Low-temperature steam and

Low-temperature steam and formaldehyde Gas concentration 15-100 mgl" Steam admission to 73°C 40-180min sterilizing time depending on type of process... 

Low temperature steam and formaldehyde Reactive chemical Indicator paper impregnated with a formaldehyde-, steam- and temperature-sensitive reactive chemical which changes colour during the sterilization process Gas concentration, temperature, time (selected cycles)... 

Fig. 20.8 Typical operating cycle for low-temperature steam and formaldehyde treatment.

One unique feature of the biomass in a bioenergy plant is that the energy supply for drying can be from exhaust flue gas or low temperature steam and water. In large scale combustion boiler systems, power is normally the target energy product... 

Some results of the constant-value pricing system are as foUow generation in a central unit at relatively low pressure, <4.24 MPa (600 psig) tremendous economic pressure to use turbines rather than motors for drives lack of incentive for high efficiency turbines excessively high temperature differentials in steam users tremendous incentive to recover waste heat as low pressure steam and a large plume of excess low pressure steam vented to the atmosphere. 

Some water vapor is also present in air and may be considered to be low-pressure, low-temperature steam. Water vapor is assumed to act... 

Table 20.3 Relative merits of ethylene exide and low-temperature steam formaldehyde (LTSF) pmcesses... 

Low temperature steam (73°C) and formaldehyde (12mg - ) Bacillus stearothermophilus 5min... 

Products Solid char produced at low temperatures liquid and gases at higher temperatures High yield of carbon monoxide, carbon dioxide, hydrogen, methane, ethane, nitrogen, and water Recoverable heat can be used to generate steam and produce electricity... 

The basic reactions of the MRG process consist of three stages (1) hydrodesulfurization of sulfur compounds in the hydrocarbon feedstock (2) low-temperature steam reforming (gasification) of desulfurized hydrocarbons and (3) methanation reaction between hydrogen and carbon dioxide in methane gas available by gassification. 

Sulfur compounds contained in hydrocarbon feedstock vary, depending on the types of crudes and their boiling points. Naphtha, for example, contains mainly mereaptans. disulfides, and thiophenes. Such sulfur compounds deteriorate the activity of the low-temperature steam-reforming MRG catalyst. They should be removed to some degree before the feedstock enters the system. Major reactions of the hy diodesulfurization step are ... 

Gasification by low-temperature steam-reforming reactions, the heart of die MRG process, is carried out between liquid hydrocarbons and steam over catalyst to fonn methane, hydrogen, and carbon oxides. In order to increase the calonfic value of product gas to the values similar to natural gas, methanation reactions are required. Hydrogen in product gas is reacted with C02 and CO to form methane, with only a small portion unconverted. Methanation reactions are ... 

The test results with the ultrasonic nozzle were obtained with an estimated steam to copper (S/Cu) ratio of 23 and the humidified Ar was injected co-currently with the CuCl2 solution. Several variables remain to be investigated, i.e. lower S/Cu ratios, counter-current instead of co-current operation, and subatmospheric pressures. LeChatelier s Principle predicts that reducing the pressure in the hydrolysis reactor should reduce the S/Cu ratio. The effect of a reduced pressure was quantified by the results of a sensitivity study using Aspen. Aspen predicts that a S/Cu ratio of 17 is needed for essentially complete conversion at 375°C and atmospheric pressure while a S/Cu ratio of 13 is required at 0.5 bar. The conceptual process design specifies that the hydrolysis reactor be run at 0.25 bar. The pressure drop in the reactor is achieved by adding a low temperature steam ejector after the condenser at the exit of the hydrolysis reactor in the conceptual design. 

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