Production of cyclopentadiene from furfural

#This application relates to processes and systems that use a furfural compound for producing five-membered carbocyclic rings that are unsaturated, such as cyclopentene and cyclopentadiene.

#Cyclopentadiene is a five-membered carbocyclic ring. Cyclopentadiene can be a valuable intermediate in the production of a number of different end products. For instance, cyclopentadiene may be used as a monomer to synthesize polycyclopentadiene and C5 hydrocarbon resins and adhesives. Cyclopentadiene can dimerize to make dicyclopentadiene, which may be used as a monomer to synthesize polydicyclopentadiene rubbers. Cyclopentene may also be used as a monomer to make polymers, resins, and adhesives. Cyclopentadienes and substituted cyclopentadienes may be used as a precursor for formation of cyclopentadienyl ligands, which can be useful in the preparation of catalysts. Current production of cyclopentadiene typically comes from products in naphtha steam crackers and fluid catalytic crackers.

#Disclosed herein is an example method for conversion of furfural compounds. The method may comprise converting a furfural compound to at least a five-membered, saturated carbocyclic ring. The method may further comprise converting the five-membered, saturated carbocyclic ring in a presence of a catalyst to at least a five-membered, unsaturated carbocyclic ring, wherein the five-membered, unsaturated carbocyclic ring is selected from the group consisting of a cyclopentene product, a cyclopentadiene product, and combinations thereof.

#This application relates to processes and systems that use a furfural compound for producing five-membered carbocyclic rings that are unsaturated, such as cyclopentene and cyclopentadiene. As used herein, the term “furfural compound” refers to furfural and substituted furfurals.

#There may be several potential advantages to the methods and systems disclosed herein, only some of which may be alluded to in the present disclosure. Advantageously, embodiments disclosed herein can provide favorable reaction thermodynamics than starting with other feeds such as n-pentane, as the embodiments may only include (a) dehydration or (b) dehydration and dehydrogenation with one equivalent of H2. Additionally, embodiments may use furfural compounds as the feed for the production of the cyclopentadiene or other five-membered, unsaturated carbocyclic rings. As the energy intensity of the conversion of the furfural compound may be low, production of the desired five-membered, unsaturated carbocyclic rings may be favored. Moreover, since furfural compounds may be bio-derived (e.g., from xylose, arabinose, etc.), the furfural compounds may be considered a renewable feedstock for the synthesis of cyclopentadiene or other five-membered, unsaturated carbocyclic rings, which can then be converted to valuable products.

#Embodiments may include conversion of a furfural compound to a five-membered, unsaturated carbocyclic ring. In at least one embodiment, furfural may be converted to either cyclopentadiene and/or cyclopentene. The process may first include conversion of the furfural compound to a five-membered carbocyclic ring, such as a cyclopentanol compound, a cyclopentanone compound, and/or cyclopentanediol compound. The five-membered carbocyclic ring can then be dehydrated and, if needed, dehydrogenated, to form the five-membered, unsaturated carbocyclic ring, such as a cyclopentene product and/or a cyclopentadiene product. In some embodiments, the cyclopentene product may be dehydrogenated to produce a cyclopentadiene product. In some embodiments, the conversion may be performed in a single step, for example using a bi-functional catalyst that can both hydrogenate/dehydrogenate and dehydrate, to form the five-membered, unsaturated carbocyclic ring from the furfural compound.