The
Shaoxing Cereal and Oil Factory - Shaoxing, Zhejiang Province
(Cleaner Production Case Study: Integrated
Technology Improvements in the Hydrogenated Oil Production)
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Company Information
Shaoxing Cereal &- Oil Factory (SCOF) is a medium sized food processing company and is one key enterprise in Shaoxing with 471 employees (among them 12 % are technical staff.) SCOF is located at the west of city and occupies a floor space of 50, 000 square meters. The SCOF can produce a broad variety of products, such as 3,000 tons man- made cream, 5,000 tons edible hydrogenated oil, 5,000 tons beer and 3,000 tons cold foodstuffs. The fixed assets of the factory is 19 million RMB and the production value is 30 million RMB annually.
Background
The environmental protection issue becomes more serious as production activity expands since executing reform and opening policy. The amount of waste water allowed to be discharged into the city sewage system permitted by the city authority is more than 500 cubic meters per day and COD concentration in the waste water is no more than 300 milligram per litre. Actually, the waste water discharged after treatment is around of 600 cubic meters per day and the COD concentration in it is about 600 milligram per litre. It is the volume and quality of waste water over the limitations set by city authority that is a bottleneck to expand production activity. There was a plan to expand the waste water treatment plant (which needs 2 million RMB investment), which has been delayed due to lack of funds.
It is a possible chance to expand production activity by reduction of wastes generation from sources and to improve the integrated environmental and economic benefits. The SCOF hopes to reduce the wastes generation and to lower the materials consumption by executing a cleaner production audit program.
Cleaner production
The company set up one cleaner production audit team headed by the company manager Mr. Ma and 3 sub-working groups which were in charge of wastes auditing, option generation and option feasibility study respectively.
The hydrogenated oil unit of the oil plant was selected as audit focus after systematically review of all unit operation of the factory, and corresponding short and medium term pollution prevention targets were created. To encourage all employees to take part in the cleaner production activity, the 100 copies of a questionnaire about pollution prevention issues was distributed to ask for opinions and suggestions, and 82 copies of them were returned. Twenty-four options were generated after analyzing and summarizing these suggestions, of which 13 options were non and low cost ones. Twelve of the 13 options were implemented and obvious economic benefits had been achieved. During period of September to December of 1993, total economic benefits was 78,000 RMB, COD emission reduction by 14. 86 tons, oil recovery by 7. 93 tons and waste water discharge reduction by 1.92 tons.
Enabling technology
The integrated technology improvements of the hydrogenated oil production (hydrogenating, alkaline refining and decolorizing and deodorizing):
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hydrogenation process will use" Dead -End Type" hydrogenation technique and equipment, the new technique has the following characteristics:
(1) adding an oil dewatering equipment
(2) adding a stirring machine in the hydrogenation reactor to realize high pressure hydrogenation
(3) installing flow meters between equipments to strengthen control of input/output quantity of oil and hydrogen -
Alkaline Refining Section will replace the separating equipment and adding process control instrument
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decolorizing and deodorizing process will adopt the most advanced equipment which can realize decolorizing and deodorizing series connection operation and automatic continuous operation.
Advantages
The environmental benefits after carrying out the integrated technology improvements mentioned above are as follows:
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COD emission reduction: 302 tons per year
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Cooling water reduction: 28. 02 cubic meters per ton of oil
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Water reduction: 30. 42 cubic meters per ton of oil
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Oil loss: from 5.73% down to 2.71%
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Catalyst consumption: from 3.2 kg down to 2.26 kg per ton of oil
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Other raw materials
Economic Benefits:
The annual economic benefits are as follows:
| Raw material savings (incl. raw materials, water, catalyst, hydrogen gas, etc.): |
263.,500 RMB |
| Oil recovery: | 568,900 RMB |
| Waste water reduction: | 415,500 RMB |
| Oil output increasing: | 580,000 RMB |
| Oil quality improving: | 2,000,000 RMB |
| Operation cost added: | -340,000 RMB |
| Sum: | 3,487,900 RMB |
The total investment of the integrated technology improvements is 10.182 million RMB. The payback period is 3.9 years and the internal rate of return is 22.36%.
The above information is from a 1995 printed publication of the China National Cleaner Production Center - Cleaner Production in China (a collection of 10 case studies.)
Mr.
Renfei Fu, engineer
Shaoxing
Cereal &- Oil Factory
25
West Guomishi Street
Shaoxing,
Zhejiang Province 312000
Tel:
+86 575 515 7146
Fax:+86
575 5156961
The factory can be contacted by email at n/a
ŠNDRC 2000-2006