Production of Light Olefins from Catalytic Cracking Bio-oil Model Compounds over La₂O₃-Modified ZSM-5 Zeolite

Abstract

Diminishing fossil fuel reserves and the increasing consumption of light olefins are driving intensive research to find a new non-petrochemical substitute resource to produce light olefins. Biomass-derived bio-oil is a promising substitute resource because it is renewable, abundant, and carbon-neutral. In this study, three bio-oil models, oleic acid (OA), methyl laurate (ML), and waste cooking oil (WCO), were catalytically cracked over La 2 O 3 -modified ZSM-5 (LaZ) aiming for production of light olefins. The content of La 2 O 3 in catalysts was adjusted to optimize the structure and properties of catalysts. The maximal light olefin yield was 131 mL/g for OA, 120 mL/g for ML, and 128 mL/g for WCO, which was obtained over the LaZ catalyst containing 6% La 2 O 3 (6LaZ). The maximal light olefin selectivity was 36.1% for OA, 30.3% for ML, and 33.8% for WCO. The obtained light olefins mainly contained propylene (13.6−17.1%), ethylene (10.7−15.4%), and butene (5.3−6.3%). Aromatic hydrocarbons and graphite were the main components in the liquid product and solid product (coke), respectively. 6LaZ exhibited better catalytic activity and anticoking ability than La-free ZSM-5, which was attributed to its appropriate porosity and acidity. The unsaturated molecular structure of feedstock was found, helping to improve the light olefin yield. Our investigations are useful for developing a new process route to produce light olefins from renewable biomass resources.

Synthesis of Highly Selective and Stable Co-Cr/SAPO-34 Catalyst for the Catalytic Dehydration of Ethanol to Ethylene

“…The observed diffraction peaks at 37° and 57° were attributed to the CoO, which confirmed the incorporation of the metal element on modified catalysts [25]. However, no obvious diffraction peaks of Cr2O3 were observed [26], suggesting that Cr2O3 might have been highly dispersed on the surface of the SAPO-34 support [27]. In general, the dispersion increased as the grain size decreased and vice versa.…”

“…Evidently, two weight loss stages are observed in the TGA curves. The first weight occurred below 300 • C and is ascribed to the sufficient removal of physically adsorbed water, while the weight loss at the temperature from 300 to 800 • C was attributed to the formation of coke [27]. The weight loss ratio of coke was much lower than the physically adsorbed water.…”

“…For each test, the ethanol was replaced with fresh feed to ensure that the reactant feed concentration was constant. Once the flowing-out from the reactor was reached, the products were cooled and the liquid products were collected through a constant-temperature circulating condenser, while the gas products were collected via a gas-collecting bag and analyzed using GC by referring to the method as described in the study [27]. Liquid products were analyzed by GC-MS (Agilent 7890B) equipped with an HP-5ms capillary column (30 m × 0.25 mm × 0.25 µm, Agilent J&W).…”

Production of Renewable Light Olefins from Fatty Acid Methyl Esters by Hydroprocessing and Sequential Steam Cracking

“…to those of the petroleum-derived hydrocarbons, rendering them easy to handle in the conventional refinery processes like fluid catalytic cracking (FCC) . Cracking of triglycerides and their derivatives over zeolites (e.g., HZSM-5) and commercial FCC catalysts has been intensively investigated in the past few decades. − The yields of C 2 –C 4 olefins vary differently but usually below 30%, with the employed catalysts and reaction conditions. Gasoline-range components formed via olefin oligomerization, cyclization, and aromatization are always the dominant products, accounting for more than half of the converted triglycerides. , Catalytic cracking of triglyceride-rich biomass is, therefore, apparently suitable to produce liquid fuels rather than light olefins.…”

The Production of Green Diesel Rich Pentadecane (C15) from Catalytic Hydrodeoxygenation of Waste Cooking Oil using Ni/Al2O3-ZrO2 and Ni/SiO2-ZrO2

“…Waste cooking oil pre-treatment was conducted according to a report by Li et al [22]. A 500 g of the waste cooking oil collected from a halal food court center in Brawijaya University was mixed with 700 mL of saturated salt solution and heated at 80 °C for 3 h under continuous magnetic stirring.…”