Biodegradation of renewable hydrocarbon fuel blends

Abstract

Biologically-produced isobutanol as a component in fuel compositions provides a valuable mechanism for introducing renewable components to fuel compositions and, at the same time, provides for reduced environmental impact of the fuel composition if it were to contaminate a given environmental area.

1 . A method for increasing the renewability of a hydrocarbon fuel composition and limiting the impact on an environmental compartment upon contamination by said hydrocarbon fuel composition, comprising adding a suitable amount of isobutanol in said hydrocarbon fuel composition for increasing the biodegradability of the hydrocarbon fuel composition. 
     
     
         2 . The method of  claim 1 , wherein the hydrocarbon fuel composition further comprises ethanol. 
     
     
         3 . The method of  claim 1 , wherein the ethanol comprises up to about 10% of the fuel composition prior to addition of isobutanol. 
     
     
         4 . The method of  claim 1 , wherein the isobutanol provides for improved biodegradation of at least one of the BTEX components of the hydrocarbon fuel composition. 
     
     
         5 . The method of  claim 1  wherein the isobutanol provides for improved biodegradation of benzene. 
     
     
         6 . The method of  claim 2 , wherein the environmental compartment includes a soil matrix and wherein the addition of isobutanol reduces the transport of ethanol in a soil matrix. 
     
     
         7 . The method of  claim 1  wherein the addition of isobutanol impedes expansion of a BTEX plume from said composition. 
     
     
         8 . The method of  claim 1 , wherein the addition of isobutanol enhances the biodegradability of various components of the hydrocarbon fuel composition. 
     
     
         9 . The method of either of  claim 4  or  5  wherein the improved biodegradation occurs under aerobic conditions. 
     
     
         10 . The method of either of  claim 4  or  5  wherein the improved biodegradation occurs under nitrate-reducing or sulfate-reducing conditions. 
     
     
         11 . A method of improving the environmental fate of a hydrocarbon fuel composition comprising isobutanol in an environmental compartment under anaerobic conditions comprising adding an electron acceptor to said compartment in an amount sufficient to increase the rate of biodegradation of one or more BTEX components. 
     
     
         12 . The method of  claim 11  wherein the electron acceptor is iron, sulfate, or nitrate, or a combination thereof. 
     
     
         13 . The method of  claim 11  wherein the electron acceptor is Fe(OH) 3 . 
     
     
         14 . The method of  claim 11  wherein the electron acceptor is NaNO 3 . 
     
     
         15 . The method of  claim 11  wherein the electron acceptor is MgSO 4 . 
     
     
         16 . The method of  claim 11  wherein the one or more BTEX components comprise toluene. 
     
     
         17 . The method of  claim 11  wherein the one or more BTEX components comprise xylene. 
     
     
         18 . The method of  claim 11  wherein the one or more BTEX components comprise benzene. 
     
     
         19 . The method of  claim 11  wherein the electron acceptor is nitrate and is added in an amount sufficient to create nitrate-reducing conditions. 
     
     
         20 . The method of  claim 11  wherein the electron acceptor is sulfate and is present in an amount sufficient to create sulfate-reducing conditions. 
     
     
         21 . The method of  claim 11  wherein the electron acceptor is nitrate and is present in an amount sufficient to create nitrate-reducing conditions and wherein toluene biodegrades in about the same number of days as isobutanol. 
     
     
         22 . The method of  claim 11  wherein the electron acceptor is sulfate and is present in an amount sufficient to create sulfate-reducing conditions and wherein toluene biodegrades in about the same number of days as isobutanol. 
     
     
         23 . The method of  claim 11  wherein the electron acceptor is nitrate and is present in an amount sufficient to create nitrate-reducing conditions and wherein benzene biodegrades in about the same number of days as isobutanol. 
     
     
         24 . The method of  claim 11  wherein the electron acceptor is sulfate and is present in an amount sufficient to create sulfate-reducing conditions and wherein benzene biodegradation is improved as compared to its biodegradation without sulfate-reducing conditions. 
     
     
         25 . The method of  claim 11  wherein the electron acceptor is sulfate and is present in an amount sufficient to create sulfate-reducing conditions and wherein benzene biodegradation is improved as compared to its biodegradation in the absence of isobutanol. 
     
     
         26 . The method of  claim 11  wherein the electron acceptor is sulfate and is present in an amount sufficient to create sulfate-reducing conditions and wherein benzene biodegradation is improved as compared to its biodegradation in the presence of ethanol. 
     
     
         27 . A composition comprising gasoline, isobutanol and at least one of Fe(OH) 3 , NaNO 3 , or MgSO 4 . 
     
     
         28 . A composition comprising gasoline, isobutanol and at least one of Fe(OH) 3 , NaNO 3 , KNO 3 , NHNO 3 , Na 2 SO 4 , CaSO 4 , MgSO 4 , chelated iron, zero-valent iron, and nano zero-valent iron.