With regard to farming operations, all N-fertilizer was assumed to be in the form of mineral fertilizer, as there is no publicly available figure known for the average use of organic fertilizer (e.g. manure) in sugar beet cultivation in Europe. All the basic inputs to sugar beet cultivation were included, that is, seed, fertilisers, pesticides and diesel consumption for field work. Nitrous oxide, soil emissions (N2O, commonly known as laughing gas) from farming were included according to Biograce (i.e. 2.7% of applied N is emitted as N2O). Transport of sugar beet and adherent soil was also accounted for, and it was assumed that all transports are by 40-t truck. The emissions related to the return of empty trucks delivering beet to the factories were also accounted for in the Biograce data.
GHG emissions linked to LUC (land use change, direct or indirect) were estimated to be negligible because all land used to grow beet, at least in the EU, is already arable land.
With regard to factories, very small inputs were excluded. Specifically, most process chemicals used in sugar production such as NaOH or HCl for pH correction or antifoaming agents were assumed not to be significant for the overall result because they were used only in small quantities. However, as limestone is a processing aid used in larger amounts (approx. 2% per tonne of beet processed), it therefore was included.7
For surplus steam, which some factories co-produce, substitutes were difficult to establish, because they depend on the local situation. Since the resulting GHG credit for surplus steam was expected to be small as an EU average, no GHG credit for surplus steam was calculated. Potential emissions from water treatment systems were, on the other hand, not taken into account because there is insufficient data available about the different types of water treatment systems in operation in EU beet sugar factories.
The emission factors of the process inputs used in the calculations are listed in Table 9.
Invertase Inhibitors From Red Beet, Sugar Beet, and Sweet Potato Roots