2.3 Research on High-Efficient Anaerobic Fermentation Technology …
45
2.3.2 High-Efficient Anaerobic Fermentation Technology
of Straws
In view of characteristics of materials containing high content of lignocellulose
and barriers of biological metabolism in anaerobic fermentation, the combined pretreatment and resourceful utilization technologies of anaerobic fermentation were
researched and integrated. This study deeply researched the key influencing factors of fermentation technologies for the coupling system of hydrogenogic and
methanogenic phases. By taking the goal of maximizing resource utilization of green
wastes with high content of lignocellulose and minimizing the cost, this research
established a system of resourceful utilization technologies of wastes containing
high content of lignocellulose in villages and towns, which provides a basis for
industrial application.
2.3.2.1 Biogas Production Performance
The CHMP-AF was performed on reed straws after being treated with cellulose R10 and the results are shown in Fig. 2.24. In the early hydrogenogenic stage, biogas
production rapidly rose in the group treated with enzyme and then slowly increased
after 12 h. The maximum cumulative biogas production in the hydrogenogenic stage
was 1360 mL, which was three times that of the control group without pre-treatment.
Volume fraction of hydrogen in the treatment group with enzyme reached the highest
of 52.1% after 12 h and then gradually decreased with reaction. In the methanogenic
stage, cumulative biogas production in the group treated with enzyme stably rose
with time and reached the highest, being 4400 mL after 353 h, which was five
times that of the control group. Volume fraction of methane significantly increased
with time. The maximum volume fraction of methane in the control group was
68.4%. Obviously, cellulase can be specifically adsorbed on cellulose structure of
straws, promoting the dissolution of plant cell walls. This can dissolve intracellular
substances out and degrade macromolecular polysaccharide, protein and lipid into
micromolecular substances, thus improving utilization efficiency and potential of
biogas production of substrates. After pre-treating straws by using cellulase R-10,
hydrogen and methane productions markedly increased.
2.3.3 TOC and TN Contents
Table 2.5 shows the utilization rates of soluble chemical oxygen demand (sCOD),
TOC, TN and reducing sugar in reed straws in anaerobic fermentation treated with
enzymes. The results demonstrated that utilization rates of sCOD, TOC and TN in
the methanogenic stage of anaerobic fermentation were significantly higher than
those in the hydrogenogenic stage. Moreover, utilization rates of all indictors after
45
2.3.2 High-Efficient Anaerobic Fermentation Technology
of Straws
In view of characteristics of materials containing high content of lignocellulose
and barriers of biological metabolism in anaerobic fermentation, the combined pretreatment and resourceful utilization technologies of anaerobic fermentation were
researched and integrated. This study deeply researched the key influencing factors of fermentation technologies for the coupling system of hydrogenogic and
methanogenic phases. By taking the goal of maximizing resource utilization of green
wastes with high content of lignocellulose and minimizing the cost, this research
established a system of resourceful utilization technologies of wastes containing
high content of lignocellulose in villages and towns, which provides a basis for
industrial application.
2.3.2.1 Biogas Production Performance
The CHMP-AF was performed on reed straws after being treated with cellulose R10 and the results are shown in Fig. 2.24. In the early hydrogenogenic stage, biogas
production rapidly rose in the group treated with enzyme and then slowly increased
after 12 h. The maximum cumulative biogas production in the hydrogenogenic stage
was 1360 mL, which was three times that of the control group without pre-treatment.
Volume fraction of hydrogen in the treatment group with enzyme reached the highest
of 52.1% after 12 h and then gradually decreased with reaction. In the methanogenic
stage, cumulative biogas production in the group treated with enzyme stably rose
with time and reached the highest, being 4400 mL after 353 h, which was five
times that of the control group. Volume fraction of methane significantly increased
with time. The maximum volume fraction of methane in the control group was
68.4%. Obviously, cellulase can be specifically adsorbed on cellulose structure of
straws, promoting the dissolution of plant cell walls. This can dissolve intracellular
substances out and degrade macromolecular polysaccharide, protein and lipid into
micromolecular substances, thus improving utilization efficiency and potential of
biogas production of substrates. After pre-treating straws by using cellulase R-10,
hydrogen and methane productions markedly increased.
2.3.3 TOC and TN Contents
Table 2.5 shows the utilization rates of soluble chemical oxygen demand (sCOD),
TOC, TN and reducing sugar in reed straws in anaerobic fermentation treated with
enzymes. The results demonstrated that utilization rates of sCOD, TOC and TN in
the methanogenic stage of anaerobic fermentation were significantly higher than
those in the hydrogenogenic stage. Moreover, utilization rates of all indictors after