Water feedstocks, experiments with

Apparatus and Procedure - The experiments with the solid feedstocks and the initial experiments on liquid samples were carried out in the apparatus shown in Figure 1A. The vapors from a stainless steel, stirred-bed carbonizer/vaporizer at 873°K were cracked at atmospheric pressure in a tube reactor heated in a platinum-wound furnace. The reactor was 30 mm ID and had a 100 mm long hot zone within 20°K of the maximum reactor temperature. Solid feedstocks were introduced at about 1 g min. from a vibratory table through a water-cooled port. Liquids were injected at the same point from a mechanically driven syringe at 0.1-0.8 ml min. The amount fed was determined by weighing the feeders. 

Almost all feedstocks of interest have such properties that they do not flow readily through cither pipes or shell of a conventional heat exchanger without distribution problems. Afler a number of alternatives had been considered it was concluded that the most adequate way of preheating is direct injection of hot water. In Fig. 3 this is done in vessel V where a stream of hot recycle water is mixed with the feed. A special way of contacting achieves efficient heat and mass transfer. It has been verified in our experiments that at 200-250°C biomass feedstocks of different origin, including wood chips, arc softened and form a pastc-like substance [7,8]. The... 

Task 1 Experiments with MSW and Water Feedstocks. The first... 

The feedstock was mixed with 3% (w/w) sulfuric acid solution in 500-mL closed universal flasks with a liquid-to-solid ratio of 8 (w/w). The moisture content of the samples was included as water in the material balances. The mixtures were allowed to stand for 10 min at room temperature in order to equilibrate the acid concentrations between the bulk phase and biomass. Hydrolysis was performed in an autoclave at 130°C for pre-established isothermal periods ranging from 2 to 240 min. The flasks were placed inside the autoclave at 100°C, and the heating time to reach 130°C was recorded. After the reaction time had elapsed, the autoclave was rapidly cooled down and the hydrolysate and solid phase were recovered by filtration (Whatman no. 1 filter paper). All experiments were done at least in duplicate. 

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