Application of bio-oil derived from plant biomass in petrochemical industry

M. BERTERO; U. SEDRAN

Advanced Conversion Technologies for Lignocellulosic Biomass

UTM Press

Lugar: Johor Bahru; Año: 2014;

The production of fuels and rawmaterials for the chemical industry from bio-oils obtained by the pyrolysis ofresidual lignocellulosic biomass is an attractive option which deserves sounderresearch. Particularly, co-processing bio-oils together with conventionalfeedstocks in existing refining processes, that is, taking advantage of presentinfraestructure, could be feasible, without the need for extra capital costs. Thecatalytic cracking of hydrocarbons (FCC) and hydrotreating processes arecertainly possible acceptors for bio-oils, since their catalysts and processconditions are proper to convert oxygenated compounds in bio-oils into highvalue products. However, bio-oils could contribute significantly to cokeyields, a fact which could be alleviated if the boil-oils are previously upgradedby means, for example, of a thermal process. Anyway, some of the present FCC technologiespermit processing residual hydrocarbons feedstocks with a high coke formingpotential, without a negative impact on process performance.  In order to know about reactionmechanisms and products in the conversion of bio-oils over FCC catalysts, thecatalytic cracking of model compounds representing the various chemical typeswhich can be found in bio-oils, of a synthetic bio-oil assembled with thosemodel compounds and of crude and upgraded bio-oil from the pyrolysis of pinesawdust was studied under FCC conditions in a MAT-type reactor. The crude andupgraded bio-oil were also studied in a CREC Riser Simulator reactor.  It was observed that phenolic andaromatic ethers as well as some cyclic ketones and furans produce significantamounts of coke (up to 16%wt.). Starting from all the chemical types it was possible to produce highvalue hydrocarbons, particularly light olefins and hydrocarbons in the gasolinerange. Moreover, the thermal upgrading of actual bio-oil decreased up to 30 %its potential to form coke and improved its processability, thus impactingpositively on the co-processing with fossil feedstocks. During co-processingwith vacuum gas oil (VGO) under typical FCC conditions in the CREC RiserSimulator reactor, it was observed that for high proportions of oxygenatedcompounds (up to 20 %), the yield of gasoline decreased and the yield of lightolefins increased, but coke yield was lower than that from pure VGO due to thedilution effect from water in the bio-oil. Following more realistic conditions(addition of 5% of bio-oil to the VGO), the distribution of products was notchanged significantly.