Page 229 - Energy from Toxic Organic Waste for Heat and Power Generation
P. 229
Comprehensive Remark 207
focus of planning and decision-making to local communities and this may
make consents harder to obtain WTE. However, there is scope for WTE
developers to define sustainable development regarding the carbon ben-
efits accruing from projects, as well as to show local benefits, for example,
favorable energy tariffs. The National Planning Policy Framework (NPPF)
is intended to replace the current set of planning policy statements and
documents, except the one on waste. This will remain in place until a new
National Waste Management Plan (NWMP) is published. Successive gov-
ernments have viewed WTE as primarily a waste management solution
rather than a valuable energy source. Consequently, its full potential has
not been realized and there is a lack of coordination between the energy
and waste management arms of policy-making. This has resulted in poorly
drafted legislation and inconsistent guidance, which has impeded deploy-
ment. The proposed electricity market reform measures, plus reviews of
existing financial incentives, have introduced uncertainty. Unless this is re-
solved, investor confidence will be damaged, making it difficult to finance
new projects.
WTE technologies can convert the energy content of different types
of waste into various forms of valuable energy. Power can be produced and
distributed through local and national grid systems. Heat can be generated
both at high and low temperatures and then distributed for district heating
purposes or utilized for specific thermodynamic processes. Several types of
biofuels can be extracted from the organic fractions of waste, to be then
refined and sold in the market. As of today, the most common and well-
developed technology is in the form of combined heat and power plants,
which treat MSW and possibly a combination of industrial, clinical, and
hazardous waste, depending on the system settings through an incineration
process. Technical and economic considerations will be, therefore, limited to
this type of plant. By definition, waste incineration is carried out with a sur-
plus of air. This process releases energy and produces solid residues as well
as a flue gas emitted into the atmosphere. Because of emission and safety
concerns, there is a certain temperature range that is demanding this type
of process. In the case of mixed waste, a furnace temperature of 1050°C is
required. A generic description of an incineration process is represented as,
waste is first deposited and then extracted from a bunker, and then it is pro-
cessed on a moving grate to achieve correct combustion. Before undergoing
the combustion phase, the incoming waste may be exposed to pretreatment,
depending on its quality, composition, and the selected incineration system.
The combustion products then exchange heat in a boiler, to supply energy