Wall catalysis, the path to a sustainable and environmentally friendly biological fuel

Abstract

A novel provision for the production of pellets, an environmentally neutral renewable fuel obtained from the main chemical components hemicellulose and lignin.

Description

Introduction

[0001] Wood, a renewable fuel composed of the chemical components lignin, cellulose, and hemicellulose, enables the generation of heat and energy when developed into pellets. Its inherent chemo-physical properties, such as the pellet's calorific value of approximately 4.7 kWh / kg (compared to lignite's 5.7 kWh / kg), are advantageous. Building upon the fundamental concept of a thermo-mechanical process for fiberizing wood chips (Layman, USA, 1858), the steam explosion method (1958) achieved an adjustment of the calorific value. However, hampered by incompatible water and air pollution, this method has not been successfully implemented in conventional pellet production. Solving this problem requires a technology that can only be achieved in combination with a temperature-pressure-oscillation-adsorption system. Steam digestion process

[0002] Heat / pressure oscillation adsorption system.

[0003] A complete departure from the aforementioned method of biomass fiberization was necessitated by the requirement for a fuel characterized by significant improvements in its chemophysical properties while minimizing environmental impact. These conditions were met using a combined heat / pressure oscillation-adsorption system. This system is characterized by minimal energy expenditure for fiberizing the cell structure of lignocellulosic biomass and 95% adsorption of the emissions generated by the process.

[0004] Long-term side effects of using saturated steam • Significant increase in water and air pollution due to the addition of water and compressed air to the closed reactor during the energy-intensive process phase. • Corrosion due to the presence of oxygen, associated with the formation of volatile organic compounds (VOCs) and odor pollution. • Highly developed machines and systems are needed to eliminate water and air pollution in order to comply with environmental protection regulations. • Global pellet production has now reached a level of approximately 50 million tons per year, without pellet manufacturers having made any serious attempt to incorporate the vapor pressure exclusion process into their business model. Description of the process flow: Innovation and change of biomass structure

[0005] The starting material for fiberizing is wood species - debarked, chopped, sorted according to DIN EN ISO 17225-4 P31 - moisture content approx. 45%. 12 - 17 1. Hardwood, e.g. birch, air-dried weight 280 kg / m³ 3 Freshly cut with 45% residual moisture, 385 kg / m³ 3 2. Coniferous wood, e.g. spruce, air-dried weight 202 kg / m³ 3 Freshly cut with 45% residual moisture, 320 kg / m³ 3 3. Process flow of heat treatment of softwood / coniferous wood, separated by wood species. 4. Chemical components of wood in weight percent of cellulose, hemicellulose, lignin spruce 41,0 21,5 29,5 birch 40,9 27,1 27,3 5. Fibre-dissolving tests - numerous alternatives 1. Test temperature: Superheated steam, e.g., 260 °C, heating < 15 min., p = 1 bar a, specific heat 1.99 kJ / kg °C. Phase transition: Superheated steam (completely dry); saturated T = 120.419 °C; superheated steam 119.581 °C. 2. Rinsing - Inerting - Venting - Ejection of the pulped product. Sequence of pressure fluctuations according to the initial moisture content of the wood species (approx. 45%) and the planned final moisture content of 10-15% after steam pressure pulping of the product. 6. Dry solid surface area after gas adsorption determined by BET measurement according to ISO 9.277:2022 E. The surface area influences dissolution rate, adsorption capacity and gas input. 1. Type of wood, e.g. spruce birch 2. Dense, air-dried wood chips kg / m 3 202 280 3. Bulk density approx. 45% residual moisture kg / m 3 354 459 4. Surface area (free energy) m 2 / g 1,302 1,190 5. Pore volume cm 3 / g 1,669 1,053 Steam pressure digestion using hot steam 13-Improvement of the fiberization of lignocellulosic biomass • Superheated steam is dry steam produced by adding heat to saturated steam (wet steam).

[0006] Superheated steam can be generated above the saturation line (Mollier diagram for steam). 26 Releasing heat without changing phases – It is considered an ideal, oxygen-free gas for the thermal degradation of the chemical component of biomass, which is approximately 65% ​​hemicellulose. In this process, the biomass (consisting of cellulose and lignin) can retain its excellent chemical and physical properties. Its degradation 17 The reduction of approximately 5% occurs at a process temperature of approximately 200-250 °C.

[0007] Hot steam - physical properties that affect the microstructure of the wood: Wood is divided into two categories: softwood and hardwood. The wood cells of both categories can be subdivided into different groups according to their function: 1) transport cells, 2) support cells, and 3) storage cells. • The cell structure of the wood is submicroscopic and allows gas diffusion to be bound through the structure of the lignocellulose-containing biomass. • The adhesive forces of moisture, such as capillary, electrosorption and chemosorption, are eliminated by the introduction of gas after complete saturation (equilibrium) of the internal wood structure. • The advantages of the chemical components of wood, namely cellulose and hemicellulose, allow moisture to be absorbed through the inner cell wall. Electrochemical polarities tend to absorb moisture and cause condensation, which leads to a pressure increase and expansion of the wood's capillary structure. • Hemicellulose exposed to elevated temperatures of 160-180 °C undergoes structural chemical changes and the formation of acetic acid (CH3COOH), which is readily water-soluble and volatile. Therefore, hemicellulose is of little value for the intended purpose; the removal of its chemical structural bond to cellulose and lignin is essential. The surface area and volume of the cell walls were presented in tabular form and exhibit a high degree of free exothermic energy of 20-50 kJ / mol (adsorption / desorption enthalpy), thus favoring application at low temperatures. At higher temperatures, however, there is no need to input a significant activation energy. • Further chemical reactions of the catalysts facilitate the breakdown of the fiber structure of the biomass. Coniferous wood, due to its higher lignin content, requires a more intensive approach. Breaking the fiber bonds in the wood requires higher pressure and temperature, along with specific chemical catalysts. H₂SO₄, for example, can be most effective with coniferous wood, but this entails additional costs for neutralization and recycling. • However, if hardwood is to be treated at all, it can be effectively treated with a hybrid of pearl millet, an environmentally friendly product that is ideally suited to the intended purpose and further reduces the energy required for fiberization. • The attractive forces are weak and the molecules are concentrated in several layers on the absorption surface, i.e., the individual particles of the starting material. • Type of gas to be adsorbed: 16'23 The higher the critical temperature of a gas, the greater the van der Waals forces and thus the adsorption; for example, the critical temperature (K) / gas = 33 / H; 126 / N2; 304 / CO2 • Surface area of ​​the adsorbent: The larger the surface area, the stronger the adsorption. In the present invention and the steam pressure digestion process, the lignocellulosic biomass, e.g., softwood species spruce, exhibits the following properties: Weight, air-dried: 202 kg / m³ 3 Weight: 45% Residual moisture: 354 kg / m³ 3 , Size of wood chips: 2.5-8 mm, with a surface area (according to ISO 92 / 7:2022 E) of 1,302 2 / g (free energy) and a pore volume of 1.669 cm³ 3 • Adsorption of the solid adsorbent: Activation means an increase in the adsorption capacity of the solid adsorbent. This can be achieved by dividing the solid adsorbent or by removing the already adsorbed gases using hot steam. • Desorption, the reverse of the adsorption process: Exothermic process, comparable to condensation during temperature increase and decrease in adsorption, i.e., gas (adsorbate) + solid (adsorbent) <-> gas adsorbed onto solid + heat. Hot steam - the steam pressure digestion 18

[0008] Steam pressure digestion involves the expansion of organic material, either to create an internal structure or to expand or break down an existing one. In steam pressure digestion, for example, a product is heated with superheated steam until the water within the cells reaches its boiling point. The pressure is then rapidly reduced to atmospheric pressure. The water content suddenly boils, and the expanding steam breaks down the structure of the biomass. • The biomass is discharged via an outlet valve with a diameter of <10% of the cylindrical reactor diameter. Designed for high actuation speed in combination with a vacuum-assisted pressure reducer and a drain valve for immediate pressure reduction. • The processes are divided into four sections according to the type of gas evolution in the biomass: 1 - Phase transition, 2 - Absorption, 3 - Adsorption, 4 - Chemical reaction. • The phase transition, due to the associated comprehensive change in mass and volume, is the most frequently used and effective method for the expansion of products and is calculated as follows: • Mass change: ΔM = Mass of vapor evaporated during steam pressure digestion per unit mass of the extrudate before steam pressure digestion. ΔM = cp*(T1-T2) / hfg = 1.83*(250-100) / 2257 = 0.122 kg steam / kg product cp = specific heat of the extrudate = 1.83 kJ / kg*K hfg = latent heat of vaporization of water at 100 °C = 2257 kJ / kg*K T1 = Product temperature before steam pressure digestion (°C); T2 = Product temperature after steam pressure digestion (°C) • Change in volume: Volume change per unit mass in m 3 / kg: (extruded product) ΔV=ΔM / ρs=cp*(T1−T2) / ρs*hfg=1.83*ΔT / 0.6*2257=0.203 m3 / kg ρs = density of steam at 1 bar pressure and 100 °C = 0.6 kg / m³ 3 • Physical adsorption: Physical adsorption is comparable to the process of condensation. The attractive forces are weak. The molecules are located in several layers on the surface. • Explosion expansion E (m 3 / sec. / kg): This is the change in system volume per unit time and mass, controlled by the pressure change rate, the heat transfer rate, or the chemical reaction rate of the gases with water until chemical equilibrium is reached. E = ΔC N2 / Δt ρN2 (m 3 / s kg), calculated average up to 12 m 3 sec. / kg and an assumed decompression time between 0.1 and 0.5 s

[0009] The explosive expansion necessitates special design precautions for the intended discharge of the dissolved biomass under vacuum. 11'16'18 . Hot steam - Handling process raw materials: Rinsing - Inerting 19'20

[0010] Purging refers to the short-term addition of an inert gas, e.g., nitrogen (N2) or carbon dioxide (CO2), to maintain a low limiting oxygen concentration (LLC) in the reactor's vapor space. A common practice is to maintain the LLC, below which deflagration cannot occur, by means of a specific gas-to-vapor ratio of • SGK for N2 / Air O2 Vol. % = Hydrogen volume 5 % or • SGK for CO2 air O2 vol.% = hydrogen volume 5.2% Recommended flushing methods are displacement flushing and vacuum flushing. 19 Use of superheated steam - process examination of the invention of the patent: 5'10'16'23

[0011] To demonstrate that the described invention is a technology suitable for both small and large businesses, tests should be carried out with samples from various types of hardwood and softwood. In particular: • The molecular structure of the wood is subjected to a complex process of desorption by hot steam, which is injected at a predetermined temperature and pressure into the closed space in the lower half of the conical reactor section. • The reaction to the supplied heat follows the convention of the Soret effect. 3'23 , that the heat from the cold side attracts moisture from the warm side, causing expansion 18 and later forces a breaking up of the wood's fiber structure, thus enabling complete desorption of moisture. • The adsorbate, i.e., the adsorbed moisture, is immediately heated upon contact with the dry hot steam and reaches every interstitial space of the biomass at a rate of 1.3-33 mm / s, occupying half the cylindrical height of the reactor for each specific volume. Up to this point, the superheated steam releases heat through convection and forces the condensation of the moisture contained in the biomass, so that the superheated steam remains in the dry range, i.e., above the steam saturation line shown in the middle of the Mollier diagram. However, the condensate does not settle on the surface of the biomass. • Hot steam is supplied until a specific moisture content of approximately 10-15% is reached, followed by a controlled phase transition to the wet steam phase*, i.e., below the saturation line, generating approximately 44.2 kJ / mol through enthalpy changes during condensation and exothermic desorption heat. Both have a positive impact on the energy balance of the system. *Mollier diagram. 27

[0012] Superheated steam units - Schematic representation of the steam pressure digestion process 1. Boiler with superheater 2. Superheater as a source of hot steam 3. Accumulator, an essential element for ensuring a continuously controlled supply of hot steam. 4. The heart of the plant for the fiberization process is the reactor, which consists of a double-walled container. • Design - Construction according to Section VIII of the ASME Boiler and Pressure Vessel Code • Loading of the biomass from above by a steam packing device designed to impart a tangential rotary motion to the feedstock on its way to the reactor bottom. 9 • Material: Austenitic stainless steel 5. Pressure cyclone - heat exchange 11'16 - In this process, biomass and steam are separated by the sudden pressure drop, with excess steam and the purified vapors being released into the extraction system of the pressure swing adsorber (PSA), whereby the majority of the VOCs are recovered through solvent regeneration but not destroyed. 6. Nitrogen purging and inerting system 19 (basic legal requirements)

[0013] The steam pressure digestion process using superheated steam includes frequent purging with nitrogen (N2) or CO2. The gas supply is ensured by a supply system from reputable suppliers, which provides for the installation of liquefied gas tanks in the event that the normal N2 supply exceeds 200 cfh. 7. The PPE 16'19 The system, a critical but indispensable component of the steam pressure digestion process, has two column control units for the recovery of all VOCs with an efficiency of > 95%. 19' 23' 25 . • To retain most of the volatile substances with high ozone formation potential generated during the fiberization process, such as m / p-xylene, toluene, propene, o-xylene, and ethylbenzene, the PSA plant is equipped with zeolite molecular sieves (e.g., 10X-0.8 nm from Linde). These substances account for approximately 30% of the total VOC emissions from the reactor's process volume. 8. High-pressure heat pump.

[0014] Hot steam plant process - energy requirements - batch operation: • Heat load: 4,100 kJ / kg - reduced by 2,257 kJ / kg due to condensation enthalpy = 1,843 kJ / kg • Reactor: Biomass inlet temperature (T) 30 °C - Outlet temperature T < 90 °C • Superheated steam max. operating temperature: 300 °C - 30 bar a - h: 2994 kJ / kg; hfg = 1.795 kJ / kg; q approx. 0.7 kg / kg • Inlet velocity of hot steam to reactor 0.5-2 kg / s; • Range of operational process parameters: - Temperature 160-300 °C, Pressure 1-30 bar a NOVELTY

[0015] 01. Use of superheated steam: Advantages for process control • Clausius-Rankine cycle 16 • The enthalpy-entropy- or Mollier 25 Diagram for steam. Total steam condensation applies.

[0016] 02. Control of the superheated steam process for pressure reduction of: • Heat supply at constant pressure p in the hot steam phase. • Heat transfer capacity = Δ (enthalpy of superheated steam - saturated steam) / ΔT (superheated steam - saturated steam) = kJ / kg °C • Enthalpy changes during evaporation = heat is adsorbed by the starting material. • Total evaporation in the hot steam phase of the Mollier diagram 27 • Superheated steam phase transition below or above the saturation line, where the steam is wet or dry at any point. 27 • The control system achieves a perfect throttling process, in which a change in enthalpy (h1-h2) or entropy (S1-S2) is achieved through pressure drop due to the use of a pressure reducing valve. • Latent heat of vaporization of water at the boiling point approximately 40.7 kJ / mol (2257 kJ / kg)

[0017] 03. Superheated steam - Transfer of chemical and physical properties. • For the desorption of one or more atomic layers • To comprehensively enclose the porous matrix of the starting material with its helpful viscosity • To generate an expansion of the micelles until they explode (Soret effect) 3'21 • To initiate the desorption process using capillary, electro- and chemical sorbates that break down the chemical structure of wood consisting of hemicellulose, cellulose and lignin. • To break up the fiber structure under specific pressure, time and temperature conditions inside the reactor's starting material in conjunction with timely controlled rinsing. • In order to ultimately obtain the structural properties of the biomass through digestion. • To reduce device corrosion. • To remove lumina from the fibers, e.g., silica SO2, a problematic mineral that hinders mechanical comminution in the hammer mill and promotes tool wear. This applies to the grinding of pellets (required in power plants), which requires additional grinding energy. • Energy savings through self-generated steam due to moisture condensation of the starting material • Improvement of the chemical and physical properties of the final product, e.g., calorific value (kWh / kg) • Absence of oxygen-depleting corrosion, odor pollution • No fire or explosion hazard, no air or water pollution

[0018] 04. Superheated steam is the solution for reducing greenhouse gases, as well as for energy savings and investment savings. • Restrictions caused by water and air ingress and the catalyst are reduced or eliminated. • Pre-drying of the starting material is no longer necessary. • If drying at all, do so on a low setting. • Reduction of investment and operating costs for an air and water treatment plant. • Reduction of the plant's CO2 emissions by limiting the emission factor of t CO2 / TJ • Reduction of operating costs, e.g. for maintenance, energy, equipment and personnel • VOCs to be extracted from the exhaust air, whose carbon (C), hydrogen (H), oxygen (O) and ash content in % by weight has a favorable effect on the calorific value 24 • Can be added to any existing wood pellet production plant. The pellets produced are of exceptionally high quality compared to standard white pellets.

Claims

[1] Novel provision for the production of pellets, an environmentally neutral renewable fuel obtained from the main chemical components hemicellulose and lignin. [2] The provision of this type of pellet enables the novelty of heterogeneous catalysis with new technical features and its kinetics, characterized by , that the chemical-physical dissolution process of the cell skeleton proceeds with the time-controlled oscillating thermal treatment of an ideal inert gas while preserving the cellulose and the embedded lignin. [3] Features according to claim 001-002, characterized by that by using an ideal inert gas as a heat transfer medium, significant economic advantages can be achieved for the resulting fuel. [4] Features according to claim 001-003, characterized by, that the regulation, (that is the change of (enthalpy h1 - h2) or (entropy S1 - S2) allows the chemical components hemicellulose and lignin to be extracted from the cell scaffold. [5] Features according to claims 001-004, characterized by The breakdown of the cell skeleton, taking into account the higher lignin content of softwood compared to hardwood, requires higher temperatures, pressure of the heat transfer medium, and also a longer residence time of the softwood biomass in the reactor. This additional effort results in an increase in the reaction rate and accelerated chemical breakdown of the cell skeleton. [6] Features according to claims 001-005, characterized by This process ensures that, unlike the steam explosion method using wet steam, no additional water or air is added to the chemical composition of the wood used as fuel. Therefore, an increase in harmful emissions is eliminated. [7] Features according to claims 001-006, characterized by , that the kinetics of homogeneous catalysis with repeated rinsing removes impurities from minerals, e.g. sulfur, phosphorus, potassium, calcium, iron from the molecular structure of the wood, resulting in improved fuel properties. [8] Features according to claims 001-007, characterized by , that the emissions caused by the dissolution of the cell structures are effectively controlled by the temperature-pressure adsorption (TDA) system associated with the method using molecular sieves made of zeolites. [9] Features according to claims 001-008, characterized by , that the inert ideal gas processed by the TDA system is stored in an accumulator and ensures that the uniform and constant inert gas requirement for the method is guaranteed. [10] Features according to claims 001-009, characterized by, that the biom, n. carried out heat treatment, is evacuated from the reactor using a vacuum-assisted pressure system and keeps the explosive expansion of the water vapor / air mixture within safe limits. [11] Features according to claims 001-010, characterized by that the application of heterogeneous catalysis does not require pre-drying of the biomass. [12] Features according to claims 001-011, characterized by that the kinetics of heterogeneous catalysis ensures the transition from a fossil, environmentally harmful fuel to an environmentally neutral fuel with the lowest energy expenditure and free from any environmentally harmful emissions.