Material and energy input and output per kg of UCOME
produced are shown in Table 1. As the production of biodiesel
generates another product which is recovered for use elsewhere,
the problem of apportioning or allocating of energy resources, raw
materials, pollutants, etc. from the common production steps
between the product studied (biodiesel) and the co-product
(glycerol) must be considered. In this study, the allocation is carried
out based on mass shares of product (UCOME) and co-product
(glycerol). The allocation factor for biodiesel works out to 0.83.
The values of inputs and outputs after allocation are also shown
in Table 1.