Method for using lignocellulose as raw material to co-produce ethyl alcohol and electric energy

Abstract

The invention discloses a method for using lignocellulose as a raw material to co-produce ethyl alcohol and electric energy. According to the method, oxidation-state heteropolyacid or its salt is adopted to pretreat the lignocellulose, most of lignin and hemicellulose are oxidized so that the accessibility of the cellulose can be remarkably improved, further conversion from the lignocellulose to ethanol is facilitated, and the heteropolyacid or its salt is reduced. The reduced-state heteropolyacid or its salt performs discharge in a liquid flow type fuel cell, so that the reduced-state heteropolyacid or its salt is re-oxidized into regenerated oxidation-state heteropolyacid or its salt while electric energy is obtained, and the oxidation-state heteropolyacid or its salt is cyclically used for pretreatment of the lignocellulose. By means of the method, the pretreated lignocellulose and biomass are directly converted into electric energy for coupling, the pretreatment process is regarded as the 'charging' process, the oxidization and regeneration process of the reduced-state heteropolyacid or its salt is regarded as the 'discharging' process, and accordingly ethyl alcohol and electric energy co-production is achieved by utilizing the lignocellulose under the mild conditions.

Description

technical field [0001] The invention belongs to the field of biomass energy, in particular to a method for co-producing ethanol and electric energy by using lignocellulose as a raw material. Background technique [0002] Lignocellulose, such as crop stalks and forestry residues, is the most abundant organic substance in nature, and it is the main raw material for the production of second-generation fuel ethanol. The production of fuel ethanol from lignocellulose generally requires steps such as pretreatment, enzymatic saccharification, fermentation, and ethanol recovery and purification. Among them, pretreatment is a key step in the production of cellulosic ethanol, and its main purpose is to improve the enzymatic hydrolysis performance of cellulose so that cellulose can be effectively saccharified into glucose. A variety of pretreatment methods have been developed, such as dilute acid pretreatment, alkali treatment, oxidation pretreatment, organic solvent pretreatment, etc...

AI Technical Summary

Problems solved by technology

Among these fuel cell technologies that indirectly use lignocellulose to generate electricity, although MFC can be operated under mild conditions below 50°C, the discharge rate is slow and the power density is often lower than 0.5mW / cm2. When raw materials and phenolic compounds are used as fuels, the power density is lower than 0.05mW / cm2

When SOFC uses syngas as fuel, it can obtain a power density as high as 1500mW / cm2, but the operation of SOFC needs to be carried out at a high temperature of 600-900°C, and impurities such as sulfur in the syngas will cause catalyst deactivation and reduce battery life. efficiency

Although DSFC can directly use solid carbon materials as raw materials, and the power density can reach 900mW / cm2, the poor contact between fuel (solid carbon) and electrodes and catalysts and serious electrode corrosion are the main bottlenecks restricting the large-scale application of DSFC.

In addition, these indirect biomass fuel cells need to combine the external biomass conversion system with the fuel cell system, not only need to add additional equipment, the process is more complicated, but also the external chemical and biological conversion causes significant losses, resulting in low conversion efficiency of biomass to electricity

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