A system and process for producing biofuel from spent coffee grounds (SCGs) comprises the steps of performing a first operation comprising the steps of obtaining spent SCGs from a source, washing the SCGs, mixing the washed SCGs with an inorganic acid and heating and stirring the washed SCGs to form a SCG slurry without separating coffee oil, drying the SCG slurry, mixing the dried slurry with a solvent and heating the dried slurry and solvent mixture to create a reaction to produce biofuel and residual grounds, and separating the biofuel from the solvent and the residual grounds. The process further includes the step of using an activation agent and heating the residual grounds and the activation agent to create activated residual grounds. Biochar is also produced without activation and heating de-oiled SCGs at lower temperatures without oxygen.

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 0.1-3 wt % of the treatment composition, the chelating agent constitutes 0.1-6 wt % of the treatment composition, and a pH of the treatment composition is at least 12.0.

A process is provided for forming a fuel or a fuel intermediate from two fermentations that includes feeding an aqueous solution comprising a fermentation product from a first bioreactor to a second bioreactor and/or a stage upstream of the second bioreactor, which also produces the fermentation product. The aqueous solution may be added at any stage of the second fermentation and/or processing steps upstream from the second bioreactor that would otherwise require the addition of water. Accordingly, the product yield is increased while fresh/treated water usage is decreased.

A premixture for producing an absorbent for removing acid gases from a fluid stream containing a) at least a tertiary amine and/or a sterically hindered secondary amine; b) a dicarboxylic acid in an amount, calculated as neutralization equivalent based on the protonatable nitrogen atoms in a), of at least 30%, wherein the dicarboxylic acid has a solubility in water at a temperature of 20° C. of not more than 15 g of dicarboxylic acid per 100 g of water; and c) 20 to 80 wt % of water. Also described is a process for producing an absorbent from the premixture. The premixture is a transportable and readily handleable solution of a dicarboxylic acid having poor solubility in water for producing an absorbent for removing acid gases from a fluid stream.

The use of the combination of (a) an amino compound and (b) a compound including a soft electrophilic centre to scavenge and retain acidic sulfide species at a higher temperature and/or scavenge acidic sulfide species at an increased rate compared to that achieved using the amino compound alone.

A method of scavenging acid sulfide species from an industrial or environmental material, the method comprising contacting the material with: (a) propenal and/or maleimide and/or ethyl-2-chloroacetoacetate; and (b) a base.

A scavenging composition and method for scavenging hydrogen sulfide and/or mercaptans from fluids. The scavenging composition comprises an alkali metal nitrite and a nitrogen-containing scavenger, and optionally an inorganic base, as a hydrogen sulfide and/or a mercaptan scavenger for hydrocarbon fluids, particularly for crude oil, field oil, fuel oil, straight run distillates, cracked distillates, residual fuels, natural gas, petroleum associated gas and the like.

Black powder flowing with hydrocarbons in a hydrocarbon pipeline is converted into a magnetorheological slurry by implementing wet scrubbing in the hydrocarbon pipeline. A flow of the magnetorheological slurry through the hydrocarbon pipeline is controlled.

A scavenger comprising a formaldehyde sulfoxylate may be used to scavenge hydrogen sulfide (H.sub.2S) from systems that are brine or mixed production. Suitable formaldehyde sulfoxylates include, but are not necessarily limited to, sodium formaldehyde sulfoxylate, zinc formaldehyde sulfoxylate, and calcium formaldehyde sulfoxylate, potassium formaldehyde sulfoxylate, magnesium formaldehyde sulfoxylate, iron formaldehyde sulfoxylate, copper formaldehyde sulfoxylate, alkene aldehyde sulfoxylates, and combinations thereof.

The present invention relates to a method for reducing the content of monoglycerides (MG), also called monoacylglycerides (MAG), especially of saturated monoglycerides (SMG), in a crude biodiesel (CB).