A process for production of biofuels from algae can include cultivating an oil-producing algae by promoting sequential photoautotrophic and heterotrophic growth. The method can further include producing oil by heterotrophic growth of algae wherein the heterotrophic algae growth is achieved by introducing a sugar feed to the oil-producing algae. An algal oil can be extracted from the oil-producing algae, and can be converted to form biodiesel.

There is described a process for producing biodiesel and related products from mixtures. There is also described a process for producing precursors and feedstock materials for producing biodiesel and related products. The processes use esterification and trans-esterification, separation and purification. Other process steps such as acidification and distillation can also be used.

A method for the desulphurisation of a gas stream containing hydrogen sulphide, in particular a combustion gas stream used for combustion in a gas turbine, wherein the gas stream is brought into contact with a scrubbing medium containing a catalyst to absorb the hydrogen sulphide, forming elementary sulphur; the catalyst is reduced on formation of the elementary sulphur; the scrubbing medium containing the reduced catalyst is fed to a regeneration stage in which the reduced catalyst is regenerated by oxidation with an oxygen-containing gas which is fed to the regeneration stage; the oxygen-containing gas is fed to the regeneration stage from a compression stage of the gas turbine; and the gas which is depleted of oxygen during regeneration of the catalyst is fed to at least one turbine stage fluidically connected downstream of the compression stage.

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 worldwide 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.

A system and method for torrefying a combination of biomass and biochar colloidal dispersion is provided.

A treatment composition for remediating for remediating H.sub.2S and other contaminant(s) in contaminated gasses comprising: an aqueous hydroxide solution containing at least one hydroxide compound at a collective concentration of 35-55 weight percent of the aqueous hydroxide solution; at least one organic acid selected from the group consisting of fulvic acid and humic acid; and a chelating agent, wherein the aqueous hydroxide solution constitutes at least 80 wt % of the treatment composition, the at least one organic acid constitutes 0.1-5 wt % of the treatment composition, the chelating agent constitutes 0.1-5 wt % of the treatment composition, and a pH of the treatment composition is at least 12.0.

A robust catalyst useful for hydrodesulfurization (HDS) of sulfur-containing hydrocarbons such as sulfur-containing diesel fuel. The catalyst contains a modified mesoporous silica, such as SBA-15, Zr atoms, Ni, Mo, Ce atoms. A method for removing sulfur from a hydrocarbon, such as diesel fuel or a refinery feedstock using the catalyst. A one-pot method for making the catalyst.

Methods are provided to prepare a low sulfur fuel from hydrocarbon sources, such as light tight oil and high sulfur fuel oil, often less desired by conventional refiners, who split crude into a wide range of differing products and may prefer presence of wide ranges (C3 or C5 to C20 or higher) of hydrocarbons. These fuels can be produced by separating feeds into untreated and treated streams, and then recombining them. Such fuels can also be formulated by combinations of light, middle and heavy range constituents in a selected manner as claimed. Not only low in sulfur, the fuels of this invention are also low in nitrogen and essentially metals free. Fuel use applications include on-board large marine transport vessels but also on-shore for large land based combustion gas turbines, boilers, fired heaters and transport vehicles and trains.

The method for producing biodiesel from microalgae using a thermo-responsive switchable solvent includes mixing a thermo-responsive switchable solvent (TSS) in a hydrophilic state with microalgae at room temperature (25 C.); maintaining the TSS-microalgae mixture in the hydrophilic state for a cell disruption time period; raising the temperature of the TSS-microalgae mixture to switch the TSS solvent to a hydrophobic state; maintaining the TSS solvent in the hydrophobic state in the presence of immobilized lipase catalyst and methanol for an extraction/reaction time period to obtain fatty acid methyl esters (FAMEs) as the oils are extracted; lowering the temperature of the TSS-microalgae mixture to switch the TSS solvent back to the hydrophilic state; and maintaining the TSS solvent in the hydrophilic state for a product separation time period. The method may further include extracting the FAMEs from the TSS-microalgae mixture with a nonpolar organic solvent to obtain the biodiesel product.

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.