INTERNATIONAL CLEANER PRODUCTION INFORMATION CLEARINGHOUSE

CASE STUDY #78

1. Headline: Integrated technology improvements in the

production of hydrogenated oil

2. Background: The environmental impacts become more serious

as production expands. The amount of waste water allowed to be

discharged into the city sewage system is less than 500 cubic

meters per day and COD concentration in the waste water is

restricted to no more than 300 milligram per litre. Actually

the amount of waste water discharged after treatment is 600

cubic meters per day and the COD concentration in it is about

600 milligram per litre. The daily quantity of this polluted

wastewater prevents any further production expansion. There

was a plan to expand the waste water treatment plant (which

would be a 2 million RMB Y investment), which has been delayed

due to lack of funds.

It would be possible to expand production activity by reducing

wastes generation at its source and by improving the links

between environmental and economic benefits. The Shaoxing

Cereal & Oil Factory (SCOF) hopes to reduce wastes generation

and to lower material consumption through a cleaner production

audit program.

SCOF is a medium-sized food processing company and is one of

the key enterprises in Shaoxing with 471 employees (12 percent

of whom are technical). SCOF is located on the west side of

the city and occupies 50,000 square meters. It produces a

broad variety of products, such as 3,000 tons of man made

cream, 5,000 tons of edible hydrogenated oil, 5,000 tons of

beer and 3,000 tons of cold foodstuff. Now the fixed assets of

the factory amount to 19 million RMB Y and the production

value is 30 million RMB Y annually.

3. Cleaner Production Principle:

4. Description of Cleaner Production Application: The

company set up one cleaner production audit team headed

by the company manager and 3 subworking groups which were

in charge of waste auditing, option generation and option

feasibility studies, respectively. The hydrogenated oil

unit of the plant was selected as the focus for the audit

after all unit operations had been reviewed and in light

of the short and medium-term cleaner production targets

that had been created. To encourage all employees to take

part in the cleaner production activity, 100 copies of

questionnaires about cleaner production issues were

distributed to collect opinions and suggestions. Eighty-

two copies were returned. Twenty-four options were

generated after analyzing and summarizing these

suggestions, of which 13 options were identified as non

and low cost ones. Twelve of these 13 options were

implemented and obvious economic benefits were achieved.

From September to December of 1993, total economic

benefits amounted to 78,000 RMB Y. COD emissions were

reduced by 14.86 tons leading to a reduction of 1.92 tons

in waste water discharge and an increase of 7.93 tons in

oil recovery.

Enabling technology: The integrated technology improvements of

hydrogenated oil production (hydrogenating, alkaline refining

and decolorizing and deodorizing) will use "DeadEnd Type"

hydrogenation techniques and equipment. The new technique has

the following characteristics:

(1) adding oil dewatering equipment

(2) adding a stirring machine in the hydrogenation reactor to

realize high pressure hydrogenation, and

(3) installing flowmeters between equipment to strengthen

control of input/output quantity of oil and hydrogen.

Alkaline Refining Section will replace the separating

equipment and add process control instruments for the

decolorizing and deodorizing processes.

5. Economics:

Oil loss: from 5.73% down to 2.71%

Catalyst consumption: from 3.2kg down to 2.26kg per ton of oil

other raw materials

Consumption: some kinds of reduction

The annual economic benefits are as follows:

RMB Y

Raw materials savings: 263,500

(raw materials, water, catalyst, hydrogen gas, etc.)

Oil recovery: 568,900

Waste water reduction: 415,500

Oil output increasing: 580,000

Oil quality improving: 2,000,000

Operation cost added: 340,000

Total 3,487,900

The total investment of the integrated technology improvements

is 10.182 million RMB Y. The payback period is 3.9 years and

the internal rate of return is 22.36%.

6. Advantages: Environmental benefits from carrying out

the integrated technology improvements are as follows:

COD emission reduction: 302 tone per year

Cooling water reduction: 28.02 cubic meter per ton of oil

Water reduction: 30.42 cubic meter per ton of oil

7. Constraints: N/A

8. Contacts:Mr. Renfei Fu, engineer

Shaoxing Cereal & Oil Factory

25 West Guomishi Street

Shaoxing Zhejiang Province

Zip Code: 312000

China

Tel: +86 575 515 7146

Fax: +86 575 5156961

9. Keywords:China, Foodstuff production

10. Reviewer's Comments: This case study was taken from the

document: "Cleaner Production in China," published by the

National Environmental Protection Agency of China. It was

edited for the ICPIC diskette in August 1995, but has not

undergone a formal technical review.