Large scale biogas plant
Sugar plants have seasonal working mode (90-120 days). Taking into consideration this factor biogas equipment can be used in two seasons working mode. During sugar plant operational period biogas plant recycles sugar beet pulp and molasses and the rest of time it can recycle other waste products or energy crops like corn silage and sugar beet tops. Biogas can be used for vehicle fueling or accumulated for technological purposes as sugar plants gas consumption is very high. Using such mode biogas plant can be operated without standstills and new start-up.
As a rule sugar plants solve their waste problems by producing dry feed. Such production is energy consumptive and economically unfeasible. Biogas and bio-fertilizer production is more attractive in that respect. Plant energy demand can be covered at waste product expense. Bio-fertilizer can be used for soil enrichment and crop yield increase.
Biogas yield:
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Biogas yield m3/t
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Sugar beet pulp, 75% wet
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110
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Plant peculiarities
Sugar plant waste products are recycled using two stage technology. First substrate gets into receiving tank with 2-5 days storage capacity. From receiving tank substrate comes to hydrolysis tank with 8-10 days of retention time and temperature between +25 / +28oÑ. First stage of fermentation – hydrolysis takes place in that reactor and second one – oxidation begins. Sugar beet pulp have tendency for quick oxidation, in order to increase pH level fermented biomass is partially loaded to the hydrolysis reactor. The bioreactor feeding system is batched, which ensures even and controlled methane formation. For substrate mixing hydraulic system is used. Produced biogas accumulated in external gasholders and used for constant electricity or fuel production.

External gasholders
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Biogas plant facilities for sugar beet pulp recycling will be sufficient for energy crop application as well. Energy crop retention time twice longer but daily loading will be considerably less. So bioreactors volume will be suitable for 60-80 days of energy crops retention time.
During operational period sugar plants consume big quantities of gas and electricity. Depending on plant demands biogas can be used for electricity or heating agent production. Treated biogas is a complete analog of natural gas.
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