Abstract: A method for producing acetic acid can improve the life of a silver-substituted ion exchange resin for removing organic iodine compounds in acetic acid. In a carbonylation process of a methanol method, an acetic acid distillation step has at least one distillation step of carrying out the purification of an acetic acid stream under conditions of a column bottom temperature of a distillation column of less than 175° C., a nickel base alloy or zirconium is used as a material of the distillation column in the distillation step, and as metal ion concentrations in a charging mixture of the distillation column in the distillation step, an iron ion concentration is less than 10,000 ppb by mass, a chromium ion concentration is less than 5,000 ppb by mass, a nickel ion concentration is less than 3,000 ppb by mass, and a molybdenum ion concentration is less than 2,000 ppb by mass.

Abstract: Processes and systems are provided to compress vapors produced in distillation and recover the heat of condensation through vapor compression and to derive mechanical, thermal, and electrical energy from a combined heat and power system, while maintaining the plant's original ability to operate. The plant's existing distillation system, steam generation, and electrical demand determine the design basis for the retrofit system that is targeted at an optimized combination of energy usage, energy cost, and environmental impact. Vapor compression (by mechanical vapor recompression and/or thermal vapor recompression) minimizes the total energy usage. Optionally, combined heat and power provides a means of converting energy between fuel, electricity, and thermal energy in a manner that best complements plant requirements and energy economics and minimizes inefficiencies and energy losses.

Abstract: The present invention relates to stable liquid pharmaceutical formulations of cyclophosphamide comprising cyclophosphamide and at least one pharmaceutically acceptable excipient wherein moisture content of the liquid formulation is less than about 2.0% by weight. The invention further relates to stable liquid formulations of cyclophosphamide prepared by a process comprising a step of reducing the moisture content from cyclophosphamide or liquid compositions of cyclophosphamide or both. The invention further relate to method of using such stable liquid formulations of cyclophosphamide for parenteral administration either as ready-to-use or ready-to-dilute for treating various cancer disorders.

Abstract: Provided is a method of separating and purifying a mixture of components having small difference in boiling point, and the method may maximize an energy collecting amount and collect a product to be desired in high purity and high yield.

Abstract: The invention relates to a method for separating acetone from acetone/water mixtures, according to which a partial flow of the acetone/water mixture is concentrated in a column operating under positive pressure in order to obtain a product with an acetone concentration of at least 80 wt. %, and a partial flow of the acetone/water mixture is concentrated in a column operating under normal pressure. The top product from the column operated under positive pressure is used to heat the bottom product of the column operated under normal pressure, by means of a heat exchanger, and the top product is then introduced into the column operated under normal pressure, above the supply of the partial flow of the acetone/water mixture. This method allows the specific energy demand for acetone separation to be significantly reduced, thereby presenting considerable cost advantages. The invention also relates to a device for carrying out such a method.

Abstract: The present application discloses a device for multistage continuous preparation of deuterium depleted water, which includes a feeding pump, a plurality of stages of separation systems connected in series, and a receiver, all of which are connected in sequence. Each stage of separation system comprises a distillation column, a vapor-liquid separator, a low-pressure steam compressor, a stream delivery pump, a three-way valve, and a stream output pipe. The present application further discloses a method for preparing deuterium depleted water, wherein natural water is fed into the device of the present disclosure, and the liquid phase stream continuously flows backwards stage by stage under the combined action of the low-pressure steam compressors and the stream delivery pumps. In a single-stage system, the deuterium is deprived depending on the difference in vapor pressure between 1H2O and 2H2O (and/or 1H2HO), and finally, the deuterium depleted water is produced.

Abstract: The present disclosure provides processes and systems for ethanol production. In one embodiment, a first beer column receives a first portion of a feed mixture including ethanol and water to form a first beer column bottom stream and a first beer column vaporous overhead stream. A beer column receives a second portion of the feed mixture. A first portion of the first beer column bottom stream is forwarded to a first beer column reboiler. A second portion of the first beer column bottom stream is forwarded to a plurality of evaporators. A condensed portion of the first beer column vaporous overhead stream is forwarded to a stripper column. The stripper column forms a feed stream, which is contacted with a separation system, thereby forming a permeate and a retentate. The permeate is forwarded directly to at least one selected from the first beer column and the stripper column.

Abstract: Separation of chlorosilane mixtures containing boron, arsenic, and/or phosphorus impurities is facilitated by a distillative separation using at least one divided column, with recycle streams to a first column being passed through an external absorbent for the impurities.

Abstract: The invention is directed to a device and associated method for recovering at least one product from a fermentation broth. The invention relates to the use of a vacuum distillation vessel to recover products, such as ethanol, from a fermentation broth, where the fermentation broth comprises viable microbial biomass, and where the recovery of the product is completed in such a manner to ensure the viability of the microbial biomass. The invention provides for product recovery at an effective rate so as to prevent the accumulation of product in the fermentation broth. To ensure the viability of the microbial biomass, the invention is designed to reduce the amount of stress on the microbial biomass. By ensuring the viability of the microbial biomass, the microbial biomass may be recycled and reused in the fermentation process, which may result in an increased efficiency of the fermentation process.

Abstract: An improvement which reduces the reflux requirement for a fractional distillation system of an alcohol production plant (40, 60, 70, 80). The improvement includes a mixing device (44) for combining a water/alcohol mixture having an enhanced alcohol content (50, 62, 72, 82) with the reflux liquid (16) in the absence of a vapor/liquid equilibrium interface to form a reflux mixture (56) for supply to the rectifier column (14). The mixture having an enhanced alcohol content may be sourced from a location along the rectifier-reflux vapor to liquid system flow path, or from another source.

Abstract: Improvements in grain alcohol distillation plants by incorporating a novel internal arrangement in the wort column and the rectifying column with distributors and accumulators inside thereof, achieving a stable and safe process in wide ranges of operation, guaranteeing the productivity of the plant and the quality of the products. The wort column features detachable perforated plates, easy to access and clean through manholes. By having easily detachable plates and, also, a manhole for each plate with “holder” type connections, the access to the interior of the column for cleaning and maintenance purposes is facilitated. The rectifying column is a special filling column with flow distributors, it has an intermediate alcohol accumulator and a condenser which is an integral part of the column that prevents the use of pumps.

Abstract: A process of mass transfer is described which utilizes latent heat transfer with little or sensible heat transfer. In a preferred process microbubbles are used under certain conditions of contact with a liquid phase to ensure highly effective mass transfer between a gaseous and liquid phase with significantly less than expected or little or no sensible heat transfer. The present invention in part provides a means by which the known state of a cold liquid of varying depths can be changed using a hot gas injected via a micro bubble inducing internal mixing without allowing the resultant mixture to reach equilibrium thereby ensuring the transfer process becomes continuous. Thus a process is described wherein at least one gaseous phase is contacted with at least one liquid phase such that the heat ratio of the system (AA) is maintained at an a value of greater than 0.5, and the mass transfer is effected by passing a gaseous phase comprising microbubbles through a liquid phase of thickness no more than 10 cm.

Abstract: Described are methods for pretreating lignocellulosic biomass that comprise thermally conditioning the biomass by flow processing an aqueous slurry of the biomass through an outer passage(s) of one or more heat exchange devices while circulating a heat exchange fluid through an inner passage(s) of the heat exchange device(s). Also described are methods for producing fermentation products, especially ethanol, from the pretreated biomass.

Abstract: In order to separate and concentrate a liquid component from a liquid multi-component mixture formed of several liquid components with different boiling temperatures, e.g. an ethanol-water mixture, a concentration apparatus (3) is proposed, with its separation section and concentration section designed as separate columns (5, 7) with different operating energy requirements. The column (7) with the higher operating energy requirements is designed for a lower temperature difference between the boiling temperature of the top of the column (29) and the boiling temperature of the bottom of the column (21) than the column (5) with lower operating energy requirements. Separate mechanical vapour compressors (15, 27) are assigned to the two columns (5, 7), said vapour compressors compressing the vapours from the top of the associated column (5, 7) and supplying the operating energy to the bottom region (11, 21) of the respective column (5, 7) by means of separate sump evaporators (9, 23) which act as, reboilers.

Abstract: Processes and systems are provided to compress vapors produced in distillation and recover the heat of condensation through mechanical vapor compression and to derive mechanical and electrical energy from a combined heat and power system, while maintaining the plant's original ability to operate. The plant's existing distillation system, steam generation, and electrical demand determine the design basis for the retrofit system that is targeted at an optimized combination of energy usage, energy cost, and environmental impact. Mechanical vapor compression minimizes the total energy usage. Combined heat and power provides a means of converting energy between fuel, electricity, and thermal energy in a manner that best complements plant requirements and energy economics and minimizes inefficiencies and energy losses.

Abstract: Processes and systems are provided to compress vapors produced in distillation and recover the heat of condensation through mechanical vapor compression and to derive mechanical and electrical energy from a combined heat and power system, while maintaining the plant's original ability to operate. The plant's existing distillation system, steam generation, and electrical demand determine the design basis for the retrofit system that is targeted at an optimized combination of energy usage, energy cost, and environmental impact. Mechanical vapor compression minimizes the total energy usage. Combined heat and power provides a means of converting energy between fuel, electricity, and thermal energy in a manner that best complements plant requirements and energy economics and minimizes inefficiencies and energy losses.

Abstract: Provided are a purification device and method. The purification device and method make most use of an internal heat source in the distillation column in the process of distilling the raw material, and reduce use of an external heat source. Thereby, the purification device and method can improve energy efficiency of all the processes.

Abstract: Process for reducing the water and carboxylic acid content of an alcohol composition containing at least one alcohol having one to four carbon atoms, water and at least one carboxylic acid having from one to four carbon atoms by contacting the alcohol composition with a desiccant bed containing at least one porous inorganic oxide material at elevated temperature. At least one of the porous inorganic oxide material(s) contains Brønsted acid sites and/or neutralized Brønsted acid sites.

Abstract: Engine system using alcohol Rankine heat recovery where the engine heat converts alcohol into hydrogen-rich gas which is then introduced into the engine cylinders. The engine system includes a source of liquid alcohol along with an internal combustion engine generating a high temperature exhaust. Structure is provided for introducing a first portion of the liquid alcohol into the engine and a series of heat exchangers forming a Rankine heat recovery cycle is provided to extract heat from the exhaust and transferring the heat to a second portion of the liquid alcohol, causing it to change phase to a gaseous alcohol. A heat exchanger/catalyst is heated by the exhaust to reform the gaseous alcohol into a hydrogen-rich reformate.

Abstract: The present invention describes substrates (feedstocks) used in the production of fuel ethanol and describes the process by which the alcohol is produced. The inventors process animal, vegetable, industrial food waste or a mixture of wastes in a process involving saccharification and fermentation reactions to produce a mixture of fuel ethanol water and carbon-dioxide, which is subsequently separated to recover 95 vol. % ethanol.

Abstract: An apparatus and method for extracting and recovering water-soluble gas and waste heat from an oven is provided. The method employs a gas-gas heat exchanger for cooling hot stack gas from the oven to a temperature higher than the dew point of the hot stack gas, a double-film-wise heat exchanger for receiving the cooled stack gas from the gas-gas heat exchanger, a condenser/heat exchanger for receiving and further cooling the stack gas from the double-film-wise heat exchanger to ambient temperature by heating a utility water stream, which can then be used for hot water and steam process services, and an ethanol recovery unit for receiving the cooled stack gas from the condenser/heat exchanger.

Abstract: A two stage scrubber process for ethanol fermentation has a first stage using fusel oil to remove the hazardous air pollutants and recover the majority of the ethanol. A second stage uses water as the scrubbing solvent to recover any residual ethanol that is stripped from the first stage.

Abstract: This invention relates to purification and/or recovery of ethanol from a crude ethanol product obtained from the hydrogenation of acetic acid. Separation and purification processes of a crude ethanol mixture are employed to allow recovery of ethanol and remove impurities. In particular, the process involves one or more sidestreams to regulate C3+ alcohols concentration in the recovered ethanol.

Abstract: An integrated bioethanol production and evaporation process and system produce reduces high quality ethanol and concentrated stillage. The process and system provide a significant energy savings over conventional bioethanol production and evaporation systems by using the energy (“vapor”) that drives the distillation process to also drive a multiple effect evaporator, preferably a multiple effect TASTE™ evaporator to “flash” or vaporize alcohol from the distillate. Additional energy savings are provided by passing fermented material through one or more pre-heaters of the multiple effect evaporator to increase the temperature of the fermented material prior to its distillation. The system preferably includes a pre-flash evaporator upstream of an alcohol recovery assembly in the direction of vapor flow and a multi-effect post-flash evaporator downstream of the alcohol recovery assembly.

Abstract: A process for removing water from an alcohol mixture, such as an ethanol mixture in the production of ethanol by hydrogenating acetic acid. The water is removed from a distillate of a first column using an adsorption unit, membrane, extractive column distillation, or a combination thereof.

Abstract: Mixtures of ethanol and water are dehydrated using starch pearls to adsorb and remove water. Vapor-phase adsorption equilibrium capacities of cassava starch pellets (tapioca pearls) having different particle sizes are disclosed, and tapioca pearl particles are shown to be surprisingly more effective for dehydrating 88 to 97% w/w feed ethanol than corn grits. The adsorption equilibrium curve and BET surface area measurement show that the adsorption capacity of tapioca pearls is a function of surface area available to water molecules. SEM images demonstrate that the particle architecture required for the adsorption and dehydration properties is that of a core-shell configuration with pre-gel starch acting as a central scaffold holding together other particles to the outer layer of the particle. The outer surface area of the pearls, populated with dry starch granules, is the main factor determining the adsorption capacity of the pearls.

Abstract: The invention provides systems and methods for the pre-concentration of a target molecule from feed solution comprising a low concentration of the target molecule.

Abstract: A system for the production of ethanol and co-products is provided. The system facilitates an overall reduction in the use of energy, for example, by reducing the mass of wet solids supplied to a distillation system. The system also reduces the amount of energy used to dry the wet solids component of a fermentation product, for example, by increasing the ethanol concentration of the wet solids. The system also facilitates the recovery of co-products including bioproducts and other biochemicals extracted from components of the fermentation product. The solids component of the fermentation product may be dried and constituted into a meal that may be used for animal feed, among other uses.

Abstract: A system for the production of ethanol and co-products is provided. The system facilitates an overall reduction in the use of energy, for example, by reducing the mass of wet solids supplied to a distillation system. The system also reduces the amount of energy used to dry the wet solids component of a fermentation product, for example, by increasing the ethanol concentration of the wet solids. The system also facilitates the recovery of co-products including bioproducts and other biochemicals extracted from components of the fermentation product. The solids component of the fermentation product may be dried and constituted into a meal that may be used for animal feed, among other uses.

Abstract: In one embodiment, the invention is to a process for producing ethanol, the process comprising the steps of carbonylating methanol in a carbonylation system in the presence of a carbonylation catalyst under conditions effective to form acetic acid; hydrogenating the acetic acid in a hydrogenation system in the presence of a hydrogenation catalyst to form a crude ethanol product comprising ethanol and water; separating the ethanol from the water to form an ethanol stream and a water stream; and directing at least a portion of the water stream to the carbonylation system, e.g., for use as an extractant in a permanganate reducing compound removal system.

Abstract: Method for dewatering a mixture of mostly ethanol and water which is split into a first partial feed flow (3) that is directed to a distillation column (32) as a reflux flow while a second partial feed flow (4) is directed to an evaporator unit (31) as an evaporator inlet flow and leaves the top of the evaporator unit as an evaporator outlet flow (6). A top discharge flow (7) from distillation column (32) is returned and combined with the evaporator outlet flow (6) to a combined flow (8) at an overpressure and which in a compressor unit (33) is compressed to a combined, compressed flow (10) which enters a dewatering unit (34) in which it is split into a water-rich permeate flow (14) and a retentate flow (11) in the form of substantially water free ethanol.

Abstract: An improved process for separation of liquid mixtures involves vapor stripping followed by mechanical compression of the vapor which is then exposed to a permeation membrane for separation of the compressed vapor. The apparatus for separating a liquid mixture of two or more solvents comprises components a stripping column, at least one over-head compressor and, thereafter, at least one selectively permeable membrane wherein the membrane separates the components of the vapor based on the different sorption and diffusion characteristics.

Abstract: A process for recovering butanol from a mixture comprising a water-immiscible organic extractant, water, butanol, and optionally a non-condensable gas, is provided. The butanol is selected from 1-butanol, 2-butanol, isobutanol, and mixtures thereof. An overhead stream from a first distillation column is condensed to recover a mixed condensate. An entrainer is added to at least one appropriate process stream or vessel such that the mixed condensate comprises sufficient entrainer to provide phase separation of the organic and the aqueous phases to provide for recovery of the butanol.

Abstract: Processes for the recovery of ethanol, useful as a fuel, from various cellulosic feedstock materials fermented to produce ethanol-containing beer are disclosed. The present invention provides a method and a system for ethanol recovery from highly viscous fermented citrus waste biomass. The systems overcome various challenges, including effectively stripping the ethanol from biomass beer in an energy efficient and economical manner that may allow for the further dehydration of the ethanol/water mix in a traditional rectifier distillation column. In certain embodiments, a series of flash stages and beer stripping columns are capable of operating with highly viscous slurries and/or feedstocks containing high levels of solids.

Abstract: A process for removing water from an alcohol mixture, such as an ethanol mixture in the production of ethanol by hydrogenating acetic acid. The water is removed from a distillate of a first column using an adsorption unit, membrane, extractive column distillation, or a combination thereof.

Abstract: A process and system for the conversion of biomass, such as spent brewers grain, into ethanol and other commercial products, such as pelletized fuel, biogas, fertilizer, and livestock feed, is disclosed. The method may include biomass pretreatment, hydrolysis, fermentation, distillation, and dehydration phases.

Abstract: An energy-efficient extractive distillation process for producing anhydrous ethanol from aqueous/ethanol feeds containing any range of ethanol employs an extractive distillation column (EDC) that operates under no or greatly reduced liquid reflux conditions. The EDC can be incorporated into an integrated process for producing anhydrous ethanol used for gasoline blending from fermentation broth. By using a high-boiling extractive distillation solvent, no solvent, is entrained by the vapor phase to the EDC overhead stream, even under no liquid reflux conditions. The energy requirement and severity of the EDC can be further improved by limiting ethanol recovery in the EDC. In this partial ethanol recovery design, ethanol which remains in the aqueous stream from the EDC is recovered in a post-distillation column or the aqueous stream is recycled to a front-end pre-distillation column where the ethanol is readily recovered since the VLE curve for ethanol/water is extremely favorable for distillation.

Abstract: A process for separating vapors, for example for separating water from ethanol, uses a gas separation membrane unit. Permeate from the membrane unit is compressed and may be used for example as heating steam for distillation. The membrane unit may have two or more stages. Permeate from a stage may be condensed and used for example as fermentation make up water, compressed and fed to the permeate from an upstream stage or heating steam, or fed to another membrane stage for further dewatering. The gas separation membrane unit may be used to remove water from a fermentation broth that has been partially dewatered, for example by one or more of a distillation column or molecular sieve.

Abstract: Processes for removing water from organic solvents, such as ethanol. The processes include distillation in two columns operated at sequentially higher pressure, followed by treatment of the overhead vapor by one or two membrane separation steps.

Abstract: The present invention is directed towards a process of condensing ethanol during the distillation stage of ethanol production by using an air-cooled condenser. Typically ethanol producing facilities use water-cooled condensers to cool the vaporized ethanol into liquid ethanol. However this water-cooled condenser uses about 50% of the water used in the cooling tower and requires replacement. Due to growing concerns and scrutiny of water usage in the ethanol producing industry air-cooled condensers in the distillation step of ethanol production can significantly conserve water.

Abstract: Processes for removing water from organic solvents, such as ethanol. The processes include distillation in two columns operated at sequentially higher pressure, followed by treatment of the overhead vapor by one or two membrane separation steps.

Abstract: A method includes operating an apparatus having a mash circulating and recirculating system with pump and fermentation tank, an atmosphere circulating and recirculating system with blower for recirculating atmosphere between the tank and an ethanol-removal station, and an integrated refrigerating heat-transfer system with first coils remote from the tank for condensing out ethanol from the atmosphere, and second coils for warming the mash. The entire apparatus can be up-sized or down-sized for specific applications. In one form, the system includes electrically-driven pump, blower, and refrigeration compressors, with the external energy consumption being entirely electrical and kept surprisingly low.

Abstract: The present invention relates to a method of anhydrous ethanol production using circulation by multiple towers' alternation, the procedure includes the steps of heating, adsorption, internal circulation, vacuum suction, washing and resolving etc. The method can prolong the life of adsorbent, reduce the heat exchanger's surface, cooling water, the equipment investment and energy consumption, provide high ethanol recovery rate and high dehydration, and protect environment.

Abstract: An energy-efficient extractive distillation process for producing anhydrous ethanol from aqueous/ethanol feeds containing any range of ethanol employs an extractive distillation column (EDC) that operates under no or greatly reduced liquid reflux conditions. The EDC can be incorporated into an integrated process for producing anhydrous ethanol used for gasoline blending from fermentation broth. By using a high-boiling extractive distillation solvent, no solvent, is entrained by the vapor phase to the EDC overhead stream, even under no liquid reflux conditions. The energy requirement and severity of the EDC can be further improved by limiting ethanol recovery in the EDC. In this partial ethanol recovery design, ethanol which remains in the aqueous stream from the EDC is recovered in a post-distillation column or the aqueous stream is recycled to a front-end pre-distillation column where the ethanol is readily recovered since the VLE curve for ethanol/water is extremely favorable for distillation.

Abstract: An energy-efficient extractive distillation process for producing anhydrous ethanol from aqueous/ethanol feeds containing any range of ethanol employs an extractive distillation column (EDC) that operates under no or greatly reduced liquid reflux conditions. The EDC can be incorporated into an integrated process for producing anhydrous ethanol used for gasoline blending from fermentation broth. By using a high-boiling extractive distillation solvent, no solvent is entrained by the vapor phase to the EDC overhead stream, even under no liquid reflux conditions. The energy requirement and severity of the EDC can be further improved by limiting ethanol recovery in the EDC. In this partial ethanol recovery design, ethanol which remains in the aqueous stream from the EDC is recovered in a post-distillation column or the aqueous stream is recycled to a front-end pre-distillation column where the ethanol is readily recovered since the VLE curve for ethanol/water is extremely favorable for distillation.

Abstract: A method for purifying an aqueous potassium hydroxide solution having rich silicon impurities has been disclosed in the invention, which is particularly related to a method that utilizes a low-carbon alcohol (such as ethanol) for extracting said aqueous potassium hydroxide solution, and includes the steps of mixing a low-carbon alcohol with an aqueous potassium hydroxide solution having rich silicon impurities; allowing the resulting mixture therefrom to divide into an aqueous phase layer and a low-carbon alcohol phase layer that contains the aqueous potassium hydroxide solution with reduced silicon impurities, and subjecting the low-carbon alcohol phase layer to a separation process for removing the low-carbon alcohol, thereby resulting in an aqueous potassium hydroxide solution having reduced silicon impurities.

Abstract: The aim of the invention is to produce alcohol from plant-based raw materials while reducing energy consumption. Said aim is achieved by separating the husk portion of cereals during grinding and feed said husk portion to a dryer (21) which dries distiller's wash as a carrier medium for distiller's wash. The lost heat of said dryer (21) is supplied to the distillation station (15) as process heat. The lost heat of a molecular sieve (45) that drains the raw alcohol is also redirected to the distillation station (15) as process heat.

Abstract: The present invention relates to a system for producing ethanol from an organic source and that operates to purify and dry ethanol from a beer source. The system for producing substantially anhydrous ethanol comprises: (a) a first distillation stripping column; (b) a second distillation rectifying column having a higher operating temperature than said stripping column; (c) a molecular sieve dehydration means in fluid communication with said rectifying column. Heat from the overhead of the second distillation rectifying column and the molecular sieve dehydration are used to heat the first distillation stripping column.

Abstract: Method for dewatering a mixture of mostly ethanol and water which is split into a first partial feed flow (3) that is directed to a distillation column (32) as a reflux flow while a second partial feed flow (4) is directed to an evaporator unit (31) as an evaporator inlet flow and leaves the top of the evaporator unit as an evaporator outlet flow (6). A top discharge flow (7) from distillation column (32) is returned and combined with the evaporator outlet flow (6) to a combined flow (8) at an overpressure and which in a compressor unit (33) is compressed to a combined, compressed flow (10) which enters a dewatering unit (34) in which it is split into a water-rich permeate flow (14) and a retentate flow (11) in the form of substantially water free ethanol.

Abstract: A method for distilling ethanol from a mash includes feeding a fluid to a first distillation column. The fluid and a distillate of the first distillation column are delivered to a second distillation column. The fed fluid and/or distillate of the second distillation column is/are purified in a first and/or last step of the method by a membrane separation process.