Catalytic Copyrolysis of Sugarcane Leaves and Low-Density Polyethylene Waste to Produce Bio-Oil and Chemicals Using Copper-Doped HZSM-35

Abstract

The effect of copyrolysis operating conditions, namely, temperature (500−650 °C), inert nitrogen flow rate (80−200 mL min −1 ), reaction time (30−75 min), and copper metal-doped HZSM-35, was examined on the product distribution and compared when different mass ratios of sugarcane leaves (SCLs) and low-density polyethylene (LDPE) were pyrolyzed with different concentrations of copper (wt %) doped into HZSM-35. The optimal bioproduction conditions were as follows: 550 °C, a N 2 flow rate of 120 mL min −1 , a reaction time of 45 min, an SCL/ LDPE mass ratio of 0.8:0.2, and the use of 0.4% Cu-ZSM-35. A synergistic effect on the liquid yield was observed when copyrolyzing the biomass−plastic mixture from 500 to 600 °C. In contrast, the experimental yield of noncondensable gas was higher than the theoretical yield at high temperature. The effect of the amount of copper doped into HZSM-35 on the product yield was insignificant, but gas chromatography−mass spectrometry analysis allowed both thermal degradation and catalytic effects on C−C cleavage due to the decomposition of volatile vapors and the occurrence of β-scission to produce aliphatics. These aliphatics were further cracked into smaller hydrocarbons; thus, the relative hydrocarbon content increased. This study demonstrates that a synergistic effect occurs between the catalytic reactions, such as deoxygenation, and pore selectivity to enhance the production of high-quality bio-oil. Furthermore, valuable chemical feedstocks can be obtained from the catalytic copyrolysis of the biomass−plastic mixture with a copper metal-doped hierarchical ZSM-35 catalyst.

Catalytic Copyrolysis of Used Waste Plastic and Lubricating Oil Using Cu-Modification of a Spent Fluid Catalytic Cracking Catalyst for Diesel-like Fuel Production

“…Additionally, the modification of Cu to the sFCC template did not significantly change the peak intensity when increasing the content of Cu impregnation into the sFCC framework, even if it contained Cu 2 O and CuO, in accordance with the metal loading amount being relatively low. 26,28 XRF analysis was performed to confirm the elemental character and elemental composition presented in Table S1, which has a mass molar ratio of Si/Al between 1.1 and 1.0 by spent FCC catalyst and 3 wt % Cu-modified-spent FCC. In addition, the modification of spent FCC with Cu impregnation illustrated that the content of copper metal corresponds to the weight percentage of Cu-modified-spent FCC of approximately 0.461 wt %.…”

“…Herein, the H-donor from the thermal decomposition of LDPE enhances the carbon−carbon bond and carbon−hydrogen bond scission of SLOs from the initial thermal decomposition and enhances further catalytic reactions to produce smaller hydrocarbons. 26,28,34 At the same time, the increase in LDPE blended with SLO exhibited a tendency to increase the diesel-like fraction to 24.59 wt %, according to the thermal decomposition of LDPE contributed to the H-radical and hydrogen radicals, 26,31 which were attached to the H-donor and subsequently facilitated the interaction of both radicals with hydrogen gas production, which enhanced the hydrogenation, hydrotreatment and further catalytic reaction. Therefore, the selectivity of diesel-like molecules tends to increase.…”

“…Thus, the catalytic performance tends to decrease when the reaction time increases, resulting in random carbon−carbon bond cleavage, which affects only the thermal decomposition of free radicals and enhances the scission of carbon−carbon bonds to obtain a large amount of small hydrocarbon compounds, enhancing the secondary cracking reaction and increasing the gas yield by continued thermal degradation over time. 26,28,35 3.2.3. Influence of the SLO/LDPE Mass Molar Ratio on the Product Yield Distribution.…”

“…It seems that SLO had a more prominent effect on the lower ratio of LDPE blended in catalytic copyrolysis and showed the product distribution and the low selectivity of the diesel-like fraction, which was similar to the catalytic pyrolysis of SLO alone. 3,5,28,32,33 By increasing the ratio of SLO/LDPE from 0.9:0.1 to 0.7:0.3, it was found that the product distribution of the diesellike fraction was markedly increased from 18.33 to 23.11 wt % due to the thermal degradation of higher amounts of LDPE, which also increased the H-radicals and hydrocarbon radicals, enhancing the chain scission of LDPE and causing the production of medium hydrocarbon compounds. Herein, the H-donor from the thermal decomposition of LDPE enhances the carbon−carbon bond and carbon−hydrogen bond scission of SLOs from the initial thermal decomposition and enhances further catalytic reactions to produce smaller hydrocarbons.…”

“…Thus, increasing the wt % Cu-modification in the sFCC template will decrease the large area on the external surface compared to that in the micropores, which shows that the increasing Cu-modification tends to be more absorbed in the external part than in the micropores. 26,28 The tests of the 3 wt % copper-impregnated sFCC show that with increasing copper concentration, the proportion of the long residue fraction greatly decreased to 26.77 wt %. Likewise, the diesel-like fraction tended to increase due to the effect of the thermal degradation reaction and catalytic activity, which also correlated with acidic active sites and high concentrations of copper.…”