The production of tert-amyl methyl ether (TAME) began at the commercial level at the end of the 1980s both in the United States and in Europe. TAME is used as a gasoline oxygenate like MTBE, but it uses another type of feedstock: tertiary olefins with five carbon chains (tert-C5 olefins) that exist among the components of the different kinds of gasoline produced in an oil refinery. The tert-C5 olefins are selectively converted into tertiary ethers employing methanol. In this way, TAME production represents an expansion of the raw material basis for producing oxygen­ates as well as the possibility of reducing the content of tertiary olefins and increas­ing the oxygen content in gasoline (Huttunen et al., 1997). TAME is obtained by the liquid-phase reaction of methanol and two of the three isoamylenes (branched olefins of five atoms of carbon): 2-methyl-1-butene and 2-methyl-2-butene. The third isoamylene (3-methyl-1-butene) is not reactive. This reaction is accomplished using acid ionic exchange resins (Oost et al., 1995). TAME solubility is compa­rable to that of ETBE (12 g/L) and can be transferred to surface water streams and groundwater as well. TAME is not easily biodegradable and is persistent in the soil and sediments (Huttunen et al., 1997). In some cases, the refineries employ blends of MTBE, ETBE, and TAME. This results in water streams having contents of these three ethers. The possibility of aerobically degrading this kind of blend using fixed bed reactors has been demonstrated (Kharoune et al., 2001).

Alternatively, the production of the ethyl homologue of TAME, the tert-amyl ethyl ether (TAEE), has been proposed as an attractive option when the ethanol production costs decrease (Ancillotti and Fattore, 1998). TAEE can be produced from isoamylenes as well, but the use of ethanol could make it renewable. In addi­tion, TAEE has one of the lowest RVPs compared to the main oxygenates used in the refineries (see Table 1.1).