Propylene glycol reactor

A 41 resin reactor, equipped with a condensor, a stirrer and a nitrogen inlet, is charged with a polyether polyol and maleic anhydride. The mixture is heated to 60 °C and the catalyst is added. The mixture is then heated to 185 °C for 10 h or until the acid number is reduced to 140mgKOH/g. Some propylene glycol is added and the mixture is maintained at this temperature for another 4h or until the acid number is lowered to about 40mgKOH/g. The yield is about 90 %. 

Two changes in the SCWO system have had a significant impact on safety. The switch from kerosene to a mixture of kerosene and propylene glycol as a feed additive should reduce operational risks, while the change from air to oxygen will introduce a new hazard. Although the committee knows of no previous accidents that would raise safety questions unique to the transpiring-wall SCWO reactor, it has expressed gen-... 

A reactor was charged with diethyl fumarate (259 g) and 1,2-propylene glycol (342 g) containing hydroquinone (0.33 g) and zinc chloride (2.04 g) as catalyst and then heated to 100°C for 1 hour and then further heated to 150°C for 7 hours. The product was then isolated and used without further purification. 

Secondly assuming that hydrolysis, reaction of propylene oxide to propylene glycol, is only significant at high pH, and at high concentration, with the condition that this reaction in solution is neglected. The concentration distribution of hydroxide ion in the bed of the SPBE reactor can be given in the form of Eq. (148) by... 

Lehtonen et al. (1998) considered polyesterification of maleic acid with propylene glycol in an experimental batch reactive distillation system. There were two side reactions in addition to the main esterification reaction. The equipment consists of a 4000 ml batch reactor with a one theoretical plate distillation column and a condenser. The reactions took place in the liquid phase of the reactor. By removing the water by distillation, the reaction equilibrium was shifted to the production of more esters. The reaction temperatures were 150-190° C and the catalyst concentrations were varied between 0.01 and 0.1 mol%. The kinetic and mass transfer parameters were estimated via the experiments. These were then used to develop a full-scale dynamic process model for the system. 

Manufacture of the polyols is usually carried out in the same reactors as for ethoxylates. The first step is to dissolve sodium hydroxide in propylene glycol and warm to 120°C. The required amount is charged to the reactor, dehydrated and padded with nitrogen. Once this is achieved propylene oxide is added as fast as it will react, maintaining the temperature at 120°C until the required molecular weight is reached. Then ethylene oxide is added at a rate, which maintains the temperature at 120°C. When all the ethylene oxide is added, the... 

You are the engineer in charge of an adiabatic CSTR producing propylene glycol by this method. Unfortunately, the reactor is beginning to leak, and you must replace it, (You told your boss several times that sulfuric acid was corrosive and that mild steel was a poor material for construction.) There is a nice overflow CSTR of 300-gal capacity standing idle it is glass-lined and you would like to use it. 

We now consider what can happen to a CSTR operating at an upper steady state when an upset occurs in either the ambient temperature, the entering femperature, the flow rate, reactor temperature, or some other variable. To illustrate, let s reconsider the production of propylene glycol in a CSTR. 

In Example 9-4 we saw how a 500-gal CSTR used for the production of propylene glycol approached steady-state. For the flow rates and conditions (e.g., Tq = 75°F, = 60° ), the steady-state temperature was 138°Fand the corresponding conversion was 75.5%. Determine the steady-state temperature and conversion that would result if the entering temperature were to drop from 75°F to 70°F, assuming that all other conditions remain the same. First, sketch the steady state conversions calculated from the mole and energy balances as a function of temperature before and after the drop in entering temperature occurred. Next, plot the "conversion,"concentration of A, and the temperature in the reactor as a function of time after the entering temperature drops from 75°F to 70°F. 

CDPSI Ag The production of propylene glycol discussed in Examples 8-4, 9-4, 9-5, 9-6, and 9-7 is carried out in a semibatch reactor. 

The epoxidation reactor effluent is sent to a propylene separation column where unreacted propylene is distilled from the propylene oxide product. The unreacted propylene is recycled to the epoxidation reactor and the propylene oxide is sent for further separation and recovery of propylene glycol by-products. 

Synthesis of poly(aspartic add) from maleic acid derivatives and from aspartic acid under microwave irradiation conditions has been described by Pielichowski et al. (Scheme 14.33) [69, 70]. The reactions were performed in propylene glycol solutions in the temperature range 160 to 230 °C in a multimode microwave reactor. Poly(aspartic acid) with number-average molecular weights of 6150 to 18 500 g mol was obtained in good yield (50 to 85%). 

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