CN111849571A - A method for preparing slurry fuel by mixing coal gasification fine residue carbon and biomass rapid pyrolysis oil - Google Patents

Abstract

The present invention discloses a method for preparing slurry fuel by mixing coal gasification fine slag carbon residue and biomass rapid pyrolysis oil, comprising the following steps: (1) using coal gasification fine slag as raw material, realizing carbon-ash separation of gasification fine slag by froth flotation technology, and separating carbon residue; (2) using biomass as raw material, preparing biomass pyrolysis oil by rapid pyrolysis technology; (3) mixing the carbon residue obtained in step (1) and the biomass pyrolysis oil obtained in step (2) to prepare slurry fuel. The present invention separates gasification fine slag carbon residue and tailings ash by froth flotation technology, realizing resource utilization of gasification fine slag. Biomass rapid pyrolysis technology obtains biomass rapid pyrolysis oil with high energy density and capable of long-distance transportation.

Description

Preparation of slurry fuel by mixing coal gasification fine residue carbon and biomass rapid pyrolysis oil Methods

technical field

The invention belongs to the technical field of slurry fuel, and particularly relates to a method for preparing slurry fuel by mixing coal gasification fine residue carbon and biomass rapid pyrolysis oil.

Background technique

Coal reserves are abundant and coal is the most important primary energy source in my country. Coal gasification technology is an important source of efficient and clean coal conversion. The gasification fine slag is one of the main coal-based solid wastes in the coal gasification process, and its carbon content is 25-50wt%. Currently, the main treatment method is landfill, which brings great challenges to the sustainable development of the environment and energy security. Effective separation and recovery of carbon residues in gasification fine slag is an important way to achieve efficient coal conversion and improve tailings ash grade. In addition, biomass as a renewable resource, plant straw or wood has been an important energy source since ancient times. However, it has the problems of low energy density and high transportation cost. How to use biomass efficiently and on a large scale is an urgent problem to be solved. Biomass rapid pyrolysis technology can convert low-density biomass into some high-energy-density biomass pyrolysis oil in a relatively short time, which can realize long-distance transportation of biomass resources and have good environmental benefits.

SUMMARY OF THE INVENTION

The object of the present invention is to provide a method for preparing slurry fuel by mixing coal gasification fine residue charcoal with biomass rapid pyrolysis oil, suspending coal gasification fine residue charcoal in biomass pyrolysis oil, and gasification fine residue residue Carbon contributes higher energy density and biomass pyrolysis oil contributes high mobility and activity.

To achieve the above object, the technical scheme adopted in the present invention is:

A method for preparing slurry fuel by mixing coal gasification fine residue carbon and biomass rapid pyrolysis oil, comprising the following steps:

(1) Using the coal gasification fine slag as the raw material, the carbon-ash separation of the coal gasification fine slag is realized by the froth flotation technology, and the residual carbon is separated;

(2) Biomass pyrolysis oil is prepared by rapid pyrolysis technology using biomass as raw material;

(3) Mixing the carbon residue obtained in step (1) and the biomass pyrolysis oil obtained in step (2) to prepare slurry fuel.

In the step (1), the loss on ignition of the obtained carbon residue is higher than 65 wt%, the calorific value exceeds 20 MJ/kg, and the proportion of the carbon residue with a size below 75 microns exceeds 80 wt%.

In the step (1), the loss on ignition of the tailings ash obtained by the froth flotation process is less than 4wt%.

In the step (2), the biomass is crop straw or wood.

In the step (2), rapid pyrolysis is carried out in an inert environment at 500°C.

In the step (2), the obtained biomass pyrolysis oil has a calorific value of 18 MJ/kg.

In the step (2), the obtained biomass pyrolysis oil needs to be stored below 5°C.

In the step (3), the residual carbon mass ratio is greater than 0 and less than or equal to 20wt%. Within the above range, adjust the ratio of carbon residue and biomass pyrolysis oil, and investigate the relationship function of the static stability, viscosity and flow behavior index of the obtained slurry fuel with respect to the residual carbon concentration, so as to make the static stability of the slurry fuel stable. The viscosity is higher than 70%, the viscosity is less than 1000mPa·s, and the flow behavior index is less than 1. Through the above three indicators, the maximum amount of residual carbon is determined to prepare slurry fuel.

Among them, the static stability was obtained by the static stability test with an assessment time of 15 days, the viscosity was obtained by the rheometer test, and the flow behavior index was calculated by the shear force and shear rate.

Beneficial effects: The present invention provides a method for preparing slurry fuel by mixing coal gasification fine residue charcoal with biomass rapid pyrolysis oil, and separating gasification fine residue charcoal and tailing ash by froth flotation technology to realize gasification Resource utilization of fine slag. Biomass rapid pyrolysis technology obtains biomass rapid pyrolysis oil with high energy density and long-distance transportation. Has the following advantages:

1. The carbon-ash separation of the gasification fine slag is realized by the froth flotation technology, and the fine slag tailing ash is upgraded while recovering the high energy density residual carbon. After the gasification fine slag, which can only be landfilled before, is treated by this process, both carbon residues with high energy density and first-grade ash with high added value are obtained.

2. Biomass is converted into high value-added biomass pyrolysis oil through mature rapid pyrolysis technology, the energy density is greatly improved and the possibility of long-distance transportation is realized, which is expected to broaden the large-scale utilization of low energy density biomass.

3. The gasification fine residue carbon and biomass pyrolysis oil are mixed to prepare slurry fuel to realize the efficient conversion of resources. The route is in line with the national conditions of sustainable energy development in my country and has certain practical significance.

Description of drawings

FIG. 1 is a flow chart of the present invention.

Detailed ways

The present invention will be further explained below in conjunction with the accompanying drawings.

As shown in Figure 1, a method for preparing slurry fuel by mixing coal gasification fine residue carbon and biomass rapid pyrolysis oil, comprising the following steps:

(1) Using coal gasification fine slag as raw material, the carbon-ash separation of the gasification fine slag is realized by froth flotation technology, and the carbon residue is separated; kg, the residual carbon with a size of less than 75 microns accounts for more than 80wt%, and the loss on ignition of tailings ash obtained by the froth flotation process is less than 4wt%, and the tailings ash can be used in the construction industry.

(2) Biomass pyrolysis oil is prepared by rapid pyrolysis technology using biomass as raw material; wherein the biomass is crop straw or wood, and the rapid pyrolysis is carried out in an inert environment of 500°C to obtain biomass pyrolysis oil. The calorific value is 18MJ/kg, and the obtained biomass pyrolysis oil needs to be stored below 5℃.

(3) Mixing the residual carbon obtained in step (1) and the biomass pyrolysis oil obtained in step (2), the mass ratio of residual carbon is greater than 0 and less than or equal to 20wt%. Within the above range, adjust the ratio of carbon residue and biomass pyrolysis oil, and investigate the relationship function of the static stability, viscosity and flow behavior index of the obtained slurry fuel with respect to the residual carbon concentration, so as to make the static stability of the slurry fuel stable. The viscosity is higher than 70%, the viscosity is less than 1000mPa·s, and the flow behavior index (pseudoplasticity) is less than 1. Through the above three indicators, the maximum amount of carbon residue is determined to prepare slurry fuel.

The present invention will be further described below in conjunction with the examples.

Example

A method for preparing slurry fuel by mixing coal gasification fine residue carbon and biomass rapid pyrolysis oil, comprising the following steps:

In step a, the coal gasification fine slag is subjected to flotation to enrich the residual carbon, the loss on ignition of the residual carbon is higher than 65wt%, the calorific value exceeds 20MJ/kg, the particle size of the flotation carbon residue is small, and the proportion of particles below 75 microns About 84wt%, the particle size is fine and can be directly used to prepare slurry fuel without grinding treatment; the loss on ignition of tailings separated by flotation process is less than 4wt%, and this index reaches the standard of first-class fly ash.

Step b, taking pine wood as an example, the biomass is rapidly pyrolyzed in an inert environment of 500 ° C to prepare pyrolysis biomass oil, the moisture content of which is within 30wt%, the viscosity is less than 100mPa·s, and the calorific value is about 18MJ/kg; The solution oil should be stored in a low temperature environment below 5 ℃ to prevent aging and deterioration during storage.

In step c, the residual carbon obtained in step a and the biomass pyrolysis oil obtained in step b are evenly mixed, and the mass ratio of the residual carbon is greater than 0 and less than or equal to 20wt%. ratio, and investigate the relationship between the static stability, viscosity and flow behavior index of the obtained slurry fuel relative to the residual carbon concentration, so that the static stability of the slurry fuel is higher than 70%, the viscosity is less than 1000mPa·s, and the flow behavior index If it is less than 1, through the above three indicators, determine the maximum amount of carbon residue to prepare slurry fuel.

Among them, the static stability was obtained by the static stability test with an assessment time of 15 days, the viscosity was obtained by the rheometer test, and the flow behavior index was calculated by the shear force and shear rate.

The invention realizes the carbon-ash separation of the gasification fine slag through the froth flotation technology, and at the same time recovers the high-energy density residual carbon, and upgrades the fine slag tailing ash. After the gasification fine slag, which can only be landfilled before, is treated by this process, both carbon residues with high energy density and first-grade ash with high added value are obtained. Biomass is converted into high value-added biomass pyrolysis oil through mature rapid pyrolysis technology, the energy density is greatly improved and the possibility of long-distance transportation is realized, which is expected to expand the large-scale utilization of low-energy-density biomass. The gasification fine residue carbon and biomass pyrolysis oil are mixed to prepare slurry fuel to realize the efficient conversion of resources.

The above are only the preferred embodiments of the present invention. It should be pointed out that for those skilled in the art, without departing from the principles of the present invention, several improvements and modifications can be made. It should be regarded as the protection scope of the present invention.

Claims (10)

1. a method for preparing slurry fuel by mixing coal gasification fine residue carbon and biomass fast pyrolysis oil, is characterized in that: may further comprise the steps: (1) Using the coal gasification fine slag as the raw material, the carbon-ash separation of the coal gasification fine slag is realized by the froth flotation technology, and the residual carbon is separated; (2) Biomass pyrolysis oil is prepared by rapid pyrolysis technology using biomass as raw material; (3) Mixing the carbon residue obtained in step (1) and the biomass pyrolysis oil obtained in step (2) to prepare slurry fuel. 2. the method for preparing slurry fuel by mixing coal gasification fine residue charcoal and biomass fast pyrolysis oil according to claim 1, it is characterized in that: in the described step (1), the loss on ignition of the obtained charcoal residue Above 65wt%, the calorific value exceeds 20MJ/kg, and the proportion of carbon residues below 75 microns exceeds 80wt%. 3. the method for preparing slurry fuel by mixing coal gasification fine residue carbon and biomass fast pyrolysis oil according to claim 1, it is characterized in that: in the described step (1), the tail obtained by the froth flotation process is separated The ash loss on ignition is less than 4wt%. 4 . The method for preparing slurry fuel by mixing coal gasification fine residue charcoal with biomass rapid pyrolysis oil according to claim 1 , wherein in the step (2), the biomass is crop straw or wood. 5 . 5. The method for preparing slurry fuel by mixing coal gasification fine residue charcoal with biomass rapid pyrolysis oil according to claim 1, characterized in that: in the step (2), rapid pyrolysis is performed at an inert temperature of 500°C. environment. 6. the method for preparing slurry fuel by mixing coal gasification fine residue carbon and biomass fast pyrolysis oil according to claim 1, is characterized in that: in described step (2), the obtained biomass pyrolysis oil heat The value is 18MJ/kg. 7. the method for preparing slurry fuel by mixing coal gasification fine residue charcoal and biomass fast pyrolysis oil according to claim 1, is characterized in that: in described step (2), the biomass pyrolysis oil obtained needs to be Store below 5°C. 8. The method for preparing slurry fuel by mixing coal gasification fine residue charcoal with biomass rapid pyrolysis oil according to claim 1, characterized in that: in the step (3), the residual charcoal mass ratio is greater than 0 and less than Equal to 20 wt%. 9. the method for preparing slurry fuel by mixing coal gasification fine residue carbon and biomass fast pyrolysis oil according to claim 8, is characterized in that: adjust the proportioning of carbon residue and biomass pyrolysis oil, and investigate gained The relationship between the static stability, viscosity and flow behavior index of the slurry fuel relative to the residual carbon concentration, the static stability of the slurry fuel is higher than 70%, the viscosity is less than 1000mPa·s, and the flow behavior index is less than 1. An index is used to determine the maximum amount of residual carbon to prepare slurry fuel. 10. the method for preparing slurry fuel by mixing coal gasification fine residue charcoal and biomass fast pyrolysis oil according to claim 9, is characterized in that: obtain static stability through the static stability test of examination time 15 days, pass The viscosity was obtained from rheometer testing, and the flow behavior index was calculated from shear force and shear rate.

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