Green Biodiesel Synthesis Using Waste Shells as Sustainable Catalysts with Camelina sativa Oil

Waste utilization is an essential component of sustainable development and waste shells are rarely used to generate practical products and processes. Most waste shells are CaCO3 rich, which are converted to CaO once calcined and can be employed as inexpensive and green catalysts for the synthesis of biodiesel. Herein, we utilized lobster and eggshells as green catalysts for the transesterification of Camelina sativa oil as feedstock into biodiesel. Camelina sativa oil is an appealing crop option as feedstock for biodiesel production because it has high tolerance of cold weather, drought, and low-quality soils and contains approximately 40% oil content. The catalysts from waste shells were characterized by X-ray powder diffraction, Fourier Transform Infrared Spectroscopy, and Scanning Electron Microscope. The product, biodiesel, was studied by 1H NMR and FTIR spectroscopy. The effects of methanol to oil ratio, reaction time, reaction temperature, and catalyst concentration were investigated. Optimum biodiesel yields were attained at a 12 : 1 (alcohol : oil) molar ratio with 1 wt.% heterogeneous catalysts in 3 hours at 65°C. The experimental results exhibited a first-order kinetics and rate constants and activation energy were calculated for the transesterification reaction at different temperatures. The fuel properties of the biodiesel produced from Camelina sativa oil and waste shells were compared with those of the petroleum-based diesel by using American Society for Testing and Materials (ASTM) standards

Utilization of waste seashells and Camelina sativa oil for biodiesel synthesis

The seafood industry produces over 100 million pounds of seashell waste every year. With landfill space diminishing quickly, ways to recycle waste materials are becoming more sought for. Herein, we utilized waste mussel, clam and oyster shells as heterogeneous catalysts for the transesterification of Camelina sativa oil as a feedstock into biodiesel. Camelina sativa oil provides a reliable solution for biodiesel production because it has high tolerance of cold weather, drought, low-fertility soils and contains approximately 40% oil content. The catalysts from waste seashells were characterized by X-ray powder diffraction and Fourier transform infrared (FTIR) spectroscopy. High biodiesel yields were achieved at a 12:1 (alcohol:oil) molar ratio with 1 wt.% waste seashell catalysts in 2 h at 65°C. Biodiesel was analyzed by 1H NMR and FTIR spectroscopy and the fuel properties of the biodiesel produced from Camelina sativa oil and waste seashells were compared with American Society for Testing and Materials standards

Syntheses and Structures of [Fe(TPA)X2](ClO4) and [{Fe(TPA)Y}2O](ClO4)2 Where TPA = Tris-(2-pyridylmethyl)amine, X = N3, or Br, and Y = N3, Br, NCO, or NCS

[Fe(TPA)(N3)2](ClO4) and [Fe(TPA)Br2](ClO4), where TPA is tris-(2-pyridylmethyl)amine, crystallize in the monoclinic space group P21/c with a = 8.7029(5) Å, b = 19.168(1) Å, c = 13.5728(7) Å, β = 101.472(3)°, and a = 8.944(3) Å, b = 16.578(6) Å, c = 15.108(6) Å, β = 103.18(2)°, respectively. The structures were determined at 150 K from 3397 reflections (1426 observed) with R = 0.063 (Rw = 0.097), and at 115 K from 5617 reflections (2261 observed) with R = 0.057 (Rw = 0.065), respectively. In both cases, the iron is pseudo-octahedral with the two halide/pseudohalide ions cis. The Fe–X bond trans to the tertiary amine is shorter. The structures of [{Fe(TPA)X}2O](ClO4)2 where X = N3, Br, NCO, and two polymorphic forms of NCS, are also reported. The azide derivative [CH3CN solvate, monoclinic P21/n, a = 11.8038(11) Å, b = 22.547(2) Å, c = 17.344(2) Å, β = 106.972(4)°, determined at 100 K from 8972 reflections (4404 observed) with R = 0.087 (Rw = 0.145)] has two distinct Fe environments—the tertiary amine is cis to the oxido bridge at one site and is trans to the oxido bridge at the other site; the trans Fe–N3° distance is longer. Both the Br and NCO derivatives are monoclinic, C2/c [with a = 16.1480(17), b = 17.2036(13), c = 16.8521(12), β = 111.204(10), data collected at 293 K, 3753 reflections (2404 observed), R = 0.069 (Rw = 0.151), and a = 15.7470(9), b = 18.2270(11), c = 16.8950(8), β = 110.666(3), data collected at 90 K, 5392 reflections (3028 observed), R = 0.064 (Rw = 0.091), respectively]. Both polymorphs of the NCS derivative are monoclinic—one is P21/c and the other P21/n [a = 11.075(2), b = 15.436(2), c = 12.351(2), β = 95.528(7), data collected at 90 K, 5378 reflections (4345 observed), R = 0.068 (Rw = 0.198), and a = 12.396(2), b = 15.428(3), c = 44.505(8), β = 95.211(7), data collected at 110 K, 16,527 reflections (6540 observed), R = 0.069 (Rw = 0.105), respectively]. For the Br, NCO and NCS dimers, each iron of the [{Fe(TPA)X}2O]2+ unit is pseudo-octahedral with the halide/pseudohalide and oxide ions cis. The oxide bridge is linear, and the two halides/pseudohalides are anti. The ranking of trans influence of the ligands is O2− ≫ Br− \u3e Cl− \u3e N3− \u3e NCO− ≥ NCS− \u3e pyridyl \u3e tertiary amine and the ranking of cis influence of the ligands is O2− ≫ N3− \u3e NCO− \u3e Cl− ≥ Br− \u3e NCS−. Graphical Abstract: The X-ray structures of two monomeric [Fe(TPA)(X)2](ClO4), where TPA is tris-(2-pyridylmethyl)amine and X = N3, and Br, and four dimeric [{Fe(TPA)Y}2O](ClO4)2, where Y =N3, Br, NCO, and NCS are presented and discussed. [Figure not available: see fulltext.