Feasibility of Using Forest Residues for Pelletization in Chihuahua, Mexico
Abstract
Due to its latitude and climate, Mexico does not have dense forests comparable to those in countries further north. However, there are two large mountain ranges running nearly parallel to the Pacific Ocean and the Gulf of Mexico. These mountains contain significant woodland which provides forest resources for the rest of the country. This industry also produces significant waste, in the form of sawdust, bark, scrap wood, and foliage, which in most cases can't be used. This residue is usually merely discarded near the sawmills that produce it, generating a pollution problem and a fire hazard. Mexico is considered an oil-producing country, and only lately has production diminished and existing oil supplies become scarce. Thus, only lately has there been an effort to characterize and quantify the country's other available energy resources, such as forest and agricultural waste. No local industry has yet tried to develop the technology to turn this waste into a more compact, homogenous, and manageable product, such as wood pellets. The wood pellet industry is highly developed in many countries, but does not yet exist in Mexico even though 72% of the total area of the country is dedicated to forestry. There are no local manufacturers of the devices and systems needed for the collection, storage, packaging, transport, and final use of the wood pellets as fuel for heating or industrial processes. As an initial step towards solving this national problem, we present an estimate of the potential for generating solid biofuels from forest waste in northern Mexico. We specifically analyze the waste generated by milling the most common tree species in this area, which include the Mexican weeping pine (Pinus patula) and the northern red oak (Quercus rubra). In order to characterize the product, we built a prototype manual pelletizer and used it to create three different pellet varieties (pine, oak, and a 50/50 mixture of both) that were subjected to calorimetric analyses. Our results show that Mexican wood pellets can easily replace fossil fuels in any kind of furnace. We performed a field study in order to quantify the available volume of forest waste, sampling the forest exploitation facilities in Ciudad Madera, Chihuahua. This city is located in northern Mexico, near one of the country's largest mountain ranges (the Sierra Madre Occidental), and is representative of other woodlands in the country. The results of our work show that it is technically feasible to turn Mexican forest waste to wood pellets, and it is thus justified to develop the industry necessary to do so.