CN115651686A

CN115651686A - Method for drying and processing biomass raw material

Info

Publication number: CN115651686A
Application number: CN202211121226.8A
Authority: CN
Inventors: 孙震; 薛冬梅; 顾时雨; 王星浩
Original assignee: China India Hengsheng Beijing Trading Co ltd
Current assignee: China India Hengsheng Beijing Trading Co ltd
Priority date: 2022-09-15
Filing date: 2022-09-15
Publication date: 2023-01-31

Abstract

The invention provides a method for drying and processing biomass raw materials. The preheater may be configured to heat the biomass from a first temperature to approximately a desired drying temperature. The drying reactor may be configured to maintain the heating of the biomass at a preset drying temperature for a specific period of time to produce a dried biomass. The furnace may be configured to generate and transport heat to the preheater and the drying reactor via one or more conduits.

Description

Method for drying and processing biomass raw material

Technical Field

The present invention relates to drying and processing of biomass, and more particularly, to a system and method for producing dense biomass using a substantially autothermal drying process.

Background

The term "biomass" may be used to include all organic matter (all matter derived from photosynthesis). Biomass may include wood, plants, vegetable oils, green waste, manure, sewage sludge, or any other form or type of organic matter.

Biomass can be converted to hydrophobic, corrosion resistant materials by a heat drying process in a low oxygen environment, and can be used as a fuel (e.g., a substitute for coal fuel, entrained flow gasification feedstock, or other fuel), soil additive, long term carbon storage mechanism, or other suitable uses. The dried biomass can also be used in existing fuel burning power plants (e.g., coal burning power plants) to facilitate renewable fuel power generation utilizing existing fuel burning infrastructure. Furthermore, the use of combusted biomass as a fuel may provide a means of providing energy for carbon neutralization because it does not export carbon content to the atmosphere.

Drying of biomass can be described as a form of mild pyrolysis, typically at temperatures between 230-320 ℃. During the drying process, the moisture present in the biomass evaporates and the biopolymers of the biomass (such as cellulose, hemicellulose and lignin) will partially decompose, releasing various types of volatile organic compounds, resulting in a loss of mass (e.g. about 30%) and a loss of chemical energy (e.g. about 10%) in the gas phase. Because the mass lost is greater than the energy, drying results in an increase in energy density, producing a solid product with lower moisture content and higher energy content than untreated biomass. The resulting product may be a solid, dry, dark brown or blackened material.

Disclosure of Invention

According to some embodiments of the present disclosure, a system may include a preheater, a drying reactor, and a furnace. The preheater may be configured to heat the biomass from a first temperature to a preset drying temperature. The drying reactor may be configured to maintain the heating of the biomass at a preset drying temperature for a specific period of time to produce a dried biomass. The furnace may be configured to generate heat and convey the heat to the preheater and the drying reactor via one or more conduits. According to other embodiments of the present disclosure, a system may include a drying reactor and a stabilizer or conditioner. The drying reactor is configured to heat the biomass to produce a dried biomass. The stabilizer or conditioner may be configured to substantially simultaneously stabilize and condition the dried biomass.

According to other embodiments of the present disclosure, a method may be provided. The method can comprise the following steps: 1. heating the biomass in a drying reactor to produce a dried biomass; 2. generating heat through one or more heat pipes and transporting the heat from the furnace to the drying reactor; 3. combusting one or more volatile organic compounds produced by the drying reactor in the furnace to produce at least a portion of the heat; 4. recycling the one or more volatile organic compounds from the drying reactor to a furnace via one or more fluid conduits; 5. heating the one or more fluid conduits such that the temperature of the volatile organic compounds when present in the one or more fluid conduits is maintained above the dew point of the volatile compounds.

Drawings

Fig. 1 is a flow diagram of an example method for preparing dried biomass according to certain embodiments of the present disclosure.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be obtained by a person skilled in the art without making any creative effort based on the embodiments in the present invention, belong to the protection scope of the present invention.

Fig. 1 illustrates a flow diagram of an example method 100 for treating biomass for drying, in accordance with certain embodiments of the present disclosure. According to some embodiments, the method 100 may begin at block 102. The method 100 may begin with field harvesting of biomass. In certain embodiments, the acquisition method may begin with the cutting or shearing 102 of a tree or other plant. The root system of the plant can be kept embedded in the soil in the case of harvesting woody and plant biomass. Cutting or shearing may allow for continued harvesting of plant species that may re-propagate or re-grow after being cut or sheared. The harvesting process may continue to collect and grade 104 the cut or sheared biomass. Collecting and fractionating may include collecting the cut or sheared biomass using suitable equipment and fractionating (stacking, transporting) for grinding or slicing. Grinding or chipping 106 may include using commercially available wood grinders, wood chippers, or other suitable tools or other similar devices that can receive the collected biomass and produce output chips of a desired size (maximum length of any size is about 10 to 15 centimeters). Grinding or cutting biomass in the field may increase the possibility of transport from the harvest site to the processing site by truck, trailer or other vehicle. After grinding or chipping 106 (and after on-site screening 108), the biomass chips may be loaded 110 into a truck, trailer, or other vehicle for transport 112 to the plant for further drying processing. Upon completion of the transport 112 from the field, the biomass may be received 114 at the plants.

Biomass pieces determined to be too large by the plant screen 116 may be conveyed to a hammer mill or other suitable device for the

mills

118, 120. The size of the bulky debris can be reduced by milling 118 or milling 120. The screen 116 may further divide the high-volume debris into two groups, where one group may include high-volume debris larger than the other group. Larger chip sets may be used for milling 118, while smaller chip populations may be used for milling 120. The chips milled in the mill 118 may be further screened (not shown) to determine chips received after the mill 118 and chips that require further milling 120. Although not shown, additional screening may be performed after

milling

118 or 120 to again separate the chips into acceptable, unacceptable, or oversized dimensions. If the chip is still too large after

milling

118 or 120, such a chip may be fed again for

milling

118 or 120.

Claims

1. A method of drying a biomass feedstock includes a preheater configured to heat the biomass from a first temperature to a preset drying temperature; the drying reactor is configured to maintain heating of the biomass at approximately a desired drying temperature for a specified period of time to produce a dried biomass; also included is a furnace configured to generate and transport heat to the preheater and the drying reactor via one or more conduits.

2. The method for drying and processing the biomass raw material according to claim 1, characterized in that: wherein the preheater and the drying reactor are thermally isolated; the first temperature is between about 50 degrees Celsius and about 60 degrees Celsius; the preset drying temperature is between about 230 degrees celsius and about 280 degrees celsius.

3. The method of claim 1, the processing system further comprising a dryer configured to reduce the moisture content of the biomass prior to the biomass being heated by the preheater.

4. The method of claim 1, further comprising a separator configured to separate biomass present in the dryer from at least one of biomass particles, steam, and volatile organic compounds present within the dryer; and a conduit configured to convey at least one of the biomass particles, steam and volatile organic compounds present in the dryer to the furnace for combustion.

5. The method of claim 1, wherein the drying reactor is configured to maintain the heating of the biomass within about 20 degrees celsius of the preset drying temperature, and wherein the preheater comprises a first portion configured to heat the biomass from a first temperature to a second temperature; and a second section configured to heat the biomass from the second temperature to a preset drying temperature.

6. A method of biomass feedstock drying process according to claim 1, the furnace further configured to combust one or more volatile organic compounds produced by at least one of a preheater and a drying reactor to produce at least a portion of the heat; the furnace is further configured to combust the biomass to generate at least a portion of the heat.

7. The method of claim 1, further comprising a stabilizing agent configured to substantially simultaneously stabilize and condition the dried biomass; the stabilizing or conditioning agent is configured to substantially simultaneously stabilize and condition the dried biomass by applying a liquid to the dried biomass.

8. The method of claim 1, further comprising a thickener to thicken the dried biomass; wherein simultaneously stabilizing and conditioning the dried biomass comprises substantially simultaneously: cooling the dried biomass and increasing the moisture content of the dried biomass.

9. The method of claim 8, wherein cooling the dried biomass comprises maintaining the dried biomass above a minimum temperature.