Biogas Utilization and Anaerobic Digestion Fermentation Residue Treatment

The biogas project with anaerobic digestion fermentation technology is an energy plant that produces biogas in an efficient way. Via co-generator, the biogas generated can be used to directly produce heat and electricity. Electricity is fed into the public power grid and heat into the heating system. Biogas may also be refined and processed into bio-methane and fed into the public gas network or gas station. About 35% dry matters of the biogas residue after dehydration can be treated with landfilled, incineration or compost. If the organic materials, like green waste, fruit waste, vegetable waste or agricultural organic waste, digested into the biogas slurry upon dry composting will be turned into quality organic manure after further processing. The biogas slurry previously generated is quality liquid fertilizer.

The produced biogas can be refined into bio-methane and fed into the public gas network or gas station. It can also be transferred into electricity and fed into the public power grid. The heat, residue and slurry can also be fully utilized.


Purification and Application of Biogas

The biogas from fermentation mainly includes methane (56%-60%), carbon dioxide, a small amount of water, hydrogen sulfide and other purities. To produce bio-methane, we mainly adopt procedures of purifying and refinement: the former is used to remove a small number of hazardous components in biogas and the latter to remove carbon dioxide from biogas. Biogas desulfurization is to remove the hydrogen sulfide in biogas. The major methods of desulfurization include dry desulfurization, wet desulfurization, as well as the latest membrane separation and biological desulfurization. Biogas desulfurization techniques include physical absorption, chemical absorption, pressure swing adsorption, membrane separation and low-temperature separation, etc. Light weight and energy conservation should be prioritized in method selection. The pressurized washing method and pressure swing absorption method are widely used.

The refined bio-methane may be used as pile fuel gas, for co-generation and for production of compressed natural gas and canned fuel gas, etc.

The biogas produced in fermentation includes CH4 (56%-60%), CO2, a small amount of water, H2S and other impurities. The refined bio-methane can be fed into pipeline, processed into compressed natural gas or canned gas, etc.


Fermentation Residue Treatment

The dry matters of biogas slags after digestion of agricultural organic waste is about 35%,and the structure is good,Use of anaerobic fermentation residues and nano materials, developed both soil improvement of low cost and environmentally friendly, Control-Loss Fertilizer, can improve the fertilizer in the soil adsorption capacity and holding water, reduce the use of nitrogen fertilizer by more than 30%.

The residue contains about 35% solid content and has gut physical micro-structure. Mixed with nano-materials it can be developed as control-loss fertilizer, which can improve the adsorption capacity and helps holding water in soil.