LV14040B - Reactor for pyrolysis of biomass - Google Patents

Abstract

A reactor for pyrolysis of biomass that comprises: a reactor chamber (18) for pyrolytic conversion of biomass having an entrance end, an opposing discharge end, and a longitudinal axis about which the reactor chamber (18) is rotatable; a heating chamber (17) disposed around the reactor chamber (18) for heating the biomass in the reactor chamber (18); an air-tight charging hopper (1, 2, 3, 4) in communication with the entrance end of the reactor chamber (18) for feeding the biomass into the reactor chamber (18); an air-tight delivery chamber (22) in communication with the discharge end of the reactor chamber (18) for extracting products of the biomass pyrolysis; a drive unit (5, 6) for rotating the reactor chamber (18) about its longitudinal axis, the reactor being characterized in that the reactor is mounted onto a base (26) in a swingable relation to each other so that a tilt angle of the reactor relative to the base (26) can be changed freely, thereby changing an orientation of the longitudinal axis of the reactor chamber (18) in a vertical plane.

Description

Description of the Invention

The invention relates to the conversion of biomass into energy, more particularly to the pyrolytic conversion of biomass into fuel in a rotary reactor.

ANALYSIS OF THE KNOWN TECHNICAL LEVEL

Biomass resources can be used as bioenergy. Biomass, including the biodegradable fraction of products of plant and animal, substance, forestry and related industries, waste and residues, is in general the biodegradable fraction of agricultural as well as industrial and municipal waste. Three uses of biomass resources have been developed: biomass for heating purposes (bio-heating); biomass for electricity generation (bioelectricity); biomass for transport fuels (transport biofuels).

As mentioned, many types of biomass are available for energy conversion. The efficiency of biomass conversion to energy is determined by the specific characteristics of the biomass conversion technology used.

Currently, the following technologies are used for the conversion of biomass into electricity:

- incineration in boilers (usually Fluid Bed pseudo-liquefied bed type) with steam production and use in the Renkin cycle; the use of this method is limited by the need to collect large quantities of biomass and the resulting air pollution, whereby the resulting combustion products, despite the complex and expensive purification and degassing systems, contain large amounts of pollutants;

- gasification of biomass and further gas combustion in gas turbines or engines; its efficiency is seriously limited by the low calorific value of the resulting fuel gas;

- the biomass pyrolysis method, if successful, allows for the production of gaseous or liquid fuels with high calorific power for power generation and seems to be particularly suitable for low-capacity in situ heat generators.

Various pyrolysis plants, in particular rotary pyrolysis reactors, for converting different types of biomass into energy are known. For example, U.S. Patent No. 5,688,117 to "Rotatable Heating Chamber with Internal Tubes for Waste", by Mayor and others, describes a relatively long rotating low temperature carbonization cylinder having a plurality of parallel heating tubes inside the waste is heated almost completely in the absence of air. In the low temperature carbonation chamber (pyrolysis reactor), the waste delivered via a waste conveyor is converted into low temperature carbonation gas and pyrolysis residues. This method of heating does not allow controlling the temperature gradient along the length of the cylinder.

Another US patent US5,657,705 to Martin and others discloses a pyrolysis process for furnace waste material which comprises a substantially cylindrical cavity for pyrolysis of waste material by rotating it about its longitudinal axis. A combustion chamber and injectors are provided around the cavity for injecting fuel and combustion retention into the combustion chamber.

The existing solutions referred to here, as well as other solutions, fail to provide efficient pyrolysis plants for the conversion of biomass into energy. Moreover, in known plants, optimum treatment can only be achieved with certain types of biomass, and due to the variability of biomass products, the performance of known plants is far from optimal.

TECHNICAL PROBLEM TO BE SOLVED

The object of the present invention is to provide a reactor for the pyrolytic conversion of biomass into energy, such as electricity and heat, with improved system efficiency in which biomass is recycled with various chemical and physical properties. Another object of the present invention is to provide a reactor for the pyrolytic conversion of biomass into energy that occurs in situ, thereby eliminating the high costs associated with the transportation of biomass.

i

SUMMARY OF THE INVENTION

The objects of the invention are achieved by a biomass pyrolysis reactor comprising: a reactor chamber for pyrolytic conversion of biomass having an inlet end and an opposite discharge end and a longitudinal axis around which the reactor chamber is rotated; a heating chamber positioned around the reactor chamber for heating the biomass in the reactor chamber; an airtight loading funnel in relation to the inlet end of the reactor chamber for introducing biomass into the reactor chamber; a sealed delivery chamber in connection with the discharge end of the reactor chamber for discharge of biomass pyrolysis products; a drive assembly for rotating the reactor chamber around its longitudinal axis. The proposed reactor is characterized in that the reactor is mounted on a substrate such that they can oscillate with respect to one another and the angle of inclination of the reactor relative to the base can be freely changed, thereby changing the orientation of the longitudinal axis of the reactor chamber in the vertical plane. It is desirable that the reactor comprises a swinging mechanism for changing the inclination.

It is desirable that the substantial part of the reactor chamber be gradually reduced in cross-section. For example, the reactor chamber may have a substantially conical shape or a substantially pyramidal shape, or any other shape having a gradually decreasing cross section.

In a preferred embodiment, the reactor comprises a basket positioned in the delivery chamber and connected to the discharge end of the reactor chamber.

The reactor preferably has a plurality of studs disposed on the inside surface of the reactor chamber to facilitate biomass flow and mixing.

According to one embodiment of the invention, the oscillation mechanism comprises an axis and a slider, in another embodiment the oscillation mechanism is electronically controlled.

According to yet another embodiment of the invention, the drive unit for cutting the reactor is adapted to continuously change the cutting speed and direction at which the drive unit can be electronically controlled.

In the preferred embodiment, the reactor includes an electronic controller for changing the cutting speed, direction and longitudinal axis orientation to control the biomass propulsion, thereby regulating the pyrolytic reaction parameters.

DESCRIPTION OF THE DRAWINGS AND SPECIFICATION OF THE DRAWINGS USED IN THEM

Fig. 1 a longitudinal sectional view of the reactor according to the present invention; Fig. 2 a cross-sectional view of the reactor along line Χ-Χ; Fig. 3 is an enlarged view of the inner wall of a rotating reactor.

The following designations are used in the drawings: 1 - vibrating funnel for loading biomass; 2 - a chamber for introduction into the auger; 3 - motor for propelling the auger; 4 - Snail conveyor for biomass injection; 5 - motor with inverter for driving the drive unit; 6 - drive unit for cutting the reactor chamber; 7 - insulated multilayer elements for thermal insulation of the reactor; Group 8 of cooled bearing reactor chamber cutting; 9 - insulated element of the heating chamber; 10 - multilayer thermal insulation element; 11 - valves for hot gas flow and reuse; 12 - valves for hot gas injection; 13 slider for adjusting the slope of the reactor chamber; 14 - support (pivot axis) for reactor oscillation; 15 - Flange connections for fastening; 16 - attachment bracket for heating chamber elements; 17 - heating chamber; 18 - reactor chamber; 19 - studs on the inside surface of the reactor chamber; 20 - valves for producing synthetic gas; 21 - grid basket for collecting charcoal; 22 a supply chamber for collecting pyrolysis products; 23 - rotary shaft rotor group; 24 - Funnel for collecting charcoal; 25 - flanges for connecting reactor chamber elements; 26 - plea.

DETAILED DESCRIPTION OF THE EXAMPLE OF THE INVENTION

As shown in Fig. 1. 1 and 2, the biomass B is pressed into a vibrating funnel 1 and an injection chamber 2 so as to drastically reduce the presence of air (O ₂ ). Feeding the biomass through the auger conveyor 4 is continuous and continuous to prevent the presence of air in the reactor chamber 18. In the auger conveyor 4, the biomass material is preheated and pushed further inside the reactor chamber 18. The auger conveyor 4 is driven by a motor 3. Funnel 1, feed chamber 2 and a funnel connected to the inlet end of the reactor chamber 18 for introducing biomass into the reactor chamber 18.

The rotating reactor chamber 18 or rotor may be in the form of a cylinder, cone or pyramid to process the biomass according to its characteristics (specific gravity, granulation, etc.). In the preferred embodiment, the reactor chamber has a shape that gradually narrows toward the discharge end.

The plurality of studs 19 located on the inner surface of the reactor chamber 18 provide continuous mixing of biomass and its gradual displacement along the length of the reactor chamber 18 towards the basket 21 and the delivery chamber 22. The studs 19 are disposed on the inner wall of the reactor chamber 18 certain sizes. Their pyramidal shape, enlarged in Fig. 3. with varying inclinations of their surfaces, allows the biomass material to be stirred and directed in the longitudinal axis, while the rotation of the reactor chamber 18 in the opposite direction slows the flow of biomass material.

The basket 21 disposed in the delivery chamber 22, which is located in connection with the discharge end of the reactor chamber 18, is constructed with a special grid to hold the solid phase of the charred substance for a certain time before collecting it in the hopper 24. This facilitates further separation of synthetic gas from the char. The discharge of the funnel 24 is continuous and controlled to minimize the loss of synthetic gas S along with the charred substance. The synthetic gas is pumped out through valve 20 and conveyed to the main unit for use.

The rotary reactor chamber 18 is composed of a plurality of elements made by flanges 25. Each element can have a length of 3000 to 5000 mm, a diameter of 1500 to 4000 mm, depending on the required productivity and the type of biomass to be recycled. The reactor chamber 18 is mounted in bearings 8, which are cooled and sealed to reduce the loss of hot gas from the heating chamber 17. The drive unit 6, containing the motor 5, rotates the reactor chamber 18 around its longitudinal axis. Drive unit 6 allows to change the speed and direction of rotation.

The heating chamber 17 is composed of multilayer thermally insulated elements 10, which are fastened to the joints 16. Each element can have a length of 3000 to 6000 mm depending on the diameter of the design.

The temperature in the heating chamber 17 is controlled by the amount of hot gas supplied through valves 12, 11 (A - D).

The slope of the reactor or the tilt of the longitudinal axis can be modified by rotating it around the pivot axis 14 under the influence of group 13. In the preferred embodiment, the group 13 is a swinging mechanism comprising a pivot axis 14 or an axis and a slider.

The pyrolysis gasification process takes place in a cylindrical, conical or pyramidal reactor chamber 18 which rotates in a heating chamber 17.

The biomass is continuously fed into the heating chamber by means of a group comprising a vibrating funnel 1 and a worm conveyor 4. This system eliminates the presence of air (O2) in the reactor.

The hot gas circulation in the heating chamber 17 is provided by a series of modular valves 11-12 arranged on a cylindrical surface and distributed along the longitudinal axis so as to create a temperature gradient during the various phases of the pyrolysis process.

The entire reactor can rotate or oscillate in the vertical plane by means of the oscillation mechanisms 13 and 14 in both directions (+/-) relative to the horizontal to guide the biomass and the gas (synthetic gas) and derivative carbon (solid fraction) and tar (liquid) fraction) - production.

Depending on the amount and nature of the biomass to be recycled, the following reactor operation and pyrolysis process control parameters are regulated:

- the rate of rotation of the reactor chamber 18 with the possibility of changing the direction of this movement;

- temperature gradient along the length of the heating chamber 17;

- reactor tilt or slope (+/-) in vertical plane;

- Quantity of gas burned and cross-circulation.

Pyrolysis (decomposition of organic materials by heating) can be carried out at temperatures between 400 and 1000 ° C to produce the intended amount of gas at the right time.

A special chamber 22 is provided at the rear of the reactor to collect the synthetic gas and pyrolysis secondary products (carbonized material and tar) for use in the main unit to produce more energy.

Materials used in the construction of the reactor prototype are special high-temperature steels, stainless steel, refractory materials, components with high heat resistance and abrasion due to the abrasion of biomass.

The reactor diagram depicted in Fig. 1 is indicative. Reactor sizes vary with the amount and properties of biomass.

The pyrolysis process is controlled by sensors that measure the temperature of the carbonaceous material and synthetic gas produced in the 3 zones of the hot chamber.

The electronic controller (computer), in the chosen embodiment PLC (programmable logic controller), with the appropriate software controls the whole process and issues signals of operating anomalies. The loaded program guides all process activity according to the type of biomass used.

Automatically adjusts:

- quantity of gas burned,

- reactor rotation speed and rollover,

- amount of biomass,

- temperature, pressure, etc.

By continuously analyzing the mixture of produced gas (synthetic gas), the electronic controller controls and corrects the process parameters (temperature gradient and biomass heating time).

In the pyrolysis process, biomass is split in such a way that a solid and gaseous phase is formed, where the gaseous phase is incinerated, generating waste gases in much smaller quantities than in other processes, such as the waste incineration process.

The solid phase is rendered inert by utilizing part of the gas generated in the passivation process, while recovering most of the energy contained in the coal, which is the main component of the solid phase.

The process is variable and can be easily managed at all stages. The efficiency may exceed 70%.

Claims (10)

1. A biomass pyrolysis reactor containing: a reactor chamber for pyrolytic conversion of biomass having an inlet end and opposite outlet end and a longitudinal axis around which the reactor chamber rotates; - a heating chamber arranged around the reactor chamber for heating the biomass in the reactor chamber; - an airtight loading funnel connected to the inlet end of the reactor chamber for introducing biomass into the reactor chamber; - an airtight delivery chamber connected to the discharge end of the reactor chamber for discharging the biomass pyrolysis products; - a drive assembly for rotating the reactor chamber around its longitudinal axis, characterized in that the reactor is mounted 'on a base such that they can oscillate relative to one another and the angle of inclination of the reactor relative to the base can be freely changed, the orientation of the longitudinal axis in the vertical plane. A reactor according to claim 1, comprising a swinging mechanism for changing the inclination angle. The reactor of claim 1, wherein a substantial portion of the reactor chamber has a cross-section which gradually decreases. The reactor of claim 1, comprising a basket disposed within the delivery chamber and associated with the discharge end of the reactor chamber. The reactor according to any one of claims 1 to 4, which comprises a plurality of studs disposed on the inside surface of the reactor chamber to facilitate biomass flow and mixing. The reactor of claim 2, wherein the oscillator comprises an axis and a slider. The reactor of claim 2, wherein the oscillation mechanism is electronically controlled. 8. Reactor according to i. or claim 7, wherein the drive assembly for rotating the reactor is adapted to gradually change the cutting speed and direction. The reactor of claim 8, wherein the drive assembly is electronically controlled. A reactor according to claim 9, comprising an electronic controller for changing the speed, direction and orientation of the longitudinal axis to control the propagation of the biomass, thereby regulating the parameters of the pyrolytic reaction.