Pyrolysis, biomass methanation

CO = 25 vol.%, C02 = 12 vol.%) not containing any hydrocarbons and a low tar (200 mg Nm 3) content at 800 °C and S/C (steam over carbon ratio) = 1.5. Problems associated with pyrolysis oil gasification are similar to those of biomass gasification. Gasification of the tar fraction and conversion of methane formed are important challenges. Both require highly active and stable steam/autothermal reforming catalysts. 

When the pyrolysis temperature increased the biochar yield decreased. The biochar yield increased with increasing particle size of the sample. The yield of biooil from pyrolysis of the samples increased with temperature. Anaerobic biogas prodnction is an effective process for conversion of a broad variety of agricultural biomass to methane to snbstitnte natnral gas and medinm calorific valne gases. 

Hydrogen production via biomass pyrolysis involves heating the biomass rapidly to high temperatures in the absence of oxygen. Products like hydrogen, methane, carbon monoxide, carbon dioxide,... 

Under idealized conditions, the primary products of biomass gasification by pyrolysis, partial oxidation, or reforming are essentially the same The carbon oxides and hydrogen are formed. Methane and light hydrocarbon gases are also formed under certain conditions. Using cellulose as a representative feedstock, examples of some stoichiometries are illustrated by these equations ... 

Next, methane and carbon monoxide can be further converted into hydrogen by means of steam reforming or the water-gas shift reaction. The most important pyrolysis reactor types are ablative, fluidized bed, circulating fluidized bed and entrained flow reactors. Hydrogen yields can vary substantially with biomass type, facility size and process conditions... 

Many other catalytic fluidized-bed processes have been tested at various scales. These include catalytic low-temperature oxidation, catalytic gasification and pyrolysis of biomass and waste plastic, production of carbon nanotubes, dry reforming of methane, hydrogenation and dehydrogenation of hydrocarbons, methanol-to-gasoline (MTC) process, synthesis of dimethyl ether (DME), and selective catalytic reduction of nitrogen... 

Another actual pyrolysis-based biorefinery concept is the Bioliq process that was developed at the Karlsruhe Institute of Technology (KIT).Bioliq aims at the production of synthetic fuels such as Fischer-Tropsch diesel and chemicals from biomass. Synthesis based on synthesis gas requires pressures of up to 10 MPa. High-pressure entrained flow gasification provides high-quality tar-free syngas with low methane contents. 

Gas made by pyrolysis of biomass, or of municipal solid waste, resembles coal syntehsis gas in composition, and can be produced in the same heating values. Gas made by anaerobic fermentation of biomass is predominantly methane and carhon dioxide. When the carbon dioxide is removed, it is a replacement for natural gas. 

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