Page 222 - Energy from Toxic Organic Waste for Heat and Power Generation

200 Energy from Toxic Organic Waste for Heat and Power Generation

the waste is collected and that also are not disposed properly. The insuffi-
cient collection and inappropriate disposal of wastes becomes a major threat
to the pollution of water, land, and air, and also it pretense risks to the hu-
man health. Around 30%–50% of populations in many developing countries
are urban. In many African countries, the growth rate of urban areas exceeds
4%. Globally, in 1985, 41% of the world population lived in urban areas,
and in 2018, it is around 80%. Developing nations spend about 20%–40%
of their municipal revenues on waste collection, processing, and disposing,
but this is not enough to keep pace with the magnitude and scope of the
problem. It is projected that the total expenditure on waste management
activities in Asia may double from an estimated $25 billion in 1999 to $50
billion in 2025. African countries, while prioritizing their environmental
concerns, have rated waste as the second most important problem after
water quality since less than 30% of urban populations have some access to
proper and regular garbage removal.

12.5 ENERGY FROM THE WASTE

The share of renewable energy sources in total energy consumption in-
creased slowly between 1990 and 2004 from 4.4% in 1990 to 6.3% in 2004.
Significant further growth will be needed to meet the indicative target of a
20% share by 2020. Compared to 1990, all renewable sources are increasing
and in relative terms; the highest increase came from wind and solar energy.
In absolute terms, 60% of the increase was accounted for by biomass, and
about 39% split equally between hydro-power and wind energy. Solar en-
ergy continues to increase very rapidly, but still accounts for less than 10%
of total renewable energy. The useful energy in the form of crude oil, gas,
and solid combustibles, such as carbon and char, can be extracted from the
disposed waste materials. This energy from waste will contribute diminutive
consumption of nonrenewable energy sources and also make the environ-
ment clean with economic growth of the nation.
For example, Abu- Qudais and Abu- Qdais extract the useful energy
from municipal solid waste (MSW) generated in Jordan accounting for
about 6% of the annual imported oil consumption of the country, resulting
in an annual saving of USD 24 million. They are converting the extracted
energy from the MSW to generate electricity. The electricity supply yield is
3
of 1.77 MW/day, which may be used for desalination of 300,000 m /day of
seawater with the help of the reverse osmosis process, which may account
for about 12% of the water consumption of Jordan/day in the year 1995.