This research estimates the number of agricultural residues burned in open field, their pollutant emissions and the energy lost in the 2,476 municipalities that make up Mexico. The emissions of Particulate Matter 10 (PM10) and 2.5 (PM2.5), Black Carbon (BC), Carbon Dioxide (CO2) and Methane Gas (CH4) at the municipal level were estimated. The bioenergy loss was also estimated, in terms of anhydrous ethanol. In addition, the economic value lost was estimated, as well as the amount of gasoline that could have been oxygenated at 6 % volume and the percentage of participation in the national gasoline demand. The results, aggregated at the national level, show that Mexico annually incinerates 4.1 million tons of corn stover which emits 13,662 tons of PM10, 11,178 tons of PM2.5, 787 tons of BC, 7.2 million tons of CO2 and 8,653 tons of CH4 to the atmosphere. If this amount of biomass were used to produce anhydrous ethanol, a volume of 1,106 million liters, worth US$840 million, could be produced, which might also be used to oxygenate 18,425 million liters of gasoline, covering approximately 100 % of the national demand for this biofuel. The results provide empirical evidence on open burning of agricultural residues in Mexico and can be used to design public policies to reduce the country's share of global pollutant emissions. ... Read more

There is global pressure to make advanced biofuels profitable. For cellulosic ethanol, three aspects remain as bottlenecks: collection of feedstocks, pretreatment methods, and enzyme production. In this paper, the first aspect is investigated, by addressing the main challenges for the logistics of agricultural residues. A logistic supply chain of corn stover collection and utilization for cellulosic ethanol production in Mexico is proposed, and a cost structure is designed for its estimation. By applying a value chain methodology, seven links and a set of three minimum selling prices (MSPs) of agricultural residues were determined. Furthermore, the harvest index (HI), crop residue index (CRI), nutrient substitution by extraction of agricultural residues, and harvest costs of corn stover were also calculated for a case study. The main results were a HI of 0.45, a CRI of 1.21, and nutrient substitution potential of 7 kg N, 2.2 kg P ₂O ₅, and 12.2 kg K ₂O per ton of corn stover. The set of the three estimated MSPs for corn stover was: $28.49 USD/ton (for delivery to the biorefinery’s gate), $31.15 USD/ton (for delivery and storage), and $48.14 USD/ton (for delivery, storage, and nutrient replenishment). Given the impact of the feedstock cost on the profitability of cellulosic ethanol, knowing details of the logistical information and its costs is critical to advancing the field of biofuels in Mexico. We also found that only 20% of farmers currently sell their residues; however, 65% of farmers would be willing to do so, a significant percentage for cellulosic ethanol production. ... Read more