Geology

Organic chemistry

Coke

Fluid catalytic cracking

Pulp and paper industry

Cracking

Biomass (ecology)

Composite number

Oceanography

Engineering

Carbon fibers

Composite material

Raw material

Chemistry

Materials science

Pyrolysis oil

Pyrolysis

Chemical engineering

Biofuel

Waste management

Energy & Fuels

Bio-oil is a mixture of organics produced from pyrolysis of biomass. The organics in bio-oil serve as the feedstock for the production of hydrogen, chemicals, biofuels, and carbon materials. In many processes for conversion of bio-oil, heating is required. The thermal treatment of bio-oil induces the polymerization/cracking of the organics in bio-oil, producing coke. Coke could lower the carbon conversion efficiency of bio-oil, clog the reactor chamber, and deactivate the catalyst, imposing the main challenge for the utilization of bio-oil involving the heating of bio-oil. This review investigates the coking issues in the processes for bio-oil upgrading including esterification, hydrotreatment, catalytic pyrolysis, pyrolysis, steam reforming, and the process for the conversion of bio-oil to carbon materials. The properties of coke formed from thermal treatment of bio-oil, the mechanism for coking of bio-oil, and the methods developed for tackling the coking of bio-oil are the focus.

Coke Formation during Thermal Treatment of Bio-oil