Diesel reforming to hydrogen over the mesoporous Ni–MgO catalyst synthesized in microfluidic platform

Combined Activated Carbon with Spent Fluid Catalytic Cracking Catalyst and MgO for the Catalytic Conversion of Waste Polyethylene Wax into Diesel-like Hydrocarbon Fuels

“…However, the temperature influence on the product distribution from pyrolysis of WPEW using MgO, in which the basic catalyst obtained a gas yield very close to pyrolysis using spent FCC due to the high temperature, is mainly affected by the thermal degradation of the WPEW polymer into both small hydrocarbons and hydrogen radicals. Then, the influence of metal oxide MgO promotes hydrogen transfer 21 , 26 , 28 , 34 and carbon–carbon cleavage through mesoporous MgO into a moderate hydrocarbon chain, while the continual cracking reaction of the medium-length hydrocarbon compound produced a large amount of a noncondensable gas. 21 , 34 It was observed that the diesel-like content gradually increased from the increasing temperature of 420 °C, which maximized a diesel-like content of 39.01 wt % and decreased to 15.65 wt % at 470 °C, while a long residue (C 32 + ) illustrated the same trend due to the influence of temperature and catalytic activity enhancing the conversion of WPEW into small hydrocarbon compounds.…”

“…Then, the influence of metal oxide MgO promotes hydrogen transfer 21 , 26 , 28 , 34 and carbon–carbon cleavage through mesoporous MgO into a moderate hydrocarbon chain, while the continual cracking reaction of the medium-length hydrocarbon compound produced a large amount of a noncondensable gas. 21 , 34 It was observed that the diesel-like content gradually increased from the increasing temperature of 420 °C, which maximized a diesel-like content of 39.01 wt % and decreased to 15.65 wt % at 470 °C, while a long residue (C 32 + ) illustrated the same trend due to the influence of temperature and catalytic activity enhancing the conversion of WPEW into small hydrocarbon compounds. Both naphtha-like and kerosene-like compounds 21 , 26 also decreased to 11.47 and 14.45 wt % at 470 °C, which represented a large amount of noncondensable gas of 32.19 wt % causing thermal decomposition and further secondary cracking during the process.…”

“…The effect of the acidic sites in the metal oxides could facilitate the dehydration reaction of organic molecules, which could also promote the cleavage of the macromolecules into small ones. 26 , 28 , 34 When using a spent FCC loading of 1–5 wt %, it was found that using a spent FCC increased the product distribution in the naphtha-like range, while kerosene, diesel, and a long residue range also decreased due to the influence of the active site on the spent FCC enhanced to promote the dehydrogenation reactions, affecting an increase in the hydrogen transfer. Alkanes and alkenes produced by WPEW could undergo secondary cracking coupled with a role of strong acidity active sites in the cleavage of C–C bonds of a moderate hydrocarbon chain in the C 12 –C 32 range to the C 5 –C 12 range, and the product distribution in the diesel-like range was 35.88 wt %, which was similar to the product yields of thermal cracking under the same process conditions.…”

“…Furthermore, an increase in the loading percentage of spent FCC in the catalytic pyrolysis of WPEW increased both Lewis acid and Brønsted acid active sites, which consisted of strong acidity and was favorable for coke formation by mass transfer of small molecules through the external surface and hindering contact between the large structure and the active sites inside the catalyst, thereby accelerating the decomposition of volatile vapor into small hydrocarbon compounds and obtaining a greater product distribution in the gas yield. ,,,, The product distribution of the liquid product consisted of naphtha from 29.31 to 35.88 wt % by the use of spent FCC loading increased from 1 to 5 wt %, whereas kerosene, diesel, and long-chain residue contents decreased to 15.03–13.51, 34.51–27.97, and 3.72–2.56 wt %, respectively. The effect of the acidic sites in the metal oxides could facilitate the dehydration reaction of organic molecules, which could also promote the cleavage of the macromolecules into small ones. ,, When using a spent FCC loading of 1–5 wt %, it was found that using a spent FCC increased the product distribution in the naphtha-like range, while kerosene, diesel, and a long residue range also decreased due to the influence of the active site on the spent FCC enhanced to promote the dehydrogenation reactions, affecting an increase in the hydrogen transfer. Alkanes and alkenes produced by WPEW could undergo secondary cracking coupled with a role of strong acidity active sites in the cleavage of C–C bonds of a moderate hydrocarbon chain in the C 12 –C 32 range to the C 5 –C 12 range, and the product distribution in the diesel-like range was 35.88 wt %, which was similar to the product yields of thermal cracking under the same process conditions.…”

“…The use of MgO, a basic catalyst with a relatively large pore size, facilitated the formation of a medium-length hydrocarbon chain and affected the rapid contact time of pyrolytic volatiles on the catalyst surface, inhibiting the subsequent cleavage reaction of long-chain hydrocarbons and the alkaline center in the basic oxides could effectively promote the fracture of the C–H bonds and C–C bonds, accelerating the formation of gaseous products and correspondingly producing a large proportion of gas. , The effect of MgO loading on the catalytic pyrolysis of WPEW was tested from 1 to 5 wt %; the liquid yield obtained from the catalytic pyrolysis of WPEW slightly fluctuated from 81.05 and 78.96 to 81.32 wt % with increasing MgO loading from 1 to 5 wt % because the operating temperature facilitated the thermal degradation of WPEW to produce hydrogen radicals and short-chain hydrocarbon radicals and underwent hydrogenation with hydrogen radicals on the MgO surface, − , which was succeeded by increasing MgO loading. It seems that an increase of MgO loading to 5 wt % achieved the highest conversion of WPEW to a liquid yield of 81.32 wt %, which consisted of naphtha-like, kerosene-like, diesel-like, and long residues contents of 21.59, 10.64, 39.01, and 10.07 wt %, respectively.…”