TWO BY TWO TANK SYSTEM AND PROCESS.

Abstract

A method and plant for the hydrolysis of a liquid substrate, having a dry solids content of between 2 and 30%, to be used in an anaerobic fermentation, digestion or other process intended to produce or extract methane or other valuable substances, the method and plant being based on the use of vacuum and several pulpers and one or more flash tanks in series for preheating and gradual pressure reduction, respectively.

Claims

1. A method for the thermal hydrolysis of a liquid substrate having a dry solids content of between 2 and 30%, preferably between 14 and 20%, and a temperature below approximately 50°C, preferably from 10 to 30°C, the liquid substrate being subsequently used in an anaerobic fermentation, digestion, or other process intended to produce or extract methane or other valuable substances in one or more reactors (R(fi)), said method being characterized in that the same number of flash tanks and pulpers are used; at least a first and a second pulper (P1 (a) and P2 (e)) in series and at least a first and a second flash tank (F1 (j) and F2 (b)) in series which are used for preheating and gradual pressure reduction, respectively, and because: a) said liquid substrate is transferred and preheated and mixed in a first pulper (P1 (a)), which is made functional at a temperature of 40 C to 90 C and a pressure of 0.2 to 0.9 barA, by flash steam injection below the liquid level of a downstream flash tank, for example, said flash tank (F2(b)), which is operated at a higher pressure than said first pulper (P1(a)) b) said pressure of 0.2 to 0.9 barA, under which said first pulper (P1(a)) is operated, is maintained by a vacuum system (V(c)) which operates to maximize the condensation of condensable vapors that do not condense when passing through said liquid substrate in said first pulper c) said preheated liquid substrate is transferred from said first pulper (P1(a)) to a second pulper (P2(e)), which is operated at a temperature of 90C to 135C and a pressure of 0.7 to 3.3 barA, and wherein said liquid substrate is subjected to further mixing and preheating by the injection of flash steam below the liquid level from a downstream flash tank, for example, said first flash tank (F1 (j)), which is operated at a higher pressure than said second pulper (P2 (e)) d) said further preheated liquid substrate is transferred from said second pulper (P2 (e)) to one or more reactors (R (fi)) operating in parallel or in series wherein said liquid substrate is heated to temperatures in the range of 140 C to 220 C, preferably in the range of 140 C to 180 C and a pressure of 3.6 to 10 barA e) said liquid substrate is transferred from said one or more reactors (R (fi)) operating in series or in parallel to said first flash tank (F1 (j)) operated at a temperature of 100 C to 140 C and a pressure of 1 to 3.6 barA so that a pressure reduction occurs, 34 7Q I jnnil 7Π7 / Β / YILI and from where the flash vapor resulting from said pressure reduction is transferred to said second pulper (P2 (e)) operated at a temperature of 90 C to 135 C and a pressure of 0.7 to 3.3 barA f) said liquid material is transferred from said first flash tank (F1 (j)) to said second flash tank (F2 (b)) operated at a temperature of 70 C to 100 C and a pressure of 0.35 to 1 barA, so that a further pressure reduction occurs, and from where the flash vapor resulting from said further pressure reduction in said second flash tank (F2 (b)) is transferred to said first pulper (P1 (a)) operated at a temperature of 40 C to 90 C and a pressure of 0.2 to 0.9 barA by means of said vacuum system.

2. A method for the thermal hydrolysis of a liquid substrate having a dry solids content of between 2 and 30%, preferably between 14 and 20%, and a temperature below approximately 50°C, preferably from 10 to 30°C, the liquid substrate being subsequently used in an anaerobic fermentation, digestion, or other process intended to produce or extract methane or other valuable substances in one or more reactors (R(fi)), said method being characterized in that: the number of flash tanks used is one less than the number of pulpers used; at least one first and one second pulper (P1(a) and P2(e)) in series and at least one flash tank F are used for preheating and gradual pressure reduction, respectively; and because: a) said liquid substrate is transferred and preheated and mixed in a first pulper (P1 (a)), which is operated at a temperature of 40 C to 90 C and a pressure of 0.2 to 0.9 barA, by flash steam injection below the liquid level of a downstream flash tank (F), which is operated at a higher pressure than said first pulper (P1(a)) b) said pressure of 0.2 to 0.9 barA, under which said first pulper (P1(a)) is operated, is maintained by a vacuum system (V(c)) which operates to maximize the condensation of condensable vapors that do not condense when passing through said liquid substrate in said first pulper c) said preheated liquid substrate is transferred from said first pulper (P1(a)) to a second pulper (P2(e)), which is operated at a temperature of 90 C to 135 C and a pressure of 0.7 to 3.3 barA, and wherein said liquid substrate is subjected to further mixing and preheating by injection of flash steam below the liquid level from one or more downstream reactors (R (fi)), operating at a higher pressure than said second pulper (P2 (e)) d) said further preheated liquid substrate is transferred from said second pulper (P2 (e)) to said one or more reactors (R (fi)) operating in parallel or in series wherein said liquid substrate is heated to temperatures in the range of 140 °C to 220 °C, preferably in the range of 140 C to 180 C, and at a pressure of 3.6 to 10 barA e) said one or more reactors (R (fi)) operating in parallel or in series are depressurized by transferring steam from the reactor headspace to said second pulper (P2 (e)) until the pressures of said one or more reactors (R (fi)) operating in parallel or in series and said second pulper (P2 (e)) are in equilibrium after which said liquid substrate is transferred from said one or more reactors (R (fi)) operating in parallel or in series to said downstream flash tank (F).

3. Method according to any of claims 1 or 2, characterized in that further a vapor cooler (VC (d)), which is interconnected between said first pulper (P1 (a)) and said vacuum system (V (c)), operates to condense and remove condensable vapors below the temperature at which said first pulper (P1 (a)) is operating.

4. Method according to any of claims 1-3, characterized in that it further includes compression steps of the remaining non-condensable vapors from the headspace of said first pulper (P1(a)), which are not condensed in said first pulper (Pl)(a)) or in said interconnected vapor cooler (VC(d)) and steps intended to inject said compressed non-condensable vapors into an anaerobic digester or any other gas treatment medium.

5. Method according to any of claims 1-4, wherein the transfer of said liquid substrate between pulpers, reactors, flash tanks, etc. is achieved at least partially by barometric pumping.

6. A plant for the thermal hydrolysis of a liquid substrate having a dry solids content of between 2 and 30%, preferably between 14 and 20%, and a temperature below approximately 50°C, preferably from 10 to 30°C, the liquid substrate being subsequently used in anaerobic fermentation, digestion, or another process intended to produce or extract methane or other valuable substances, said plant comprising the same number of flash tanks and pulpers, and: - at least a first and a second pulper (P1(a) and P2(e)) interconnected directly or indirectly in series, - a vacuum system (V(c)) interconnected by piping to one of said at least two pulpers (P1(a)), - one or more reactors (R(fi)) operating in parallel or in series and interconnected by piping to one of said at least two pulpers (P2(e)), which is not interconnected to said system of vacuum (V(c)),- at least a first and a second flash tank (F1(j) and F2(b)): - which are interconnected directly or indirectly in series, - of which one (F1(j)) is interconnected by piping to said one or more reactors (R(fi)) operating in parallel or in series, - each of which is individually interconnected by piping to one of the at least two pulpers (P1(a) and P2(e)), and - of which each can be individually operated at a higher pressure than one of the at least two pulpers (P1(a) and P2(e)) with which it is individually interconnected by piping and wherein: a) said first pulper (P1(a)) can be operated at a temperature of 40°C to 90°C and a pressure of 0.2 to 0.9 barA, by injecting flash steam below the liquid level from one of said at least two flash tanks downstream to which it is individually interconnected, For example,said second flash tank (F2 (b)) b) said vacuum system can maintain said pressure of 0.2 to 0.9 barA, under which said first pulper (P1 (a)) is to be operated and can be operated to maximize the condensation of condensable vapors that do not condense when passing through said liquid substrate in said first pulper c) said second pulper (P2 (e)) can be operated at a temperature of 90 C to 135 C and a pressure of 0.7 to 3.3 barA, by injecting flash steam below the liquid level from one of said at least two flash tanks downstream to which it is individually interconnected, for example,said first flash tank (F1(j)) d) said one or more reactors (R(fi)) operating in parallel or in series can operate at temperatures in the range of 140°C to 180°C and a pressure of 3.6 to 10 barA e) said liquid substrate can be transferred from said one or more reactors (R(fi)) operating in series or in parallel to said first flash tank (F1(j)) operated at a temperature of 100°C to 140°C and a pressure of 1 to 3.6 barA in such a way that a pressure reduction occurs, and from where the flash vapor resulting from said pressure reduction can be transferred to said second pulper (F2(b)) operated at a temperature of 90°C to 135°C and a pressure of 0.7 to 3.3 barA f) said liquid material can be transferred from said first flash tank (F1(j)) to said second flash tank (F2(b)) operated at a temperature of 70 C to 100 C and a pressure of 0.35 to 1 barA, so that a further reduction in pressure occurs,and from where the flash vapor resulting from said additional pressure reduction in said second flash tank (F2 (b)) can be transferred to said first pulper operated at a temperature of 40 C to 90 C and a pressure of 0.2 to 0.9 barA by means of said vacuum system.

7. A plant for the thermal hydrolysis of a liquid substrate having a dry solids content of between 2 and 30%, preferably between 14 and 20%, and a temperature below approximately 50°C, preferably from 10 to 30°C, the liquid substrate being used in an anaerobic fermentation, digestion, or other process intended to produce or extract methane or other valuable substances, said plant comprising one or more pulpers and / or flash tank(s), and: - at least a first and a second pulper (P1(a) and P2(e)) interconnected directly or indirectly in series, - a vacuum system (V(c)) interconnected by piping to one of said at least two pulpers (P1(a)), - one or more reactors (R(fi)) operating in parallel or in series and interconnected by piping to one of said at least two pulpers (P2(e)), which is not interconnected to said vacuum system (V (c)),- at least one flash tank (F): - which is interconnected by piping to said one or more reactors (R(f)) operating in parallel or in series, - which is interconnected by piping to one of the at least two pulpers (P1(a), and - which is capable of operating at a higher pressure than that of one of the at least two pulpers (P1(a)) with which it is individually interconnected by piping and wherein: a) said first pulper (P1(a)) can be operated at a temperature of 40°C to 90°C and a pressure of 0.2 to 0.9 barA, by injecting flash steam below the liquid level from said flash tank downstream to which it is interconnected (F), b) said vacuum system can maintain said pressure of 0.2 to 0.9 barA,under which said first pulping is to be operated!' (P1 (a)) and can be operated to maximize the condensation of condensable vapors that do not condense when passing through said liquid substrate in said first pulper c) said second pulper (P2 (e)), can be operated at a temperature of 90 C to 135 C and a pressure of 0.7 to 3.3 barA e) said one or more reactors (R (fi)) operating in parallel or in series can operate at temperatures in the range of 140 C to 220 C, preferably in the range of 140 C to 180 C, and a pressure of 3.6 to 10 barA f) said liquid substrate can be transferred from said one or more reactors (R (fi)) operating in series or in parallel to said flash tank (F),by depressurizing said one or more reactors (R (fi)) operating in parallel or in series by transferring steam from the reactor headspace to said second pulper (P2 (e)) until the pressures of said one or more reactors (R (fi)) operating in parallel or in series and said second pulper (P2 (e)) are in equilibrium, after which said liquid substrate can be transferred from said one or more reactors (R (fi)) operating in parallel or in series to said flash tank (F).

8. A plant according to any of claims 6 or 7 further comprising a steam cooler (VC(d)) interconnected between said first pulper (P1(a)) and said vacuum system (V(c)), which can operate at a temperature below the working temperature of said first pulper (P1(a)), thereby allowing the removal of condensable vapors that do not condense in said first pulper (P1(a)).

9. Plant according to any of claims 6-8, characterized in that it further includes means for compressing the remaining non-condensable vapors from the headspace of said first pulper (P1(a)), which do not condense in said first pulper (P1(a)) or in said interconnected steam cooler (VC(d)) and means for injecting said compressed non-condensable vapors into an anaerobic digester or any other gas treatment means.

10. Plant according to any of claims 6-9, further comprising containers to be used for at least partial transfer of said liquid substrates by barometric pumping.

11. A plant according to any of claims 6-10, further comprising: - Pipes for transferring said liquid substrate, having a dry solids content of between 2 and 30% and a temperature below approximately 50°C, directly to any of said at least two pulpers (P1(a) and P2(e)), said pipe being equipped with one or more shut-off valves allowing selection of which of said at least two pulpers (P1(a) and P2(e)) the liquid substrate, having a dry solids content of between 2 and 30% and a temperature below approximately 50°C, is to be transferred to. - Pipe connections allowing the transfer of said liquid substrate from any of said at least two pulpers (P1(a) and P2(e)) to any one or more reactors (R(fi)).- Pipe connections that allow ventilation from any one or more of said reactors (R (fi)) to any one of said at least two pulpers (P1 (a) and P2 (e)). - Pipe connections that allow the transfer of said liquid substrate from any one or more of said reactors (R (fi)) to any one or more of said flash tanks. - Pipe connections that allow the diversion of said vacuum system (V (c)).

12. A method for modernizing an existing plant for the hydrolysis of a liquid substrate, having a dry solids content of between 2 and 30%, preferably between 14 and 20%, and a temperature below approximately 50°C, preferably from 10 to 30°C, the liquid substrate being to be used in an anaerobic fermentation, digestion, or other process intended to produce or extract methane or other valuable substances, such that said modernization ensures that said plant comprises at least the features of a plant according to claim 6.

13. A method for modernizing an existing plant for the hydrolysis of a liquid substrate, having a dry solids content of between 2 and 30%, preferably between 14 and 20%, and a temperature below approximately 50°C, preferably from 10 to 30°C, the liquid substrate being to be used in an anaerobic fermentation, digestion, or other process intended to produce or extract methane or other valuable substances, such that said modernization ensures that said plant comprises at least the features of a plant according to claim 7.

14. A method for modernization according to any of claims 12 or 13, further comprising ensuring that said plant comprises a steam cooler (VC(d)) interconnected between said first pulper (P1(a)) and said vacuum system (V(c)), which can be operated at a temperature below the working temperature of said first pulper (P1(a)), thereby allowing the removal of condensable vapors that do not condense in said first pulper (P1(a)).

15. A method for modernization according to any of claims 12-14, further comprising ensuring that said plant comprises means for compressing the remaining non-condensable vapors from the headspace of said first pulper (P1(a)), which do not condense in said first pulper (P1(a)) or in said interconnected vapor cooler (VC(d)), and means for injecting said compressed non-condensable vapors into an anaerobic digester or any other gas treatment means.

16. A method for modernization according to any of claims 11-15, wherein the transfer of said liquid substrate is achieved at least partially by barometric pumping through a heat transfer and mixing unit, connected to a live steam system that pressurizes the vessel of said unit, and possibly connected to a system for generating a vacuum to increase the filling rate of said vessel of said unit, and wherein said vessel of said unit is equipped to discharge said liquid substrate to a reactor or return the substrate to a preheating vessel.

17. Modernization method according to claim 16, characterized in that the volume of said heat transfer and mixing unit is equal to the filling volume of the desired reactor.

18. Modernization method according to claim 17, characterized in that said heat transfer and mixing unit is further used to measure the filling of the reactor.

19. A method for modernization according to any of claims 12-14, further comprising ensuring that said plant comprises: - Pipes enabling the transfer of said liquid substrate, having a dry solids content of between 2 and 30% and a temperature below approximately 50°C, directly to any of said at least two pulpers (P1(a) and P2(e)), said pipe being equipped with one or more shut-off valves enabling the selection to which of said at least two pulpers (P1(a) and P2(e)) said liquid substrate, having a dry solids content of between 2 and 30% and a temperature below approximately 50°C, is to be transferred.- Pipe connections that allow the transfer of said liquid substrate from any of said at least two pulpers (P1(a) and P2(e)) to any of said one or more reactors (R(fi)). - Pipe connections that allow ventilation from any of said one or more reactors (R(fi)) to any of said at least two pulpers (P1(a) and P2(e)). - Pipe connections that allow the transfer of said liquid substrate from any of said one or more reactors (R(fi)) to any of said one or more flash tanks. - Pipe connections that allow the diversion of said vacuum system (V(c)).