Soybean oil pyrolyzed distillate, which consisted mainly of alkanes, alkenes, and carboxylic acids had a CN of 43, exceeding that of soybean oil (37.9) and the ASTM minimum value of 40 (154). The viscosity of the distillate was 10.2 cSt at 38°C, which is higher than the ASTM specification for DF2 (1.9-4.1 cSt) but considerably below that of soybean oil (32.6 cSt). Short-term engine tests were carried out on this fuel (155).

Used cottonseed oil from the frying process was decomposed with Na2C03 as catalyst at 450° to give a pyrolyzate containing mainly C8.20 alkanes (70%) besides alkenes and aromatics (156). The pyrolyzate had lower viscosity, flash point, and PP than DF and equivalent calorific values. The CN of the pyrolyzate was lower.

Rapeseed oil methyl esters were pyrolyzed at 550 to 850°С and in nitrogen dilution (157). The major products were linear 1-alkenes, straight-chain alkenes, and unsaturated methyl esters. CO, C02, and H2 were contained in the gas fraction. The C1(M4 alkenes and short-chain unsaturated esters were optimally produced at 700°.

Catalytic conversion of vegetable oils using a medium severity refinery hydroprocess yielded a product in the diesel boiling range with a CN of 75-100 (158). The main liquid product was a straight-chain alkane. Other products of the process included propane, water, and C02.

Soybean, babassu and some less common vegetable oils were hydrocracked with a NiMo/Y-Al203 catalyst sulfided in situ with elemental sulfur under hydrogen pressure (159). Various alkanes, alkylcycloalkanes, and alkylbenzenes were observed. Oxygen in the oil feed was liberated as C02, H 20, and CO. Decarboxylation was indicated by water and C02. C M formation indicated acrolein decomposition. Differences between more saturated and unsaturated oils were observed. Besides NiM0/y-Al203, an NiSi02 catalyst was studied {160) in the hydrocracking of vegetable oils at 10-200 bars hydrogen pressure and 623-673 K. The resulting product was a mixture of hydrocarbons, mainly alkanes, in the diesel fraction. Hydrogenolysis of palm oil over Ni/Si02 or over Co at 300° and 50 bar gave a nearly colorless oil, mainly C15.17 alkane {161). The same process gave soft solid with 80.4% C,7 alkanes when applied to rapeseed oil. An octadecane model compound gave 50% conversion over Co/oil catalyst to C17 alkane as the main product.

Catalytic hydrocracking (Rh-Al203 catalyst) of soybean oil at 693 К and 40 bar hydrogen pressure gave liquid products which were distilled to gasoline and gas oil boiling-range hydrocarbons {162). Decarboxylation / decarbonylation was again noted.

Crude and partially hydrogenated soybean oil were decomposed by passage over solid acidic A1203 or basic MgO {163). The degree of unsaturation of the oil influenced product formation. Partially hydrogenated soybean oil yielded more hydrocarbons while crude soybean oil yielded a mixture of oxygenated products and hydrocarbons of lower mean molecular weight. The products derived from MgO cracking showed more unsaturates and aromatics than those from A1203 decomposition.

Kolbe electrolysis of the potassium salts of coconut fatty acids and acetic acid reportedly gave a liquid with good DF properties {164) and the products resembled those from pyrolytic procedures. This product contained 83% alkanes, mainly even-numbered compounds from Сю.24, with C12_18 being the most abundant.