20 research outputs found
Palm Oil Conversion to Bio-Jet and Green Diesel Fuels over Cobalt Phosphide on Porous Carbons Derived from Palm Male Flowers
Porous carbon was successfully synthesized from palm male flowers (PMFs), using microwave-assisted potassium hydroxide (KOH) activation and was used as a catalyst support for the conversion of palm oil into bio-hydrocarbons, in fractions of green diesel and bio-jet fuel. Palm male flower-derived porous carbon (PC), consolidated with well dispersed cobalt phosphide (CoP) nanoparticles, was synthesized by simple wet-impregnation with subsequent thermal treatment. The physicochemical properties of the synthesized CoP/PC catalysts were evaluated by various techniques including proximate and ultimate elemental analysis, FTIR, XRD, N2 sorption, SEM, TEM–EDS, and NH3-temperature programmed desorption (TPD). The effects of the pyrolysis temperatures (600−900 °C), used for the impregnated samples before the reduction process, on catalyst properties and catalytic performance were investigated. Moreover, the effect of a liquid hourly space velocity of 0.5–1.5 h−1 and reaction temperatures of 340–420 °C was studied in the palm oil conversion. The catalyst pyrolyzed at 600 °C possessed the greatest particle dispersion and surface area, and showed the highest yield of liquid hydrocarbon product (C9–C18). We also found that the high pyrolysis temperature above 800 °C partially transformed the Co2P phase into CoP one which significantly exhibited higher cracking activity and bio-jet selectivity, due to the improved acidity of the catalyst
Deoxygenation of Waste Chicken Fats to Green Diesel over Ni/Al<sub>2</sub>O<sub>3</sub>: Effect of Water and Free Fatty Acid Content
The
deoxygenation of waste chicken fat containing a high degree of free
fatty acids (FFAs) and water has been implemented to produce a green
diesel, known as biohydrogenated diesel (BHD). The effect of the water
and free fatty acid content in the chicken fat on the conversion,
BHD yield, and liquid/gas product distribution was investigated over
a Ni/γ-Al<sub>2</sub>O<sub>3</sub> catalyst in a trickle-bed
reactor. The major reaction pathway was decarbonylation/decarboxylation
(DCO/DCO<sub>2</sub>), whereas hydrodeoxygenation was minor. Methane
from methanation of the resultant CO/CO<sub>2</sub> and propane cracking
was a major gaseous product. The FFA and water content improved the
BHD yield and the overall contribution of the DCO/DCO<sub>2</sub>.
The presence of water accelerated the breakdown of the triglyceride
molecules into FFAs. Therefore, waste chicken fat from food industries
containing a high degree of FFAs and water content can be used as
a low-cost feedstock for renewable diesel production without requirement
of a pretreatment process
Pebax/Modified Cellulose Nanofiber Composite Membranes for Highly Enhanced CO<sub>2</sub>/CH<sub>4</sub> Separation
This work explored
the use of biomass-derived cellulose nanofibers
as an additive to enhance the separation performance of Pebax membranes
for the removal of CO2 from biogas. Succinate functional
groups were modified on the cellulose nanofiber (SCNF) to incorporate
more CO2-attracting functional groups before they were
added to the polymer matrix. A small addition of SCNF up to 0.5 wt
% had no significant impact on the polymer chain packing of Pebax
but significantly enhanced the tensile strength and separation performance
in both CO2 permeability and CO2/CH4 selectivity. On the other hand, increasing the SCNF addition amount
above 1 wt % resulted in a slight alternation of membrane microstructure,
i.e., lowering crystallinity, stiffer structure, and reduced tensile
strength. At high loading, the CO2 permeability and CO2/CH4 selectivity of the composite membrane were,
however, found to decline. This behavior is explained by a greater
propensity for interaction among the CO2-attracting functional
groups of SCNF and Pebax at elevated SCNF loadings, leading to fewer
functional groups available for CO2 sorption. The optimal
0.5% SCNF loading (Pebax/SCNF-0.5) demonstrated a CO2 permeability
of 263.8 Barrer and selectivity of 19.9 under 4 bar pressure and an
operating temperature of 30 °C. These separation performances
increased by 29.69% permeability and 39.04% selectivity compared with
those of pure Pebax. These highly impressive results corresponded
to the increases in the levels of CO2 dissolution and diffusion
via hydrophilic SCNF nanofillers in Pebax. This work could strongly
advance the research and development of gas separation technology
based on polymeric membranes with the utilization of biobased nanofillers
for energy and environmental sectors