Isoamylenes TAME from

There are two fresh feedstreams. One is methanol. The other is a mixture of C5 components that contains reactive isoamylenes plus other C5 paraffins, naphthenes, and olefins. This C5 stream typically comes from a petroleum refinery light-ends unit that separates light hydrocarbon components generated in catalytic cracking into various streams. Because the boiling points of aU of the C5 components are quite similar, it is uneconomical to separate out the isoamylene reactants from the other C5s. The C5 fresh feedstream contains 24 mol% reactive isoamylenes. The remaining components are pentanes and pentene (largely isopentane), which are inert in the TAME reaction. 

The most common ethers being used as additives are methyl tertiary butyl ether (MTBE), and tertiary amyl methyl ether (TAME). Many of the larger refineries manufacture their own supplies of MTBE and TAME by reacting isobutylene and/or isoamylene with methanol. Smaller refineries usually buy their supplies from chemical manufacturers or the larger refineries. 

Even though new MTBE plants are not being built in North America, CD is used currently for the production of other oxygenates such as TAME or ETBE, which being less soluble in water (i.e., less tendency to be transported in groundwater) are being considered or used as alternative octane enhancers. Ethyl-tert-butyl ether is produced from the etherification of ethanol and isobutylene while TAME production requires isoamylene and methanol. A simulation of the industrial production of a green octane enhancer from... 

TAME is produced by liquid-phase synthesis from methanol and isoamylenes. Among the three isoamylenes only 2-methyl-l-butene (2MB1) and 2-methyl-2-butene (2MB2) are reactive in etherification 3-methyl-1-butene (3MB1) is non-reac-tive. Besides the two synthesis reactions, the isomerization of the reactive isoamylenes takes place simultaneously [10]... 

Both etherification reactions are exothermic, i.e. the equilibrium isoamylenes conversion to TAME decreases with temperature. The isomerisation reaction at operation temperature (between 60°C and 120°C) favours the 2-M2B formation and this component will have the greatest concentration in the reaction mixture. From kinetic point of view this situation is not advantageous because a higher reactivity amylene (2-MIB) is replaced by a lower reactivity one (2-M2B). The two olefins (2-MlB and 2-M2B) used in the synthesis are fed as a hydrocarbon mixture resulted as the C5 fraction... 

In experiment 13, reflux ratio is 2, the molar feed ratio methanol/isoamylenes is 0.9, with a total feed rate of 22.8 kg/h. Simulated profiles agree well with the corresponding experimental data. However, for this experiment, the TAME mass fraction in the bottom is slightly overpredicted, while the calculated bottom temperature is lower. This can be explained by the dimer and oligomer formation from isoamylene which is not considered in the model. 

Other desirable ether compounds for gasoline blending can be made in a similar process. For example, ethyl tertiary butyl ether (ETBE) is made from ethanol and isobutylene. Tertiary amyl methyl ether (TAME) is made from methanol and isoamylene. 

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