Abstract
Production of chemicals and second generation ethanol from lignocellulosic material integrated to first generation sugarcane biorefineries presents potential for industrial implementation, since significant part of the infrastructure may be shared between both first and second generation plants. Additionally, chemicals from renewable resources have attracted increasing attention, mainly for their market prices (usually higher than commodities as biofuels) and potential for replacing oil-based products used as feedstock in the chemical industry.
The production of chemicals through the alcoholchemistry route uses catalysts to convert ethanol into desired products according to catalysts activity and selectivity. One of the possibilities in the alcohol chemistry route is to use ethanol to produce n-butanol that can be sold as feedstock for the chemical industry and as drop-in biofuel for gasoline powered engines. Due to catalyst selectivity, this process generates also other chemicals, which can be purified to be sold as feedstock for the chemical industry. Previous studies have pointed out that the use of ethanol in a biorefinery to produce n-butanol presents good economic and environmental impacts. Nevertheless, results obtained for the economic return of the n-butanol biorefinery compared to autonomous ethanol plants were very similar, which can be unattractive for investors dealing with the high risks involved in a novel biorefinery process.
In this work, the possibility of enhancing the financial and environmental impacts of n-butanol and other high value chemicals production integrated to a second generation sugarcane biorefinery is explored. Computer simulation is used to quantify the influence of technical parameters, including down-stream operations required to separate coproducts, adding value to the mix of products and commercial flexibility. Risk analysis is used to evaluate uncertain parameters such as the investments in n-butanol and second generation ethanol plants and the market prices assumed for the new products. Results obtained show that production of n-butanol and other high valued chemicals integrated to a first and second generation sugarcane biorefinery could be an economically and environmentally attractive alternative. However, the financial risk involved is high and hugely dependent on the selling prices of the new products of the portfolio investigated in this work, mainly n-butanol.
