Systems and methods for selecting and enhancing fermentation in a bioreactor

Abstract

Systems and methods for enhancing volatile fatty acid, ammonia, or dihydrogen production in a fermentation bioreactor are presented. Energy efficient evaporation methods and systems are disclosed. The integration of the bioreactor and energy efficient evaporation enables use in existing bioreactors. Also disclosed is a method for further recycling fermentation products in a bioreactor for wastewater applications.

Description

Technical Field

[0001] The present invention relates to a system and method for processing a feed containing soluble or particulate carbonaceous material in a bioreactor. In particular, the present invention drives the selection or enhancement of decomposition, fermentation or acetate oxidation of carbonaceous materials in a bioreactor. More specifically, the system and method of the present invention can enhance the production of volatiles (including but not limited to volatile fatty acids, NH3 or H2) and recovery from the bioreactor, especially in a fermentation bioreactor, by physically or chemically selecting reactions that drive the formation of these volatiles (including selecting relevant organisms) and subsequently removing them. Background Art

[0002] Bioreactors are widely used in industry to use microorganisms and alternatively use related enzymes as catalysts to carry out chemical conversions in liquid culture fluids. Feed broth (feed broth) is added to the bioreactor in which there is a microorganism, and the microorganism carries out the desired chemical conversion, forms a treated broth, and removes the treated broth after being kept for an appropriate time in the bioreactor. Bioreactors are widely used in fermentation (including but not limited to food processing and pharmacy) industry and wastewater treatment industry. In the latter, the feed broth is often urban or industrial wastewater, or a slurry fluid called sludge containing a significant proportion of particulate matter. This particulate matter is often a large complex biopolymer, which needs to be decomposed into smaller molecules in a process called hydrolysis, which is usually carried out by the extracellular enzyme produced by the microorganism present in the bioreactor outside the microorganism cell before the final conversion in the microorganism cell. In some cases, hydrolytic enzymes are added to the bioreactor to further accelerate particle processing. In other cases, the bioreactor is maintained under favorable conditions to enhance this hydrolysis. Bioreactors for processing particles or soluble substances are usually fully mixed stirred reactors, wherein the hydraulic retention time (hydraulic retention time) HRT and the solids retention time (solidsretention time) SRT are the same. Other reactors, including plug flow, batch and sequencing batch reactors, are also possible for the purpose of the present invention. The hydraulic retention time is the average time that the fluid stays in the bioreactor, and the solids retention time is the average time that the granular solids (including the microorganisms and enzymes responsible for the conversion occurring in the bioreactor) stay in the bioreactor. It is expected that HRT and SRT will be decoupled (uncouple) in the bioreactor, because this enables the process of strengthening the treatment of liquid with a shorter retention time than the solid. Although it is desirable to have this separation, it has been confirmed that it is difficult to achieve for bioreactors to process particle matrices, because there is no simple method to distinguish particles, microorganisms, soluble matrices and the enzymes responsible for particle hydrolysis from each other. The hydrolysis of particles is considered to be the rate-limiting step in the bioreactor, and therefore, concentrating hydrolytic enzymes and microorganisms independently of the liquid in the bioreactor to enhance hydrolysis will significantly enhance the output of the bioreactor.

[0003] In addition, depending on the pH, hydrolysis products such as volatile fatty acids (VFA), ammonia (NH3), dihydrogen (H2) and the like may be inhibitory to some microorganisms and / or enzymes (e.g., but not limited to, feedback inhibition). For example, VFA will become increasingly inhibitory as the pH decreases, while NH3 will become increasingly inhibitory as the pH increases.

[0004] Therefore, there is a need for a system and method to enhance the hydrolysis or decomposition of carbonaceous materials in a bioreactor, particularly while reducing and / or controlling energy consumption. Summary of the invention

[0005] The present invention proposes an efficient method for improving the hydrolysis treatment of feeds containing particulate carbonaceous material. In particular, the present invention allows decoupling the HRT from the SRT of active ingredients involved in the hydrolysis of particles in a bioreactor, in particular by microorganisms and enzymes, hereinafter also referred to as hydrolyzing microorganisms and hydrolytic enzymes, respectively. Such active ingredients include microorganisms and enzymes involved in the hydrolysis and / or inhibitory products produced by the hydrolysis.

[0006] According to the present invention, a portion of the culture solution contained in the bioreactor is removed and at least partially evaporated to form a concentrate and an evaporate. The portion removed from the bioreactor contains microorganisms and hydrolysis products, in which volatile inhibitory compounds are present. Partial evaporation of this portion allows the formation of an evaporate, which contains at least a portion of the volatile inhibitory compounds originally contained in the removed portion, while the concentrate contains at least the microorganisms originally contained in the removed portion. Inhibitory compounds are usually unionized, smaller product (or intermediate) molecules (such as VFA, dihydro, ammonia, methane, alcohol, aldehyde or ketone), so they are also easy and conducive to evaporation. Therefore, this concentrate contains a reduced amount of volatile inhibitory compounds originally contained in the removed portion. By returning at least a portion of the concentrate to the bioreactor and collecting the evaporate, the accumulation of inhibitory compounds in the bioreactor is reduced, hydrolysis is improved, and the HRT of the active ingredient is decoupled from the SRT. The driving force of the reaction is the nature and concentration of the volatile compound, the temperature and pressure (including negative pressure) in the evaporator. These characteristics are regulated in the present invention in a novel device and system that combines the formation of volatiles with their removal, as required, by physical or chemical selection supported by reactions considered in Henry's law. The associated evaporation decouples the hydraulic and solids retention times of the fermentation products (ammonia, H2, VFA) relative to other products in the bioreactor.

[0007] The hydrolytic enzymes and microorganisms are actually non-volatile macromolecules that remain in solution when evaporation occurs. Therefore, evaporating a portion of the water in the bioreactor will selectively remove the volatile molecules, including water and inhibitory hydrolysis products, and retain the non-volatile molecules in the bioreactor.

[0008] By providing such decoupling of HRT and SRT, the present invention allows for enhanced hydrolysis or decomposition of particles in a bioreactor by concentrating the microorganisms / enzymes in the bioreactor and extracting inhibitory hydrolysis products from the bioreactor.

[0009] However, evaporation is an energy intensive operation that is not easily justified by gains in intensification of the process. In one embodiment of the invention, at least a portion of the evaporated material may be condensed and the heat of condensation recovered by using methods including, but not limited to, heat exchangers, heat pumps, or vapor recompression, for example, to evaporate a portion of the fraction removed from the bioreactor. The invention also provides a way to recover and reuse the energy required to evaporate the fluid, thereby significantly reducing the energy requirements of the process evaporation. Depending on the reaction and evaporation occurring, the reaction products may be included in the solids residence time within the reactor or in the evaporated fraction.

[0010] In one embodiment, the present invention also discloses a method of condensing and distilling evaporated volatiles by targeting a temperature or pressure for recovery of a specific distillate, such as VFAs (such as but not limited to acetic acid, propionic acid, butyric acid), dihydrogen, methane, ammonia, or any specific product or group of products to be recovered. The heat of reaction and heat of condensation can be advantageously used to manage the distillation process. A variety of distillates can be recovered.

[0011] Management of the ionized and unionized fractions (or protonated and unprotonated fractions via pH management) of the hydrolysis or decomposition products is also contemplated in the context of the materials and reactions used for evaporation, both in the context of their harvest as product and in the context of their impact on any reactions occurring within the bioreactor or any downstream reactors.

[0012] Vaporizing the contents of a bioreactor directly within the bioreactor presents several technical challenges: either the evaporation temperature is too high to be compatible with the microbial catalysts, enzymes and microorganisms, resulting in their inactivation, or a high vacuum must be applied directly in the bioreactor vessel to achieve a practically effective evaporation rate at a low temperature compatible with the biocatalyst. Thus, direct application of a vacuum to a bioreactor is possible on a small scale, but once the process is scaled up to large bioreactors, the structural requirements on the vessel will be significant and the cost of constructing such a bioreactor vessel will be difficult to justify compared to the volume reduction achieved by the intensification of the process. The present invention solves this problem in addition to the high energy requirements of evaporation.

[0013] Description of the invention

[0014] According to a first aspect, the present invention relates to a method for treating a feed containing carbonaceous material in a bioreactor, the method comprising:

[0015] a) hydrolysis of the feed in a bioreactor using microorganisms and enzymes,

[0016] b) removing a portion of the contents of the bioreactor, said removed portion comprising microorganisms, enzymes and hydrolysis products, said hydrolysis products comprising volatile inhibitory compounds,

[0017] c) evaporating a portion of said removed portion and forming an evaporate containing at least a portion of the volatile inhibitory compounds initially contained in said removed portion and a concentrate containing at least the microorganisms initially contained in said removed portion;

[0018] d) returning at least a portion of the concentrate to the bioreactor, and

[0019] e) collecting the evaporated material.

[0020] The process of the invention allows the concentration of microorganisms and / or enzymes within the bioreactor, thereby enhancing the hydrolysis of particles contained in the feed.

[0021] In one embodiment, the evaporate may contain at least one of volatile fatty acids, ammonia, dihydrogen, and CO2. Thus, collecting the evaporate may alleviate inhibition caused by volatile fatty acids and / or dihydrogen and / or ammonia in the bioreactor by removing such volatiles, or by changing the pH in the bioreactor to alleviate inhibition caused by the altered pH or protonated or deprotonated species caused by the pH change. Changes in pH are most often driven by changes in the balance associated with the production or removal of acids and bases, although the addition of chemicals is also possible.

[0022] In one embodiment, at least a portion of the collected evaporites may be condensed to form condensate and non-condensable evaporites.

[0023] In this embodiment, (i) the non-condensable evaporants may be further treated to remove at least one substance selected from dihydrogen, ammonia, CO2 and volatile fatty acids, or (ii) the condensate may be distilled to recover at least one distillate, or both steps (i) and (ii) are possible. Advantageously, the treatment of the non-condensable evaporants may be a washing treatment with an acid or base or a solvent to further capture a product stream containing non-condensable volatile substances (such as but not limited to VFA, ammonia, CO2) and recover a treated gas containing at least dihydrogen.

[0024] Additionally or alternatively, the condensate or at least one of the distillates may be used as feedstock for a chemical cell (for peak demand mitigation) for use in, or in, electricity or gas grids, biofuels, industrial or urban or agricultural or household products, nutrient removal or recovery, disinfection or any other process.

[0025] In one embodiment, the heat of condensation can be recovered for further use, for example using a heat pump or a mechanical vapour recompression system or a heat exchanger, optionally for evaporation step b) or for hydrolysis step a). Advantageously, the recovered heat is used for hydrolysis step a).

[0026] The method of the invention is carried out while the bioreactor is in operation. In other words, steps b) to e) are carried out during the hydrolysis step a).

[0027] In one embodiment, the bioreactor is a fermentation bioreactor.

[0028] In one embodiment, at least one parameter selected from the group consisting of the redox potential and the pH value in the bioreactor may be controlled in step a):

[0029] - maintaining said at least one parameter within its set point range by setting a set point range having a lower limit and an upper limit for said at least one parameter and activating steps b) to e), or

[0030] - maintaining said at least one parameter at its set point value by setting a set point value for said at least one parameter and continuously performing steps b) to e), or

[0031] - by setting activation cycles with a certain activation frequency and activating steps b) to e) during a set duration in each activation cycle.

[0032] During the activation of steps b) to e), the at least one parameter may be controlled using one or more of the following controls (i) to (v):

[0033] (i) adding at least one chemical selected from the group consisting of an acid, a base, an oxidizing agent, and a reducing agent,

[0034] (ii) controlling the frequency of removal of the fraction removed from the bioreactor in step b),

[0035] (iii) by controlling the flow rate of the fraction removed from the bioreactor in step b), (iv) by controlling the temperature of the evaporation step c),

[0036] (v) controlling the pressure of the evaporation step c).

[0037] In one embodiment, the pH in the bioreactor in step a) can be controlled (e.g., but not limited to, spontaneously produced or modified acids, bases, or buffers) to enhance the production of specific hydrolysis products, such as, but not limited to, VFAs, ammonia, dihydrogen, CO2.

[0038] Advantageously, the pH in the bioreactor may be controlled at a pH of 3 to 7, preferably 3 to 6, more preferably 4 to 6, most preferably 5 to 6. Such pH control may enhance the production of VFAs.

[0039] Advantageously, the pH in the bioreactor may be controlled at a pH of 8 to 10.5, preferably 9 to 10. Such pH control may enhance the production of ammonia.

[0040] Redox control allows the selection of a specific biochemical reaction within a bioreactor. Advantageously, the redox potential in a bioreactor can be controlled at a value of +350mV to -400mV. The upper limit of the redox potential value can be +350mV, +300mv, +250mV, +200mV, +100mV or +50mV. The lower limit of the redox potential value can be -400mV, -350mV, -300mV, -250mV. Depending on the biochemical reaction under consideration, the redox potential can be controlled within a set point range or at a set point value within any of the aforementioned lower and upper limits.

[0041] In one embodiment, the method of the present invention may further comprise the steps of providing a feed containing carbonaceous material and subjecting the feed to a hydrolysis step a), the step of providing a feed containing carbonaceous material comprising a heat treatment sub-step. The presence of the heat treatment sub-step allows to reduce the viscosity of the feed and increase its dry matter content, thereby reducing the size of the container (less water in the contained volume), making it easier to mix, pump or transfer (less thixotropy), and increasing the production of VFA and / or ammonia and / or H2.

[0042] In one embodiment, the method of the invention may further comprise subjecting the effluent resulting from the hydrolysis step a) and optionally the part of the centrate not returned to the bioreactor to a heat treatment and optionally to an anaerobic digestion process.

[0043] According to a second aspect, the present invention relates to a system for a feed containing carbonaceous material in a bioreactor, the system comprising: a bioreactor, a feed supply for the bioreactor, an evaporator, and pipes, valves and pumps fluidly connecting the above-mentioned parts of the system, wherein the bioreactor is fluidly connected to an inlet of the evaporator, the evaporator comprising a first outlet for concentrate and a second outlet for evaporated, the first outlet being fluidly connected to the bioreactor.

[0044] Such a system is advantageously suitable for carrying out the method of the invention.

[0045] In one embodiment, the system may further include a condenser, at least one source of cold fluid connected to the condenser, wherein the condenser is fluidly connected to the second outlet of the evaporator, the condenser including a first outlet for condensate and a second outlet for non-condensable fluid.

[0046] Advantageously, the system may also include at least one of the following features:

[0047] (i) a scrubber and a source of at least one chemical selected from an acid, a base, and a solvent, the source of at least one chemical being fluidly connected to the scrubber, and the scrubber being fluidly connected to the second outlet of the condenser,

[0048] (ii) a distillation device connected to the first outlet of the condenser.

[0049] Advantageously, the system may further comprise a heat recovery device selected from a heat pump, a heat exchanger, a mechanical vapor recompression system, connected to the condenser to recover the condensation heat and to the bioreactor or evaporator to provide heat thereto, preferably to the bioreactor.

[0050] Advantageously, the system may further comprise at least one parameter control subsystem for controlling at least one parameter of the bioreactor, wherein the at least one parameter is selected from the group consisting of redox potential and pH value in the bioreactor, the subsystem being configured as follows:

[0051] - setting a set point range having a lower limit and an upper limit for the at least one parameter, and executing the following commands to maintain the at least one parameter within its set point range:

[0052] C1) removing a portion of the contents of the bioreactor and introducing the removed portion into an evaporator, the removed portion comprising microorganisms, enzymes and hydrolysate, the hydrolysate comprising a volatility inhibiting compound,

[0053] C2) evaporating a portion of said removed portion to form an evaporate comprising at least a portion of the volatile inhibitory compounds initially contained in said removed portion and a concentrate comprising at least the microorganisms initially contained in said removed portion,

[0054] C3) returning at least a portion of the concentrate to the bioreactor,

[0055] C4) collecting the evaporated material,

[0056] or

[0057] - setting a setpoint value for said at least one parameter and successively executing commands C1) to C4) in order to maintain said at least one parameter at its setpoint value,

[0058] or

[0059] - Setting activation cycles with a certain activation frequency, and executing commands C1) to C4) during the set duration in each activation cycle.

[0060] Advantageously, the parameter control subsystem can also be configured to control at least one parameter in the bioreactor during execution of commands C1) to C4) by: (i) adding at least one chemical selected from an acid, a base, an oxidant and a reductant; (ii) controlling the frequency of removal of the portion removed from the bioreactor; (iii) controlling the flow rate of the portion removed from the bioreactor; (iv) controlling the temperature of the evaporator; (v) controlling the pressure of the evaporator; or a combination of one or more of (i) to (v).

[0061] In any of the embodiments described, the parameter control subsystem typically comprises: at least one parameter sensor to measure the at least one parameter in the bioreactor, such as a pH sensor or a redox potential sensor or both; and one or more processors, such as a microprocessor or a microcontroller, connected to the parameter sensor and appropriate valves and / or pumps of the system. The parameter control subsystem may also include one or more tanks containing chemicals (acids, bases, oxidants, reductants), as well as pipes, valves and pumps for controlling the addition of chemicals. The parameter control subsystem, more specifically the one or more processors, may be configured, in particular programmed, to implement the commands C1) to C4) and / or steps b) to e) of the method of the invention, in particular by implementing a feedback loop, and optionally to control the at least one parameter in the bioreactor by one or more of the actions (i) to (v) described above. Communication means may be provided between the parameter control subsystem and the corresponding parameter sensors and appropriate valves and / or pumps, the communication means being optionally bidirectional.

[0062] The separation of the evaporator from the bioreactor is a distinguishing feature of the present invention. This distinguishing feature provides different construction materials that may be required for the generally larger bioreactor, which may be under atmospheric pressure or positive pressure, relative to the generally smaller evaporator, which may be under vacuum or negative pressure (with the bioreactor pressure as a reference). Therefore, the use of this method with a fluid circulation loop between the two devices provides construction economy and enhancement. In fact, the bioreactor can be any existing or reused concrete or steel tank at a facility where the main focus is on biological reactions, and the evaporator is such a functional tank that is used as a physical selector device to utilize the underlying physical laws to regulate the management of volatiles and water. The control subsystem of pH and redox potential is an optional feature that combines these two devices together to control and bridge the controlled reactions, one is basically controlled by biology (in the bioreactor) and the other is basically controlled by physics (in the evaporator). Therefore, the physical driving force in the evaporator can control the selection of biology and its preferred reactions in the bioreactor. Chemical control based on pH and redox potential management can also control the selection of biology. This method allows a large number of and / or differentiated biological reactions to be selected in the bioreactor. DETAILED DESCRIPTION

[0063] definition

[0064] The terms used herein are for the purpose of describing specific embodiments only and are not intended to limit the subject matter of the present disclosure. Although the following terms are believed to be well understood by those of ordinary skill in the art, the following definitions are set forth to facilitate explanation of the subject matter of the present disclosure.

[0065] Unless otherwise defined below, all technical and scientific terms used herein are intended to have the same meaning as those generally understood by those of ordinary skill in the art. Reference to the technology employed herein is intended to refer to the technology generally understood in the art, including variations of those technologies that are apparent to those skilled in the art or replacement of equivalent technologies. When describing the subject matter of the present disclosure, it should be understood that a certain number of technologies and steps are disclosed. Each of these technologies and steps has individual benefits, and each may also be used in combination with one or more or in some cases with all other disclosed technologies.

[0066] The aspects and embodiments disclosed herein are not limited in application to the details of the construction and arrangement of the components set forth in the specification or shown in the drawings. The aspects and embodiments disclosed herein can be practiced or executed in various ways. In addition, the words and terms used herein are for illustrative purposes and should not be considered as limiting. The use of "includes," "comprising," "having," "containing," "involving," and variations thereof herein is intended to cover the items listed thereafter and their equivalents as well as additional items.

[0067] The primary clarification process or primary treatment generally reduces the solid and / or organic content of the wastewater to be treated. It is generally a sedimentation phase, possibly assisted by the previous addition of coagulants and / or flocculants, during which the wastewater is placed in a storage tank or a settling tank. The solids contained in the wastewater settle to the bottom of the tank and are collected there. This phase produces a so-called "primary sludge" and an effluent with a reduced solid content.

[0068] A secondary biological process or secondary treatment is a biological treatment in which organic matter, nitrogen compounds and / or phosphorus compounds in the effluent from the primary treatment are assimilated or broken down by aerobic and / or anaerobic and / or anoxic microorganisms. This secondary treatment also produces so-called "biological sludge".

[0069] The term “aliquot” means “portion” in the general meaning of “portion.” In the present specification, “aliquot” and “portion” are used indiscriminately.

[0070] In the present invention, a fermentation bioreactor is an aerobic, anoxic or anaerobic bioreactor in which fermentation reactions occur to form products such as, but not limited to, VFAs, alcohols, aldehydes, ketones, hydrogen (H2), carbon dioxide.

[0071] Volatile inhibitory compounds are volatile compounds that are inhibitory and / or toxic to the microorganisms and / or enzymes contained in the bioreactor.

[0072] The term "evaporation" refers to the general process by which any substance changes from a liquid state to a gaseous state. When the liquid contains water, the gas obtained may contain more or less steam, depending on the evaporation conditions. Thus, the term "evaporation" includes degassing, in which the gas phase consists mainly of non-condensable products, optionally saturated with water. The term "evaporation" also includes processes in which the gas phase consists mainly of steam and non-condensable products.

[0073] The term "hydrolysis" or "decomposition" includes the decomposition and / or solubilization of soluble or particulate carbonaceous material and / or macromolecules. The terms "hydrolysis" and "decomposition" are used interchangeably.

[0074] The terms "redox" and "oxidation-reduction" are used interchangeably.

[0075] The terms "base" and "alkali" are used interchangeably. The terms "hydrogen" and "dihydrogen" are used interchangeably.

[0076] Acids, bases, oxidants or reductants can be solid, liquid, gaseous, ionic or charged forms. Acids, bases, oxidants and reductants are relative terms and depend on the medium. For example, a chemical can be an acid or a base, depending on the pH of the medium (e.g., evaporator or bioreactor contents). For example, a chemical can be an oxidant or a reductant, depending on the redox potential state of the medium (e.g., evaporator or bioreactor contents).

[0077] The expression "negative pressure" refers to the pressure of the evaporator, with the pressure of the bioreactor as a reference. Thus, such a negative pressure corresponds to a pressure lower than the pressure of the bioreactor, where the pressure of the bioreactor is usually maintained at atmospheric pressure or positive pressure. The negative pressure may or may not be a vacuum pressure, but it is likely that the vacuum pressure is usually operated at a negative pressure.

[0078] A subsystem is part of a system, and in the present invention, not all subsystems need to include or meet the requirements of the present invention or contribute to the inventiveness. Some subsystems are optional and are embodiments that can enhance the overall system. At least four subsystems are described: a bioreactor, an evaporator, a pH control subsystem, and a redox control subsystem. Smaller subsystems can be timer control methods, etc., which are not explicitly called out, but are still described in this specification.

[0079] The term "evaporator" refers to one or more tanks, one or more containers, or one or more devices that can be used in part for an evaporation reaction to remove solutes or solvents. Water is a typical solvent and volatile compounds are typical solutes. Both reactions are governed by the laws of physics. The hydraulic residence time of an evaporator is often on the order of several minutes or hours. The evaporator can be under negative pressure or vacuum pressure, the term "negative" being a relative term determined by the pressure of the bioreactor as previously described.

[0080] The term "bioreactor" refers to one or more tanks, one or more containers, or one or more devices that can be used to maintain organisms in a culture medium or in a fluid suspension or in a layered manner, in a batch, sequential batch or continuous process, i.e., a completely mixed, intermittently mixed or plug flow, or any combination of these configuration methods. Other configurations can also maintain such organisms. The hydraulic retention time of a bioreactor is often on the order of several hours or several days, for example 1 to 8 days.

[0081] The dry solids content can be determined by "APHA, 2005. Standard Methods for the Examination of Water and Wastewater. American Public Health Association. Washington, DC."

[0082] Class A biosolids is the designation for dewatered and heated sewage sludge that meets the U.S. EPA's guidelines for unrestricted land use. Class A biosolids meet the pathogen requirements of 25 Pennsylvania Code § 271.932(a) and the vector attraction reduction requirements of 25 Pennsylvania Code § 271.933(b)(1)-(8). Therefore, Class A biosolids are virtually pathogen-free and can be legally used as fertilizer on farms and gardens and sold as compost or fertilizer to home gardeners.

[0083] Numerical ranges expressed by endpoints include all integers and, where appropriate, fractions contained within the range (e.g., 1 to 5 may include 1, 2, 3, 4 when referring to, for example, the number of elements, and may also include one, two, or three significant digits when referring to, for example, measured values, such as 1.5, 2, 2.75, and 3.80). The expression of endpoints also includes the listed endpoint values ​​themselves (e.g., 1.0 to 5.0 includes both 1.0 and 5.0). Any numerical ranges recited herein are intended to include all subranges contained therein, including any values ​​with one, two, or three significant digits within a particular range.

[0084] Feed

[0085] The feedstock treated in the present invention contains carbonaceous material.

[0086] The feed may contain any material intended for use in a fermentation reaction, including but not limited to mining, agricultural, industrial or domestic derived materials, including raw or waste products from any process that produces such carbonaceous materials, including the organic fraction of municipal solid waste (OFMSW) and wastewater sludge.

[0087] The feed containing carbonaceous material may be, but is not limited to, sludge produced in a liquid processing train in a wastewater treatment plant or any other sludge.

[0088] The sludge may be, but is not limited to, primary sludge from the underflow of a primary clarification process, or biological sludge from a secondary biological process in wastewater treatment, such as, but not limited to, waste activated sludge, or a combination of primary sludge and biological sludge.

[0089] The primary sludge may have been previously thickened, for example to a dry solids content of 2-15 wt%.

[0090] The feed used in the present invention may be previously subjected to one or more sub-steps selected from a thickening step, a screening step, a dehydration step, a dilution step. These sub-steps may be part of a providing step, which may or may not include a heat treatment sub-step.

[0091] The dry solids concentration of the feed used in the present invention may be 1-50m%, preferably 1-40m% or 1-35m%, for example 2-15m% or 15-30m% or 17-25m%, or in any range bounded by two of these limits.

[0092] The carbonaceous material may be in dissolved, colloidal or particulate form.

[0093] The feed also contains water. Any presence of water sufficient to drive the biological reaction is considered suitable.

[0094] Non-limiting examples of possible thickening devices, screening devices and dewatering devices are given in the description of the drawings.

[0095] The optional step of providing a feed containing carbonaceous material

[0096] In one embodiment, the feed treated in step a) comes from a providing step comprising a thermal treatment sub-step.

[0097] The heat treatment sub-step may include a thermal hydrolysis process (THP) and / or a hydrothermal carbonization (HTC) process. In the THP process, the sludge, which typically has a dry matter content of 12% to 25% (mass%), is maintained at a temperature of 140°C to 170°C, typically for 30 minutes to 60 minutes. The HTC process is typically operated at a temperature of 180°C to 280°C in a non-oxidizing atmosphere for a period of several minutes to several hours.

[0098] Such a providing step may be a thermal hydrolysis process. Such a providing step may also include one or more sub-steps selected from a thickening step, a screening step, a dehydration step, and a dilution step, which are generally performed before the thermal hydrolysis sub-step.

[0099] Hydrolysis step a)

[0100] The hydrolysis step a) is carried out in a bioreactor containing a microorganism and an enzyme, such as a fermentation bioreactor or any other bioreactor in which the decomposition of carbonaceous materials occurs. The microorganism may comprise or consist of a single strain or a consortium of microorganisms. The enzyme may be an enzyme produced by the microorganism present in the bioreactor and / or may be an enzyme produced by other microorganisms and introduced into the bioreactor as an external enzyme source.

[0101] The hydrolysis step a) allows the production of VFAs, dihydrogen and ammonia as well as other hydrolysis products.

[0102] Bioreactors can be operated by adding dioxygen as in aerobic or microaerobic digestion processes, but can also be operated anaerobically without adding dioxygen as in anaerobic digestion, fermentation vessels or reactor processes. However, in other cases, dioxygen is provided, but the fermentation reaction still occurs or is actually enhanced in the bioreactor. An example of an aerobic process (the application is not limited to this process) with a fermentation reaction is the high temperature aerobic digestion of sludge from a wastewater treatment plant, which is also known by the acronym ATAD, which comes from "autothermal thermophilic aerobic digestion". In the bioreactor, microorganisms grow to decompose the carbonaceous materials present in the sludge, and produce carbon dioxide and water in the case of aerobic processes, while the organisms of the microorganisms in anaerobic digestion work together to convert the granular matrix present in the sludge into a soluble matrix and into methane and carbon dioxide in a series of reactions. In aerobic and anaerobic bioreactors, excess gas is released from the liquid product. Ammonia is also released during the protein hydrolysis in the bioreactor and may become a significant process bottleneck. Similarly, products such as volatile fatty acids, i.e., VFAs (including acetic acid, propionic acid, butyric acid, and higher acids), alcohols, aldehydes, and ketones may also be released. By using any of the above processes, it is explicitly disclosed that alternative electron acceptors / donors or oxidants or reductants may be used to enhance or modulate the fermentation rate or extent.

[0103] As explained with reference to the evaporation step, a portion of the contents of the bioreactor is removed from the reactor and evaporated, and the concentrate is partially returned to the bioreactor. The evaporation of volatile products can affect a change in the pH value and / or a change in the redox potential in the bioreactor, thereby allowing the selection and / or intensification of the reactions within the bioreactor.

[0104] The reactions that occur in the bioreactor to decompose the carbonaceous materials contained in the feed are generally carried out under acidic or alkaline conditions. Reactions carried out under acidic conditions generally enhance the production of VFAs and other hydrolysis products. Reactions carried out under alkaline conditions generally enhance the production of NH3 and other hydrolysis products.

[0105] Depending on the pH, reaction products such as unionized VFAs and ammonia may be inhibitory.

[0106] Therefore, in the present invention, the volatility suppressing compound includes one or more of volatile fatty acids, ammonia, and dihydrogen.

[0107] Removal of these toxic volatile compounds can alleviate this inhibition within the process / reactor or in downstream processes / reactors, thereby increasing conversion and improving yield.

[0108] Furthermore, monitoring of the redox potential allows the determination of biological reactions occurring within the bioreactor. Thus, by setting the redox potential within or outside the redox potential range for a specific biological reaction, a specific biological reaction can be selected.

[0109] In one embodiment, at least one parameter selected from the redox potential and pH in the bioreactor is controlled during step a), for example by a pH control subsystem and / or a redox potential control subsystem connected to the bioreactor, to enhance specific reactions within the reactor. A single subsystem that controls both pH and redox potential is also possible.

[0110] In one embodiment, bioreactor is a fermentation vessel, wherein preferably produces volatile fatty acid.In fermentation vessel, observe high concentration of volatile fatty acid and dihydro, its degree is to reduce pH value, protonated volatile fatty acid forms, and observe the inhibition caused by the generation of volatile fatty acid.Volatile fatty acid, dihydro and / or ammonia net removal (net removal) from fermentation vessel occurs in the cycle of partial removal as previously mentioned, evaporation and return concentrate.As the result of net acid removal, if the amount of the described acid removed in evaporation process is greater than the amount of the acid produced by the organism in bioreactor, the pH value in bioreactor will increase.In this embodiment, the pH value in bioreactor can be controlled at 3 to 7, preferably 3 to 6, more preferably 4 to 6, most preferably 5 to 6 pH value.

[0111] It may be necessary to add acid to operate the bioreactor at such low pH values. Examples of acids that may be used include, but are not limited to, hydrochloric acid, organic acids, and any acidic gas or liquid produced during the hydrolysis step a) that is typically recovered from an evaporation or condensation step, such as a gas or liquid containing CO2 or VFA (wherein the gas containing CO2 may be an acid or a base, depending on the initial pH value).

[0112] In another embodiment, the bioreactor is operated at a high pH and preferably produces NH. In this embodiment, the pH in the bioreactor may be controlled at a pH of 8 to 10.5, preferably 9 to 10. Addition of alkali may be required to operate the bioreactor at such high pH values, ammonia inhibition may limit the fermentation process, and removing ammonia in the evaporator will alleviate this inhibition while recovering the ammonia.

[0113] Examples of bases that can be used include, but are not limited to: potassium hydroxide, calcium hydroxide, sodium hydroxide, lime, magnesium oxide, potash; and carbonates or bicarbonates of sodium, magnesium, calcium and potassium; any salt of a strong base / weak acid; and any alkaline gas or liquid produced during the hydrolysis step a) and typically recovered from an evaporation or condensation step, such as a CO2- or ammonia-containing gas or liquid.

[0114] In another embodiment, the extraction of VFAs and ammonia can be performed in the same container or in sequenced containers, where, for example, one volatile can be removed after a second volatile has been sufficiently removed. Here, for example, the method can begin with an alkaline hydrolysis step (toward the pKa of ammonia) to remove unionized ammonia and allow the pH to drop (toward the pKa of the VFAs) after sufficient ammonia has been removed to remove unionized VFAs. The opposite approach is also possible, where VFA extraction is performed prior to ammonia extraction. Volatile extracts from the reaction can be used to drive a change in pH from high to low or from low to high.

[0115] Other reactions that can be promoted or hindered by pH control are precipitation reactions (e.g., amorphous and crystalline materials such as struvite, violet iron, hydroxyapatite, brushite, etc.), which depend on the type of evaporated solute, which can directly or indirectly (e.g., by changing pH, redox potential or temperature) affect the solubility of the reaction and the yield of precipitate. These reactions can be supported by the addition of iron, magnesium or calcium compounds.

[0116] The control of pH can be performed by any of the previously described arrangements, e.g. Figure 2 The invention is described in detail in the description of the present invention, which can be applied to any embodiment disclosed in this specification.

[0117] Methods for managing pH can be simultaneous (where reactions that increase pH are balanced by reactions that decrease pH), spatially sequential (such as transfer or interchange between reactors and evaporators), or temporally sequential (such as in bandwidth control within a vessel).

[0118] Similarly, removal of volatiles from the evaporator (particularly those containing reducing or oxidizing equivalents) can cause changes in the redox potential in the bioreactor, which can be advantageously used to manage control of the redox potential, either increasing or decreasing it, in a simultaneous or sequential manner, as has been described for pH.

[0119] In one embodiment, the bioreactor includes providing any alternative electron acceptor, such as (including but not limited to) air or dioxygen or nitrate, which is increased to favorably increase the hydrolysis rate in a transient (in space or time), bandwidth or equilibrium (simultaneous reactions) manner, while optionally simultaneously or sequentially controlling (by transient (in space or time), bandwidth or equilibrium redox potential management) unfavorable reactions (optionally such as aerobic metabolism or methanogenesis).

[0120] The redox potential in the bioreactor can be controlled at a value between +350 mV and -400 mV to control the production of VFA, dihydrogen, ammonia or other volatile intermediates, which can then be evaporated in the subsequent step b). The person skilled in the art is familiar with how to select the redox potential value to select a specific biochemical reaction.

[0121] It may be necessary to add an oxidizing agent or a reducing agent to maintain the redox potential at a set point value or within a set point range. Such an oxidizing agent or a reducing agent may be a liquid or a gas.

[0122] Examples of oxidants that may be used include electron acceptors, such as dioxygen, nitrates or iron ions, air, including any gas or liquid generated during the hydrolysis step a) and containing an oxidant.

[0123] Examples of reducing agents that may be used include electron donors such as, but not limited to, dihydrogen, including any gas or liquid produced during the hydrolysis step a) and containing a reducing agent.

[0124] The addition of oxidant / reductant can be carried out using a blower or a bubble-free system (including but not limited to membrane aerated biofilm) or using an electrical system (such as but not limited to cathode, anode, electron beam, proton beam or electrolysis), where dioxygen or dihydrogen can be recycled, generated in situ or sourced from an external source when used.

[0125] For example, the redox potential value can be maintained at a value slightly higher (less negative) than a reaction that supports methanogenesis (e.g., any value greater than -50 mV) or lower than a value typical for denitrification (e.g., any value less than 0 mV). Adding electron acceptors such as dioxygen, nitrates, or iron ions helps to increase or balance the redox potential conditions in a manner that maximizes the hydrolysis rate, minimizes the methanogenic rate, and preferably produces intermediate fermentation products. These redox potential values ​​for control can deviate from the above-mentioned redox potential values ​​(between 0 and -50 mV) by + / -50 mV or up to 200 mV. For example, the range of values ​​can be from 150 mV of an upper limit to -250 mV of a lower limit, or any value therebetween. The goal is to maximize both the rate and extent of production of volatile compounds for evaporation. Each value is selected to increase or decrease the reaction rate or stoichiometry and ultimately select or deselect organisms (including but not limited to acetolytic methanogens, hydrogen utilizing methanogens, acetate oxidizing organisms, sulfate reducing bacteria, fermentative bacteria or all types of low redox bacteria (including but not limited to acidogenic bacteria, acetogenic bacteria, methanol or ethanol producing bacteria), acetate oxidizing bacteria, sulfur oxidizing bacteria or sulfur reducing bacteria, iron oxidizing bacteria or iron reducing bacteria, facultative anaerobic denitrifiers or aerobic heterotrophs). While it is generally desirable to inhibit methanogenesis in these reactions and redox potentials involving hydrolysis and acetate oxidation, it is also possible to subsequently promote additional acetate oxidation or methanogenesis (e.g., at redox values ​​below -250 mV), and portions of the selection process are considered to be within the scope of the invention.

[0126] Thus, inhibitory volatiles may be managed by adjusting the redox potential and / or pH during the evaporation step. In one example, a redox potential set point range may be set between the removal and production of hydrogen between the bioreactor and the evaporator.

[0127] A cyclic redox potential set point range may be set between oxidation and reduction of iron or sulfur (or any metal or non-metal) or any other species that may undergo cyclic redox related to its valence state in the bioreactor.

[0128] In one embodiment, hydrolysis can be carried out at any mesophilic or thermophilic temperature that is intended to pasteurize pathogens (including Class A biosolids) or pathogen indicator organisms (e.g., fecal coliforms or E. coli <1000 MPN / g), or increase the reaction rate. Alkaline conditions can also increase the reaction rate or achieve favorable conditions that support the destruction of pathogens or their indicator organisms.

[0129] The solids retention time of the hydrolysis step a) is generally from 1 to 8 days.

[0130] In another embodiment of the invention, vector attraction reduction (VAR) as described by volatile solids (VS) destruction or removal can meet stabilization targets as described in any global regulation, including but not limited to the United States, Canada, the European Union, the United Kingdom, Australia, New Zealand, India, China, or Southeast Asia. The percentage of VS destruction or removal in the bioreactor can be between 10% and 60%, depending on the reaction rate and the initial VS concentration, and the remaining VS can be as low as 30% remaining, but more likely closer to 50% remaining. VAR can also be achieved by drying (e.g., increasing the dry solids content to greater than >50%) or by increasing the pH (e.g., greater than pH = 10). Combination methods can also manage VAR.

[0131] The effluent produced by the hydrolysis step a) in the bioreactor can be subjected to an optional thermal treatment, preferably followed by an anaerobic digestion process. The thermal treatment can be a THP process or an HTC process or a hydrothermal liquefaction (HTL) process or a pasteurization process or a combination of two or more of these processes. The THP process and the HTC process are as described above. The HTL process is usually carried out at 200 to 320° C. at a pressure of 40 to 180 bar in the presence of dioxygen or air. The pasteurization process is usually carried out at 70° C. These processes (methods) are all well known to those skilled in the art and will not be described further.

[0132] The final anaerobic digestion process (which can be mesophilic or thermophilic) allows:

[0133] - Energy recovery (complete recovery of volatile solids VS and generate energy to make the system energy neutral / positive);

[0134] - Proper dewatering, as the sludge downstream of the bioreactor will still have VFA concentrations that may hinder polymer consumption / sludge conditioning and proper dewatering.

[0135] The hydrolysis step may occur alone or in the context of other processes, including thermal processes (such as, but not limited to, thermal hydrolysis or hydrothermal carbonization), thickening processes, dehydration processes, precipitation or crystallization processes, digestion processes, drying (including, but not limited to, bio-drying) processes, pyrolysis processes, or any processes where co-conversions thereof are beneficial.

[0136] Evaporation step

[0137] During this step, some or all of the volatile compounds contained in the portion removed from the bioreactor are evaporated.

[0138] In step b), part of the contents of the bioreactor may be removed from the bioreactor by any suitable means including pipes, valves, pumps.

[0139] Typically, in the evaporation step c), part of the water and other volatile substances contained in the removed portion, such as but not limited to carbon dioxide, ammonia, volatile fatty acids, low molecular weight fermentation compounds, hydrogen sulfide or other odorous sulfur reduced compounds, are evaporated from the removed portion to form an evaporate, and the volume of the removed portion is reduced to form a concentrate.

[0140] At least a portion of the concentrate containing the biocatalyst (microorganisms and / or enzymes) is returned to the bioreactor where it is mixed with the contents of the bioreactor. The portion of the concentrate not returned to the bioreactor can be subjected to an optional heat treatment, preferably followed by an anaerobic digestion process. The heat treatment can be a THP process or a HTC process or a HTL process or a pasteurization process or a combination of two or more of these processes. In particular, the concentrate not returned to the bioreactor can be mixed with the effluent generated by the bioreactor before being subjected to the optional heat treatment and the optional anaerobic digestion process.

[0141] The evaporated product containing steam, ammonia and other volatile substances such as volatile fatty acids is collected.

[0142] The evaporation step c) is usually carried out at a temperature and pressure selected so as to avoid damaging the microorganisms and / or enzymes contained in the portion to be evaporated. A person skilled in the art knows how to select a temperature and / or pressure that will not damage and / or weaken the microorganisms and / or enzymes, depending on their properties.

[0143] Typically, the evaporation step c) is operated at the same temperature as the bioreactor or at a temperature below the bioreactor temperature.

[0144] Typically, the evaporation step c) is operated at a negative pressure relative to the pressure inside the bioreactor, vacuum being one possibility for negative pressure operation. In other words, step c) is typically operated at a pressure lower than the pressure inside the bioreactor.

[0145] When the temperature is above the boiling point of the removed fraction (which generally corresponds to the boiling point of water) at the operating pressure, the evaporation step c) is a degassing step in which the evaporant is a vapor consisting mainly of non-condensables with little or no steam.

[0146] When, at the operating pressure, the temperature is equal to or lower than the boiling point of the removed fraction, step c) is an evaporation step, wherein the evaporant is a vapor consisting mainly of steam and incondensables. Since the pressure is lower than in the previous case, it is expected that the amount of incondensables extracted will be higher.

[0147] Typically, the temperature of the evaporation step c) is as high as possible, but similar to or lower than the bioreactor temperature, ideally in the thermophilic range, although the invention is also applicable to mesophilic bioreactors. When the bioreactor is operated under thermophilic conditions, the temperature may be in the range of 45-75°C, and when the bioreactor is operated under mesophilic conditions, the temperature may be in the range of 20-45°C.

[0148] Typically, the pressure of the evaporation step c) is between 33 and 800 mbar absolute. The extent of evaporation of the solvent in the process is controlled by controlling the evaporation pressure in step c) during evaporation, which enables evaporation of the gases dissolved in the removed portion while controlling the evaporation rate.

[0149] The evaporation step may be operated in an evaporator external to the bioreactor, such as, but not limited to, a forced circulation evaporator, or a rising or falling film evaporator, or an agitated thin film evaporator, or a multiple effect evaporator or a self-cleaning evaporator, or a further flash evaporator (some also call it a flash cooler process), or other evaporators obvious to those skilled in the art. Such an evaporator may be used as a degassing drum when the operating temperature is above the boiling point of the removed fraction, or as a boiler when the operating temperature is equal to or below the boiling point of the removed fraction.

[0150] The evaporator is usually equipped with a system for limiting and controlling the evaporation pressure and temperature inside the evaporator, for example a vacuum generating device, such as a vacuum pump, connected to its headspace.

[0151] Optional condensation step

[0152] In some embodiments, at least a portion of the collected evaporites may be condensed, thereby forming condensate and non-condensable evaporites.

[0153] Typically, the temperature of the evaporant is lowered to a point where a portion of the volatile molecules condense.

[0154] Most of the condensation that occurs is condensation of the steam forming the condensate. The condensate also contains other volatile substances that are partially condensed and dissolved in the liquid, such as, but not limited to, ammonia or volatile fatty acids, carbonic acid or sulfur compounds. The condensate can be reused in the process for pH control and / or redox potential control of the bioreactor, depending on its composition.

[0155] This step is typically performed in a condenser connected to at least one cold fluid source. The cold fluid source may be a heat pump or any other suitable cold fluid source, such as but not limited to a cooling tower or a chiller. In some embodiments, the condenser may be of a type capable of recovering the heat of condensation using equipment such as but not limited to a heat exchanger, a heat pump, a mechanical vapor recompression system, and the like.

[0156] In some embodiments, when operating the system at a high evaporation rate (e.g., when step c) is operated at a temperature equal to or below the boiling point of the removed portion), it is advantageous to recover the heat of condensation of the evaporated fluid, in which case a mechanical vapor recompression unit (or any other device that allows for such heat recovery, as listed above) can be integrated to condense the fluid vapor in the evaporate and return the heat of condensation to the bioreactor.

[0157] The recovered heat of condensation is preferably used as a heat source for the bioreactor, although its use as a heat source for the evaporator is also possible.

[0158] The evaporites remaining after passing through the condenser are non-condensable evaporites.

[0159] Most often, the condensation step is not optional and the condenser forms a subsystem with the evaporator.

[0160] Optional treatment of non-condensable evaporates

[0161] In some embodiments, the non-condensable evaporates (also referred to as non-condensable fluids) may be further processed to remove species that may be present in significant amounts, such as dihydrogen, CO2, ammonia, or VFAs.

[0162] The treatment of non-condensable evaporants is usually carried out in a scrubber, such as but not limited to a spray tower or a venturi scrubber, a membrane scrubber or other types of scrubbers that are obvious to those skilled in the art. In the scrubber, a source of acid or base or solvent or a combination thereof may be needed to recover the desired substance, for example, acid can be used to recover ammonia, and base is used to recover VFA. Alternatively or in combination, appropriate solvents can be used to recover some volatile compounds. A pH controller is usually part of these scrubber systems to maintain the pH of the scrubbing liquid in the scrubber at a set pH level to optimize the capture of the desired substance. The scrubber usually produces two main effluent streams: a product stream with captured substances and acid, base or solvent, and a treated gas. Depending on the treatment performed, the treated gas may contain dihydrogen alone or mixed with other gases, such as ammonia, VFA or CO2. Therefore, the treated gas can be reused in the process of pH control and / or redox potential control for bioreactors of the present invention, depending on its composition. Similarly, the product stream can be reused in the process for such control.

[0163] Optional distillation of condensate

[0164] In one aspect of the invention, the distillation process is considered to be used to remove one or more specific materials from the condensate by any type of distillation process, which includes but is not limited to: simple distillation (e.g., cooling in a condenser to a receiving vessel), short path distillation (a short trip to a condenser), molecular distillation (where desired vapor molecules are forced into the condenser by vacuum or temperature drop, and undesirable molecules are eliminated by moving in the opposite direction), fractional distillation (vapor is distilled multiple times to separate components), thin film distillation (such as in a heated cylinder with blades and rollers), or rotating belt distillation (e.g., in a long column, using a rotating belt to force vapor production, which then converts it to liquid and improves separation).

[0165] Depending on the composition of the distillate, the distillate can be reused in a process for pH control and / or redox potential control of a bioreactor.

[0166] This optional distillation is usually carried out in a distillation apparatus. BRIEF DESCRIPTION OF THE DRAWINGS

[0167] The invention will be better understood with reference to the accompanying drawings, which show exemplary embodiments of the invention.

[0168] Figure 1 A first embodiment of the system and method of the present invention is schematically shown.

[0169] Figure 2A second embodiment of the system and method of the present invention is schematically shown.

[0170] Figure 3A A third embodiment of the system and method of the present invention is schematically shown.

[0171] Figure 3B A fourth embodiment of the system and method of the present invention is schematically shown.

[0172] Figure 4 A graph showing the HAC fraction and the number of flash distillations required as a function of pH.

[0173] Figure 5 A fifth embodiment of the system of the present invention is schematically shown.

[0174] In the drawings, like reference numerals refer to like elements.

[0175] One embodiment of the method is Figure 1 . The system 100 comprises a bioreactor 10 (here a fermentation bioreactor), a feed supply 1 to the bioreactor, an evaporator 20 (typically comprising a temperature and pressure control device 21), and pipes, valves and pumps that fluidly connect the above parts of the system. The bioreactor 10 is fluidly connected to an inlet 22 of the evaporator 20, and the evaporator 20 comprises a first outlet 23 for concentrate and a second outlet 24 for evaporated product, the first outlet 23 being fluidly connected to the bioreactor 10.

[0176] The temperature and pressure control device 21 of the evaporator 20 may include one or more pumps, one or more valves, one or more pressure gauges and / or one or more temperature sensors, and typically includes a programmable regulating unit (such as but not limited to a microcontroller) for controlling these elements.

[0177] In one embodiment, bioreactor 10 receives a feed source having a carbonaceous material such as, but not limited to, sludge produced in a liquid processing train of a wastewater treatment plant.

[0178] The bioreactor 10 is connected to an external evaporator 20, such as but not limited to: a forced circulation evaporator, or a rising film or falling film evaporator, or an agitated thin film evaporator, or a multiple effect evaporator or a self-cleaning evaporator, or a further flash evaporator (also known as a flash cooler process), or other evaporators obvious to those skilled in the art.

[0179] The bioreactor and / or evaporator 20 is connected to a heat source 30, here a heat exchanger, which drives the evaporation process and / or drives the heating of the bioreactor, and the evaporator 20 is provided with a system (part of the control device 21) for limiting and controlling the evaporation pressure and temperature inside the evaporator 20, such as a vacuum pump connected to its head space. In some embodiments, where the evaporator 20 is a flash evaporator, the sensible heat of the liquid is used to drive the evaporation process performed under reduced vacuum pressure in the flash chamber. Some of the volatiles removed from the evaporator 20 can be sent back to the evaporator in order to change or adjust the pH or redox potential, or to promote volatilization, control stoichiometry or manage reaction rate.

[0180] Temperature and pressure are controlled in the evaporator 20 to avoid damaging the microorganisms responsible for the catalyst activity in the bioreactor. Typically, the temperature in the evaporator is similar to or lower than the temperature in the bioreactor. Some cooling of the aliquot 101 returned to the bioreactor typically occurs due to the evaporation process.

[0181] An aliquot 101 of the contents of the bioreactor 10, i.e., a portion of the culture fluid contained in the bioreactor, is transferred to an external evaporator 20, where a portion of the water and other volatile substances such as, but not limited to, carbon dioxide, ammonia, volatile fatty acids, low molecular weight fermentation compounds, hydrogen sulfide or other odorous sulfur-reducing compounds are evaporated from the aliquot 101 to form an evaporate 102, and the volume of the aliquot is reduced to form a concentrate 103. At least a portion of the concentrate 103 containing the biocatalyst is returned to the bioreactor 10 to be mixed with the contents of the bioreactor therein. The evaporate 102 containing steam, ammonia and other volatile substances such as volatile fatty acids is collected.

[0182] In some embodiments, Figure 1 As shown, the evaporate 102 is directed to a condenser 40 where the evaporate temperature is reduced to a point where a portion of the volatile molecules are condensed. Thus, the condenser comprises a first outlet 41 for the condensate 104 and a second outlet 42 for the non-condensable fluid 105.

[0183] However, in other embodiments, the evaporates are collected and processed to remove odors or to recover non-condensable molecules such as CO2, NH3, H2, CH4.

[0184] In some embodiments, the condenser 40 may be of a type capable of recovering the heat of condensation using a device such as, but not limited to, a heat exchanger 30. Thus, the recovered heat of condensation HF1 may be provided to the bioreactor 10 and / or the evaporator 20, preferably as Figure 1In the latter case, if desired, another heat source (not shown) can be connected to the evaporator.

[0185] At least one cold fluid source CF (here provided by a heat pump 50 but not limited thereto) is connected to the condenser 40. In one embodiment, the heat pump 50 is connected to the heat exchanger 30 to provide heat HF2.

[0186] The evaporants remaining after passing through the condenser are non-condensable evaporants 105. Figure 1 In the embodiment shown, the non-condensable evaporation 105 (also referred to as non-condensable fluid) is further processed to remove substances such as dihydrogen, CO2, ammonia or VFA that may exist in significant amounts. Here, the processing of the non-condensable evaporation 105 is carried out in a scrubber 60, which is, for example, but not limited to, a spray tower or a venturi scrubber or other types of scrubbers that are obvious to those skilled in the art. In this scrubber system, a chemical source CS1 (such as acid or alkali or both or solvent) may be required to recycle the desired substance, for example, acid is used to recycle ammonia, and alkali is used to recycle VFA. A pH controller is usually a part of this scrubber to maintain the pH value of the scrubbing liquid in the scrubber at a set pH level to optimize the capture of the desired substance. It is also possible to use a solvent to recover the substance. The scrubber 60 produces two main effluent streams: a product stream 106 with captured substances and acid, alkali and / or solvent, and a treated gas 107 containing dihydrogen.

[0187] Can be obtained from Figure 1 Three liquid streams are removed from the system in: one is the condensate 104 produced in the condenser 40; a second is a portion of the contents of the bioreactor 10, generally considered to be the bioreactor effluent 108; and a third is the product 106 from the scrubber 60, if a scrubber is used.

[0188] In some embodiments, including any of the embodiments described herein, the system 100 includes a parameter control subsystem 80 of the bioreactor 10, which is electrically connected to a pump that removes the aliquot 101 from the bioreactor 10 to the evaporator 20 and returns the concentrate 103 to the bioreactor 10, thereby forming an extraction loop. The frequency of removal and circulation of the aliquot 101 and the concentrate 103 is controlled by the parameter control subsystem 80 to cause a change in the pH value in the bioreactor, which will alleviate the inhibition associated with volatile fatty acids, dihydrogen and / or ammonia, and / or cause a change in the redox potential, which will select a specific biochemical reaction. The parameter control subsystem 80 is configured to control a parameter of the bioreactor, such as pH, redox potential. The parameter control subsystem 80 can also be configured to control these two parameters, or two parameter control subsystems 80 can be provided, each parameter control subsystem 80 controlling a single parameter.

[0189] For example, once the increase in pH reaches a defined set point (corresponding to the upper limit of the set pH range), the parameter control subsystem 80 will stop the circulation of the aliquot 101 to the evaporator 20 to allow acid accumulation and pH reduction; at a determined set point for pH reduction (corresponding to the lower limit of the set pH range), the parameter control subsystem 80 will start the circulation to the evaporator again to remove acid and increase pH. In this way, pH fluctuations above and below a set of selected set points are generated, thereby alleviating acid / dihydrogen inhibition in the bioreactor, achieving acid / dihydrogen extraction and accelerating the process.

[0190] In some other cases, significant pH fluctuations are not desired, and the system is run on a more continuous basis to further enhance acid extraction.For example, the parameter control subsystem 80 is configured to maintain the pH at a pH set point.

[0191] However, in other embodiments, the parameter control subsystem 80 may include or consist of a timer that is used to turn the pump on and off to create a cycle of the contents 101 of the bioreactor 10 to the evaporator 20 to remove the acid / dihydrogen and return the concentrate 103 to the bioreactor 10 in a specific cycle. When the pump is off, acid accumulates and the pH decreases, and when the pump is on, acid extraction occurs. The frequency and length of the on and off intervals can be calibrated to maximize the formation and extraction of acid / dihydrogen.

[0192] In other embodiments, the vacuum set point in the evaporator can be controlled to increase or decrease the efficiency of stripping of volatile materials, thereby providing a means to achieve pH control. For example, the parameter control subsystem 80 is then electrically connected to a pump that controls the pressure within the evaporator and is configured to reduce the vacuum within the evaporator by controlling (ultimately stopping) the pump.

[0193] In yet other embodiments, the bioreactor 10 receives the addition of a chemical CS2, such as an acid including but not limited to a CO2-containing gas or a VFA-containing gas, or a base including but not limited to a CO2-containing gas or an ammonia-containing gas, to further reduce / increase and control the pH within the bioreactor 10, thereby enhancing the extraction of volatile compounds in the evaporator. For example, an acid such as but not limited to hydrochloric acid may be used to reduce the pH to 5.5 and enhance the removal of VFAs in the evaporator; while a base such as but not limited to calcium hydroxide may be used to increase the pH to 8 or 9 or higher to enhance the removal of ammonia in the evaporator 20. Acidification of the bioreactor may also be achieved by adding a CO2-containing gas or a VFA-containing gas, such as a portion of the treated gas 107 leaving the scrubber 60, or a portion of the non-condensable evaporants 105 leaving the condenser 40, as Figure 1 Schematic diagram in the figure.

[0194] Addition of acid or base CS2 can be directly in the bioreactor 10, or in the recycle line to the evaporator, or at other locations to further enhance extraction.

[0195] The addition can be part of a parameter control subsystem 80 and operate continuously or intermittently to optimize overall system performance. In this case, the parameter control subsystem 80 may include one or more capacities containing alkali or acid, and / or a supply of gas containing CO2 or any other gas, and pipes, valves and pumps for commanding the addition of alkali, acid or gas containing CO2 or any other gas in the system. The parameter control subsystem 80 is then electrically connected to the pump and / or valve. The parameter control system also includes a parameter sensor 81 and one or more processors 82 in the bioreactor. The parameter sensor can be a pH sensor or an oxidation-reduction potential sensor, or the parameter control subsystem can include a pH sensor and an oxidation-reduction potential sensor.

[0196] External bases or buffers may also be used, including but not limited to caustic, lime, magnesia, potash, and carbonates or bicarbonates of sodium, magnesium, calcium, and potassium. Any salt of a strong base / weak acid may also be used.

[0197] like Figure 1The parameter control subsystem shown can be a redox potential control subsystem for managing dihydrogen production and evaporation (instead of VFA production and evaporation), and the addition of chemical CS2, for example, can include external or internal (through recycling) supply of dihydrogen, dioxygen, or an electrical process (including but not limited to electrolysis, or using a cathode or anode, or including but not limited to sacrificial cathodes or anodes). The transition does not occur between pH values, but rather between redox potential values ​​as previously described.

[0198] Subsystems combining pH control and redox potential control are also possible, thus creating a complex method for simultaneous or series of removals. Artificial intelligence control systems can be set up to remove a variety of volatile products.

[0199] The actual control can be manual or online, where the analyzer is located in the laboratory, in a bioreactor or evaporator, or is handheld. The readings can be continuous, intermittent (periodicity can vary on the order of seconds, minutes, hours, or days). In many cases, the actual reading may not be as important as the change in the reading, such as between two set points, so some drift of the analyzer is allowed. These can be evaluated and compensated for using artificial intelligence algorithms and underlying stochastic indicators.

[0200] In one embodiment, a subsystem of combined pH control and redox potential control, the substrate for the anaerobic Clostridium producing dihydrogen is VFA, and the control of this unionized substrate using pH control affects the production of dihydrogen by managing substrate limitation, while redox potential control helps control the use of dihydrogen (by preventing methane generation, if necessary), because the increase in redox potential improves hydrolysis, and subsequent fermentation conversion to VAF and further conversion from VFA to dihydrogen. Therefore, by controlling the two subsystems and the evaporation step, the combination of the two parameter control subsystems can maximize (by eliminating the bottleneck of VFA substrate and redox potential) or alternatively minimize (by making the VFA substrate and redox potential become bottlenecks) dihydrogen production, whichever is desired. The evaporation of dihydrogen or VFA removes the inhibitory effects of these volatile compounds. It should be noted that the combined use of at least two of these three concepts (pH control, redox potential control and evaporation) is contemplated in the present invention as a means of selecting desired reactions and deselecting undesirable reactions. Therefore, the proposed method can ultimately select or deselect response-associated bacteria or archaea at steady state.

[0201] The above-mentioned control of pH value and / or redox potential can be applied to any embodiment of the system of the present invention.

[0202] Figure 2One embodiment of the system 100 is shown, among other embodiments, in which the distillation apparatus 70 is used to further concentrate specific target compounds present in the condensate 104 . Figure 2 Describes the Figure 1 The same system but with the addition of a distillation apparatus 70 to receive the condensate and further process the condensate. Like elements are designated by like reference numerals. Here, the distillation apparatus 70 receives heat HF3 to produce one or more distillates 109. Figure 1 The described recycling of condensate or processed gas may be included in this embodiment.

[0203] Figure 3A An embodiment of the system 100 is shown, for example Figure 1 or Figure 2 The system presented in , as part of the overall process flow diagram for sludge treatment in a wastewater treatment plant 200. This embodiment is exemplary, as one skilled in the art can envision many variations of the location, in particular using alternative thickening devices or screening devices, or having multiple arrangements for heat recovery and energy use optimization, as well as adding dilution water to optimize viscosity, and using different evaporation devices or thermal hydrolysis devices. There are a variety of thermal hydrolysis processes on the market, and the present invention can be integrated with any of them. Figure 3A The embodiment described in this document does not exclude the application of the invention with other thermal hydrolysis processes.

[0204] exist Figure 3A The thickened sludge 201 having a typical dry solids concentration of 2-15% (mass %) may be primary sludge produced during primary treatment of wastewater prior to a biological process, or may be waste biological sludge produced during secondary biological treatment, such as waste activated sludge from an activated sludge process, or may be a combination of thickened primary sludge and waste biological sludge. Figure 3A In the illustrated embodiment, the sludge 201 is screened in a solid screening process 90 to remove foreign matter that may interfere with downstream processing. Figure 3A The sieved sludge 203 is conveyed to the blending tank 110 for storage and steady feeding to the dewatering device, in this case the centrifuge 120, but other devices such as filtering devices may also be used, thereby forming two streams: a centrifuge stream 204 containing mainly water and a dewatered sludge stream 205, which is also called dewatered cake due to its consistency, having a typical solid concentration between 15% and 30% (mass %). Dilution water DW is usually added at this stage to dilute the sludge 205, although in some processes no dilution water is used.

[0205] In some embodiments, after the addition of dilution water DW, the solid concentration in the sludge delivered to the pulper is about 17% to 25% (mass %). The pulper 130 then receives steam St1 from the flash tank 150 to further help dilute the sludge 205 to have a dry solid content of 15%-20% (mass %) to preheat it and homogenize it. After the pulper 130, the sludge 205 is conveyed to one or more high-pressure reactors 140, where thermal hydrolysis occurs while injecting steam St2, which in this example is generated in the combined heat and power unit CHP, but can also be steam St2 generated by other sources. Some excess steam St3 in the reactor 140 is directed to the pulper 130 for preheating. After the thermal hydrolysis step in the reactor 140, the heat-treated sludge 206 is directed to the flash tank 150, where a sudden release of pressure occurs, thereby evaporating some water and destroying the integrity of the sludge components, thereby further enhancing the hydrolysis of the sludge and forming a hydrolyzed sludge 207 with a low viscosity. The evaporation that occurs in the flash tank 150 cools the sludge, but depending on the downstream process, additional cooling may be required. In this embodiment, the hydrolyzed sludge 207 can be transported to a cooling process, which can be carried out in a heat exchanger (not shown) or in a secondary flash process (not shown), but other means are also obvious to those skilled in the art. Depending on the overall thermal balance of the system, the cooler can be bypassed and the hydrolyzed sludge 207 can be directly transported to the bioreactor 10.

[0206] The low viscosity of the hydrolyzed sludge 207 is advantageous for biological processes using high solids concentrations and coupled evaporators. However, depending on the thermal hydrolysis process, additional dilution water DW may be added at this point to further tailor the properties of the hydrolyzed sludge 207 to the requirements of the downstream processes.

[0207] exist Figure 3A In the illustrated embodiment, the hydrolyzed sludge 207 is delivered to the system 100, such as previously described in Figure 1 and Figure 2 The system 100 described in the claims, wherein the formation of volatile fatty acids or the amination or dihydrogenation of proteins is facilitated by extraction in the evaporator. Like elements are indicated by like reference numerals. Figure 3AIn , "H" represents heat generated or received by the device. 110 refers to waste sludge that may not be returned to the bioreactor and may be combined with the effluent leaving the bioreactor 10. As previously described, the pH value and / or redox potential of the bioreactor 10 can be controlled by a parameter control subsystem (not shown here) for controlling the pH value, the redox potential, or both, to enhance the removal of the VFAs or ammonia or dihydrogen produced. For example, operating the bioreactor 10 at a pH value of 3 to 7 will result in better removal of VFAs in the evaporator 20, while operating at a pH value of 8-10 will result in better removal of ammonia in the evaporator 20. In addition, operating between redox potential values ​​between +50mV or -250mV will result in better removal of hydrogen. As previously described, Figure 3A The purposes of this disclosure are exemplary, and different ways of collecting and optimizing energy usage may be used. Likewise, different types of evaporation processes may be applied, including but not limited to flash evaporation or flash cooling, and the use of dilution water may be integrated as part of the process. The bioreactor 10 may also include a parameter control subsystem as previously described to drive the evaporation process and optimize the extraction of VFA or ammonia. Figure 3A The process described in the embodiment includes a thermal hydrolysis sub-step performed by elements 130, 140, 150. This thermal hydrolysis sub-step can be performed, for example, using However, there are other thermal hydrolysis processes that can reduce the viscosity of the sludge to enable the use of liquid evaporation to extract the volatile compounds, and these thermal hydrolysis processes can also be incorporated in alternative embodiments of the present invention.

[0208] Figure 3B An example of using the present invention as part of a sludge treatment train in a wastewater treatment plant 200 is further shown, where the fermentation bioreactor 10 is operated at a high solids concentration after dewatering. Other configurations are possible, and a person skilled in the art can find variations of the treatment train that best suits local conditions. Figure 3B Describes the Figure 3AThe same system but without elements 130, 140, 150. The dewatered cake 205 (optionally diluted with water (DW)) is sent directly to the bioreactor 10 here. When the fermentation bioreactor 10 is operated at a high solid concentration, the evaporator 20 is particularly useful because it can stably remove fermentation products that produce product inhibition in the fermentation reaction, such as VFA, thereby alleviating inhibition and achieving more complete conversion. As previously described, the pH value and / or redox potential of the fermentation bioreactor 10 can be controlled using a parameter control subsystem (not shown). As in the previous application, the evaporator 20 can be connected to a condenser 40 to recover acids and heat that can be collected and recycled and reused in the fermentation process. The waste sludge 110 is collected and advantageously transported to downstream processing in the anaerobic digestion process, or anaerobic digestion is subsequently performed in the thermal hydrolysis process to further stabilize the sludge and remove fermentation products that may interfere with the final dehydration. The waste sludge 110 is usually treated with the effluent leaving the bioreactor 10.

[0209] Figure 4 The effect of operating the fermenter at different pH values ​​on the efficiency of VFA removal in the evaporator is shown. As the pH value decreases, the volatile part of the acid (referred to as the VFA part in the figure) increases, so the extraction efficiency in the evaporator increases. This is represented by the number of flash distillations or cycles required to obtain 90% (mass %) of VFA removal in the fermentation broth (fermentation broth) when it passes through the evaporator. It can be clearly seen from this figure that it is beneficial to enhance the efficiency of the extraction operation at lower pH values.

[0210] Figure 5 An embodiment of the invention is shown in which the evaporator 20 is a flash evaporator, also marketed as a flash cooler, connected to a fermenter 10 for extracting VFAs or ammonia or dihydrogen. Figure 5 The system 100 shown may be used in any of the aforementioned embodiments. In one embodiment, the hydrolyzed sludge 207 from the thermal hydrolysis process is the input sludge 1 to the fermenter 10 .

[0211] In one embodiment, fermenter 10 is operated at an SRT of 0.5 to 3 days. However, in other embodiments, fermenter 10 is operated at an SRT of 4 days. Fermenter 10 is equipped with at least one parameter control subsystem 80 to maintain the pH and / or redox potential of its contents at a defined set point, or within a range of pH or redox potential. Chemical CS2, such as an acid (or a treated gas enriched in CO2, such as from Figure 2The treated gas of the scrubber 60, or non-condensable evaporants) or alkali can be added to the system through the parameter control subsystem according to the need of pH control to meet its purpose, and / or oxidants or reductants can be added to the system through the parameter control subsystem according to the need of redox potential control to meet its purpose. For example, in one embodiment, when VFA needs to be extracted, hydrochloric acid can be added to bring the pH value to a set point of about 5.5 units. However, in other embodiments, when ammonia needs to be extracted, a base such as calcium hydroxide can be added to bring the pH value to a set point of about 9 units. However, in another embodiment, an oxidant such as air or dioxygen (O2) can be added to bring the redox potential up to 0mV or higher, or a reductant such as an electrochemical substance or dihydrogen can be added to reduce the redox potential to -100mV or lower. The contents of the fermenter 10 are circulated back and forth to the flash evaporator 20 (also sold on the market as a flash cooler) to flash evaporate water and volatile compounds under vacuum in the first chamber 25. These vapors are directed to the second chamber 26, where a cooling fluid is added to a shell and tube heat exchanger to form a cooling loop 160 to cause the vapor to condense, thereby forming a condensate 104 containing VFA or ammonia or dihydrogen, depending on the pH and / or redox potential of the fermenter. The remaining liquid (concentrate 103) in the first chamber 25 is returned to the fermenter 10 to complete the extraction loop 28. Due to the cooling effect of evaporation, the returned concentrate 103 is colder than the feed to the flash chamber 25. The fermenter 10 is typically equipped with a temperature control system that will add heat to the unit as needed. In some embodiments, the temperature of the fermenter 10 is controlled for medium temperature conditions (20-45°C), while in other embodiments, the temperature is controlled for high temperature conditions (45-75°C). Steam can be added for heating, and some dilution water is also provided to maintain the viscosity of the fermenter contents. In other cases, a heat exchanger coupled to the fermenter can be used to add heat H, in which case dilution water DW may be necessary for viscosity control. The heat source for heating the bioreactor's heat exchanger may be heat recovered using a heat pump or heat from a vapor recompression system coupled to the evaporator 20. Excess sludge 110 is removed from the system at a different location, in one embodiment, a portion of the return centrate from the flash chamber.

[0212] In one aspect of the invention applicable to any of the foregoing embodiments, the vapor and / or condensate is stored as a chemical "on-demand battery" to help promote downstream reactions in downstream reactors (e.g., digesters) to specifically generate desired products (e.g., dihydrogen or methane or any other compound or precipitate, as needed). Such on-demand batteries can contribute to peak electrical load requirements and be used as a power / energy supply in combination with a turbine or engine, hydrogen battery, or methane / natural gas grid network. The distilled or condensed products can be raw materials for any downstream industrial process (e.g., but not limited to food processing, plastic manufacturing, or fertilizers) or consumer products (e.g., but not limited to detergents). The distilled or condensed products can also be used as a carbon source in biological nutrient removal processes (denitrification, deammoniation, or biological phosphorus removal) or recycling processes (e.g., but not limited to ammonium sulfate, struvite, brushite, blue iron ore), disinfection (peracetic acid or performic acid).

[0213] The hydrolysis process that may occur can be improved by adding chemicals, heat or electrical input (including but not limited to acids, bases, oxidants, reductants, electron beams, proton beams, thermal treatments). The products produced by the methods of the present invention can be used in many applications, such as household, urban, agricultural or industrial applications, as cleaning agents, disinfectants, bioreaction substrates, biofuels (including but not limited to biohydrogen, biomethanol, biomethane or bioethanol), pH or redox management substrates, etc.

[0214] Having thus described several aspects of at least one embodiment of the present invention, it should be appreciated that various alternatives, modifications, and improvements will readily occur to those skilled in the art. Such alternatives, modifications, and improvements are intended to be a part of this disclosure and are intended to fall within the spirit and scope of the present invention. Therefore, the foregoing description and drawings are merely exemplary.

[0215] The systems contemplated in the present invention include, but are not limited to, heat pumps, mechanical vapor recompression equipment, condensers, distiller and related equipment, vacuum, negative pressure (e.g., including controlled or uncontrolled flash) or positive pressure (e.g., steam, venturi or pump), or power supply units, external heat sources (e.g., solar cells, chemicals, electricity or batteries, or mechanical vapor recompression or heat pumps) or heat exchangers, hydrocyclones, screens or any separation device for two liquids or a liquid and a precipitate or other product produced, a base or acid source and mixing it into a device (e.g., a stirred mill or mixer).

Claims

1. A method for treating a feed containing carbonaceous material in a bioreactor, the method comprising: a) hydrolyzing the feed in the bioreactor using microorganisms and enzymes, b) removing a portion of the contents of the bioreactor, the removed portion comprising microorganisms, enzymes and hydrolysate, the hydrolysate comprising volatile inhibitory compounds, and c) evaporating a portion of the removed portion to form an evaporate containing at least a portion of the volatile inhibitory compounds initially contained in the removed portion and a concentrate containing at least the microorganisms initially contained in the removed portion; d) returning at least a portion of the concentrate to the bioreactor, and e) collecting the evaporated material.

2. The method of claim 1, wherein at least a portion of the collected evaporites is condensed to form condensate and non-condensable evaporites.

3. The method according to claim 2, wherein: (i) further treating the non-condensable evaporate to remove at least one substance selected from dihydrogen, ammonia, CO2 and volatile fatty acids; or (ii) subjecting the condensate to distillation to recover at least one distillate; or (i) and (ii).

4. The method according to claim 2 or 3, wherein: The condensate or at least one of the distillates is used as a feedstock for a chemical cell used in or for electricity or gas grids, biofuels, industrial or urban or agricultural or household products, nutrient removal or recovery, disinfection or any other process.

5. Process according to any one of claims 2 to 4, wherein the heat of condensation is recovered for further use, optionally for the evaporation step c) or for the hydrolysis step a).

6. The method according to claim 5, wherein: The heat of condensation is recovered using a heat pump or a mechanical vapor recompression system or a heat exchanger.

7. The method according to any one of claims 1 to 6, wherein in step a) at least one parameter selected from the group consisting of pH and redox potential in the bioreactor is controlled by: - maintaining said at least one parameter within its set point range by setting a set point range having a lower limit and an upper limit for said at least one parameter and activating steps b) to e), or - maintaining said at least one parameter at its set point value by setting a set point value for said at least one parameter and continuously performing steps b) to e), or - by setting activation cycles with a certain activation frequency and activating steps b) to e) during a set duration in each activation cycle.

8. The method according to claim 7, wherein: During the activation of steps b) to e), the at least one parameter is controlled in step a) by: (i) adding at least one chemical selected from the group consisting of an acid, a base, an oxidizing agent, a reducing agent; (ii) by controlling the frequency of removal of the portion removed from the bioreactor in step b); (iii) by controlling the flow rate of the portion removed from the bioreactor in step b); (iv) by controlling the temperature of the evaporation step c), (v) by controlling the pressure of the evaporation step c); or by a combination of one or more of (i) to (v).

9. The method according to claim 7 or 8, wherein: In step a), the pH value in the bioreactor is controlled at a pH value of 3 to 7 or at a pH value of 8 to 10.5, and / or wherein the redox potential in the bioreactor is controlled at a value of +350 mV to -400 mV.

10. The method according to any one of claims 1 to 9, further comprising at least one of the following steps: - a step of providing a feed containing carbonaceous material, comprising a heat treatment sub-step and subjecting said feed to step a); - A step of subjecting the effluent resulting from said hydrolysis step a) and optionally the portion of said centrate not returned to said bioreactor to a thermal treatment and optionally to an anaerobic digestion process.

11. A system (100) for processing a feed containing carbonaceous material in a bioreactor (10), the system (100) comprising: The bioreactor (10), the feed supply (1) for the bioreactor, the evaporator (20), and pipes, valves and pumps for fluidly connecting the above parts of the system; the bioreactor (10) is fluidly connected to an inlet (22) of the evaporator (20), and the evaporator (20) includes a first outlet (23) for concentrate and a second outlet (24) for evaporated product, the first outlet (23) being fluidly connected to the bioreactor (10).

12. The system (100) according to claim 11 further includes a condenser (40), to which at least one cold fluid source (50) is connected, the condenser (40) is fluidly connected to the second outlet (24) of the evaporator, and the condenser (40) includes a first outlet (41) for condensate and a second outlet (42) for a non-condensable fluid.

13. The system (100) of claim 12, further comprising at least one of the following features: (i) a scrubber (60) and a source of at least one chemical selected from an acid, a base or a solvent fluidly connected to the scrubber, and the scrubber is fluidly connected to the second outlet (42) of the condenser, (ii) A distillation device (70) connected to the first outlet (41) of the condenser.

14. The system (100) according to claim 12 or 13 further comprises a heat recovery device (30) selected from a heat pump, a heat exchanger, and a mechanical vapor recompression system, wherein the heat recovery device is connected to the condenser (40) to recover the condensation heat, and is connected to the bioreactor (10) or the evaporator (20) to provide heat thereto.

15. The system (100) according to any one of claims 11 to 14, further comprising at least one parameter control subsystem (80) for controlling at least one parameter of the bioreactor selected from the group consisting of pH and redox potential in the bioreactor, the subsystem being configured to: - setting a set point range having a lower limit and an upper limit for the at least one parameter, and executing the following commands to maintain the at least one parameter within its set point range: C1) removing a portion of the contents of the bioreactor and introducing the removed portion into the evaporator, the removed portion comprising microorganisms, enzymes and hydrolysate, the hydrolysate comprising a volatility inhibiting compound, C2) evaporating a portion of said removed portion to form an evaporate and a concentrate, said evaporate comprising at least a portion of said volatile inhibitory compounds initially contained in said removed portion, and said concentrate comprising at least said microorganisms initially contained in said removed portion, C3) returning at least a portion of the concentrate to the bioreactor, C4) collecting the evaporated material, or - setting a setpoint value for said at least one parameter and successively executing commands C1) to C4) in order to maintain said at least one parameter at its setpoint value, or - Setting activation cycles with a certain activation frequency, and executing commands C1) to C4) during the set duration in each activation cycle.

16. A system according to claim 15, wherein the parameter control subsystem (80) is also configured to control at least one parameter in the bioreactor during the execution of commands C1) to C4) by: (i) by adding at least one chemical selected from acids, bases, oxidants and reductants; (ii) by controlling the removal frequency of the portion removed from the bioreactor; (iii) by controlling the flow rate of the portion removed from the bioreactor; (iv) by controlling the temperature of the evaporator; (v) by controlling the pressure of the evaporator; or by a combination of one or more of (i) to (v).

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