Coal gas blending method and system meeting SO2 emission standard and heat value requirement

Abstract

The application discloses a coal gas blending method and system meeting SO2 standard emission and calorific value requirements, relates to the technical field of SO2 standard emission, and aims at solving the problem of insufficient economy of the existing SO2 standard emission method of the heating furnace coal gas; the application comprises the following steps: according to the composition of the to-be-burned gas, the actual value and the theoretical emission limit of the SO2 in the flue gas after burning, the actual total sulfur content and the maximum allowable value of the to-be-burned gas are calculated; the to-be-burned gas is divided into two types, i.e., sulfur-exceeding gas and low-sulfur gas; at least one of the two types of gas is mixed; the SO2 in the flue gas after mixing does not exceed the theoretical emission limit, and a plurality of mixed gas proportions are obtained; the mixed gas is classified into a calorific value standard group and a non-standard group; at least one mixed gas in each group is mixed and blended to meet the calorific value requirement; and according to the blending result, each to-be-burned gas is supplied to the heating furnace in proportion; the application has the advantages of simple steps, convenient operation, low cost, good economy and easy realization.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of SO2 emission standard, in particular to a coal gas deployment method and system meeting SO2 emission standard and heat value requirement. BACKGROUND

[0002] The heating furnace is the main energy consumption and pollutant emission equipment in the rolling process. Under the premise of meeting the heating quality requirements, both the extreme energy efficiency and the pollutant emission standard should be achieved. The treatment of flue gas pollutants mainly includes two ways: source treatment and end treatment. From the analysis of the source of flue gas pollutants of the heating furnace, SO2 is mainly brought in from the burning of coal gas. Since the rolling heating furnace is matched with the rolling mill and related to the product structure, it has the characteristics of many points and wide surfaces. Whether the source treatment of the coal gas is carried out by the fine desulfurization or the end treatment of the flue gas is carried out by the volume expansion of several times, there are many problems in the technical reliability, economy and feasibility (general layout, desulfurization and denitrification product treatment).

[0003] The invention patent with the publication number CN106435077A and the name of a blast furnace gas dry purification method and system adopts a chemical chain combustion reactor and two adsorption towers. The heat release of the chemical chain combustion reaction is used to heat the carrier gas, and then the high-temperature carrier gas is used to desorb and regenerate the adsorbent. The desorbed NH3 is introduced into the chemical chain combustion reactor to react with the oxidized oxygen carrier. When the adsorbent in the adsorption tower is desorbed, air is introduced into the chemical chain combustion reactor to oxidize and regenerate the reduced oxygen carrier. Two parallel adsorption towers are used for alternating adsorption and regeneration, so as to realize the efficient dry purification of blast furnace gas. This method is used to adsorb S elements in blast furnace gas by chemical method, which involves heating, use of desulfurizer and addition of treatment equipment. Although it can completely remove harmful impurities such as ammonia, chlorine and sulfur in blast furnace gas, this method has high energy consumption, high investment cost, poor economy, complex equipment maintenance and operation, and high cost. Therefore, a coal gas deployment method and system meeting SO2 emission standard and heat value requirement are needed to solve this problem. SUMMARY

[0004] The purpose of the present application is to provide a coal gas deployment method and system meeting SO2 emission standard and heat value requirement, so as to solve the problem of insufficient economy of the existing heating furnace coal gas SO2 emission standard method.

[0005] In order to achieve the above purpose, the present application provides the following technical scheme: a coal gas deployment method meeting SO2 emission standard and heat value requirement, comprising the following specific steps:

[0006] 1) According to the composition of each to-be-burned gas, the actual value and the theoretical emission limit of SO2 in the burned flue gas, the actual total sulfur content and the maximum allowable value of a plurality of to-be-burned gases are calculated respectively;

[0007] 2) According to the actual total sulfur content and the maximum allowable value of each gas to be burned, each gas to be burned is divided into two categories: sulfur-exceeding gas and low-sulfur gas. Assuming that at least one of each of the two types of gas is mixed, and the SO2 in the flue gas after mixing does not exceed the theoretical emission limit, a plurality of mixed gas ratios are obtained;

[0008] 3) According to the heat value requirement, the mixed gas is classified into a heat value standard group and a non-standard group. Assuming that at least one mixed gas in each group is mixed and adjusted to meet the heat value requirement, and finally according to the mixed and adjusted results, each gas to be burned is supplied to the heating furnace in proportion.

[0009] Preferably, the composition of the gas to be burned is analyzed by a gas analyzer in real time online or offline sampling; the actual value of SO2 in the flue gas after burning is obtained by CEMS online monitoring.

[0010] Preferably, the actual total sulfur content and the maximum allowable value of the gas to be burned are calculated as follows: dry flue gas SO2 = theoretical emission limit × 21 / (21-base oxygen), SO2 in wet flue gas = dry flue gas SO2 × (100-wet flue gas water content) / 100, S element in wet flue gas = SO2 in wet flue gas × 32 / 64, maximum allowable value = S element in wet flue gas × theoretical wet flue gas volume; actual total sulfur content of the gas to be burned = SO2 actual value of the flue gas after burning × maximum allowable value / theoretical emission limit.

[0011] Preferably, in step 2), the SO2 in the flue gas after mixing does not exceed the set emission limit, and the set emission limit is less than the theoretical emission limit.

[0012] Preferably, the set emission limit = theoretical emission limit × 90%.

[0013] Preferably, the gas to be burned includes coke oven gas, blast furnace gas, converter gas and natural gas.

[0014] Preferably, in step 2), if there is no sulfur-exceeding gas, there is no need to obtain mixed gas, and step 3) directly uses the gas to be burned instead of the mixed gas according to the heat value classification and then adjusts according to the method in step 3); if the heat value of the gas to be burned meets the standard, there is no need for adjustment or adjustment in any way.

[0015] Another technical scheme provided by the present application is a coal gas blending system for implementing the above method, comprising a combustion reaction furnace, a chimney, a coal gas tank, a flue gas analyzer and a coal gas analyzer. The combustion reaction furnace is provided with a burner connected with a coal gas branch pipe and an air branch pipe for providing combustion and combustion-supporting gas. The gas inlet end of the coal gas branch pipe is connected to the coal gas tank, the gas inlet end of the coal gas tank is connected to a gas inlet pipe network, and a coal gas pressurizing machine is further arranged in the middle of the coal gas branch pipe. The gas outlet of the combustion reaction furnace is connected to the chimney through a flue gas main pipe. The coal gas branch pipe is connected with a coal gas taking pipe and connected to the coal gas analyzer. The middle part of the chimney is connected with a flue gas taking pipe and connected to the flue gas analyzer for taking gas for detection.

[0016] Preferably, the gas inlet pipe network comprises a plurality of to-be-burned gas branch pipes, and each branch pipe is respectively provided with a flow regulating valve.

[0017] Preferably, the coal gas analyzer detects the contents of H2, CH4, CO, C n H m , CO2, O2, N2 and H2O in the to-be-burned gas; and the flue gas analyzer adopts CEMS.

[0018] Compared with the prior art, the present application has the following beneficial effects:

[0019] 1. The coal gas blending method meeting the SO2 standard emission and heat value requirements has simple steps and convenient operation, and can be implemented by simply modifying the original heating furnace equipment without the need for adding large-scale equipment, thereby being low in cost, good in economy, easy to implement, and capable of meeting the heat value requirements and SO2 standard emission requirements after blending.

[0020] 2. The coal gas blending method and system meeting the SO2 standard emission and heat value requirements can realize standard emission of heating furnace flue gas pollutants through blending means, are particularly suitable for dealing with the characteristics of many points and wide range of steel rolling heating furnaces and heat treatment furnaces, are high in feasibility and good in economy, and are the practical needs of meeting the green and low-carbon development requirements of "carbon peak and carbon neutralization" and "steel enterprise ultra-low emission" and taking into account the enterprise cost reduction and benefit increase requirements. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 The figure is a schematic diagram of the coal gas blending system of the present application.

[0022] In the figure: 1, combustion reaction furnace; 2, burner; 3, coal gas branch pipe; 4, air branch pipe; 5, flue gas main pipe; 6, chimney; 7, flue gas taking pipe; 8, flue gas analyzer; 9, coal gas taking pipe; 10, coal gas analyzer; 11, coal gas pressurizing machine; 12, coal gas tank; 13, gas inlet pipe network. DETAILED DESCRIPTION

[0023] A coal gas blending method meeting SO2 standard emission and heat value requirements comprises the following specific steps:

[0024] 1) According to the composition of each gas to be burned, the actual value of SO2 in flue gas after burning and the theoretical emission limit, the actual total sulfur content and the maximum allowable value of each gas to be burned are calculated respectively. The specific calculation method can be referred to: dry flue gas SO2 = theoretical emission limit x 21 / (21- baseline oxygen), SO2 in wet flue gas = dry flue gas SO2 x (100-wet flue gas water content) / 100, S element in wet flue gas = SO2 in wet flue gas x 32 / 64, maximum allowable value = S element in wet flue gas x theoretical wet flue gas volume; actual total sulfur content of gas to be burned = actual value of SO2 in flue gas after burning x maximum allowable value / theoretical emission limit; wherein the composition of the gas to be burned can be analyzed by a gas analyzer in real time online or offline sampling; the actual value of SO2 in flue gas after burning is obtained by conversion of CEMS online monitoring;

[0025] 2) According to the actual total sulfur content and the maximum allowable value of each gas to be burned, each gas to be burned is divided into two categories: sulfur-exceeding gas and low-sulfur gas. Assuming that at least one of each of the two types of gas is mixed, and the SO2 in flue gas after mixing does not exceed the theoretical emission limit, a plurality of mixed gas ratios are obtained. In addition, in order to ensure not to exceed, a set emission limit less than the theoretical emission limit is generally used for mixing, for example, set emission limit = theoretical emission limit x 90%, or set emission limit = theoretical emission limit-5mg / Nm 3 and the like;

[0026] 3) According to the heat value requirement, the mixed gas is classified into heat value standard group and non-standard group. Assuming that at least one mixed gas in each group is mixed and adjusted to meet the heat value requirement, finally each gas to be burned is supplied to the heating furnace according to the mixing and adjusting results.

[0027] In a more preferred embodiment, the gas to be burned includes coke oven gas, blast furnace gas, converter gas and natural gas.

[0028] In addition, if there is no sulfur-exceeding gas in step 2), there is no need to obtain mixed gas, and at this time, step 3) directly uses the gas to be burned instead of mixed gas according to the heat value classification and adjusts according to the method in step 3); if the heat value of the gas to be burned meets the standard, there is no need to adjust or can be adjusted in any way.

[0029] For example, Figure 1As shown, a coal gas allocation system meeting SO2 emission standard and heat value requirement includes a combustion reaction furnace 1, a chimney 6, a coal gas tank 12, a flue gas analyzer 8 and a coal gas analyzer 10. The combustion reaction furnace 1 is provided with a burner 2 connected with a coal gas branch pipe 3 and an air branch pipe 4 for providing combustion and combustion-supporting gas. The gas inlet end of the coal gas branch pipe 3 is connected to the coal gas tank 12, the gas inlet end of the coal gas tank 12 is connected to a gas inlet pipe network 13, and a coal gas pressurizing machine 11 is further arranged in the middle of the coal gas branch pipe 3. The gas outlet of the combustion reaction furnace 1 is connected to the chimney 6 through a flue gas main pipe 5. The coal gas branch pipe 3 is connected with a coal gas taking pipe 9 and connected to the coal gas analyzer 10. The middle of the chimney 6 is connected with a flue gas taking pipe 7 and connected to the flue gas analyzer 8 for taking gas for detection.

[0030] The combustion reaction furnace 1 can be a heating furnace mainly composed of a furnace body, an air and coal gas supply system, a combustion system (a plurality of air and coal gas burners arranged in the hearth), a flue gas discharge system and the like. The main purpose is to ensure that the coal gas is fully combusted and the materials in the heating furnace are heated. The hearth temperature is preferably controlled at 800-1300℃, and the materials in the heating process do not affect the composition of the flue gas. Of course, the combustion reaction furnace 1 can also be a steel rolling heating furnace, a heat treatment furnace and the like.

[0031] The burner 2 is used for proportionally mixing the coal gas and air sent through the coal gas branch pipe and the air branch pipe, and sending them into the combustion reaction furnace for combustion to heat the materials.

[0032] The chimney 6 is only used for discharging gas, and therefore an induced draft fan can be used as a substitute.

[0033] The flue gas taking pipe 7 is used for collecting flue gas from the chimney and conveying it to the flue gas analyzer. It is made of corrosion-resistant materials such as stainless steel and polytetrafluoroethylene, and preferably has an electric heat tracing function to meet the relevant CEMS analysis sampling requirements and ensure that the composition of the flue gas does not change during the conveying process.

[0034] The flue gas analyzer 8 can adopt a CEMS online monitoring system for real-time detection of the composition of the flue gas (SO2, O2). It adopts a sampling and cold drying method, and the technical requirements meet the relevant CEMS requirements. The technical performance preferably meets the requirements of a repeatability error Cv≤1% and a linearity error ≤1% FS.

[0035] The coal gas taking pipe 9 is used for collecting gas from the coal gas branch pipe and conveying it to the coal gas analyzer. It is preferably made of corrosion-resistant materials such as stainless steel and polytetrafluoroethylene.

[0036] The coal gas analyzer 10 is used for real-time or offline detection of the contents of H2, CH4, CO, CO2, O2, N2 and H2O in the gas to be burned. The technical performance preferably meets the requirements of a repeatability error Cv≤1% and a linearity error ≤1% FS. n H m

[0037] ​The coal gas pressurizing machine 11 is used for mixing the coal gas and pressurizing the same to about 10 kPa before sending into the combustion reaction furnace to meet the combustion control requirement.

[0038] The coal gas tank 12 is used for mixing, buffering and storing the gas to be burned.

[0039] In an alternative structure, the gas inlet pipe network 13 comprises a plurality of gas branches to be burned, and each branch is provided with a flow regulating valve for realizing the proportioning, and other existing ways can also be used to realize the mixing of the gas in the calculated proportion.

[0040] Embodiment:

[0041] The fuels for the heating furnace of Ma Steel Rolling Mill mainly include blast furnace gas, coke oven gas, converter gas and natural gas; the actual value and the maximum allowable value of the total sulfur content of various fuels are calculated as follows:

[0042] The calculation principle is to use the combustion flue gas backstepping method, that is, according to the composition of the coal gas and the actual value (the converted value in the online cems) and the emission limit of SO2 in the burned flue gas, the actual value and the maximum allowable value of the total sulfur content in the coal gas are derived through the related combustion and material balance calculation.

[0043] Table 1: Summary table of composition and calorific value of four kinds of fuels

[0044]

[0045] Taking the coke oven gas as an example:

[0046] According to GBT13338-2018 "Basic Rules for Determination and Calculation of Industrial Fuel Furnace Heat Balance", the related combustion material balance calculation model:

[0047] Theoretical dry air amount L0g=0.0238(H2 s +CO s )+0.0952×CH4 s +0.0476×3×CmHn s -0.0476×O2 s

[0048] Theoretical flue gas amount V0=0.01(CO s +3CH4 s +3CmHn s +CO2 s +H2 s +N2 s +H2O s )+0.79×L0g

[0049] Theoretical wet flue gas amount V0s=V0+0.00124×gk×L0g

[0050] Moisture content of wet flue gas H2O 、s = 0.01((2CH4 s + H2 s + CmHn s + H2O s ) + 0.00124 x gk x a x L0g) / Vns x 100

[0051] Substituting the calculation gives:

[0052] Table 2: Summary of coke oven gas composition and combustion parameters (%, V / V)

[0053]

[0054] Note: The moisture content of the gas H2O s , the volume moisture content is 3.79% under the condition of gas temperature 30℃ and saturation. The moisture content of dry air gk: 20.09g / Nm 3 , which is calculated by the hygrometer display dry ball 30℃, wet ball 25℃.

[0055] The maximum allowable value of total sulfur in coke oven gas is calculated according to the "Opinions on Promoting the Implementation of Ultra-low Emission in Iron and Steel Industry" issued by the Ministry of Ecology and Environment in April 2019. The oxygen content is 8% (GB28665-2012 stipulates: under the 8% baseline oxygen), the dry flue gas SO2 emission limit is 50mg / Nm 3 ; under the condition of 0% oxygen, dry flue gas SO2 = 50 x 21 / (21-8) = 81mg / Nm 3 ; the SO2 in wet flue gas = 81 x (100-wet flue gas moisture content) / 100 = 60.35mg / Nm 3 , in which S element = SO2 in wet flue gas x 32 / 64 = 30mg / Nm 3 ; S element in gas = S element in wet flue gas x theoretical wet flue gas volume = 30 x 4.438 = 134mg / Nm 3 , that is, if the gas meets the requirement of flue gas SO2 less than 50mg / Nm 3 , the total sulfur content should be less than 134mg / Nm 3 .

[0056] The actual value of total sulfur in coke oven gas is calculated: if the actual value of flue gas SO2 (the converted baseline value in online CEMS) is 93mg / Nm 3 , the actual value of total sulfur in gas = 134 / 50 x 93 = 250mg / Nm 3 .

[0057] The actual value of SO2 in flue gas produced by blast furnace gas, converter gas and natural gas is respectively: 37mg / Nm3 , 19 mg / Nm 3 , 3 mg / Nm 3 , 3 mg / Nm

[0058] Table 3: Actual and maximum allowable values of total sulfur

[0059]

[0060] From the actual production environmental safety control point of view, the SO2 emission limit is 45 mg / Nm 3 , as the basis, the guarantee value of total sulfur of each gas is calculated to control production.

[0061] Control logic: if the actual value of total sulfur of each single gas is less than its guarantee value, the flue gas generated by heating single gas or mixed gas can achieve standard emission;

[0062] Table 4: Actual and guarantee values of total sulfur

[0063]

[0064] The actual value of total sulfur of the above coke oven gas is greater than its guarantee value, which can achieve standard emission by adjusting the gas ratio, and the specific ratio calculation is as follows:

[0065] The amount of blast furnace gas needed to be mixed into 1 unit volume of coke oven gas

[0066] = 129 / 10 = 12.94 units, the heat value of coke oven / blast furnace mixed gas is 1060 kcal / Nm 3 ;

[0067] The amount of converter gas needed to be mixed into 1 unit volume of coke oven gas = 129 / 41 = 3.15 units, the heat value of coke oven / converter mixed gas is 2126 kcal / Nm 3 ;

[0068] The amount of natural gas needed to be mixed into 1 unit volume of coke oven gas = 129 / 271 = 0.48 units, the heat value of coke oven / natural gas mixed gas is 5078 kcal / Nm 3 .

[0069] Table 5: Summary table of gas allocation to meet the standard emission requirement

[0070]

[0071] Gas heat value allocation strategy to meet the standard emission requirement

[0072] The combustion heat value requirement is 2400 kcal / Nm3 It can be seen that the calorific value of the coke oven / blast furnace and coke oven / converter mixed gas is relatively low, and a coke oven / natural gas mixed gas with a higher calorific value needs to be added to meet the calorific value requirements.

[0073] The amount of coke oven / natural gas mixture required to be added per unit volume of coke oven / blast furnace mixed gas = (2400-1060) / (5078-2400) = 0.5004 unit volume. The proportions of various coal gases in the mixed gas are: coke oven gas 27.35%, blast furnace gas 61.87%, and natural gas 10.79%.

[0074] The amount of coke oven / natural gas mixture required to be added per unit volume of coke oven / converter mixed gas = (2400-2126) / (5078-2400) = 0.1025 unit volumes. The proportions of various gases in the mixed gas are: coke oven gas 28.15%, converter gas 68.84%, and natural gas 3.01%.

[0075] Table 6: Summary Table of Blending under the Requirements of Calorific Value

[0076]

[0077] Both of these supply ratios can simultaneously meet the calorific value requirements and SO2 emission standards. The distribution equipment involves simple modifications to the existing heating furnace, such as... Figure 1 As shown, the main additions are a gas holder 12 and branch pipes with adjustable flow rates, as well as a gas analyzer 10 with sampling pipelines (some heating furnaces originally had this analysis equipment).

[0078] Currently, the above method has been successfully tested in Maanshan Iron & Steel's No. 4 Steel Rolling Mill 2250 heating furnace and other applications, verifying its scientific validity, accuracy, and applicability. It achieves SO2 emission compliance in an extremely economical way while meeting calorific value requirements.

[0079] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

[0080] Any aspects of this invention not described in detail are well-known to those skilled in the art.

Claims

1. A coal gas blending method for meeting SO2 emission standard and heat value requirement, characterized in that, The method comprises the following specific steps: 1) According to the composition of each gas to be burned, the actual value of SO2 in flue gas after burning, and the theoretical emission limit, the actual total sulfur content and the maximum allowable value of each gas to be burned are calculated respectively. The calculation method of the actual total sulfur content and the maximum allowable value of the gas to be burned is as follows: SO2 in dry flue gas = theoretical emission limit × 21 / (21- baseline oxygen), SO2 in wet flue gas = SO2 in dry flue gas × (100- moisture content of wet flue gas) / 100, S element in wet flue gas = SO2 in wet flue gas × 32 / 64, maximum allowable value = S element in wet flue gas × theoretical wet flue gas volume, actual total sulfur content of gas to be burned = actual value of SO2 in flue gas after burning × maximum allowable value / theoretical emission limit; 2) According to the actual total sulfur content and the maximum allowable value of each gas to be burned, each gas to be burned is divided into two categories: sulfur-exceeding gas and low-sulfur gas. Assuming that at least one of each of the two types of gas is mixed, and the SO2 in the flue gas after mixing does not exceed the theoretical emission limit, a plurality of mixed gas ratios are obtained; 3) According to the heat value requirement, the mixed gas is classified into a heat value standard group and a non-standard group. Assuming that at least one mixed gas in each group is mixed and adjusted to meet the heat value requirement, and finally each gas to be burned is supplied to the heating furnace according to the mixing and adjusting results.

2. The coal gas blending method satisfying SO2 standard emission and heat value requirement according to claim 1, characterized in that: The composition of the gas to be burned is analyzed by a gas analyzer in real time online or offline sampling; the actual value of SO2 in flue gas after burning is obtained by CEMS online monitoring.

3. The coal gas blending method satisfying SO2 standard emission and heat value requirement according to claim 1, characterized in that: In step 2), the SO2 in the flue gas after mixing does not exceed the set emission limit, and the set emission limit is less than the theoretical emission limit.

4. The coal gas blending method of claim 3, wherein the coal gas blending method satisfies SO2 emission standard and heat value requirement. The set emission limit = theoretical emission limit × 90%.

5. The coal gas blending method of claim 1, wherein: The gas to be burned includes coke oven gas, blast furnace gas, converter gas and natural gas.

6. The coal gas blending method according to any one of claims 1 to 5, wherein the coal gas blending method satisfies SO2 emission standards and calorific value requirements. If there is no sulfur-exceeding gas in step 2), no mixed gas is needed, and step 3) directly uses the gas to be burned instead of the mixed gas according to the heat value classification and then adjusts according to the method in step 3); if the heat values of all the gases to be burned meet the standard, no adjustment is needed or the adjustment can be made in any way.

7. A gas conditioning system for implementing the method of any one of claims 1 to 6, characterized by: It comprises a combustion reaction furnace (1), a chimney (6), a gas tank (12), a flue gas analyzer (8) and a gas analyzer (10). The combustion reaction furnace (1) is provided with a burner (2) connected with a gas branch pipe (3) and an air branch pipe (4) for providing combustion and combustion supporting gas. The gas inlet end of the gas branch pipe (3) is connected to the gas tank (12), the gas inlet end of the gas tank (12) is connected to the gas inlet pipe network (13), and the middle part of the gas branch pipe (3) is further provided with a gas pressurizing machine (11). The gas outlet of the combustion reaction furnace (1) is connected to the chimney (6) through the flue gas main pipe (5). The gas branch pipe (3) is connected with a gas taking pipe (9) and connected to the gas analyzer (10). The middle part of the chimney (6) is connected with a flue gas taking pipe (7) and connected to the flue gas analyzer (8) for taking gas detection. The gas inlet pipe network (13) comprises a plurality of gas branch pipes to be burned, and each branch pipe is respectively provided with a flow regulating valve.

8. The coal gasification system of claim 7, wherein: The coal gas analyzer (10) detects H2, CH4, CO, C n H m O2, N2, H2O content in the gas to be burned; the flue gas analyzer (8) adopts CEMS.

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