Code for Technical and Economic Evaluation of Chlor-alkali Industry

Procedures for Technical and Economic Accounting of Chlorine and Alkali Industries – Ion Exchange Electrolysis Method Table of Contents Preface Chapter 1: Foundations and Bases for Technical and Economic Accounting Chapter 2: Finished Products, Semi-Finished Products, Work-in-Process, and By-products Chapter 3: Accounting for Quality Indicators Chapter 4: Accounting for Technical and Economic Indicators Chapter 5: Accounting for Unit Consumption of Products Chapter 6: Calculation of Total Energy Consumption Appendix: Forms for Calculating Product Consumption and Total Energy Consumption Preface Technical accounting is an important aspect of enterprise management, and the procedures for technical and economic accounting serve as important technical bases and guidelines for industrial statistics and accounting across various departments and industries. Technical and economic accounting is used to comprehensively reflect the conditions and level of a company’s production, operation, and management. In order to standardize the criteria and methods for the technical and economic evaluation of caustic soda production using the ion exchange membrane process, the former Ministry of Chemical Industry and the China Chlor-Alkali Industry Association jointly formulated the \"Rules for Technical and Economic Evaluation of Caustic Soda Production by Ion Exchange Membrane Electrolysis\" (revised version) in 1995. Given the revisions to certain standards and statistical rules in recent years, as well as the need to align accounting practices with international standards, some provisions of the original \"Technical and Economic Accounting Regulations for Caustic Soda Production via Ion-Exchange Membrane Electrolysis\" (revised version) are no longer suitable for the current circumstances. Therefore, this regulation has been formulated as a result of a second revision to the original document. Chapter 1: Foundations and Bases of Technical-Economic Accounting. Technical-economic accounting is an important aspect of enterprise management, and the regulations governing technical-economic accounting serve as important technical bases and guidelines for industrial statistics, as well as for technology and cost accounting. Its content and specific calculation methods shall comply with the regulations of **the relevant authorities. In order to standardize the technical and economic evaluation methods for chlorine and caustic soda production using ion membrane electrolysis and to align them with international standards, this regulation was formulated by introducing the concept of electrolytic units and corresponding estimation methods based on the existing technical and economic evaluation guidelines for caustic soda production via diaphragm electrolysis. It transforms the previous evaluation approach, which was based on electrolytic caustic soda production, into one that focuses on electrolytic units (ECUs), with both chlorine and caustic soda being evaluated concurrently. The full English name for electrolysis unit (ECU) is ELECTRIC-CHEMICAL UNIT, which means electrolysis unit. According to calculations, each electrolysis unit can produce 1 unit of chlorine and 1.087 units of caustic soda (on a percent basis) per unit of chlorine produced. The formula is: 1ECU = CL2 + 1.087NaOH. An electrolyzer without high-purity hydrochloric acid can produce 1 unit of chlorine and 1.13 units of caustic soda (sodium hydroxide on a percent basis) per electrolysis cell. The formula is: 1 ECU = CL2 + 1.13 NaOH. 1. The basis for technical and economic accounting: Accurate measurement of materials (products) is a fundamental requirement for technical and economic accounting; the degree of accuracy in measurement directly affects the results of such accounting as well as the consistent application of technical and economic analysis methods. Therefore, it is necessary to improve measuring instruments (equipment) and strengthen the measurement management of materials (products); estimation or approximation is not allowed. Enterprises should establish sound metrology departments, assign dedicated staff to be fully responsible for the use, assessment, calibration, and maintenance management of various instruments and metering equipment. The departments using the measuring devices must strictly comply with relevant regulations. The calibration, verification methods, and intervals for measuring equipment of various instruments shall be carried out in accordance with **relevant regulations**. 1.1 The measurement of solid materials (products), liquid materials (products), water, electricity, steam, as well as other gases must be accurate and truthful, with weight and volume conversions carried out in accordance with relevant regulations. 2. Basis for technical and economic accounting: Original records, quality inspection, and material management are prerequisites for conducting proper technical and economic accounting, and they serve as the basis for such accounting. 2.1 Original records: The enterprise shall have a designated department responsible for the management of original records, to ensure that they are timely, complete, accurate, and in good condition. 2.2 Quality inspection: The company’s technical management department and quality inspection unit are respectively responsible for implementing and overseeing the compliance with the quality standards and inspection procedures issued by relevant **departments**, as well as meeting any special quality requirements set by customers. 2.3 Material acceptance and inventory: Relevant departments within the enterprise must implement a system for physical inspection of finished products (semi-finished products, work-in-progress), raw materials, fuel materials, and auxiliary materials. Following the principle that \"those who consume (use) them are responsible for recording their usage,\" samples of these materials should be taken for analysis, and inventory checks should be conducted at the end of each month. In particular, strict compliance with **relevant regulations** is required regarding the acceptance of finished products as well as key raw materials and fuel materials. For inventory surpluses (deficits), the reasons must be identified and actions taken in accordance with relevant regulations. 2.4 To strengthen internal economic accounting within enterprises, each enterprise should, based on these regulations, establish detailed accounting rules for specific processes and work teams. 3. Measurement items, units, specifications, and number of decimal places 3.1 Finished products, semi-finished products, and work in progress are shown in Table 1. Name, Unit, Conversion Specification, Decimal Place, Unit Consumption, Total Quantity: Solid Caustic Soda, Liquid Caustic Soda, Pure Salt, Water, Coarse Salt, Water, Chlorine Gas, Hydrogen Gas, Electrolytic Alkali, Concentrated Alkali, Filtered Brine, Secondary Brine, Freshwater, Water. t, t, t, t, t, Nkm3, t, t, t, t, t. NaOH 100%, NaOH 100%, NaCL 100%, NaCL 100%, NaOH 100%, NaOH 100%, NaCL 100%, NaCL 100%, NaCL 100%. Three digits, three digits, three digits, three digits, three digits, three digits, three digits, three digits, three digits, three digits, three digits, three digits, three digits, three digits, three digits, three digits, three digits. 3.2 The raw materials, fuels, power sources, and auxiliary materials are shown in Table 2. Name, Unit, Conversion Specification, Decimal Point, Unit Consumption, Total Amount, Unit Consumption, Total Amount: Raw Salt, Raw Salt, Converted Raw Salt from Brine, Pure Alkali, Salt, Acid, Alkali for Internal Use, High-Purity Hydrochloric Acid, Calcium Chloride, kg/t, kg/t, kg/t, kg/t, kg/t, kg/t, kg/t, kg/t, kg/t, kwh/t, kwh/t, kwh/t, kwh/t, t/t, t/t, t/t, kg/t, kg/t, Nm3/t, G/t, kg/t, kg/t, sets/t, t, t, t, t, t, t, t, t, kwh, kwh, kwh, kwh, t, t, t, t, Nkm3, kg, t, t, sets, NaCL 100% (in physical form), NaCL 100%, Na2CO3 100% (in physical form), Converted to Percentage, In Physical Form, Converted to Percentage, In Physical Form, In Physical Form, Standard State, In Physical Form, Zero Level, Zero Level, Zero Level, Two Digits, Two Digits, Two Digits, Two Digits, Two Digits, Zero Level, Zero Level, Zero Level, Zero Level, Three Digits, Two Digits, Two Digits, Two Digits, Two Digits, Two Digits, One Digit, Two Digits, Two Digits, Two Digits, Three Digits, Three Digits, Three Digits, Three Digits, Three Digits, Three Digits, Three Digits, Zero Level, Zero Level, Zero Level, Zero Level, Zero Level, Zero Level, Zero Level, Three Digits, Three Digits, Three Digits, Three Digits, Three Digits, Three Digits, Zero Level. Electrolysis Electricity, Actual DC Consumption, DC-Converted Value, AC Electricity, Motor Power, Steam, Water, Others, Water, Fuel, Oil, Fuel, Coal, Fuel, Gas, Ruthenium Powder, Molten Salt, Sulfuric Acid, Packaging Materials. Note: For enterprises that use brine, it is required to calculate separately the actual consumption of brine and the consumption of brine converted to 100% raw salt. 2. Calculate the consumption of raw salt on a per-100 basis by taking into account both the consumption based on the original salt amount and the consumption based on 100% of that original salt amount, and then determine the overall consumption of raw salt on a per-100 basis. Chapter 2 Finished Goods, Semi-finished Goods, Work-in-Process, and By-products 4. Finished goods refer to solid (liquid) caustic soda and chlorine that have completed the entire production process during the reporting period, have passed quality inspection, are properly packaged, and have gone through the warehousing procedures. 4.1 The production of caustic soda is calculated on an equivalent basis of 100% sodium hydroxide; ion-exchange membrane caustic soda can include solid caustic soda and liquid caustic soda. Solid alkali is classified by its physical form into solid, flake, and granular forms; liquid alkali is divided into different grades based on its concentration. The conversion of production volume should be calculated as 100% based on the sodium hydroxide content specified in **standards, corporate standards, or sales agreements with customers; any amount exceeding these standard or specified levels shall not be counted toward the production volume, and can be considered as alkali loss. 4.2 The caustic soda used by this enterprise for the production of other products can have its output quantity calculated after the warehousing procedures are completed. 4.3 The alkali used for regenerating ion exchange resins during the production process by ion membrane electrolysis, the alkali used for purifying brine and neutralizing chlorine in weak brine, as well as the alkali used for membrane immersion and tank filling, should be classified as alkali for internal use and not included in the production volume. 4.4 Chlorine refers to the chlorine that is produced during the electrolysis process, and after dehydration and drying, is delivered in compliance with the technical control specifications. 5. Semi-finished products refer to those that have gone through one or several processing steps in the caustic soda production process, have passed quality checks by the control room, and have undergone handover procedures, but still require further processing. 5.1 Secondary refined brine refers to the brine that has gone through the processing steps and meets the technical control requirements before being fed into the electrolyzer. 5.2 Electrolytic alkali refers to the electrolytic alkaline solution produced in the electrolysis process. 5.3 Concentrated alkali refers to the concentrated alkali solution obtained through evaporation. 6. Work-in-progress refers to products that have not yet completed the production process of caustic soda and are currently in various stages of processing; finished products that have been processed within a certain stage but not yet inspected, or that have been inspected but for which the handover procedures have not yet been carried out; as well as products that have completed the entire production process but have not yet been inspected and stored. 6.1 Brine refers to the solid salt from the material feeding stage in the brine production process up to the salt-precipitation equipment, as well as the brine pumped from underground, the salt sludge in the sludge washing unit and the sludge washing water, as well as the brine that has not had Ca+2 and Mg+2 removed. Brine refers to the solid salt in the brine processing stage from the point of measurement until it reaches the salt dissolving equipment, as well as the salt sludge and washing water in the sludge washer, all of which have not had Ca+2 and Mg+2 removed. Brine water refers to brine obtained in the brine processing step by removing Ca2+ and Mg2+, without adding hydrochloric acid for neutralization. Secondarily filtered brine refers to brine that has had the residual suspended solids removed from it. Secondly refined brine refers to the brine that has undergone secondary filtration through an ion exchange resin column to remove Ca2+, Mg2+, and other polyvalent cations from it. 6.2 Brackish water refers to the brackish water remaining in the electrolysis process and the brine process, including the brackish water inside the electrolytic cell. 6.3 Electrolytic alkali refers to the electrolytic alkali solution remaining in each process step. 6.4 Alkaline solution refers to the accumulated evaporated concentrated alkaline solution, the alkaline solution remaining in the falling film evaporator, the alkaline substance at the bottom of the soda solidification tank, the tank cleaning water, and the alkaline solution inside the soda solidification tank. 6.5 Liquid caustic refers to liquid caustic that has passed inspection but has not yet been packaged and shipped, or concentrated caustic that has been packaged but for which the warehousing procedures have not yet been completed. 6.6 Solid alkali refers to the solid alkali that is awaiting inspection in the solid alkali processing stage, or has passed the inspection but has not yet gone through the warehousing procedures, including unqualified solid alkali. 7. By-product refers to the hydrogen produced simultaneously during the production process in the electrolysis unit. 7.1 Hydrogen: The yield should be calculated using a hydrogen flow meter on the tiller. For enterprises that do not meet the required conditions, the calculation is as follows: Hydrogen production for the current period = Production of electrolytic caustic soda for the current period (converted to 100% NaOH) × 0.28

Chapter 3: Calculation of Quality Indicators
8. Pass rate of initial inspection for liquid caustic soda
Pass rate of initial inspection for liquid caustic soda (%) = × 100%
9. Pass rate for solid (liquid) caustic soda
Pass rate for solid (liquid) caustic soda (%) = × 100%
10. Rate of first-class products among solid (liquid) caustic soda
Rate of first-class products among solid (liquid) caustic soda (%) = × 100%
11. Rate of top-quality products among solid (liquid) caustic soda
Rate of top-quality products among solid (liquid) caustic soda (%) = × 100%
12. Weight compliance rate
Weight compliance rate (%) = × 100%

Chapter 4: Calculation of Technical and Economic Indicators
13. Conversion efficiency
Conversion efficiency (%) = × 100% or: Conversion efficiency (%) = × 100%
13.1 The amount of alternating current used is determined based on the alternating current meter installed by the power supply department. For enterprises that do not have such a meter, the amount of alternating current consumed by the DC system is calculated by subtracting the amount indicated by the alternating current meter installed in the power system from the total amount indicated by the alternating current meter installed by the electricity utility company. 13.2 Direct current charge: Enterprises that have the conditions for measurement shall follow the provisions in 1.1 of these regulations; those without such conditions shall calculate it using the following formula: Direct current charge = Average current intensity × Actual total voltage × Actual operating time of the electrolyzer × 10-3. 13.2.1 Average current intensity: Average current intensity (A) = 13.2.2 Average current density: The current passing through a unit area of the anode. Average current density (A/m2) = 13.2.3 Actual operating time of the electrolyzer (h) = Total operating hours of the electrolyzer (h). 14. Cathode current efficiency: Cathode current efficiency (%) = ×100%. 14.1 Production volume of electrolytic alkali during this period = Alkali delivered during this period + Alkali used internally in the electrolysis process + Remaining alkali in the electrolysis process at the end of the period minus that at the beginning of the period. 14.2 Theoretical production volume of electrolytic alkali during this period = 1.492×10-6 (t/Ah) × Average current intensity during this period (A) × Average number of operating electrolyzers × Actual operating time of the electrolyzers (h). 14.2.1 Average number of operating electrolyzers = Where: Total operating hours of the electrolyzers = Number of operating electrolyzers × Operating time of the electrolyzers. 15. Voltage efficiency: Voltage efficiency (%) = ×100%, or: Voltage efficiency (%) = ×100%. Where: The theoretical decomposition voltage is 2.19 V; the actual value is 2.17 V at 25°C or 2.07 V at 85°C. 16. Standardized direct current consumption: Standardized direct current consumption = Direct current consumption (kwh/t) – (Anode current density – Standard current density)×10-2×ka – (Alkali concentration – ke)×10-2×ke – (Alkali temperature – 90)×kb. 16.1 Anode current density (A/m2) = 16.2 The standardized direct current consumption is based on the anode current density, with the standard current density for ion-exchange membrane electrolyzers being 3000 A/m2. 16.3 ka refers to the increase or decrease of 14 (kwh/t) in the standard direct current consumption of ion membrane electrolyzers for every 100 A/m2 change in current density ； Kc refers to the increase or decrease of 1% in the concentration of the electrolytic alkali, which results in an increase or decrease of 10 (kwh/t) in the equivalent standard direct current consumption of the ion-exchange membrane electrolyzer ； Kb refers to the increase or decrease of 7 (kwh/t) in the equivalent standard direct current consumption of ion-exchange membrane electrolyzers for every 1°C change in the temperature of the electrolyte alkali ； Ke refers to the standard concentration of the ion-exchange membrane alkali. 17. Alkali loss rate
17.1 Liquid alkali loss rate (%) = ×100%
17.2 Concentrated alkali loss rate (%) = ×100%
17.3 Segmental loss rate of liquid alkali (%) = ×100%
17.4 Segmental loss rate of solid alkali (%) = ×100%
17.5 Total loss rate of liquid alkali (%) = ×100%
Where: The coefficient for the amount of electrolytic alkali used in concentrated alkali production = 17.6 Total loss rate of solid alkali (%) = ×100%
18. Physical labor productivity of workers involved in solid (liquid) alkali production (tons/person) = 18.1 The average number of workers required for producing solid (liquid) alkali includes those working from the salt production stage up to the packaging and delivery of solid (liquid) alkali, as well as the workers responsible for analyzing semi-finished products, carrying out maintenance tasks, and repairing tanks in the workshop (branch plant). The number of workers needed for solid (liquid) alkali production is determined based on the separation coefficient of solid (liquid) alkali. 18.2 Separation coefficient of solid (liquid) alkali = Chapter 5: Calculation of unit consumption of products 19. Provisions for calculating unit consumption of products 19.1 The output of a temporary electrolysis unit is assumed to be equal to the production volume of electrolytic alkali; first, calculate the various raw materials, as well as fuels and energy required by the electrolysis unit (for producing electrolytic alkali). Then, in accordance with the accounting requirements, the various raw materials, fuels, and power consumed for electrolytic alkali and chlorine before and after separation are calculated. After separation, the various consumptions of electrolytic alkali and chlorine are separately calculated based on the consumptions of the electrolysis unit (electrolytic alkali); the separation ratio is 53% for electrolytic alkali and 47% for chlorine. 19.2 The unit product consumption refers to the amount of various raw materials, auxiliary materials, fuel, power, water, steam, etc., consumed per unit of output of the products put into storage during the reporting period, across the entire production and maintenance process as well as during startup and shutdown operations. 19.3 All various raw materials, auxiliary materials, fuels, power, water, steam, etc., consumed in the production of caustic soda and chlorine as well as during maintenance and start-up/shutdown operations, shall be included in the calculation of unit consumption for chlorine and caustic soda. Caustic soda for internal use shall not be included in the inventory volume; all raw materials, auxiliary materials, fuels, etc. consumed for such caustic soda are to be covered by the product itself. 19.4 The quantities of raw materials, auxiliary materials, fuel, etc., that constitute the revenue of the workshop are determined based on those delivered by the supply and storage department and accepted by the workshop. Any losses that occur during transportation or storage, either within or outside the factory, prior to delivery to the workshop are treated as losses incurred during transit or in storage by the supply and storage department, and such losses shall not be included in the amount of materials used in production. 19.5 The calculation of unit consumption is based on the first-in-first-out principle, with parallel calculations carried out in four steps: brine preparation, electrolysis, evaporation, and solid alkali production. 20. Calculation of product specific consumption 20.1 Calculation of the production volume of electrolysis units, electrolytic caustic soda after separation, chlorine gas, and concentrated caustic soda, as well as the production volume of solid (liquid) caustic soda 20.1.1 Calculation of the production volume of electrolysis units (electrolytic caustic soda) When calculating for this project, the production volume of electrolysis units is equal to the production volume of electrolytic caustic soda. ①Electrolytic caustic production volume = Actual amount of electrolytic caustic solution produced during the period (including the caustic soda used internally as a result of electrolysis). It consists of three parts: 32% liquid caustic soda that is delivered as a finished product, and the electrolytic caustic soda used in subsequent processes for falling-film (or rising-film) reactions, as well as the caustic soda used internally. ② The ending inventory of electrolytic caustic soda = the ending inventory of electrolytic caustic soda from saltwater processing, electrolysis, and evaporation processes. ③ The amount of electrolytic caustic soda entering storage = the measured quantity converted to 100% electrolytic caustic soda = the production volume of electrolytic caustic soda during the period – the amount of high-purity caustic soda used internally – the amount of liquid caustic soda sold + the change in the inventory of electrolytic caustic soda from the beginning to the end of the period. 20.1.2 Calculation of concentrated caustic soda production volume ① The production volume of concentrated caustic soda = the amount of concentrated caustic soda produced through evaporation during the period. This consists of two parts: high-concentration liquid caustic soda that is delivered as a finished product, and the concentrated caustic soda used in subsequent processes to produce solid caustic soda. ② The ending inventory of concentrated caustic soda = the ending inventory of concentrated caustic soda from evaporation and solid caustic soda production processes. ③ The amount of concentrated caustic soda used in the solid caustic soda production process = the amount of concentrated caustic soda sent to that process + the change in the inventory of concentrated caustic soda from the beginning to the end of the period. 20.1.3 Calculation of solid (liquid) caustic soda production volume The production volume of solid caustic soda = the amount that enters storage during the period. The production volume of liquid caustic soda = the amount that enters storage during the period. 20.1.4 Calculation of chlorine gas production volume The production volume of chlorine gas should be calculated based on the readings from the chlorine gas flow meter. For enterprises that do not meet the requirements, the calculation is as follows: Chlorine production for the current period = Alkali production from electrolysis for the current period (converted to 100% NaOH) × 0.92; for electrolyzers that do not use high-purity hydrochloric acid, the factor used is 0.885. 20.2 Calculation of Raw Salt Consumption 20.2.1 Brine Electrolysis Section ① Initial salt inventory in the brine processing stage = Salt inventory at the end of the previous period in this stage. ② Amount of raw salt used during the current period = Measured quantity of raw salt taken by the workshop × Average NaCl content in raw salt (%) + Measured volume of brine supplied to the workshop (cubic meters) × Average salt content in brine (g/l) × 10-3. ③ Final salt inventory in the brine processing stage = Final inventory of raw salt in crude brine and purified brine + Final inventory of raw salt + Total salt inventory in weak brine at the end of the period. ④ Amount of salt transferred from the brine processing stage to the electrolysis section = ① + ② – ③. ⑤ Initial salt inventory in the electrolysis section = Salt inventory at the end of the previous period in this section. ⑥ Final salt inventory in the electrolysis section = Total salt inventory remaining in the electrolytic cells (a constant) + Total salt inventory remaining in filters and filtered brine tanks + Total salt inventory remaining in resin towers and secondary brine tanks + Total salt inventory remaining in weak brine tanks + Total salt inventory remaining in primary brine tanks. ⑦ Amount of salt transferred to the evaporation section = ④ + ⑤ – ⑥. 20.2.2 Evaporation Section ① Initial salt inventory in the evaporation section = Salt inventory at the end of the previous period in this section. ②Salt amount received in the evaporation section = Salt amount transferred from the electrolysis section. ③The salt balance at the end of the period in the evaporation section = the total salt amount of electrolytic alkali remaining at the end of the period in the evaporation section + the total salt amount of concentrated alkali remaining at the end of the period. ④The amount of finished salt produced in the evaporation section = ① + ② – ③. 20.2.3 When calculating the consumption of raw salt, it is necessary to first determine the consumption per 100 units, and then convert this value into the actual amount of raw salt consumed, based on the average content of raw salt during that period. 20.3 Accounting for alternating current (direct current), water, steam, power, and other raw materials 20.3.1 Electrolysis section ① Opening balance = Closing balance of the previous period ② Amount used during the current period = The quantity actually put into production in the workshop after measurement ③ Closing balance = Closing balance coefficient for electrolytic alkali × ② Closing balance coefficient for electrolytic alkali = Closing amount of electrolytic alkali ÷ Production volume of electrolytic alkali during the current period ④ Amount transferred to the evaporation section = ① + ② – ③ 20.3.2 Evaporation section ① Opening balance = Closing balance of the previous period ② Amount used during the current period = The quantity actually put into production in the workshop after measurement ③ Amount received by the evaporation section = Amount transferred from the electrolysis section, i.e., (20.3.1④) ④ Closing balance = Closing balance coefficient for concentrated alkali × (② + ③) Closing balance coefficient for concentrated alkali = Closing amount of concentrated alkali ÷ Production volume of concentrated alkali during the current period ⑤ Amount transferred to the finished products section = ① + ② + ③ – ④ 20.4 Calculation of the unit consumption of electrolysis units, electrolytic alkali, chlorine gas, and solid (liquid) alkali finished products 20.4.1 Calculation of the unit consumption of electrolysis units (electrolytic alkali) before separation Unit consumption of electrolysis units (electrolytic alkali) = 20.4.2 Calculation of the unit consumption of electrolytic alkali after separation Unit consumption of electrolytic alkali after separation = 20.4.3 Calculation of the unit consumption of chlorine gas finished products Unit consumption of chlorine gas finished products = 20.4.4 Unit consumption of solid (liquid) alkali finished products Unit consumption of solid (liquid) alkali finished products = 20.4.5 Consumption refers to various raw materials, fuel materials, auxiliary materials, as well as water, electricity, steam, etc., used in the production process of electrolysis units (electrolytic alkali). 20.4.6 The consumption of solid (liquid) alkali in the finished products refers to all raw materials, fuel materials, auxiliary materials, as well as water, electricity, steam, etc. – namely, those raw materials, fuel materials, auxiliary materials, water, electricity, steam, etc. transferred from the evaporation section – multiplied by the distribution coefficient of solid (liquid) alkali, plus all raw materials, fuel materials, auxiliary materials, water, electricity, steam, packaging materials, etc. related to the income generated in the solid alkali (liquid alkali) production process during the current period. The consumption of chlorine includes the raw materials and energy for the chlorine treatment section. 20.4.7 Calculation of allocation coefficients ① Steam allocation coefficient (%) = ×100%. Here, the concentration coefficient should be determined based on the amount of water used for evaporating alkali of different specifications: 45% = 1, 48% = 1.07, 50% = 1.11. ② Allocation coefficients for alternating current, direct current, and auxiliary materials (%) = ×100%. Here, the total amount of concentrated alkali in the evaporation section and the finished product section = 100% of the solid alkali produced + the alkali loss during the solid alkali production process + 100% of the liquid alkali produced + the alkali loss during the packaging process. ③ The allocation coefficient for power and electricity should be determined based on actual measurements or according to the production capacity of alkali evaporators of different specifications. Evaporator production capacity (kg/m2h) = Chapter 6 Calculation of total energy consumption and savings 21. Subject matter and scope of application These regulations specify the methods for calculating the energy consumption and savings associated with electrolytic caustic soda production. These regulations are applicable to the assessment of energy consumption for electrolytic caustic soda products, and they serve as the basis for chemical enterprises to calculate and record the energy consumption of such products. 21.1 Content and scope of energy consumption for electrolytic caustic soda products: The electrolytic caustic soda products specified in these regulations refer to finished caustic soda produced by the electrolysis of table salt and that meets ** standards. The production processes for caustic soda by electrolysis include two methods: membrane electrolysis and ion-exchange membrane electrolysis. The production volume of caustic soda produced by electrolysis is calculated based on 100% sodium hydroxide; defective products are not included in the final product volume, while the energy consumed by these defective products is fully counted in the total energy consumption. 22. Definition and classification of the comprehensive energy consumption of caustic soda produced by electrolysis 22.1 The comprehensive energy consumption of caustic soda produced by electrolysis refers to the amount of energy consumed in the production process of such caustic soda, expressed in terms of standard coal, as determined through a comprehensive calculation of all types of energy used by the enterprise during the reporting period. It includes various energy consumption and loss amounts in the production system, auxiliary production systems, and affiliated production systems, including the energy used as raw materials and inputs; it does not include the energy consumed in production, infrastructure construction, or technological upgrade projects, nor the energy exported outside. 22.2 The energy consumption of the caustic soda production system by electrolysis refers to the primary energy, secondary energy, and energy-consuming working fluids actually consumed within the caustic soda production area during the reporting period. 22.3 The energy consumption and losses of the auxiliary production systems and auxiliary production facilities of enterprises located outside the caustic soda production area are allocated using the proportion of consumption method. 22.4 Recycle the waste heat, excess energy, and chemical reaction heat generated within the caustic soda production area, with no energy consumption counted. For devices outside this zone that are recycled, the energy actually recovered from them is deducted from the energy consumption of this zone. However, the hydrogen produced as a by-product of electrolytic caustic soda production within the caustic soda production area is counted as part of the energy consumption. 22.5 The production area for caustic soda specified in this standard refers to the entire electrolytic caustic soda production system, starting from the intake of raw materials and energy such as brine, electricity, and steam in measured quantities at the beginning of the production process, up to the measured storage of the finished caustic soda and the intake of associated chlorine and hydrogen gases into the main pipelines. It consists of three parts: process units, auxiliary facilities, and supporting facilities. It does not include post-treatment systems such as chlorine drying and hydrogen drying. 22.6 A process unit refers to the complete set of processes and equipment involved, ranging from the primary conveying devices that transport raw salt or brine to the salt dissolving tank after metering, to the rectifier transformer where the alternating current used for electrolysis is metered before proceeding further, all the way up to the metering, packaging, and storage of the finished caustic soda. 22.6.1 The process equipment for ion membrane electrolysis includes processes such as rectification, brine preparation, secondary purification of brine, ion membrane electrolysis, dechlorination of fresh brine, evaporation, solid alkali production, and metered packaging and storage of the final caustic soda. 22.7 Auxiliary facilities refer to the energy-consuming fluids and safety and environmental protection devices provided for process units. 22.7.1 Associated facilities refer to those specifically designed for process units, such as offices, control rooms, rest areas, changing rooms, bathhouses, mechanical repair areas, intermediate analysis facilities, cell management units, electrolyzer repair facilities, membrane adsorption units, anode assembly areas, anode repair facilities, as well as facilities for testing and repairing ion exchange membranes. 22.7.2 Chlorine and hydrogen output boundaries. Chlorine and hydrogen generated in the electrolytic caustic soda production enter the main pipes respectively, which serve as the output boundaries. In the ion-exchange membrane process, the chlorine gas generated by the dechlorination of brackish water or the waste chlorine gas that is not sent to auxiliary facilities for absorption and treatment is considered to be within the boundaries of the dechlorination unit. 23. The energy consumption of caustic soda produced by electrolysis methods must be based on accurate measurement. 23.1 The alternating current used for electrolysis is determined by the reading on the AC meter connected to the rectifier transformer ； Steam and other energy sources as well as energy-consuming working fluids are based on the metering readings at the point of entry into the caustic soda production area. 23.2 The calorific values of various energy sources must be converted into the standard unit of coal for uniform measurement. The calorific value of various energy sources is based on the values measured by the enterprise during the reporting period. In the absence of actual measurement conditions, the coefficients for converting various energy sources to standard coal as provided in Appendix A shall be used. The equivalent thermal value of electricity purchased by enterprises is 11.84 megajoules/kilowatt hour (2828 kcal/Kw.H). Self-produced secondary energy and energy-consuming working fluids are calculated based on the equivalent calorific value of the enterprise. 24. Calculation of the comprehensive energy consumption for caustic soda produced by electrolysis method 24.1 The comprehensive energy consumption for caustic soda produced by electrolysis method is divided into three categories: total comprehensive energy consumption, comprehensive energy consumption per unit of product, and comparable comprehensive energy consumption per unit of product. 24.2 Basis for calculating the total comprehensive energy consumption of caustic soda produced by electrolysis 24.2.1 The total comprehensive energy consumption of caustic soda produced by electrolysis refers to the total amount of various energy sources consumed in the production of such caustic soda during the reporting period. 24.2.2 Calculation of the total comprehensive energy consumption for caustic soda produced by electrolysis The total comprehensive energy consumption for caustic soda produced by electrolysis is calculated using the following formula: E = Where: E – the total comprehensive energy consumption for caustic soda produced by electrolysis, in tons of standard coal ； e —— The physical quantity of various energy sources consumed in the production of caustic soda by electrolysis during the reporting period, in tons ； ef — the physical amount of energy used by various auxiliary and supporting production systems, as well as the amount of energy lost, in terms of tons, for the products produced during the reporting period via electrolytic soda production ； k —— a coefficient for converting a certain type of energy into standard coal ； 24.2.3 Calculation of the comprehensive energy consumption for electrolytic caustic soda products The comprehensive energy consumption for electrolytic caustic soda products refers to the total amount of energy used to produce a unit volume of such products. The comprehensive energy consumption per unit of caustic soda produced by electrolysis is calculated using the following formula: Ed = Where: Ed represents the comprehensive energy consumption per unit of caustic soda produced by electrolysis, in tons of standard coal per ton ； E — Total comprehensive energy consumption for caustic soda produced by electrolysis method, in tons of standard coal ； W — Total production volume of caustic soda products produced by electrolysis during the reporting period, in tons. 24.3 Calculation of the comprehensive energy consumption per unit of alkali produced by electrolysis method. The comprehensive energy consumption per unit of alkali produced by electrolysis method is an energy value calculated for the purpose of comparing energy usage within the industry involved in the production of alkali via electrolysis. This calculation involves making adjustments by deducting or adding factors that are not comparable, based on the overall energy consumption associated with alkali produced by electrolysis. 24.3.1 The comprehensive energy consumption per unit of caustic soda produced by electrolysis method can be calculated using the following formula: Ek = Where: Ek – Comprehensive energy consumption per unit of caustic soda produced by electrolysis method, in tons of standard coal per ton ； E — Total comprehensive energy consumption for caustic soda produced by electrolysis method, in tons of standard coal ； Ez – The increase in the comprehensive energy consumption per unit of product within the caustic soda production sector under electrolytic methods, in tons of standard coal ； Ey——Reduction in the comprehensive energy consumption per unit of product within the caustic soda production via electrolysis process, in tons of standard coal ； W —— Quantity of caustic soda products produced by electrolysis during the reporting period that were stored, in tons ； 24.4 Calculation of the overall energy savings for caustic soda produced by electrolysis method: The overall energy savings for caustic soda produced by electrolysis method refer to the reduction in the total amount of energy consumed in producing a given quantity of such caustic soda. 24.4.1 The amount of energy saved in the production of caustic soda by electrolysis is calculated using the following formula: △E = (Ej – Eb) × W. Where: △E represents the amount of energy saved in the production of caustic soda via electrolysis, in tons of standard coal ； Ej—— Comprehensive energy consumption per unit of caustic soda produced by the base-period electrolysis method, in t of standard coal per t ； Eb —— Comprehensive energy consumption per unit of caustic soda produced by electrolysis during the reporting period, in t of standard coal per t ； W —— The quantity of caustic soda products produced by electrolysis during the reporting period that were stored, in tons. Appendix: Types of Energy
Appendix A – Name, Unit, Conversion Factor
Raw coal: kg, 0.7143 kg per standard coal/kg
Coke: kg, 0.9714 kg per standard coal/kg
Crude oil: kg, 1.4286 kg per standard coal/kg
Fuel oil: kg, 1.4286 kg per standard coal/kg
Gasoline: kg, 1.4714 kg per standard coal/kg
Kerosene: kg, 1.4714 kg per standard coal/kg
Diesel: kg, 1.4571 kg per standard coal/kg
Oilfield natural gas: kg, 1.3300 kg per standard coal/kg
Gas field natural gas: kg, 1.2143 kg per standard coal/kg
Liquefied natural gas: kg, 1.7143 kg per standard coal/kg
Steam: kg, 0.1286 kg per standard coal/kg
Well water: kg, 0.0857 kg per standard coal/kg
Deionized water: kg, 0.9714 kg per standard coal/kg
Electricity: kwh, 0.1229 kg per standard coal/kwh
Hydrogen: kg, 0.3686 kg per standard coal/kg
Purified coal: kg, 0.9000 kg per standard coal/kg
(1) Intermediate coal after washing: kg, 0.2857 kg per standard coal/kg
(2) Coal slurry: kg, 0.2857–0.4286 kg per standard coal/kg
Blast furnace gas: kg, 1.5714 kg per standard coal/kg
Coke oven gas: kg, 0.5714–0.6143 kg per standard coal/kg
Other types of gas: kg, [value not specified] per standard coal/kg
(1) Producer gas: kg, 0.1786 kg per standard coal/kg
(2) Gas from heavy oil catalytic cracking: kg, 0.6571 kg per standard coal/kg
(3) Gas from heavy oil thermal cracking: kg, 1.2143 kg per standard coal/kg
(4) Gas produced from coke: kg, 0.5571 kg per standard coal/kg
(5) Gas produced by pressure vaporization: kg, 0.5143 kg per standard coal/kg
(6) Water gas: kg, 0.3571 kg per standard coal/kg
Coal tar: kg, 1.1429 kg per standard coal/kg
Crude benzene: kg, 1.4286 kg per standard coal/kg