Liquefaction continued process

In conclusion, the technology of total liquefaction of apple allows to work with a continuous process with less labour and faster than with a classical one, to get a high and constant yield during the whole processing season at a very high level (93- 95%), to get a pulp with a low content of solids (about 20% in volume) which can be centrifuged instead of pressed (lower investment in equipment), to decrease the quantity of waste pomace, to decrease the production costs. Liquefaction technology allows to process different fruits with the same process, at last to liquefy fruits for which no equipment had been developed to extract the juice or for which the use of pectinases did not allow to get juice such as tropical fruits. 

Elliott, D.C., et al., 2015. Hydrothermal liquefaction of biomass developments from batch to continuous process. Bioresource Technology 178 (0), 147—156. 

Work has also continued on the solvent-refined coal + hydrocracking concept (the NT.SL, or non-integrat-ed, two-stage liquefaction process), and a pilot plant was operated by Amoco, DOE and the Electric Power Research Institute (EPRI) from 1974 to 1992. 

The concentration of chlorine in the total permeate continuously decreases as the process continues. This is illustrated by Fig. 7.5, showing the percentage of the nitrogen originally present which accompanies permeation of 80% and 90% of the chlorine. The purity of the gas is a measure of its utility in further processing. One option is to recycle the permeate to the liquefaction process. This is discussed in more detail in Section 7.3.3. 

After World War II, direct liquefaction of coal became uneconomical as the use of lower-cost petroleum products became more widespread. However, the German process of indirect coal liquefaction, the Fischer-Tropsch process, continued to hold some interest. The Fischer-Tropsch process first involved production of a carbon monoxide and hydrogen-rich synthesis gas by the controlled gasification of coal followed by a catalytic reaction process to yield a valuable mixture of hydrocarbon products. Simplified Fischer-Tropsch reactions are shown by the following equations ... 

Catalysts in coal liquefaction are used in moving-bed, ebulating-bed, and fixed-bed processes. Disposable iron catalysts must be used in moving beds. More expensive Co-Mo and Ni-Mo catalysts are used in either ebulating or fixed beds, and catalyst deactivation rates and ultimate lifetime are of concern (80, 81). In ebulating beds, a small portion of fresh catalyst is continuously fed to balance the catalyst being purged. 

This term is restricted here to equipment in which finely divided solids in suspension interact with gases. Solids fluidized by liquids are called slurries. Three phase fluidized mixtures occur in some coal liquefaction and petroleum treating processes. In dense phase gas-solid fluidization, a fairly definite bed level is maintained in dilute phase systems the solid is entrained continuously through the reaction zone and is separated out in a subsequent zone. 

Starch Liquefaction. Starch in its natural state is only degraded slowly by CC-amylases. To make the starch susceptible to enzymatic breakdown, it is necessary to gelatinize and liquefy a slurry with a 30—40% dry matter content. Gelatinization temperature depends on the type of starch (67) com is the most common source of industrial starches followed by wheat, tapioca, and potatoes. Liquefaction is achieved by adding a heat-stable a-amylase to the starch slurry. The equipment used for liquefaction may be stirred tank reactors, continuous stirred tank reactors (CSTR), or a jet cooker. Most starch processing plants liquefy the starch with a single enzyme dose in a process using a jet cooker (Fig. 9). 

Solid soils are commonly encountered in hard surface cleaning and continue to become more important in home laundry conditions as wash temperatures decrease. The detergency process is complicated in the case of solid oily soils by the nature of the interfacial interactions of the surfactant solution and the solid soil. An initial soil softening or "liquefaction", due to penetration of surfactant and water molecules was proposed, based on gravimetric data (4). In our initial reports of the application of FT-IR to the study of solid soil detergency, we also found evidence of rapid surfactant penetration, which was correlated with successful detergency (5). In this chapter, we examine the detergency performance of several nonionic surfactants as a function of temperature and type of hydrocarbon "model soil". Performance characteristics are related to the interfacial phase behavior of the ternary surfactant -hydrocarbon - water system. 

Analyses of coals which have been processed in the continuously operated pilot plants are listed in Table 1. Process liquid yields from the liquefaction step for these coals are shown in Figure 4 for different residence times in the liquefaction reactor. Longer residence time increases conversion of coal to liquids, but also increases hydrocracking of liquids to gas. 

Tomlinson, G. C., Gray, D., Neuworth, M. B., andTalib, A., The Impact of Rank-Related Coal Properties on the Response of Coals to Continuous Direct Liquefaction Processes, Sandia Contractors Report, SAND85-7238 (Oct. 1985). 

For some reactions listed in Table 1-4A, the fixed-bed reactor is operated under cocurrent-upflow conditions. Unlike the trickle-flow condition, this type of operation is normally characterized by bubble-flow (at low liquid and gas rates) and pulsating-flow (at high gas flow rates) conditions. Normally, the bubble-flow conditions are used. In the SYNTHOIL coal-liquefaction process, both pulsating-and spray-flow conditions are used, so that the solid reactant (coal) does not plug the reactor. In bubble flow, the gas is the dispersed phase and the liquid Ls a continuous phase. In pulsating flow, pulses of gas and liquid pass through the reactor. In the spray-flow regime, the gas is a continuous phase and the liquid is a dispersed phase. 

Effect of Recycle on Liquefaction and Product Distribution. It Is Important that the product oil from a coal liquefaction process should have a low viscosity so that It could be used for preparing coal-oll slurries for recycling In a continuous liquefaction process. The product oil should also exhibit reactivity or solvency for the coal so that the viscosities do not deteriorate with prolonged recycling operation. 

An early system designed for the sulfur-deprived process required several days to poise the cells for Hj production. This transition period represented lost production compared to continuous operation. Daily start-up of the photobioreactor at sunrise may also decrease production if it extends into the daylight hours. Some other operations, for example, H2 liquefaction processes, would not be a logical choice for a diurnal cycle because of the losses and inefficiencies of starting up and shutting... 

Liquefaction units (not to be confused with the hydrogenation processes) using continuous stirred tank reactors, at Niigata and Sapporo. 

The 1973 petroleum crisis intensified research on coal liquefaction and conversion processes. The technology developed in this field was later harnessed in chemical recycling of plastics. Mastral et al. [32], for example, employed two different batch reaction systems (tubing bomb reactors and magnetically stirred autoclave) and a continuous reactor (swept fixed bed reactor). Chemical recycling techniques such as pyrolysis [28, 33-38] or coliquefaction with coal [39, 40] convert plastic wastes into hydrocarbons that are valuable industrial raw materials. 

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