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Biomass fly ash and biomass bottom ash 27

Lignocellulosic crops. They are named lignocellulosic species because their major
components are lignin and cellulose. They are usually applied to produce heat and
electricity through combustion processes; however, they can be used to produce bio-
fuels as methanol and ethanol after conversion processes. They are classified as:
Woody crops: short rotation coppice, poplar and eucalyptus,
Grass crops: sorghum, kenaf, prickly pear, whole crop maize, reed canary grass or
miscanthus.

2.1.3 Advantages and disadvantages of biomass energy
The use of energy sources other the usual ones necessarily involves solving the
problem of availability and profitability. One form of energy is not going to dis-
place another if it is not, at least, equally accessible, manageable and economically
affordable. Biomass, as an energy source, satisfies all these requirements, in addi-
tion to having further advantages:
Renewable energy source. It comes from abundant and natural resources as well as from
waste, in consequence it is regenerated rapidly.
Improves waste management. The elimination of agricultural and industrial waste, in
many cases, supposes a problem, nevertheless its use to produce energy has important
associated advantages, for example: the reduction of the contamination, fire risks and
occupation of space in landfills; low production and transportation costs; reduction of
CO 2 emissions; generation of jobs; and contribution to rural development.
Reduces agricultural environmental impacts. Using agricultural biomass as biomass
energy instead of burning or disposing in landfill can not only reduce the risks of forest
fires but also can reduce insect plagues.
The creation of jobs in rural areas is encouraged.
Cheap energy source. The cost of this type of energy could be up to 3 or 4 times cheaper.
Multiple use. Nowadays, the performance and technology of systems to produce energy

with biomass are very advanced so that they could be used in many applications due to
different energy conversion technologies, for example, transport, heat and electricity pro-
duction, etc.
Local production. Consequently, the use of biomass reduces the need to import foreign
fuels and the dependence on fossil fuels.
Clean energy. Promoting biomass in energy production can reduce pollution emissions
such as CO, HC and NO and better protect the environment.
Despite the important advantages provided by biomass, it also has some
disadvantages:
It requires a large space to be produced and stored before being converted into energy.
It is not entirely clean. Although the levels of pollutants are far less than those produced
by fossil fuels, the combustion of biomass produces some GHG and particle matter.
High water footprint. A great deal of water is needed for some energy crops to be pro-
duced resulting in biomass having a high water footprint.
High production costs, especially due to high transportation costs as well as necessary
pre-treatment processes. For example, biomass is characterised by high humidity, so it is
necessary to apply drying technologies which implies a previous energy consumption that
increases production costs.
Networks and distribution channels are not as developed as in the case of liquid and/or
solid fuels.