you find it to be useful, we encourage you to send us any relevant publications from your organization. To request for the full paper, please fill in the publications request form

View the listing of Other Working Papers

 

 

wordpress visitor counter