Development of a bidimensional analysis approach for n-butanol and electricity production in apple pomace biorefineries in a Mexican context

Apple pomace (AP) is a by-product generated from the transformation of fresh apple into different products of the food industry; however, it remains largely underutilized. This work presents a proposal and bidimensional analysis (economic and environmental) for biorefineries to produce n-butanol, acetone, and ethanol, utilizing AP in a Mexican context. The biorefinery was simulated by using the software SuperPro Designer v.11.0 (R). This study evaluated the impact of seasonality, plant capacity, and the fermentation technology on n-butanol total production cost (TPC). The two proposed fermentation schemes were evaluated as follows: (a) standard fermentation biorefinery (SFB) that proposes the use of a pure culture for the fermentation of soluble sugars into ABE and the cellulosic fraction is burned to produce steam and power; and (b) a hybrid biorefinery fermentation scheme (HBFS) that produces ABE from soluble sugars and the cellulosic fraction is fermented to produce additional ABE employing an anaerobic consortium. Seasonality impacts at higher extent TPC than the plant capacity by 80% compared with 60%, respectively. Results have shown a n-butanol TPC of $1.32/kg and $0.71/kg for SFB and HBFS, respectively, for a plant capacity of 500 metric tons of AP per day. The environmental indicators for SFB and HSBF are 4.05 x 10(2) and 0.61 x 10(2) gCO(2eq)/MJ(out); 2.2 and 1.1 L-Fresh water/MJ(out); and 2.3 x 10(2) and 6.2 x 10(3) kg(disposable waste)/MJ(out), respectively. The economic indicators for SFB and HSBF are 5.41 and 5.41 MJ(out)/kg(soluble sugar); 7.99 x 10(7) and 2.04 x 10(7) USD/MJ(out); 2.04 x 10(-4) and 6.2 x 10(-4) MJ(out)/MJ(Transport); and 8.30 x 10(-5) and 1.7 x 10(-3) Delta USD/USDTotal Import, respectively.