Renewable Isoprene By Sequential Hydrogenation of Itaconic Acid and Dehydra-Decyclization of 3-Methyl-Tetrahydrofuran

2018 Spring Symposium

Omar Abdel­rah­man, Post-Doc, Paul Dauen­hauer Group, Depart­ment of Chem­i­cal Engi­neer­ing & Mate­r­i­al Sci­ence, Uni­ver­si­ty of Min­neso­ta, 421 Wash­ing­ton Ave. SE, Min­neapo­lis, MN 55455

Abstract — The cat­alyt­ic con­ver­sion of bio­mass-derived feed­stocks to val­ue added chem­i­cals is an impor­tant chal­lenge to alle­vi­ate the depen­dence on petro­le­um-based resources. To accom­plish this, the inher­ent­ly high oxy­gen con­tent of bio­mass com­pounds, such as that of lig­no­cel­lu­losic bio­mass, requires sig­nif­i­cant reduc­tion via hydrodeoxy­gena­tion strate­gies. The unsat­u­rat­ed car­boxylic acid ita­con­ic acid (IA) can be pro­duced from bio­mass via fer­men­ta­tion path­ways, for exam­ple. A path­way of inter­est is the con­ver­sion of IA to iso­prene, facil­i­tat­ing the renew­able pro­duc­tion of an indus­tri­al­ly rel­e­vant diolefin. IA can be suc­ces­sive­ly hydro­genat­ed to yield 3-methyl tetrahy­dro­fu­ran (3-MTHF), in a one-pot cas­cade reac­tion, where a Pd-Re bimetal­lic cat­a­lyst results in an 80% yield to 3-MTHF. The 3-MTHF can then be con­vert­ed to iso­prene, and oth­er pen­ta­di­enes, through an acid cat­alyzed vapor-phase dehy­dra-decy­cliza­tion. Mul­ti­ple sol­id acid cat­a­lysts, includ­ing alu­mi­nosil­i­cates, met­al oxides and phos­pho­rous mod­i­fied zeo­lites, were screened for the dehy­dra-decy­cliza­tion step. A new class of cat­alyt­ic mate­ri­als, all sil­i­con
phos­pho­rous con­tain­ing zeo­lites, were found to be the most selec­tive (70% iso­prene and 20% pen­ta­di­enes), where the major side reac­tion involved is a retro-prins con­den­sa­tion of 3-MTHF to butane and formalde­hyde. Through kinet­ic stud­ies, an inves­ti­ga­tion into the effect of Brøn­st­ed acid strength, pore size and oper­at­ing con­di­tions on the selec­tiv­i­ty to iso­prene are dis­cussed. The prospect of apply­ing this dehy­dra-decy­cliza­tion strat­e­gy to oth­er sat­u­rat­ed cyclic ethers will also be dis­cussed, which enables the pro­duc­tion of oth­er diolefin mol­e­cules of inter­est such as buta­di­ene and lin­ear pen­ta­di­enes.

Ref­er­ences:
[1] Abdel­rah­man, O. A.; Park, D. S.; Vin­ter, K. P.; Span­jers, C. S.; Ren, L.; Cho, H. J.; Zhang, K.; Fan, W.; Tsap­at­sis, M.; Dauen­hauer, P. J. ACS Catal. 2017, 7, 1428–1431.