The cost of collection varies among the machines and depends
not only on the parameters shown in Fig. 5 but also on the investment
and maintenance cost of the machines. This cost range from
US$12 to US$18 per ton of straw. Similarly, assuming that the collected
straw is for anaerobic digestion (Nguyen et al., 2016), the
value of biogas generated (390 m3 t−1 of straw) for about 160 Liters
of kerosene is about US$160. It means that straw collection cost
only accounts for 8–13% of the output value of processing.