Steam wood ratio

Ib-MAF/hr Bed Temperature. F Pressure, psig Residence Time. min Steam Feed Rate. Ib/hr Hydrogen Feed Rate. SCFH Steam/Wood Ratio. Ib/lb-MAF Hp/Wood-C Ratio. IbM/lbM H2 in Feed Gas. vol %... 

Figure III shows the effect of solids residence time on net Btu yield. There is a question as to whether the high Btu yield shown for the pellets containing 20 percent recycled wood ash is due to the catalytic effect of the wood ash or the relatively high steam/wood ratio used for that run. Further experiments are needed to isolate the catalytic effects from the effects of other process parameters.

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

Increasing the steam/wood ratios over the range of 0 to 0.45 Ib/lb significantly increased carbon conversion. 

In 1999 a new gasifier was installed at the Institute. This gasifier has the same basic design as mentioned above, but an improved operation performance as the previous one. The experiments, shown in this paper, were carried out in the old pitot plant as well as the new one. As fuel for the experiments wood pellets were used. These have the advantage, that the water contents is very low (<10%) and it is a standardised fuel with nearly the same composition over the whole year. The steam-fuel ratio was varied from 0,18-0.8 kg steam per kg dry fuel. The steam-fiiel ratio is calculated in the following way ... 

Type of gasifying agent—whether steam or hydrogen. Feed gas/wood ratio. 

Figure 1. Induction of xylanases in Trichoderma harzianum. The ratios of xylanase to endocellulase activities were determined in the culture filtrates of T. harzianum grown on steam treated aspenwood. Aspen chips were steam treated from 20 to 240 s at 240° C to produce a series of samples with a variable content of xylan and cellulose. The specific content of these carbohydrates were expressed as the ratio of xylan to glucan. Enzyme activities were determined on culture filtrates of 300 mL batch cultures of T. harzianum grown on these wood samples at a loading of 1% (w/v) as described by Saddler and Mes-Hartree (66). Enzyme activities were also determined in culture filtrates of T. harzianum grown on Avicel, Solka Floe and oat spelts xylan.

Steam bending has severe limitations in the quality and number of species of wood that can be bent (27). In general straight grained high density northern hardwoods usually give a minimum radius of curvature ratio or a minimum failure rate. 

Novolaks were prepared using a phenol-to-formaldehyde molar ratio of 4 1 with 5 mole percent of H2SO4 added as a catalyst. Typically, 47 g liquid phenol (91.7% assay), 3 g paraformaldehyde, and 30 mL water plus the required acid catalyst were added to a three-neck, 250-mL round bottom flask. The flask was fitted with a reflux condenser and stirrer. The mixture was refluxed for 2 to 4 hours with the oil bath at 115 °C then, the mixture was neutralized with 50% (w/w) NaOH and the excess phenol removed by steam distillation for 5 to 6 hours. The remaining viscous oily residue was washed repeatedly with boiling water. A novolak with the P/N fraction was prepared as described above with 1 1 by volume phenol and P/N fraction and half of the amount of formaldehyde. Initial wood-gluing testing with this novolak indicates wood failure rather than glueline failure. 

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