Wood steam gasification

Table 19. Product Gases from Steam Gasification of Wood...

The percentage of hydrogen in gaseous products from the samples of hazelnut shell, tea waste and spruce wood increased from 43.3 to 56.9%, 41.0 to 53.9% and 40.0 to 51.5% by volume, respectively, while the final air-steam gasification temperature was increased from 900 to 1250 K (Figs. 6.14 to 6.16). 

TABLE 9.6 Laboratory-Scale Results for Catalyzed Steam Gasification of Wood Reaction conditions... 

Steam gasification of wood char and the effect of hydrogen inhihition on the chemical kinetics... 

Several studies have focused on the influence of wood type on CO2 gasification and steam gasification A general conclusion is that the ash content, composition and its catalytic properties explain the differences among the fuels. In particular, Hansen et al. refer to the potassium content of the ashes as being especially relevant. 

Capart, R. Gelus, M. (1988). A volumetric mathematical model for steam gasification of wood char at atmospheric pressure, Energy from Biomass 4. Proceedings of the 3rd comractors meeting, Paestum, 25-27 May, pp. 580-583. 

Hemati, M. Laguerie, C. (1988). Determination of the kinetics of the wood sawdust Steam-gasification of charcoal in a thermobalance, Entropie, No. 142, pp. 29-40. 

Barrio, M., Gpbel, B, Risnes, H., Henriksen, U., Hustad, J.E. Sprensen, L.H, Steam gasification of wood char and the effect of hydrogen inhibition on the chemical kinetics. This conference. 

A process for the conversion of biomass into methanol by means of an HTGR has been proposed [3]. Wood, represented by the chemical formula C6Hg.6403.7, is gasified by superheated steam. Electrolytic hydrogen is added to the product gas and then converted to methanol or methane. Both heat and electricity are provided by an HTGR. The partial processes of steam gasification, water splitting and methanol / methane synthesis are summarized in the overall reaction [3] ... 

Research described in this paper focuses on the second step of the gasification process, and details the effects of temperature and residence time on product gas formation. Cellulose is used as a feedstock for pyrolytic volatiles formation. Earlier papers (JS.M) have discussed the effect of steam on cellulose pyrolysis kinetics. Two recent papers (1, 1 6) presented early results on pelletized red alder wood pyrolysis/gasification in steam. Future papers will discuss results using other woody materials, crop residues, and manures (17,1 ). Research to date indicates that all biomass materials produce qualitatively similar results in the gasification reactor described in the following section of this paper. Effects of pressure on the heat of pyrolysis of cellulose are also discussed as a prelude to future papers detailing the more general effects of pressure on reaction rates and product slates. 

Figure 4. Effect of steam/wood ratio on net BTU yield (gas) in Steam gasification...

Among the various products that can be synthesized from biomass, methanol was selected because of its versatile applicability to the electricity, transportation, and chemical sectors. Conversion of methanol from biomass is achieved via oxygen-steam gasification followed by shift conversion and methanol synthesis. Three feedstocks were selected for conversion to methanol—wood residue, corn stover, and furfural residue. Availability of... 

In early 1900s, biomass gasification processes were also widely used to manufacture synthetic gases for production of fuels, chemicals, and hydrogen. During World War II, over 1 million air-blown gasifiers were built to produce synthetic gas from wood and charcoal to power vehicles and to generate steam and electricity.3... 

In liquefaction systems wood and wood wastes are the most common fuelstocks. They are reacted with steam or hydrogen and carbon monoxide to produce liquids and chemicals. The chemical reactions that take place are similar to gasification but lower temperatures and higher pressure are used. Liquefaction processes can be direct or indirect. The product from liquefaction is pyrolytic oil which has a high oxygen content. It can be converted to diesel fuel, gasoline or methanol. 

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