Catalytic Deoxygenation of Hydrolyzed Oil of Chlorella Vulgaris Microalgae over Lanthanum-Embedded HZSM-5 Zeolite Catalyst to Produce Bio-Fuels

Abstract

Microalgae is one of the most important sources of green hydrocarbons because it contains a high percentage of lipids and is likely to reduce reliance on fossil fuels. Several zeolite-based catalysts have a short lifetime due to coke-formation deactivation. In this study, a lanthanum-modified HZSM-5 zeolite catalyst for the conversion of crude oil into non-oxygenated compounds (hydrocarbons) and oxygenated compounds has been investigated. The crude oil of Chlorella Vulgaris microalgae was extracted using Soxhlet and converted into hydrolyzed oil (HO) through a transesterification reaction. The experiments were conducted in a batch reactor (300 °C, 1000 rpm, 7 bar of N2, the catalyst to the algal HO ratio of 15% (wt.%) and 6 h). The results were organized into three groups: product yield, chemical composition, and carbon number distribution. The liquid products were investigated, including their elemental composition, higher heating value (HHV), atomic ratios of O/C and H/C, and degree of deoxygenation (DOD%). The loading of lanthanum into HZSM-5 zeolite with different loading percentages enhanced the acid sites needed for the algal HO conversion. Among all the synthesized catalysts, 10%La/HZSM-5 produced the highest conversion of the algal HO, the highest yield of hydrocarbons, the highest HHV, and the highest DOD%; those were 100%, 36.88%, 34.16 MJ/kg, and 56.11%, respectively. The enhanced catalytic conversion was due to the presence of lanthanum, which alters the active sites for the desired reactions of catalytic deoxygenation. The main effect of the modification of the parent HZSM-5 zeolite with lanthanum led to adjusting the acidic sites needed to increase the conversion (%) of the algal HO in the catalytic deoxygenation process and thus increase the hydrocarbon yield (%), which in turn led to an increase in the HHV and DOD%. The proposed La-based zeolite composite is promising for different energy applications due to its unique benefits compared to other expensive and less-stable catalysts.

Decomposition of Thermally Stable Fuel Using a Cerium-Modified Zeolite Catalyst and Endothermic Characteristics

“…Increasing the metal doping ratio of lanthanum and samarium deformed the crystallinity of H-ZSM5, resulting in a decrease in the peak intensity. 22 The shape of the graph is similar to that of H-ZSM5, indicating that the ratio of metal doping is small.…”

“…In the cerium regenerative zeolite, new peaks can be found at 28, 38, 48, and 55°, which are in accordance with peaks indicating the coupling of CeO 2 . , On the other hand, in the case of the zeolite modified with lanthanum and samarium, there is no new peak. Increasing the metal doping ratio of lanthanum and samarium deformed the crystallinity of H-ZSM5, resulting in a decrease in the peak intensity . The shape of the graph is similar to that of H-ZSM5, indicating that the ratio of metal doping is small.…”

Bimetallic Lanthanum-Cerium-Loaded HZSM-5 Composite for Catalytic Deoxygenation of Microalgae-Hydrolyzed Oil into Green Hydrocarbon Fuels

“…Before the current investigation, we published two different studies that explored in detail the catalytic deoxygenation process for the algal HO under identical operating conditions (batch reactor, 300 • C, 1000 rpm, 7 bar of N 2 inert gas (initial pressure), catalystto-algal HO ratio = 15% (wt.%), and 6 h). The first study focused on loading Lanthanum on the parent HZSM-5 zeolite at various loading weight percentages (5%La/HZSM-5, 10%La/HZSM-5, and 15%La/HZSM-5) [49], while the second focused on loading Cerium at various loading weight percentages (5%Ce/HZSM-5, 10%Ce/HZSM-5, and 15%Ce/HZSM-5) [50].…”