The results of the proximate and ultimate analysis of the grape stalk
are shown in Table 1. The grape stalk contains 8.7% ash, 63.13% volatile
matter and 21.17 fixed carbon. The ultimate analysis revealed that the
grape stalk used was composed mainly of carbon (41.58%), hydrogen
(4.92%) and oxygen (52.16%), as expected for most lignocellulosic
material.