Abstract: A process and/or system for processing a pressurized gas mixture by membrane separation. Portions of the pressurized gas mixture are withdrawn and provided as a plurality of pressurized gas streams at successively lower pressures. Each portion, provided as a respective pressurized gas stream, is provided for processing in a respective membrane system, each of which is at a different pressure level. Partially purified streams produced by one or more membrane systems are provided for processing at lower pressure levels (e.g., where they are combined with one of the pressurized gas streams). Accordingly, costs associated with recycle compression are reduced and/or eliminated.

Abstract: A process for converting lignocellulosic biomass to fuel, wherein lignocellulosic feedstock is soaked in a sulfuric acid solution to demineralize the feedstock, the demineralized feedstock is pretreated at a temperature between 150° C. and 230° C. and a pH between 1 and 2.5, at least part of the pretreated material is converted to a fermentation production such as ethanol, and at least a portion of a secondary stream, such as still bottoms from the distillation of ethanol, is converted to biogas by anaerobic digestion. Soaking the lignocellulosic feedstock in sulfuric acid solution reduces the amount of sulfuric acid required for the pretreatment, and thus the amount of sulfate carried downstream to the anaerobic digestion. This increases the biogas yield and/or xylose yield. A recycling process, wherein mineralized soaking liquid produced in the soaking process is fed to cation exchange to remove minerals, reduces excess waste of the sulfuric acid and water usage.

Abstract: A process for producing a fuel from lignocellulosic biomass is disclosed. The process includes obtaining a feedstock comprising lignocellulosic biomass, pretreating a slurry containing the lignocellulosic feedstock, sulfur dioxide, and optionally a bisulfite salt, at temperatures between 110° C. and 160° C. for at least 30 minutes. The pretreatment includes subjecting the slurry to a pH adjustment, which includes adding alkali to the slurry, removing lignosulfonic acid from the slurry, or a combination thereof.

Abstract: A process for producing a fuel from lignocellulosic biomass is disclosed. The process includes obtaining a feedstock comprising lignocellulosic biomass, feeding the feedstock and sulfur dioxide into a pretreatment reactor, wherein a total amount of sulfur dioxide in the pretreatment reactor is greater than 70 wt % based on dry weight lignocellulosic biomass, and heating the feedstock and sulfur dioxide in the pretreatment reactor at one or more temperatures between 110° C. and 150° C. for more than 60 minutes.

Abstract: A process for converting lignocellulosic biomass to glucose or ethanol includes subjecting the lignocellulosic biomass to a lignosulfonic acid pretreatment, wherein the lignosulfonic acid has a concentration of sulfonate groups in acid form that is greater than 0.02 mol/L and a total amount of sulfur dioxide is greater than 15 wt % based on dry weight of lignocellulosic biomass.

Abstract: A process for converting lignocellulosic biomass to glucose or ethanol includes subjecting the lignocellulosic biomass to a SO2 pretreatment within the temperature range 110° C.-150° C. Good glucose yields have been achieved when the SO2 pretreatment is conducted for more than 90 minutes and when the total amount of SO2 available is greater than 20 wt % based on dry weight of lignocellulosic biomass.

Abstract: A process for producing a fuel from a softwood. A feedstock containing softwood is pretreated, where the pretreating includes heating the feedstock in a pretreatment liquor containing sulfur dioxide and bisulfite salt. The heating is conducted between 110° C. and 160° C. The pretreatment liquor has a sulfur dioxide concentration that is greater than 6.5 wt % on liquor and a pH at 25° C. that is less than 1.3. The cellulose in the pretreated material is hydrolysed to glucose. The glucose may be fermented to a fermentation product such as ethanol.

Abstract: A process for processing lignocellulosic biomass that includes pretreating lignocellulosic biomass, wherein the lignocellulosic biomass is heated in a pretreatment liquor containing sulfur dioxide and bisulfite salt, at a temperature between 120° C. and 150° C., for at least 30 minutes. The pH of the pretreatment liquor at 25° C. is less than 1.3, the concentration of sulfur dioxide is greater than 9.4 wt % (on liquor), and the concentration of alkali is between 0 wt % and 0.42 wt % (expressed as hydroxide, on liquor).

Abstract: A method of processing biogas that includes obtaining a mobile tank containing biogas at a pressure greater than 1000 psig, connecting the mobile tank to a pressure let down system, and depressurizing the mobile tank to remove biogas therein. The depressurization includes removing gas from the mobile tank using the pressure let down system, and introducing a warming gas into the mobile tank.

Abstract: Provided herein is a process for producing a fermentation product from a lignocellulosic feedstock. The process comprises soaking a lignocellulosic feedstock in an aqueous solution to produce a soaked feedstock. The soaked feedstock is at least partially dewatered and the at least partially dewatered feedstock is subjected to pretreating. The pretreatment chemical is sulfur dioxide, sulfurous acid or a combination thereof and can be added to the process at any stage prior to and/or during pretreatment. The pretreated feedstock composition is fed to an enzymatic hydrolysis conducted at a temperature that is higher than 58° C. The cellulose in the pretreated feedstock composition is hydrolyzed with cellulase enzymes in the presence of the dissolved solids to produce glucose. The glucose is fermented to produce the fermentation product.

Abstract: A process for converting lignocellulosic biomass to glucose or ethanol includes subjecting the lignocellulosic biomass to a lignosulfonic acid pretreatment, wherein the lignosulfonic acid has a concentration of sulfonate groups in acid form that is greater than 0.02 mol/L and a total amount of sulfur dioxide is greater than 15 wt % based on dry weight of lignocellulosic biomass.

Abstract: A process for converting lignocellulosic biomass to glucose or ethanol includes subjecting the lignocellulosic biomass to a SO2 pretreatment within the temperature range 110° C.-150° C. Good glucose yields have been achieved when the SO2 pretreatment is conducted for more than 90 minutes and when the total amount of SO2 available is greater than 20 wt % based on dry weight of lignocellulosic biomass.

Abstract: A process for producing a fuel from lignocellulosic biomass is disclosed. The process includes obtaining a feedstock comprising lignocellulosic biomass, feeding the feedstock and sulfur dioxide into a pretreatment reactor, wherein a total amount of sulfur dioxide in the pretreatment reactor is greater than 70 wt % based on dry weight lignocellulosic biomass, and heating the feedstock and sulfur dioxide in the pretreatment reactor at one or more temperatures between 110° C. and 150° C. for more than 60 minutes.

Abstract: A process for producing alcohol from lignocellulosic biomass includes adding at least one of sulfur dioxide and sulfurous acid to the lignocellulosic biomass to provide an effective sulfur dioxide dosage and/or effective sulfur dioxide slurry concentration, each of which is calculated using the ratio of the volume of the slurry in the pretreatment reactor to the total volume of the pretreatment reactor, within a predetermined range.

Abstract: Provided herein is a process for producing one or more products from a lignocellulosic feedstock. The process comprises treating the lignocellulosic feedstock by contacting the feedstock at least sulfur dioxide, sulfurous acid, or a combination thereof to produce a pretreated feedstock comprising one or more sulfonic acids. A process stream comprising one or more sulfonic acids is subsequently treated in a wet oxidation step to produce a stream comprising at least soluble oxidized phenolic compounds. The soluble oxidized phenolic compounds are then fed to an anaerobic digestion to produce methane. Optionally, hydrogen sulfide is produced during the anaerobic digestion. The hydrogen sulfide may then be converted to an acid selected from sulfur dioxide, sulfurous acid or a combination thereof in one or more steps. The acid may then be re-used in treatment as desired.

Abstract: Provided herein is a process for producing one or more products from a lignocellulosic feedstock. The process comprises treating the lignocellulosic feedstock by contacting the feedstock at least sulfur dioxide, sulfurous acid, or a combination thereof to produce a pretreated feedstock comprising one or more sulfonic acids. A process stream comprising one or more sulfonic acids is subsequently treated in a wet oxidation step to produce a stream comprising at least soluble oxidized phenolic compounds. The soluble oxidized phenolic compounds are then fed to an anaerobic digestion to produce methane. Optionally, hydrogen sulfide is produced during the anaerobic digestion. The hydrogen sulfide may then be converted to an acid selected from sulfur dioxide, sulfurous acid or a combination thereof in one or more steps. The acid may then be re-used in treatment as desired.

Abstract: A process for producing alcohol from lignocellulosic biomass includes adding at least one of sulfur dioxide and sulfurous acid to the lignocellulosic biomass to provide an effective sulfur dioxide dosage and/or effective sulfur dioxide slurry concentration, each of which is calculated using the ratio of the volume of the slurry in the pretreatment reactor to the total volume of the pretreatment reactor, within a predetermined range.

Abstract: A process for hydrolyzing a pretreated lignocellulosic feedstock is disclosed herein. The process comprises hydrolyzing the pretreated lignocellulosic feedstock with an enzyme mixture comprising at least cellulase enzymes to produce a hydrolyzed slurry comprising glucose and lignin solids. The hydrolyzing is conducted in the presence of a polymer, such as an aliphatic polyether. A solids-liquid separation is conducted to recover lignin solids from a process stream comprising the lignin solids and the polymer. A process stream is then obtained comprising recovered lignin solids resulting from the solids-liquid separation. Also provided are processes for recovering the polymer from the lignin solids and/or from solution.

Abstract: Provided herein is a process for producing a fermentation product from a lignocellulosic feedstock. The process comprises soaking a lignocellulosic feedstock in an aqueous solution to produce a soaked feedstock. The soaked feedstock is at least partially dewatered and the at least partially dewatered feedstock is subjected to pretreating. The pretreatment chemical is sulfur dioxide, sulfurous acid or a combination thereof and can be added to the process at any stage prior to and/or during pretreatment. The pretreated feedstock composition is fed to an enzymatic hydrolysis conducted at a temperature that is higher than 58° C. The cellulose in the pretreated feedstock composition is hydrolyzed with cellulase enzymes in the presence of the dissolved solids to produce glucose. The glucose is fermented to produce the fermentation product.

Abstract: The present invention provides a process for producing a fermentation product from a lignocellulosic feedstock. The process comprises soaking a lignocellulosic feedstock in an aqueous solution to produce a soaked feedstock. The soaked feedstock is at least partially dewatered and the at least partially dewatered feedstock is subjected to pretreating in the presence of sulfur dioxide, sulfurous acid or a combination thereof to produce a pretreated feedstock composition. The pretreated feedstock composition is fed to an enzymatic hydrolysis in which the concentration of dissolved solids fed to the enzymatic hydrolysis is at least 50% (w/w) of the concentration of dissolved solids in the pretreated feedstock composition. The cellulose in the pretreated feedstock composition is hydrolyzed with cellulase enzymes in the presence of the dissolved solids to produce glucose. The glucose is fermented to produce the fermentation product.