Treatment of hydrocarbon streams, and in one non-limiting embodiment refinery distillates, with reducing agents, such as borohydride and salts thereof, alone or together with at least one co-solvent results in reduction of the sulfur compounds such as disulfides, mercaptans, thiophenes, and thioethers that are present to give easily removed sulfides. In one non-limiting embodiment, the treatment converts the original sulfur compounds into hydrogen sulfide or low molecular weight mercaptans that can be extracted from the distillate with caustic solutions, hydrogen sulfide or mercaptan scavengers, solid absorbents such as clay or activated carbon or liquid absorbents such as amine-aldehyde condensates and/or aqueous aldehydes.

Compositions corresponding to marine diesel fuels, fuel oils, jet fuels, and/or blending components thereof are provided that include at least a portion of a natural gas condensate fraction. Natural gas condensate fractions derived from a natural gas condensate with sufficiently low API gravity can provide a source of low sulfur, low pour point blend stock for formation of marine diesel and/or fuel oil fractions. Natural gas condensate fractions can provide these advantages and/or other advantages without requiring prior hydroprocessing and/or cracking.

Naphtha boiling range compositions are provided that can have improved combustion properties (relative to the research octane number of the composition) in spark ignition engines and/or compression ignition engines. The improved combustion properties can be achieved by controlling the total combined amounts of n-paraffins and isoparaffins that include a straight-chain propyl group (R.sub.1CH.sub.2CH.sub.2CH.sub.2R.sub.2). For such a straight-chain propyl group, R.sub.2 can correspond to any convenient C.sub.xH.sub.y group that can appear in a paraffin or isoparaffin. R.sub.1 can correspond to a hydrogen atom, making the straight-chain propyl group a terminal n-propyl group; or R.sub.1 can correspond to any convenient C.sub.xH.sub.y group that can appear in a paraffin or isoparaffin.

A light fraction fuel composition for compression-ignited engines comprises about 25 v/v % to about 50 v/v % commercial diesel fuel; about 40 v/v % to about 69 v/v % straight run heavy naphtha about 5 v/v % to about 10 v/v % n-butanol; and about 0.2 v/v % to about 1.7 v/v % 2-Ethylhexyl nitrate. The relative percentages of commercial diesel fuel and straight run heavy naphtha are controlled to obtain a cetane number of at least 51 for a selected engine.

Provided is a crude oil additive comprising a pyrolysis oil fraction. In some embodiments, the crude oil additive further comprises a dispersant. Also provided are methods of preparing the crude oil additive as well as methods for reducing the viscosity of crude oil and methods for increasing the API gravity of crude oil.

A method for producing a gasoline alternative by mixing FT light naphtha obtained through Fischer-Tropsch synthesis using renewable power with bioalcohol obtained from biomass, includes: determining a mixing ratio of the bioalcohol to the FT light naphtha based on an octane value of the FT light naphtha, a blending octane value of the bioalcohol, and a predetermined target octane value; determining a hydrogenation ratio for hydrogenation of olefin contained in the FT light naphtha to paraffin such that the gasoline alternative has an olefin content ratio of 10 vol % or less based on the determined mixing ratio of the bioalcohol and an olefin content ratio of the FT light naphtha; hydrogenating the FT light naphtha according to the determined hydrogenation ratio; and mixing the bioalcohol with the hydrogenated FT light naphtha according to the determined mixing ratio of the bioalcohol.

Treatment of hydrocarbon streams, and in one non-limiting embodiment refinery distillates, with high pH aqueous reducing agents, such as borohydride, results in reduction of the sulfur compounds such as disulfides, mercaptans and thioethers that are present to give easily removed sulfides. The treatment converts the original sulfur compounds into hydrogen sulfide or low molecular weight mercaptans that can be extracted from the distillate with caustic solutions, hydrogen sulfide or mercaptan scavengers, solid absorbents such as clay or activated carbon or liquid absorbents such as amine-aldehyde condensates and/or aqueous aldehydes.

The present invention relates to use of Perovskite type of materials as combustion improver in gaseous and liquid fuels. Structurally, the Perovskite material consists of ABO.sub.3, A.sub.xB.sub.1-xC.sub.yO.sub.3 or A.sub.xB.sub.1-xC.sub.yO.sub.3 kind of material with stoichiometric deficiency and oxygen deficient sites. More particularly, the present invention relates to the nanosized perovskite materials stably dispersed in hydrocarbon medium and compatible to the fuel has been used to improve the combustion process and generate more heat output.

The present invention relates to a fuel composition comprising: (i) 60 to 94% by mass of a hydrocarbon mixture comprising: (a) 35 to 55% by mass of aromatic compounds; (b) 30 to 50% by mass of a mixture of n-paraffins and iso-paraffins containing at least 5 carbon atoms, with a ratio of the amount of iso-paraffins to the amount of n-paraffins greater than or equal to 3; and (c) 5 to 15% by mass of naphtenes; (ii) 5 to 36% by mass of ethanol; and (iii) 1 to 10% by mass of butane. This composition is useful for fuelling a spark ignition engine in motor vehicles intended for use by the general public or in competition.

For the shipping industry, these fuels provide solutions to long outstanding technical problems that heretofore hindered supply of low sulfur marine fuels in quantities needed to meet worldwide sulfur reduction goals. Marine shipping use of high sulfur bunker oils is reported as largest source of world-wide transportation SOx emissions. When ships on the open seas burn cheap low grade heavy bunker oils high in sulfur, nitrogen and metals, the SOx, NOx, and metal oxides go to the environment. This invention converts essentially all of each barrel of crude feed to a single ultraclean fuel versus conventional refining where crude feed is cut into many pieces, and each piece is sent down a separate market path meeting various different product specifications. When in port, ships can use these fuels to generate and sell electricity to land based electrical grids to offset fuel cost in an environment-friendly manner.