The
five main methods of waste management are source reduction, recycling,
composting, waste-to-energy, and landfill. All these methods no longer can be a
single method of waste disposal but rather there need to be a co-disposal
program. Asian countries can no longer practice “open burning” method and
landfill dumping which had to abide to strict regulations. There are numerous
attempts and efforts to try and change “waste” into another by-product. One of
the measures is to recycle the used product to another reusable product.
Biomass is any sort of vegetation-trees, grasses,
plants parts such as leaves, stems and twigs, and ocean plants. From it, we can
extract a wealth of stored energy. Biomass is available from various
industries—including agriculture, forest products, transportation, and
construction—that dispose of large quantities of wood and plant products.
Whether cultivated or growing wild, biomass represents a huge renewable energy
source.
Renewable energy is any energy source that can be
either replenished continuously or within a moderate timeframe. Renewable power
sources include solar power, biomass power, wind power, hydropower, and
geothermal power.
Biomass power is the use of biomass feedstocks
instead of the usual fossil fuels (natural gas or coal) to produce electricity.
If biomass is cultivated and harvested properly, it is a renewable resource
that can be used to generate power on demand, with no net additional
contribution to global air emissions.
During photosynthesis, plants combine carbon dioxide
from the air and water from the ground to form carbohydrates, which form the
building blocks of biomass. The solar energy that drives photosynthesis is
stored in the chemical bonds of the structural components of biomass. If we
burn biomass efficiently (which extracts the energy stored in the chemical
bonds), then oxygen from the atmosphere combines with the carbon in plants to
produce carbon dioxide and water.
If we took all the biomass available today, the
energy content in that fuel would produce an estimated 2,740 Quads, with just 1
Quad equal to 1,000,000,000,000,000 Btus.
It can produce electricity, liquid fuels, gaseous
fuels, and a variety of useful chemicals, including those currently
manufactured from petroleum. Because the energy in biomass is less concentrated
than the energy in fossil fuels, our new technology can make this energy
resource competitive with coal, oil, and natural gas. Industry and agriculture
need superior energy crops and cost-effective conversion technologies to expand
the use of renewable biomass.
At present, the world population uses only about 7%
of the annual production of biomass. There is an abundance of biomass that we
can tap.
While the actual ratio of components varies among
species, biomass averages 75%
carbohydrates or sugars and 25% lignin.
Worldwide, biomass is the fourth largest energy
resource after coal, oil, and natural gas. It is used for heating (such
as wood stoves in homes and for process heat in bio-processing industries), cooking
(especially in many parts of the developing world), transportation (fuels
such as ethanol) and, increasingly, for electric power production. There
are estimates of about 35,000 MW of installed capacity using biomass worldwide,
with about 7,000 of that in the United States. Most of this capacity is in the
pulp and paper industry in combined heat and power systems.
In its mixed waste form, MSW typically contains
materials not suitable for use at Bio-Power facilities. Although a large
fraction of the mass of municipal solid waste originates from plant matter the
mixture with other urban wastes precludes its use in Bio-Power facilities.
Materials recovery facilities that keep clean biomass materials (e.g. wood
pallets, wood shavings and tree trimmings) segregated from other wastes are a
potential source of biomass fuels. Biomass, when used in modern power systems,
produces fewer emissions than conventional solid fuels used in power plants.
Biomass is one of the oldest fuels known to humanity.
Although basic, the primitive campfire illustrates the nature of using biomass
for power. When the biomass is burned, it produces heat. In a power plant, this
heat is used to turn water into steam. The steam is then used to turn turbines,
which are connected to electric generators. Gasifiers heat the biomass to
convert it into a gas that can be used in high efficient power systems, such as
combustion turbines or fuel cells.
Energy crops are crops that are grown for the
specific purpose of producing energy (electricity or liquid fuels) from all or
part of the resulting plant. Switch grass, alfalfa, willow, poplar and
eucalyptus are examples of plants that can be grown as energy crops.
Right now, wood is most widely used because
wood-fired power systems have been in use for a long time and are well
understood. In addition, there is an abundance of wood residue available for
use in power systems from bio-processing industries such as the wood products
industry. However, the development of gasifiers may make many other biomass
fuels usable for producing electricity.
Virtually every part of the world has a biomass
resource that can be tapped to create power.
Biomass gasifiers are reactors that heat biomass in a
low-oxygen environment to produce a fuel gas that contains from one fifth to
one half (depending on the process conditions) the heat content of natural gas.
For biomass, this process takes place at about 850 degrees C.
