Fossil energy requirement for

Table 16.2. Fossil Energy Requirements for the Biodiesel Life Cycle...

Figure 1.11 Fossil energy requirement for petrochemical polymers and PLA. The cross-hatched area of the bars represent the fossil energy used as chemical feedstock (i.e., fossil resource to build the polymer chain). The solid part of the bars represented the gross fossil energy used for the fuels and operation supplies used to drive the production processes. PC = polycarbonate HIPS = high-impact polystyrene GPPS = general purpose polystyrene LDPE = low-density polyethylene PET SSP = polyethylene terephthalate, solid-state polymerization (bottle grade) PP = polypropylene PET AM = polyethylene terepthalate, amorphous (fiber and film grade) ...

The life cycle indicators for PTT are computed in terms of a new functional unit - 1 kg of PTT. Figure 3 shows the fossil energy required for the production of PTT from biobased PDO and PTA. The energy required for the production of PDO is dwarfed by that used in making PTA. 

The most important current technique for the thermal destmction of waste is incineration, where the energy required for destmction is provided by oxidation of the waste, sometimes supplemented with a fossil fuel. The major question about all thermal destmction techniques is whether products from the process—either traces of umeacted parent compound or compounds synthesized from the parent compound at high temperature— will pose a health hazard. 

As can be seen from the reaction equations, the splitting of water requires different amounts of energy dependent on how much of the carbon contained in the (fossil) raw materials is converted into CO2. The energy released during this conversion is consumed in the splitting process and does not need to be introduced from outside. The theoretical energies required for the production of 1 Nm of hydrogen are listed in Table 5-4. 

Figure 6.1. Fossil energy required forPLA and for a number of petroleum-based polymers [VM 03]...

There is not only a need but also an urge to use waste biomass resources in the production of biofuels, due to the many envirorunental and economic impacts from the conventional fossil-based transportation fuels. The conversion routes applied to biomass for fuel production widely include thermo-chemical, hydrothermal and biochemical. All the three conversion methods are well-suited to achieve the energy requirements for being ecofriendly processes. However, in the present context both thermochemical and hydro-thermal conversion are foimd effective to produce an energy dense liquid bio-oil that could not only be used as a transportation fuel but also for heat and power generation. 

---