Evaluation method of industrial organic solid waste pyrolysis based on entropy increase principle

Abstract

The invention relates to the technical field of organic solid waste pyrolysis, in particular to an evaluation method for industrial organic solid waste pyrolysis based on an entropy increase principle. According to the technical scheme, firstly, the input total entropy value is calculated based on the entropy value of an input substance of the pyrolysis system, then, the output total entropy value is calculated based on the entropy value of an output substance of the pyrolysis system, then, the entropy change value generated by the pyrolysis system is calculated based on the total entropy value of the input substance and the total entropy value of the output substance, and finally, the entropy change value generated by the pyrolysis system is calculated. And calculating a comprehensive entropy effect index based on the entropy change value generated by the pyrolysis system so as to evaluate the pyrolysis system by using the comprehensive entropy effect index. Therefore, according to the technical scheme, the entropy generated in the pyrolysis process can be analyzed, a theoretical basis can be provided for improving the energy conversion efficiency and reducing negative influences on the environment in the industrial organic solid waste pyrolysis process, and the method has guiding significance in achieving a sustainable development mode of industrial organic solid waste utilization.

Description

Technical Field

[0001] The invention relates to the technical field of organic solid waste pyrolysis, and in particular to an evaluation method for industrial organic solid waste pyrolysis based on the entropy increase principle. Background Art

[0002] my country's industrial organic solid waste has a large output and high organic content, and has significant resource potential. At the same time, pyrolysis technology has become a fast and efficient method for treating industrial organic solid waste with its advantages of flexible operation, low cost and high energy recovery efficiency.

[0003] However, existing research has mostly focused on the quantitative analysis of energy, with less attention paid to quality differences in energy use and generation.

[0004] Therefore, there is an urgent need for an evaluation method for the pyrolysis of industrial organic solid waste based on the principle of entropy increase to analyze the entropy generated during the pyrolysis process. Summary of the invention

[0005] The invention provides an evaluation method for pyrolysis of industrial organic solid waste based on the entropy increase principle, which can analyze the entropy generated in the pyrolysis process.

[0006] The present invention provides an evaluation method for pyrolysis of industrial organic solid waste based on the entropy increase principle, comprising:

[0007] The total entropy value of the input is calculated based on the entropy value of the input material of the pyrolysis system; wherein the input material includes industrial organic solid waste, diesel, air, water and electricity; the pyrolysis system is used to perform pyrolysis treatment on the industrial organic solid waste;

[0008] Calculating the total entropy of the output based on the entropy of the output material of the pyrolysis system; wherein the output material includes biochar, bio-oil, waste gas, wastewater, ash and thermal entropy loss;

[0009] Calculating the entropy change value generated by the pyrolysis system based on the total entropy value of the input material and the total entropy value of the output material;

[0010] A comprehensive entropy efficiency index is calculated based on the entropy change value generated by the pyrolysis system, so as to evaluate the pyrolysis system using the comprehensive entropy efficiency index.

[0011] It can be seen from the above scheme that the present invention provides an evaluation method for pyrolysis of industrial organic solid waste based on the principle of entropy increase. First, the total entropy value of the input is calculated based on the entropy value of the input material of the pyrolysis system, and then the total entropy value of the output is calculated based on the entropy value of the output material of the pyrolysis system. Then, the entropy change value generated by the pyrolysis system is calculated based on the total entropy value of the input material and the total entropy value of the output material. Finally, the comprehensive entropy efficiency index is calculated based on the entropy change value generated by the pyrolysis system, so as to evaluate the pyrolysis system using the comprehensive entropy efficiency index. Therefore, the above technical scheme can analyze the entropy generated by the pyrolysis process. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0013] Figure 1 A schematic flow chart of an evaluation method for pyrolysis of industrial organic solid waste based on the entropy increase principle provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0014] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0015] See also Figure 1 One embodiment of the present invention provides a schematic flow chart of an evaluation method for pyrolysis of industrial organic solid waste based on the principle of entropy increase, the method comprising:

[0016] Step 100, calculating the total entropy value of the input based on the entropy value of the input material of the pyrolysis system; wherein the input material includes industrial organic solid waste, diesel, air, water and electricity; the pyrolysis system is used to perform pyrolysis treatment on the industrial organic solid waste;

[0017] Step 102, calculating the total entropy value of the output based on the entropy value of the output material of the pyrolysis system; wherein the output material includes biochar, bio-oil, waste gas, wastewater, ash and thermal entropy loss;

[0018] Step 104, calculating the entropy change value generated by the pyrolysis system based on the total entropy value of the input material and the total entropy value of the output material;

[0019] Step 106: Calculate a comprehensive entropy efficiency index based on the entropy change value generated by the pyrolysis system, so as to evaluate the pyrolysis system using the comprehensive entropy efficiency index.

[0020] In this embodiment, the total entropy of the input is first calculated based on the entropy of the input material of the pyrolysis system, and the total entropy of the output is calculated based on the entropy of the output material of the pyrolysis system. Then, the entropy change value generated by the pyrolysis system is calculated based on the total entropy of the input material and the total entropy of the output material. Finally, the comprehensive entropy efficiency index is calculated based on the entropy change value generated by the pyrolysis system, so as to evaluate the pyrolysis system using the comprehensive entropy efficiency index. Therefore, the above technical solution can analyze the entropy generated by the pyrolysis process.

[0021] In some embodiments, the entropy generated by the pyrolysis process of EVA in waste photovoltaic modules is calculated. The functional unit is set to 1 ton of EVA pyrolysis. First, the EVA raw material is dried, EVA and N2 are introduced, and the EVA is dried at 100°C under normal pressure. After drying, the hot N2 and the dried EVA are separated and discharged. The dried EVA is passed into a pyrolysis reactor and pyrolyzed at 500°C to obtain volatile matter and ash. The volatile matter is fully condensed to obtain pyrolysis oil and pyrolysis gas, wherein the pyrolysis oil can be recycled, and the pyrolysis gas can be mixed with air and burned. The heat released by combustion is used to heat the pyrolysis system, and finally the flue gas is discharged. Therefore, for the EVA pyrolysis process, the main inputs are EVA, N2 and air, and the outputs are mainly pyrolysis oil products, waste flue gas and ash. The entropy calculation data generated by the pyrolysis of 1 ton of EVA is shown in Table 1 (showing the input entropy, value, output entropy, value and generated entropy).

[0022] Table 1 Entropy generated by conventional pyrolysis of EVA (MJ / K)

[0023]

[0024] If solar energy is introduced to provide heat for the EVA pyrolysis system and pyrolysis gas is output as a product, the entropy calculation results generated by the pyrolysis of 1 ton of EVA are shown in Table 2 (showing the input entropy, value, output entropy, value and generated entropy).

[0025] Table 2 Entropy generated by solar partial replacement of pyrolysis of EVA (MJ / K)

[0026]

[0027] From the calculation, it can be seen that the entropy generated by the conventional pyrolysis process of EVA is positive, but it becomes negative after the introduction of solar energy, indicating that the EVA pyrolysis system becomes more orderly and efficient after the introduction of solar heating. This means that under such environment and conditions, the operation within the system becomes more regular and coordinated, and the reduction of waste and pollutant emissions reduces the disorder output of the EVA pyrolysis system to the environment, thereby reducing the output entropy. In addition, the reduction in output entropy also means an improvement in energy conversion efficiency. In the solar pyrolysis scenario, pyrolysis gas is output as an effective energy product. Compared with the combustion of pyrolysis gas and emission of flue gas in the traditional pyrolysis scenario, less energy is lost in useless forms, and more energy can be effectively converted into useful forms, thereby directly improving the efficiency of energy conversion and reducing the disorder of the system.

[0028] The data in each case is as follows:

[0029] For the positive entropy production case: a1=0.2, b1=0.15, c1=0.1, d1=1.

[0030] For the case of negative entropy production: a2=0.1, b2=0.2, c2=0.05, d2=0.5.

[0031] Taking into account the absolute values ​​of positive and negative entropy production: a3=0.15, b3=0.1, c3=0.05, d3=0.5.

[0032] Weight coefficients: ω1=0.3, ω2=0.5, ω3=0.2.

[0033] The CEEI calculation data of the EVA pyrolysis process are shown in Table 3 (showing the function name, conventional pyrolysis of EVA and solar partial substitution pyrolysis of EVA).

[0034] Table 3 CEEI calculation results of EVA pyrolysis process

[0035]

[0036] From the above results, the performance of the conventional pyrolysis system of EVA is poor, while the solar partial replacement pyrolysis of EVA is better than the conventional pyrolysis of EVA. The solar partial replacement pyrolysis system of EVA can convert more input energy into useful output, improve the overall efficiency, and the system can more effectively utilize the input energy and improve the output quality. In practical applications, the performance of the system can be judged according to the CEEI value, which provides an important reference for system optimization and decision-making.

[0037] Therefore, through the above analysis, there are two main directions for optimizing the pyrolysis process. The first is to improve the efficiency of energy conversion, such as introducing renewable energy, efficiently separating and collecting pyrolysis products (solid, liquid and gas), and making reasonable use of them to improve the overall energy utilization rate. In addition, the waste heat generated by the pyrolysis process can be recovered for drying or preheating feed, etc., to reduce energy consumption. The second is to reduce waste and pollutant emissions. Using clean energy such as solar energy and wind energy to provide energy for the pyrolysis process can significantly reduce pollutants generated by the combustion of fossil fuels.

[0038] The analysis can quantify the quality and availability of energy in the pyrolysis system as shown in Table 4 (showing the name, conventional pyrolysis components, and solar pyrolysis components). By calculating the The value can clearly show the effective energy in the system that can be used to do work.

[0039] Table 4 EVA pyrolysis process Analyze the results

[0040]

[0041] Through the above data table, we can clearly understand the input fuel and the production of pyrolysis gas, bio-oil and other products It can also help determine the energy loss links and loss amounts in the system. The analysis mainly focuses on the quality and availability of energy, but the irreversible nature of energy conversion is not intuitive enough. The entropy increase principle, from the perspective of the second law of thermodynamics, explains more deeply why there will always be energy loss and unavailability in the actual process, and further explains the irreversibility of energy loss during use. For example, in some complex pyrolysis conditions, only relying on Analysis may not accurately explain some phenomena that seem to be reasonable energy utilization but are actually inefficient. At this time, the principle of entropy increase can reveal potential irreversible processes and increased disorder, supplementing the explanation of The fundamental cause of energy degradation not covered in the analysis, the entropy increase principle provides a macroscopic perspective to evaluate the overall thermodynamic performance of the system, while The analysis focuses more on the microscopic quality and conversion efficiency of energy. Analysis and the entropy increase principle can complement each other in case analysis, providing a comprehensive assessment from micro to macro, which can more comprehensively and deeply evaluate the energy utilization of the system and provide more powerful guidance for the optimization and improvement of the system.

[0042] This method applies the entropy analysis method to the evaluation of the pyrolysis process of industrial organic solid waste, conducts an inventory analysis of the pyrolysis process of industrial organic solid waste, calculates the entropy generated in the pyrolysis stage of industrial organic solid waste under functional units, and analyzes the entropy generated in the pyrolysis process to identify the optimization direction of the pyrolysis process. This evaluation method can provide a theoretical basis for improving the energy conversion efficiency and reducing the negative impact on the environment in the pyrolysis process of industrial organic solid waste, provide a direction for further optimizing the energy conservation and emission reduction work of the process, and provide a reference for the evaluation of the thermodynamic properties of the energy utilization of industrial organic solid waste, which has guiding significance for the realization of a sustainable development model for the utilization of industrial organic solid waste.

[0043] In one embodiment of the present invention, the entropy value of industrial organic solid waste is determined by the following formula:

[0044]

[0045] In the formula, m IOSW is the quality of industrial organic solid waste, HHV IOSW is the high calorific value of industrial organic solid waste, and T is the standard temperature.

[0046] In this embodiment, the system boundaries of the pyrolysis process of industrial organic solid waste are clarified. The starting boundary of this method is the collection of industrial organic solid waste, and the ending boundary is the acquisition of biochar and bio-oil products. The pyrolysis system covers the stages of transportation, pretreatment, pyrolysis, cooling, and heating. The impacts it produces mainly include electrical equipment such as crushers, dryers, and blowers, transportation vehicles, and energy resource inputs and pollutant emissions caused by biochar cooling and pyrolysis gas combustion.

[0047] Determine the types of substances or energy at the input boundary and the output boundary of each stage in the pyrolysis process of industrial organic solid waste, and at the same time determine the input quantity list of each substance or resource at each stage, the temperature list of the input substance, and determine the output quantity list and temperature list of the output substance of each substance or energy at each stage.

[0048] In one embodiment of the present invention, the entropy value of diesel is determined by the following formula:

[0049]

[0050] In one embodiment of the present invention, the entropy value of air is determined by the following formula:

[0051] S air =S airS ×m air

[0052] In the formula, S airS is the specific entropy of air, m air For the quality of air.

[0053] In one embodiment of the present invention, the entropy value of air is determined by the following formula:

[0054] S water =S waterS ×m water ;

[0055] In the formula, S waterS is the specific entropy of water, m water For the quality of water.

[0056] In one embodiment of the present invention, the entropy value of electricity is determined by the following formula:

[0057]

[0058] In the formula, Q elec is the amount of input electricity.

[0059] In one embodiment of the present invention, the total entropy value of the input is determined by the following formula:

[0060]

[0061] In the formula, S IOSW is the entropy of industrial organic solid waste, S dies is the entropy of diesel, S air is the entropy of air, S water is the entropy of input water, S elec is the entropy of electricity.

[0062] In one embodiment of the present invention, the entropy value of biochar is determined by the following formula:

[0063]

[0064] In the formula, m biochar is the quality of biochar, HHV biochar is the high calorific value of biochar, T biochar is the temperature of biochar.

[0065] In one embodiment of the present invention, the entropy value of bio-oil is determined by the following formula:

[0066]

[0067] In the formula, m bio-oil is the quality of bio-oil, HHV bio-oil is the high calorific value of bio-oil, T bio-oil is the temperature of the bio-oil.

[0068] In one embodiment of the present invention, the entropy value of the exhaust gas is determined by the following formula:

[0069]

[0070] In the formula, m i is the mass of gas, S i is the specific entropy of the gas.

[0071] In one embodiment of the present invention, the entropy value of the wastewater is determined by the following formula:

[0072] S ww =m ww ×S wwS

[0073] In the formula, m ww is the quality of wastewater, S wwS is the specific entropy of wastewater.

[0074] In one embodiment of the present invention, the entropy value of ash is determined by the following formula:

[0075]

[0076] In the formula, Q ash is the heat of ash, T ash is the temperature of the ash, c ash is the specific heat capacity of ash, m ash is the mass of ash, △T is the temperature difference.

[0077] In one embodiment of the present invention, the entropy value of the thermal entropy loss is determined by the following formula:

[0078] S loss =S IOSW ×3%.

[0079] In one embodiment of the present invention, the total entropy value of the output is determined by the following formula:

[0080]

[0081] In the formula, S biochar is the entropy of biochar, S bio-oil is the entropy of bio-oil, S exha is the entropy of the exhaust gas, S ww is the entropy of wastewater, S ash is the entropy of ash, S loss is the thermal entropy loss during the pyrolysis process.

[0082] In one embodiment of the present invention, the entropy change value generated by the pyrolysis system is determined by the following formula:

[0083]

[0084] In the formula, is the total entropy value input for the pyrolysis system, is the total entropy output by the pyrolysis system, is the entropy change value produced by the pyrolysis system.

[0085] In one embodiment of the present invention, the comprehensive entropy efficiency index is determined by the following formula:

[0086]

[0087] In the formula, ω1 is the first weight coefficient, ω2 is the second weight coefficient, and ω3 is the third weight coefficient. is the first function, is the second function, is the third function.

[0088] In one embodiment of the present invention, the sum of the first weight coefficient, the second weight coefficient and the third weight coefficient is 1.

[0089] In one embodiment of the present invention, the first function is determined by the following formula:

[0090]

[0091] In the formula, when , a1, b1, c1 and d1 are the first set of specific coefficients.

[0092] In one embodiment of the present invention, the second function is determined by the following formula:

[0093]

[0094] In the formula, when , a2, b2, c2 and d2 are the second set of specific coefficients.

[0095] In one embodiment of the present invention, the third function is determined by the following formula:

[0096]

[0097] Wherein, a3, b3, c3 and d3 are the third group of specific coefficients.

[0098] In one embodiment of the present invention, the comprehensive entropy efficiency index is used to evaluate the pyrolysis system, including:

[0099] When the comprehensive entropy efficiency index is greater than a first preset value, the entropy production of the pyrolysis system is poor; wherein the first preset value is a positive number;

[0100] When the comprehensive entropy efficiency index is less than the first preset value and greater than the second preset value, the entropy production of the pyrolysis system is poor; wherein the second preset value is a positive number;

[0101] When the absolute value of the comprehensive entropy efficiency index is less than the second preset value, the entropy production of the pyrolysis system is good;

[0102] When the comprehensive entropy efficiency index is negative and its absolute value is greater than the third preset value, the entropy production of the pyrolysis system is good.

[0103] In this embodiment, the better the entropy production is, the higher the energy efficiency of the system is, and the greater the contribution to sustainable development is.

[0104] In some embodiments, when the comprehensive entropy efficiency index is in a relatively high positive range, it indicates that the negative impact of the system's positive entropy production is large, the system performance is poor, and measures need to be taken to reduce the positive entropy production;

[0105] When the comprehensive entropy efficiency index is in a relatively low positive range, although the system has positive entropy production, the impact is relatively small and can be gradually optimized;

[0106] When the comprehensive entropy efficiency index is close to zero, the system is in a relatively balanced state, but there is still room for improvement;

[0107] When the comprehensive entropy efficiency index is in the negative range, it indicates that the system negative entropy production is dominant, the system performance is good, and the larger the negative value, the better the system performance.

[0108] The above specific embodiments further illustrate the purpose, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above are only specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

[0109] It should be noted that the terms "comprises", "includes" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or apparatus that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or apparatus.

[0110] Finally, it should be noted that the above is only a preferred embodiment of the present invention, which is only used to illustrate the technical solution of the present invention, and is not used to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention are included in the protection scope of the present invention.

Claims

1. An evaluation method for pyrolysis of industrial organic solid waste based on the principle of entropy increase, characterized in that: The method comprises: The total entropy value of the input is calculated based on the entropy value of the input material of the pyrolysis system; wherein the input material includes industrial organic solid waste, diesel, air, water and electricity; the pyrolysis system is used to perform pyrolysis treatment on the industrial organic solid waste; Calculating the total entropy of the output based on the entropy of the output material of the pyrolysis system; wherein the output material includes biochar, bio-oil, waste gas, wastewater, ash and thermal entropy loss; Calculating the entropy change value generated by the pyrolysis system based on the total entropy value of the input material and the total entropy value of the output material; A comprehensive entropy efficiency index is calculated based on the entropy change value generated by the pyrolysis system, so as to evaluate the pyrolysis system using the comprehensive entropy efficiency index.

2. The method according to claim 1, characterized in that The entropy value of the industrial organic solid waste is determined by the following formula: In the formula, m IOSW is the quality of industrial organic solid waste, HHV IOSW is the high calorific value of industrial organic solid waste, T is the standard temperature; The entropy value of the diesel is determined by the following formula: The entropy value of the air is determined by the following formula: S air =S airS ×m air In the formula, S airS is the specific entropy of air, m air For the quality of air; The entropy value of the air is determined by the following formula: S water =S waterS ×m water ; In the formula, S waterS is the specific entropy of water, m water For the quality of water; The entropy value of the electricity is determined by the following formula: In the formula, Q elec is the amount of input electricity.

3. The method according to claim 2, characterized in that The total entropy value of the input is determined by the following formula: In the formula, S IOSW is the entropy of industrial organic solid waste, S dies is the entropy of diesel, S air is the entropy of air, S water is the entropy of input water, S elec is the entropy of electricity.

4. The method according to claim 3, characterized in that The entropy value of the biochar is determined by the following formula: In the formula, m biochar is the quality of biochar, HHV biochar is the high calorific value of biochar, T biochar is the temperature of the biochar; The entropy value of the bio-oil is determined by the following formula: In the formula, m bio-oil is the quality of bio-oil, HHV bio-oil is the high calorific value of bio-oil, T bio-oil is the temperature of the bio-oil; The entropy value of the exhaust gas is determined by the following formula: In the formula, m i is the mass of gas, S i is the specific entropy of the gas; The entropy value of the wastewater is determined by the following formula: S ww =m ww ×S wwS In the formula, m ww is the quality of wastewater, S wwS is the specific entropy of wastewater; The entropy value of the ash is determined by the following formula: In the formula, Q ash is the heat of ash, T ash is the temperature of the ash, c ash is the specific heat capacity of ash, m ash is the mass of ash, △T is the temperature difference; The entropy value of the thermal entropy loss is determined by the following formula: S loss =S IOSW ×3%。 5. The method according to claim 4, characterized in that The total entropy value of the output is determined by the following formula: In the formula, S biochar is the entropy of biochar, S bio-oil is the entropy of bio-oil, S exha is the entropy of the exhaust gas, S ww is the entropy of wastewater, S ash is the entropy of ash, S loss is the thermal entropy loss during the pyrolysis process.

6. The method according to claim 5, characterized in that The entropy change value generated by the pyrolysis system is determined by the following formula: In the formula, is the total entropy value input for the pyrolysis system, is the total entropy output by the pyrolysis system, is the entropy change value produced by the pyrolysis system.

7. The method according to claim 6, characterized in that The comprehensive entropy efficiency index is determined by the following formula: In the formula, ω1 is the first weight coefficient, ω2 is the second weight coefficient, and ω3 is the third weight coefficient. is the first function, is the second function, is the third function.

8. The method according to claim 7, characterized in that The sum of the first weight coefficient, the second weight coefficient and the third weight coefficient is 1.

9. The method according to claim 8, characterized in that The first function is determined by the following formula: In the formula, when When , a1, b1, c1 and d1 are the first set of specific coefficients; The second function is determined by the following formula: In the formula, when When , a2, b2, c2 and d2 are the second set of specific coefficients; The third function is determined by the following formula: Wherein, a3, b3, c3 and d3 are the third group of specific coefficients.

10. The method according to claim 9, characterized in that The method of evaluating the pyrolysis system by using the comprehensive entropy efficiency index includes: When the comprehensive entropy efficiency index is greater than a first preset value, the entropy production of the pyrolysis system is poor; wherein the first preset value is a positive number; When the comprehensive entropy efficiency index is less than the first preset value and greater than the second preset value, the entropy production of the pyrolysis system is poor; wherein the second preset value is a positive number; When the absolute value of the comprehensive entropy efficiency index is less than the second preset value, the entropy production of the pyrolysis system is good; When the comprehensive entropy efficiency index is negative and its absolute value is greater than the third preset value, the entropy production of the pyrolysis system is good.

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