Supplying the ethanol demand for 2030 in Brazil as a land-based climate change mitigation alternative: Implications on greenhouse gases emissions.

Transitioning from a fossil-based to a bio-based economy is crucial to climate action and achieving neutrality in greenhouse gas (GHG) emissions. Biofuel production is an essential land-based GHG mitigation alternative. However, it raises concerns about biodiversity conservation, competition with food production, and net GHG emissions associated with direct land-use change (dLUC).

A Novel Kinetic Modeling of Enzymatic Hydrolysis of Sugarcane Bagasse Pretreated by Hydrothermal and Organosolv Processes.

Lignocellulosic biomasses have a complex and compact structure, requiring physical and/or chemical pretreatments to produce glucose before hydrolysis. Mathematical modeling of enzymatic hydrolysis highlights the interactions between cellulases and cellulose, evaluating the factors contributing to reactor scale-up and conversion rates. Furthermore, this study evaluated the influence of two pretreatments (hydrothermal and organosolv) on the kinetics of enzymatic hydrolysis of sugarcane bagasse.

Dimer-assisted mechanism of (un)saturated fatty acid decarboxylation for alkene production.

The enzymatic decarboxylation of fatty acids (FAs) represents an advance toward the development of biological routes to produce drop-in hydrocarbons. The current mechanism for the P450-catalyzed decarboxylation has been largely established from the bacterial cytochrome P450 OleT. Herein, we describe OleTP, a poly-unsaturated alkene-producing decarboxylase that outrivals the functional properties of the model enzyme and exploits a distinct molecular mechanism for substrate binding and chemoselectivity.

A Novel Fungal Lipase With Methanol Tolerance and Preference for Macaw Palm Oil.

Macaw palm is a highly oil-producing plant, which presents high contents of free fatty acids, being a promising feedstock for biofuel production. The current chemical routes are costly and complex, involving highly harsh industrial conditions. Enzymatic processing is a potential alternative; however, it is hampered by the scarce knowledge on biocatalysts adapted to this acidic feedstock.

Techno-economic analysis and climate change impacts of sugarcane biorefineries considering different time horizons.

Background: Ethanol production from lignocellulosic feedstocks (also known as 2nd generation or 2G ethanol process) presents a great potential for reducing both ethanol production costs and climate change impacts since agricultural residues and dedicated energy crops are used as feedstock. This study aimed at the quantification of the economic and environmental impacts considering the current and future scenarios of sugarcane biorefineries taking into account not only the improvements of the industrial process but also of biomass production systems. Technology assumptions and scenarios setup were supported by main companies and stakeholders, involved in the lignocellulosic ethanol production chain from Brazil and abroad.

Investigation of uncertainties associated with the production of n-butanol through ethanol catalysis in sugarcane biorefineries.

This study evaluated the viability of n-butanol production integrated within a first and second generation sugarcane biorefinery. The evaluation included a deterministic analysis as well as a stochastic approach, the latter using Monte Carlo simulation. Results were promising for n-butanol production in terms of revenues per tonne of processed sugarcane, but discouraging with respect to internal rate of return (IRR).

Adsorption characteristics of cellulase and β-glucosidase on Avicel, pretreated sugarcane bagasse, and lignin.

Although adsorption is an essential step in the enzymatic hydrolysis of lignocellulosic materials, literature reports controversial results in relation to the adsorption of the cellulolitic enzymes on different biomasses/pretreatments, which makes difficult the description of this phenomenon in hydrolysis mathematical models. In this work, the adsorption of these enzymes on Avicel and sugarcane bagasse pretreated by the hydrothermal bagasse (HB) and organosolv bagasse (OB) methods was evaluated. The results have shown no significant adsorption of β-glucosidase on Avicel or HB.

Utilization of pentoses from sugarcane biomass: techno-economics of biogas vs. butanol production.

This paper presents the techno-economics of greenfield projects of an integrated first and second-generation sugarcane biorefinery in which pentose sugars obtained from sugarcane biomass are used either for biogas (consumed internally in the power boiler) or n-butanol production via the ABE batch fermentation process. The complete sugarcane biorefinery was simulated using Aspen Plus®. Although the pentoses stream available in the sugarcane biorefinery gives room for a relatively small biobutanol plant (7.

Butanol production in a first-generation Brazilian sugarcane biorefinery: technical aspects and economics of greenfield projects.

The techno-economics of greenfield projects of a first-generation sugarcane biorefinery aimed to produce ethanol, sugar, power, and n-butanol was conducted taking into account different butanol fermentation technologies (regular microorganism and mutant strain with improved butanol yield) and market scenarios (chemicals and automotive fuel). The complete sugarcane biorefinery with the batch acetone-butanol-ethanol (ABE) fermentation process was simulated using Aspen Plus®. The biorefinery was designed to process 2 million tonne sugarcane per year and utilize 25%, 50%, and 25% of the available sugarcane juice to produce sugar, ethanol, and butanol, respectively.

Integrated versus stand-alone second generation ethanol production from sugarcane bagasse and trash.

Ethanol production from lignocellulosic materials is often conceived considering independent, stand-alone production plants; in the Brazilian scenario, where part of the potential feedstock (sugarcane bagasse) for second generation ethanol production is already available at conventional first generation production plants, an integrated first and second generation production process seems to be the most obvious option. In this study stand-alone second generation ethanol production from surplus sugarcane bagasse and trash is compared with conventional first generation ethanol production from sugarcane and with integrated first and second generation; simulations were developed to represent the different technological scenarios, which provided data for economic and environmental analysis. Results show that the integrated first and second generation ethanol production process from sugarcane leads to better economic results when compared with the stand-alone plant, especially when advanced hydrolysis technologies and pentoses fermentation are included.

Second generation ethanol in Brazil: can it compete with electricity production?

Much of the controversy surrounding second generation ethanol production arises from the assumed competition with first generation ethanol production; however, in Brazil, where bioethanol is produced from sugarcane, sugarcane bagasse and trash will be used as feedstock for second generation ethanol production. Thus, second generation ethanol production may be primarily in competition with electricity production from the lignocellulosic fraction of sugarcane. A preliminary technical and economic analysis of the integrated production of first and second generation ethanol from sugarcane in Brazil is presented and different technological scenarios are evaluated.

Simulation of integrated first and second generation bioethanol production from sugarcane: comparison between different biomass pretreatment methods.

Sugarcane bagasse is used as a fuel in conventional bioethanol production, providing heat and power for the plant; therefore, the amount of surplus bagasse available for use as raw material for second generation bioethanol production is related to the energy consumption of the bioethanol production process. Pentoses and lignin, byproducts of the second generation bioethanol production process, may be used as fuels, increasing the amount of surplus bagasse. In this work, simulations of the integrated bioethanol production process from sugarcane, surplus bagasse and trash were carried out.

Enzymatic recovery and purification of polyhydroxybutyrate produced by Ralstonia eutropha.

Polyhydroxybutyrate (PHB) is the most studied among a wide variety of polyhydroxyalkanoates, bacterial biodegradable polymers known as potential substitutes for conventional plastics. This work aimed at evaluating the use of enzymes to recover and purify the PHB produced by Ralstonia eutropha DSM545. Screening experiments allowed the selection of trypsin, bromelain and lysozyme among six enzymes, based on their efficiency in lysing cells of a non-PHB producing R.