evaluation of a zero discharge technology for palm oil ... study.pdffor this the use of zero...
TRANSCRIPT
1st Part
Identification of system boundary to
be evaluated
2nd Part
Monitoring of milling operation
and waste management
practices
3rd Part
Mass balance analysis of the system
subjected to the system boundary
defined in the first part
Evaluation of a Zero Discharge Technology for Palm Oil Mill in Malaysia: A Real Case Study In Sabah
MALAYSIAN PALM OIL BOARD (MPOB)
Ministry of Plantation Industries and Commodities
No.6, Persiaran Institusi, Bandar Baru Bangi, 43000 Kajang, Selangor, Malaysia. Tel: 603-87694672 Fax: 603-89262971
Website: http://www.mpob.gov.my
-------------------------------------- Abstract -------------------------------------- Rapid growth of palm oil production in Malaysia in the last few decades has caused major problems to the environment; namely the large waste effluent discharged into
the rivers and methane emission from palm oil mill effluent to the atmosphere. This study evaluates the performance of zero discharge technology in palm oil mill through
management of solid and liquid waste produced at the end of the milling process. This technology suggests that the total composting of solid waste sprayed with liquid
waste in the presence of thermophilic microbes will be able to evaporate all the liquid, thus resulting in zero effluent discharge. Constant monitoring of a newly developed
mill having a composting plant, involving important variables in the palm oil processing and composting process has been completed. We found that total evaporation of
water from the liquid waste through the composting process was successfully achieved during the 12 months of continuous monitoring, subject to some limitation
caused by palm fruits processing capacity. The nutrient-rich compost was in excellent condition for use as a fertilizer in oil palm plantation. While others are making
efforts in complicated treatment of waste effluent, this technology appears to have put itself in an attractive position for eliminating wastes from palm oil mills. This
holistic design of zero discharge technology is a promising technology for the palm oil mills to address the concern of Malaysian government towards producing greener
and cleaner technology
1. The rapid growth of palm oil industry has also witnessed a significant
increase in the production of effluent and other biomass by products from
palm oil mills, causing an adverse impact on the environment , if not treated
effectively. Malaysian palm oil mills still practicing effluent discharge into
water courses continue to be cause for grave concern to Malaysian
regulatory bodies and NGOs particularly Sabah
2. This has prompted the state government and the local authority to revise
down gradually the limit for biochemical oxygen demand (BOD) from
1,000mg/L in 1980 to 100mg/L in 2010. The proposed limit of 20mg/L to be
implemented in the near future has triggered the industry to vigorously
accelerate its research activities to comply with the impending regulations
3. An ideal solution promising to be capable of addressing the present pollution
problem is the zero effluent discharge system, the dream of all millers
4. A commercial zero discharge mill in Sabah has been evaluated for its
efficiency and performance
1. The mill integrated with the effective management of waste
was able to achieve zero discharge based on this study
2. Production of nutrient rich compost is very much valuable for
the plantation
3. The composting plant capacity has to be tailored to serve the
requirement of the designed mill processing capacity. If the
mill decides to process more crop than what the composting
plant is capable of handling, there will be an accumulation of
surplus effluent.
The authors wish to express their gratitude to Nexus Technology
Consultancy for the assistance provided throughout the study as
well as the mill management for allowing us to conduct the study at
Yuwang Palm Oil Mill.
Results
Acknowledgement
Introduction
Key design of the zero discharge technology for palm oil mills and the limitations of
the technology are summarized as below:
1. The mill was designed with the primary objective of using minimum water for
processing. For this the use of zero dilution decanter (eco-D) helped to reduce
water addition. The isolation of water used in kernel recovery station from the palm
oil processing line effectively reduced mill water usage from typical value of 0.65t to
0.55t per tonne FFB processed
2. The designed evaporation capacity of the composting plant is subjected to the limit
of processing of FFB up to 600 tonnes per day as shown in Fig. 3
3. Waste water from the mill was treated separately instead of lumping them all as
POME. The decanter slurry and sterilizer condensate were mixed with shredded
EFB for composting as shown in Fig.1
4. Highly active thermophillic microbes associated with the composting process were
able to perform massive evaporation of 330 tonnes of water per day (Fig. 2) from
the compost heap with the aid of a mechanical compost agitating machine
5. Since the composting plant capacity is strictly limited to the 600 tonnes per day FFB
processing, any excess FFB processed would result in an accumulation of
effluent for which buffer ponds will be needed for its storage. This happened from
October onwards (Fig. 3) but the mill had the buffer ponds for the storage of the
excess effluent.
6. Buffer ponds were purposely built to retain the excess POME as shown in Table 1,
and may be recycled in composting plant later during the low crop season.
7. Nutrient-rich compost produced at the end of the process was dispatched to the
plantation as a valuable bio-fertilizer
Discussion
Nu’man Abdul Hadi, Zulkifli Ab Rahman, Yahaya Hawari, Keng Beng Keong
Figure 2: Evaporation of POME from compost heap throughout 2011 – weekly average
Methodology
Subject Description Details MT / m3
A Total POME produced by mill
9th Oct – 31st Dec 2012
33,140
B Total POME absorbed & evaporated 28,185
C Excess POME to buffer ponds 4,955
D Rainfall (9th Oct – 31st Dec 2011) 0.4215 m x 3,200 m2 1,349
POME Accumulated (C + D) 6,304
E Buffer pond 1 capacity 30 m x 20 m x 2.2 m 1,320
F Buffer pond 2 capacity 30 m x 20 m x 2.2 m 1,320
G Buffer pond 3 capacity 50 m x 40 m x 2.2 m 4,400
Buffer Ponds Capacity (E + F + G ) 7,040
Figure 3: Daily average of FFB processed throughout 2011 – 30 days moving average
Table 1: Mass balance on the accumulation of water during the excessive
operation of mill throughput
Figure 1: Process diagram of zero discharge technology showing the composting plant
integrated with the palm oil mill processing line
Palm Oil Mill
Sterilizer
Condensate
Composting Plant Leachate
Pits
Buffer
Ponds
Leachate Drain
Decanter
Slurry EFB
Leachate POME
CPO
Palm
Kernel
FFB
Compost (To Plantation)
System Boundary
Conclusion
The evaluation study was conducted in Yuwang Palm Oil Mill in
collaboration with Nexus Technology Consultancy, throughout the whole
year 2011. The overall approach of this study was conducted in three parts: