Handbook of Biofuels Production, 2nd Edition

10.3. Advantages and limitations

One of the most important advantages of AD is the production of a methane-rich gas (Fig. 10.2). In view of the fact that the feedstocks used for AD are renewable biomass they do not deplete fossil fuels. Moreover, the energy recovery from the biogas does not contribute to greenhouse gas emissions. On the other hand, the utilization of the digestate as fertilizer or soil conditioner reduces the need to produce inorganic fertilizers and, thus, reduces further the fossil fuel consumption required for commercial fertilizer production (Fig. 10.2). As a result, AD provides economic benefits through energy and fertilizer substitution from waste biomass.

Figure 10.2 Utilization of AD products.

Another important advantage ...