Wild Cane Potential to Produce Gaseous Fuels via Air-Steam Thermal Gasification

Abstract

Various alternative fuel technologies have been proposed as a solution to the negative environment impact caused by greenhouse emissions from fossil fuel combustion processes. One of those alternatives technologies is the inclusion of biomass (fuel crops and agricultural and municipal wastes) as feedstock to produce gaseous and liquid fuels via thermal gasification processes. Biomass thermal gasification is a clean technology, which does not increase the atmosphere carbon concentration since biomass is a neutral carbon energetic source. Wild cane is an invasive grass with a remarkable ability to establish and spread quickly. Thus, it has the potential to yield high biomass for the production of energy. Moreover, wild cane is considered as one of the species that most produces energy per hectare crop. Although wild cane occurs as a weed in most of the Colombian geography, it does not have an extensive potential use. However, wild cane can be included as feedstock for the production of bio-fuels via partial oxidation or thermal degradation (pyrolysis). Fuels produced through this technology can be used for heat o power generation in order to decrease the dependence of farms on fossil fuels. The current paper presents results on the wild cane potential to produce gaseous fuels through thermal gasification using air-steam mixtures for partial oxidation. Also, wild cane thermochemical properties are presented. The CEA (chemical equilibrium with applications) program from NASA was used to estimate the production of gaseous fuels as a function of the operating conditions, which include equivalence ratio (Φ) and steam to fuel ratio (S:F). Based on gas composition, the energy density of the gaseous fuels was estimated. Furthermore, the energy conversion was also calculated in order to estimate the efficiency of the gasification process. Wild cane thermochemical properties were obtained using ultimate, proximate, and thermogravimetric analyses (TGA). Thermogravimetric analyses were carried out using N2 as carrier gas and under different heating rates (β: 10, 20, and 35 °C/min). Based on TGA data and using the isoconversional method (i.e., free-model), the activation energy (E) was estimated. In general, the results show that the increase in operating conditions (equivalence ratio (Φ) and steam to fuel ratio (S:F)) results in gaseous mixtures rich in H2 and with a low CO content. On the other hand, the CH4 production is only possible at Φ > 4 and increases with increased Φ. The average activation energy was ∼ 162 KJ/Kmol.