NL2037750B1 - Removal and storage of carbon emissions through biolysis - Google Patents

Abstract

A method for removal and for removal and storage of carbon emissions through biolysis comprises the following steps: placing a mixture of biomass and water in an oxygen-free environment with increased pH, and in that environment increasing the temperature of the mixture and subjecting the mixture to a pressure just above atmospheric pressure in order to generate a saturated vapor, separating lighter, fully soluble fractions from the saturated vapor from heavier, saturated fractions in order to obtain from the saturated vapor a fine water vapor with humic components dissolved in it, condensing the fine water vapor, collecting the condensate and realizing sedimentation of solid particles in order to obtain a solution of humic acids from the condensate, and lowering the pH of the solution containing humic acids and separating sediment resulting therefrom from the remaining fraction of the solution. Abstract to be published with figure 1

Description

Title: Removal and storage of carbon emissions through biolysis

The invention relates generally to removal of carbon from the natural carbon cycle, with the underlying aim of reducing the carbon footprint.

The invention provides a new method of carbon dioxide removal (CDR,

Carbon Dioxide Removal) that can be categorized as biomass-based carbon removal followed by storage of the product obtained (BiCRS, Biomass Carbon Removal and

Storage). Currently, for the purpose of removing carbon from the air, a method combining biological energy with carbon dioxide capture and storage (BECCS, Bio

Energy with Carbon Capture and Storage) is often applied. This method emphasizes energy production at the expense of some carbon dioxide removal. In this sense, produced energy can be seen as a missed opportunity to remove carbon. Bioenergy, obtained by burning wood, among other things, is wrongly promoted as a green energy solution in that context. Research has shown that emissions per unit of electricity from biomass can be even higher than from fossil fuels, depending on factors in the supply chain, such as biomass type, biomass moisture content and transportation distance. BECCS plants currently operate primarily with combustion or fermentation. Despite capturing some carbon dioxide, the plants are still net emitters, with emissions to supply the supply chain outweighing captured emissions. The carbon removal potential of BECCS is currently under debate, and BiCRS offers a new solution.

By shifting the primary focus from BECCS to BICRS, i.e., from bioenergy production to carbon removal, BICRS solutions can be implemented on a regional or local scale in the short term. An important fact is that most likely within a few years the value of carbon is going to exceed the value of bioenergy, which means BiCRS solutions do not have to involve the sale of energy to be viable. Pyrolysis and biolysis are alternative, non-energy BICRS solutions. Of these, biolysis offers the opportunity to look at the optimal mix for energy and carbon from a different perspective.

It is an objective of the invention to provide a BiCRS solution that is effective and cost-effective, and that allows full operation on sustainably generated green electricity. The stated objective is achieved through a method for removing carbon from biomass and fixing the carbon, comprising: - mixing the biomass with water and increasing the pH of the mixture,

- placing the mixture of biomass and water in an oxygen-free environment, and in that environment increasing the temperature of the mixture and subjecting the mixture to a pressure just above atmospheric pressure in order to generate a saturated vapor from the mixture, in which phytonutrients from the plant cells that are part of the biomass are dissolved in a water fraction, - separating lighter, fully soluble fractions from the saturated vapor from heavier, saturated fractions in order to obtain from the saturated vapor a fine water vapor with humic components dissolved in it, - condensing the fine water vapor, - collecting the condensate and realizing sedimentation of solid particles in order to obtain a solution of humic acids from the condensate, and - lowering the pH of the solution containing humic acids and separating sediment resulting therefrom from the remaining fraction of the solution.

The invention provides a method which when carried out yields emissions containing carbon dioxide and carbon dioxide equivalents, capturing and sequestering the carbon dioxide and carbon dioxide equivalents. The amount of carbon dioxide to be captured and sequestered is calculated by comparing BECCS and BICRS data and relating those to the available input for a given project. Carbon emissions, sulfur emissions and nitrogen emissions are captured and removed.

Further, when the invention is applied, marketable products such as humic acids (AHS, Accelerated Humic Substances or EHS, Enhanced Humic Substances) and hydrochar are produced. This is done in an oxygen-free environment, particularly in a reactor. Organic material such as green waste, manure and wood is fixed in the said humic acids and hydrochar during an oxygen-free reaction, under defined physiological/biochemical/thermal conditions. The invention eliminates oxidation (combustion) of biomass and also prevents metabolic processes of microorganisms from taking place, unlike what is normally the case in nature and during digestion, fermentation and composting. The process is a form of bio-mimicry, converting organic matter to fixed carbon, except that the biolysis process takes a few hours rather than many centuries. The final product hydrochar is a pure form of carbon that has not been subjected to decomposition, digestion, fermentation, oxidation or combustion.

A device configured to perform the method according to the invention, which may be characterized as a method for removal and storage of carbon emissions through biolysis, may comprise in particular the following components: - a reactor for receiving and containing the mixture of biomass and water, - mechanisms for controlling the temperature in the reactor, controlling the pressure in the reactor, and ensuring low oxygen conditions in the reactor, - a separation unit for receiving the saturated vapor, separating lighter, fully soluble fractions from the saturated vapor from heavier, saturated fractions, and discharging fine water vapor thus obtained, - a condenser unit for receiving and condensing the fine water vapor, and - a phase separator for receiving and fractionating the condensate.

The device may be designed for batch implementation of the method for removal and storage of carbon emissions through biolysis, but it is also possible that the device may be designed for continuous implementation of the method. In practice, the latter option will usually be preferred. For example, the device may be designed to process 20 tons of biomass per day in a continuous process.

In the following, a process is described as a practical example of what is possible in the context of the invention. Biomass derived from streams of waste, including manure, verge waste and kitchen waste, is mixed with water and a light chemical component with pH increasing effect. After a time period in the order of an hour, the mixture is ground into a slurry and introduced into the reactor through an automatic feed system. Relatively hard waste such as wood waste is first pre- soaked, for example for a day, wherein optionally amylase (enzymes) may be added as an accelerator.

Under almost atmospheric pressure of 1.1 bar and a temperature of around 100°C, a cracking process is initiated in the reactor, during which the phytonutrients are extracted from the biomass cells and dissolve in the water fraction of the mixture.

In fact, this involves supercritical water because the pressure is a few percent higher than atmospheric pressure and thus the temperature rises a few percent above 100°C. lt is an insight of the invention that the elevated pH combined with time and temperature causes the cells to open without the need for high pressure. The reactor is heated with propane or by other means such as solar or green electricity. The slurry is continuously stirred by an agitator in the reactor which initially slowly raises the temperature to the boiling point of water. The reactor then continues to operate at the same operational temperature, producing vapor containing extracted phytonutrients dissolved in it.

Heating with propane is the least harmful in terms of carbon dioxide and significantly cheaper than electric heating. It is possible to add application of microwaves (MAE, Microwave Assisted Extraction) or ultrasound (UAE, Ultrasound

Assisted Extraction) to the pretreatment to open up the cells so that the reaction time can be shorter.

The separation unit may comprise a coke drum with a rectification column above it. The hot water vapor rises and exits the reactor at an upper end of it through the coke drum. In the separation unit, lighter, fully soluble fractions are passed through to the condenser unit, while the heavier, saturated fractions, with any solid particles that do not reach suspension, are returned to the reactor for further extraction and separation. The condensed vapors are described as produced humic acids (AHS, Accelerated Humic Substances or EHS, Enhanced Humic Substances).

These are collected in the phase separator. Here, solid particles (humic) settle, oil is separated through a natural skimming process and the humic acids remain in solution. The humic acids are then further processed to achieve separation of humic and fulvic acids. To this end, the pH of the solution is lowered by adding a light chemical component. The humic acid settles while the fulvic acid remains in solution.

Through centrifugation and filtration, the fractions are separated and collected in separate tanks. The molecular composition of the humic acid and fulvic acid varies such that these acids can be traded as two different products, with the fulvic acid having a significantly higher value than humic acid. The particles that do not dissolve during the cracking process and remain in the reactor are primarily mineral found carbon components (hydrochar). The hydrochar is automatically drained from the reactor and is dry. The hydrochar is an interesting end product with economic value.

It follows from the above that the reactor is the place in the device where biomass with an elevated pH is received and brought to a higher temperature and pressure creating a saturated vapor. It is practical when an agitator is used to keep the biomass composition and temperature in the reactor homogeneous. Stirring also achieves good mixing of the biomass with the pH increasing agent. The vapor passes through the coke drum to the rectification column, with heavier particles (that are not in suspension) falling back into the reactor. For the rectification column, at a certain temperature, only a fine water vapor containing the dissolved humic components (polyphenols, saponins, polysaccharides, alkaloids, fatty acids, amino acids, terpenes, etc.) passes through the column. Heavier particles re-enter the reactor through the coke drum for further treatment. In the condensing unit, the vapor condenses to liquid humic substances, and in the phase separator, by reducing the 5 pH, separation of humic acid and fulvic acid is accomplished.

As suggested above, a unique aspect of the method according to the invention is that no pressure is applied to extract the contents of the biomass cells. Chemistry in conjunction with temperature and residence time are the key variables in the process. Conventionally, pressure is applied as a variable. This is used to obtain a rapid progression of the process, allowing more biomass to be processed in a shorter time. Surprisingly, however, it turns out that it is not necessary to increase pressure significantly. Additional advantages are then that the quality of the outgoing products increases and that it is not necessary to apply pressure vessels so that risks are reduced.

The aforementioned and other aspects, features and advantages of the invention will be further clarified by the following description, wherein reference will be made to the drawing, wherein equal reference numerals indicate equal or similar parts, and in which: figure 1 diagrammatically shows a perspective view of a practical embodiment of a plant according to the invention, configured for removal and storage of carbon emissions through biolysis; and figure 2 is a diagram of components of the plant and connections between the components.

Figure 1 schematically shows a perspective view of a practical embodiment of a plant 100 according to the invention, configured for removal and storage of carbon emissions through biolysis, in the manner already described in the foregoing. In the figure a number of components of this plant 100 can be distinguished, including a reactor 10, a separation unit (coke drum) 20, a condenser unit 30, a phase separator and a biomass system 60. These components are located in a frame structure 101.

Figure 2 is a diagram of the above-mentioned and more components of the plant 100 and connections between them. The following is an explanation.

Connected to a feed 11 for the reactor 10 is the biomass system 60 with a shredder 61, a feed 62 for solid biomass to the shredder 61, a feed 63 for water to the shredder 61, and two tanks 64, 65 for taking the mixture from the shredder 61 and soaking the mixture. A suitable pumping system may be provided for moving the mixture from the shredder 61 to the two tanks 64, 65. The tanks 64, 65 are also connected to a feeder 66 for material usable for process activation. A screw hopper 67 and a pump 68 are provided to receive the mixture from the tanks 64, 65 and convey it to the feed 11 for the reactor 10, which comprises a hopper.

A conduit 51 leading from the reactor 10 to a chimney 50 for exhausting gases from the reactor 10 includes a heat recovery unit 52 for extracting heat from the gases moving through this conduit 51. A blower 53 is provided for supporting flow in this conduit 51.

A burner 12 is provided at the reactor 10, and an agitator 13 is provided in the reactor 10. Further, a screw system 14 for carbon removal is connected to the reactor 10.

A vessel 31 for collecting liquid is connected to the condenser unit 30. The liquid is fed via a pump 32 and a valve system 33 as desired to a receptacle 34 of the liquid for recovery and cleaning, which receptacle 34 is provided with a drain 35, to the feed 11 for the reactor 10, and to a reactor with mixer 70 connected via a pump 71 to the phase separator 40 for extracting humic acids from the liquid. Optionally, the liquid can be drained directly from the vessel 31 through a drain 36 of the vessel 31.

The phase separator 40 comprises a pressure filter 41 for separating humic, a stabilization tank 42 in which the pH of the humic acids is lowered, an acid supply 43 for the stabilization tank 42, lines 44, 45 with tanks 46, 47 at the end for separately collecting humic and fulvic acid in liquid form from the stabilization tank 42, and also a centrifuge 48 connected to lines 44, 45. To generate the various flows required in the phase separator 40, a pump 80 is provided behind the pressure filter 41. Valve systems 81, 82, 83 are also used in the phase separator 40 to direct the various flows as appropriate.

Both the humic separated in the pressure filter 41 and semi-solid material from the centrifuge 48 are fed to a dryer 85. This dryer 85 is heated with heat extracted by the heat recovery unit 52 from the gases flowing from the reactor 10 to the chimney 50. Behind this dryer 85 is a unit 86 for carbon removal. This allows the plant 100 to produce dry, solid carbon as a usable end product during operation, as well as at least humic acid and fulvic acid in liquid form.

It will be clear to a person skilled in the art that the scope of the invention is not limited to the examples discussed in the foregoing, but that various changes and modifications thereof are possible without departing from the scope of the invention as defined in the appended claims.

Claims (15)

CONCLUSIONS 1. Method for removing carbon from biomass and fixing the carbon, comprising: - mixing the biomass with water and increasing the pH of the mixture, - placing the mixture of biomass and water in an oxygen-free environment, and in that environment increasing the temperature of the mixture and subjecting the mixture to a pressure just above atmospheric pressure in order to generate a saturated vapor from the mixture, in which phytonutrients from the plant cells that form part of the biomass are dissolved in a water fraction, - separating lighter, completely soluble fractions from the saturated vapor from heavier, saturated fractions in order to obtain a fine water vapor from the saturated vapor with humus components dissolved therein, - condensing the fine water vapor, - collecting the condensate and allowing solid particles to settle in order to obtain a solution of the condensate containing humic acids, and - lowering the pH of the solution containing humic acids and separating the resulting sediment from the remaining fraction of the solution. A method according to claim 1, wherein the pressure to which the biomass is subjected in the oxygen-free environment is in a range of 1 bar to 1.5 bar. The method of claim 1 or 2, wherein in the oxygen-free environment the temperature of the biomass is increased to approximately 100°C. Method according to any of claims 1 to 3, wherein energy for increasing the temperature of the biomass in the oxygen-free environment is obtained by combustion of propane. 5. A method according to any one of claims 1 to 4, wherein the biomass is stirred. 6. A method according to any one of claims 1 to 5, wherein the biomass is soaked in water before increasing its pH. 7. A method according to any one of claims 1 to 6, wherein the biomass is ground into a slurry before being introduced into the oxygen-free environment. 8. Method according to any of claims 1 to 7, wherein oil is also separated from the condensate via a natural skimming process. 9. A method according to any one of claims 1 to 8, wherein the separation of sediment from the remaining fraction of the solution containing humic acids is accomplished by centrifugation and filtering. An apparatus (100) configured to carry out the method according to any one of claims 1 to 9, comprising: - a reactor (10) for receiving and containing the mixture of biomass and water, - mechanisms for controlling the temperature in the reactor, controlling the pressure in the reactor, and ensuring oxygen-poor conditions in the reactor, - a separation unit (20) for receiving the saturated vapour, separating lighter, fully soluble fractions from the saturated vapour of heavier, saturated fractions, and discharging fine water vapour thus obtained, - a condenser unit (30) for receiving and condensing the fine water vapour, and - a phase separator (40) for collecting and fractionating the condensate. The apparatus (100) of claim 10, wherein the mechanism for controlling the temperature in the reactor comprises a proprane burner (12). Device (100) according to claim 10 or 11, wherein an agitator (13) is located in the reactor (10). An apparatus (100) according to any one of claims 10 to 12, comprising separate tanks (46, 47) for receiving and holding different fractions separated from the concentrate. An apparatus (100) according to any one of claims 10 to 13, wherein the separation unit (20) comprises a coke drum with a rectification column above it. An apparatus (100) according to any one of claims 10 to 14, comprising a dryer (85) for drying outgoing material from the phase separator (40), and a heat recovery unit (52) for extracting heat from outgoing gases from the reactor (10) and supplying the heat to the dryer (85).