Cleaner production technology and cleaner production evaluation for non-wood pulping in China
3. CLEANER PRODUCTION EVALUATION INDICATOR SYSTEM
National Development and Reform Commission, Ministry of Environmental Protection of the People’s Republic of China, Ministry of Industry and Information Technology of the People’s Republic of China joint issued the cleaner production evaluation indicator system for pulp and paper industry on April 15th in 2015，which can be applied to the paper enterprise which produce wood pulp, non-wood pulp, waste paper pulp, news paper, printing and writing paper, tissue, coated paper, wrapping paper and cardboard (NDRC, MEP and MIIT. Announcement No.9, 2015).
3.1 Principles of cleaner production evaluation
The following principles were followed in the selection of the cleaner production evaluation indicators:
- Emphasize both on the process control and the treatment at the end of pipe;
- The technology and management are both important;
- Highlight the total amount control of pollutant;
- Operability；
- Consider both quantitative and qualitative indicators.
3.2 Indicators, benchmark and weight value of bleached chemical non-wood-pulp
Cleaner production evaluation indicator system for pulp and paper industry put forward the requirements to wood pulp, non-wood pulp, waste paper pulp, news paper, printing and writing paper, tissue, coated paper, wrapping paper and cardboard. This paper only introduces the requirements for non-wood pulp.
The cleaner production evaluation indicator system for non-wood pulp includes five indicators, production process and equipment requirements, resources and energy utilization indicators, resource utilization indicators, pollutant indicators, and environmental management requirements (NDRC, MEP and MIIT. Announcement No.9, 2015). Table 6 shows the weight value of the five first level indicators.
47 Table 6. The weight value of the five first level indicators.
The first level indicators Weight value I Production process and equipment requirements 0.3 Resources and energy consumption indicators 0.2
Resource utilization indicators 0.2
Pollutant indicators 0.15
Cleaner production management indicators 0.15
Under every first level indicator, there are many second indicators requirements as follows.
3.2.1 Production process and equipment requirements
Table 7 shows the production process and equipment requirements for non-wood pulp, including the requirements of handling, cooking, washing, screening, bleaching, chemical recovery system and energy recovery system (NDRC, MEP and MIIT. Announcement No.9, 2015).
Table 7. Production process and equipment requirements The second indicators
Weight value
II
Benchmark I Benchmark II Benchmark III
Handle
wheat straw
0.1
Dry and wet preparation, Flushing water recycling
bagasse, reed In addition to pulp of bagasse /wet storage, dry wet reed pulp preparation
Cooking
wheat straw
0.1
Low energy consumption continuous cooking or batch cooking,
Oxygen delignification
Low energy consumption continuous cooking or batch cooking,
bagasse, reed
Washing wheat straw
0.1 Multistage countercurrent washing bagasse, reed
Screening wheat straw
0.15 Fully enclosed
pressure screening Pressure screening Pressure screening bagasse, reed
Bleaching wheat straw
0.2 ECF or TCF ClO2 or H2O2 partly substitute chlorine
ClO2 partly substitute chlorine bagasse, reed
Chemical recovery system 0.25
Has chemical recovery system, has waste condensed water vapor extraction and by-product recovery system
Has chemical recovery system Energy recovery system 0.1 Has cogeneration system Has heat
recovery system 3.2.2 Resources and energy consumption indicators
Resources and energy consumption indicators include water consumption per product and energy consumption per product (NDRC, MEP and MIIT. Announcement No.9, 2015). The two indicators are very important for a pulp factory and are also easy to monitor and calculate.
Water consumption during the production of pulp mainly include：
- Main production process, including the handle plant, pulping plant, and so on;
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- Auxiliary process, including boiler, air compressor station, sewage treatment plant and so on;
- Accessorial process, including office, eatery, bathroom, toilet and so on.
Energy consumption during the production of pulp mainly includes:
- Primary energy, including coal, oil, natural gas and so on;
- Secondary energy, including stream, electricity and so on;
- Energy carrier, including cooling water, compressed air and so on.
All these energy need convert to standard coal equivalent. Table 8 shows the requirement of the resources and energy consumption indicators for non-wood pulp.
Table 8. Resources and energy consumption indicators The second indicators Unit Weight
value II
Bench mark I
Bench mark II
Bench mark III Water
consumption per product
wheat straw
m3/ADT 0.5
80 100 110
bagasse, reed 80 90 100
Energy
consumption per product
wheat straw
kg/ADT 0.5
420 460 550
bagasse, reed 400 440 500
3.2.3 Resource utilization indicators
Table 9 shows the requirements of the resource utilization indicators for non-wood pulp, which include black liquor extraction rate, alkali recovery rate, alkali furnace thermal efficiency, water recycling rate, utilization rate of boiler slag and rate of white mud residue (NDRC, MEP and MIIT.
Announcement No.9, 2015).
Table 9. Resource utilization indicators The second indicators Unit Weight
value II
Bench mark I
Bench mark II
Bench mark III Black liquor
extraction rate
wheat straw
% 0.17
88 85 80
reed 92 90 88
bagasse 90 88 86
Alkali recovery rate
wheat straw
% 0.29
80 75 70
bagasse, reed 85 80 75
Alkali furnace thermal efficiency % 0.23 65 60 55
Water recycling rate % 0.17 85 80 75
Utilization rate of boiler slag % 0.06 100 100 100
Rate of white mud residue % 0.08 1.0 1.2 1.5
3.2.4 Pollutant indicators
Table 10 shows the requirements of the pollutant indicators for non-wood pulp, which include waste water generation per product, COD generation per product and AOX generation per product (NDRC, MEP and MIIT. Announcement No.9, 2015).
49 Table 10. Pollutant indicators
The second indicators Unit Weight
value II
Bench mark I
Bench mark II
Bench mark III Waste water
generation per product
wheat straw
m3/ADT 0.47
60 85 90
reed 60 75 85
bagasse 70 75 85
COD generation per product
wheat straw
kg/ADT 0.33
150 200 230
bagasse, reed
Soda
method 110 165 230
Kraft chemical
method
125 175 230
AOX generation per product kg/ADT 0.2 0.4 0.6 0.9
3.2.5 Cleaner production management indicators
Cleaner production management indicators mainly include requirements on environmental laws, regulations, standards, industry policy, cleaner production audit, environment managements system, and so on (NDRC, MEP and MIIT. Announcement No.9, 2015).
3.3 Evaluation method
3.3.1 Indicators dimensionless
Xij represents the j-th second indicator under the i-th first level indicator; gk represents the benchmark of the second indicator, g1 is level I, g2 is level II, g3 is level III. Ygk (Xij) is the membership function for the second indicator Xij (NDRC, MEP and MIIT. Announcement No.9, 2015).
3.3.2 General evaluation index calculation
wi represents the weight value of the first level indicator, ωij represents weight value of the j-th second level indicator under the i-th first level indicator. m represents the number of the first level indicators, and ni represents number of the second indicators under the i-th first level indicator.
3.4 Evaluation of cleaner production enterprise
Table 11 shows the criteria for different levels of cleaner production enterprise, which include internationally cleaner production advanced enterprise, nationally cleaner production advanced enterprise and nationally general cleaner production level enterprise (NDRC, MEP and MIIT.
Announcement No.9, 2015).
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Table 11. Evaluation of cleaner production enterprise
Cleaner production level Evaluation index
Level I (Internationally cleaner production advanced)
Meet the following conditions：
-YI ≥ 85
All determined indicators can meet Benchmark I requirements
Level II (Nationally cleaner production advanced )
Meet the following conditions：
-YII ≥ 85
All determined indicators can meet Benchmark II requirements
Level III (Nationally general cleaner production level)
Meet the following conditions：
YII = 100
All determined indicators can meet Benchmark II requirements 3.5 Application of cleaner production evaluation indicator system
3.5.1 Apply in cleaner production audit
The cleaner production evaluation indicator system is applied widely. It can be applied in cleaner production audit to evaluate the current situation and set cleaner production target and cleaner production priority. Government can use cleaner production evaluation system to check and accept the result the cleaner production audit.
3.5.2 Apply in environmental impact assessment
During environmental impact assessment, it is important to analyze the construction projects according to the cleaner production indicators, and this will reduce the adverse impact on humans and the environment. According the Chinese regulations, the evaluation according to cleaner production should be part of the environmental impact assessment report.
3.5.3 Apply in the industry admittance system
During the development of a city or an industry park, we always need to decide what kind of industry or what kind of enterprise should be encourage or obsolete. Cleaner production evaluation indicator system provides an important support to admittance system. For example, a new industry park request all paper factory which want to develop in the industry park need to arrive the level II of cleaner production standard .