Producing Hydrocarbon Fuels From Lignocellulose-drived Oxygenates Catalyzed By Ru/HAP+HZSM-5

The large-scale exploitation of fossil resources accelerated the development of the world economy,simultaneously caused many serious problems,such as energy crisis,climate warming,and global politics,economy,and security problems caused by uneven geographical distribution of energy.The problems force people to look for renewable energy which is expected to replace fossil resources.As the only sustainable organic carbon source on the earth,biomass has the potential to replace petroleum in the production of fuels and chemicals.However,the energy economy based on biomass is still developing,because the developed petrochemical technology is not suitable for processing biomass-derived compounds.Unlike petroleum,biomass has high oxygen content and low heat value.Therefore,complex hydrodeoxygenation(HDO)treatment is required before it can be used as transportation fuels.Lignocellulose has abundant reserves,low price and fast growth rate,and is the most ideal biomass raw material.Diesel and jet fuel are two important transportation fuels.Currently,they are produced mainly from non-renewable petroleum.The sustainable supply of diesel and jet fuel is related to national security and social stability.At present,researchers have developed a variety of ways to produce diesel or jet fuel from lignocellulose-derived platform compounds.Most of the processes could be summarized as follows:first,a C-C bond coupling reaction of lignocellulose-derived platform compounds was carried out to obtain the condensation intermediates with a longer carbon chain;subsequently,alkanes were obtained by HDO of the condensation products.The latter step is still challenging due to the requirement of high temperature and H2 pressure,which leads to high energy consumption,equipment and operation costs and safety risksIn this study,a mild(160? and 4 MPa H2)one-pot catalytic HDO system based on Ru/HAP combined with the HZSM-5 catalyst was developed,and a series of diesel or jet fuel range alkanes(C8-C18)were obtained from nine complicated lignocellulose-derived oxygenates with a desired yield.Ru/HAP was characterized by a series of analyses,indicating that the electron donor effect of HAP led to the generation of highly dispersed electron-rich Ru,which demonstrated stronger hydrogen activation and hydrogenolysis ability.When the acidic HZSM-5 catalyst was mixed with Ru/HAP,the HDO activity of the catalyst was significantly promoted.This work provided an efficient way for liquid fuel production from lignocellulose-derived oxygenates.The stability and recyclability of the Ru/HAP+HZSM-5 catalyst were investigated.The formation of oligomers and the structure change of HZSM-5 led to the catalyst deactivation.