Palm oil mill

Mustapha, S., Ashhuby, B., and Azni, I., Start-up strategy of a thermophilic upflow anaerobic filter for treating palm oil mill effluent, Process Safety and Environmental Protection, 81 (4), 262-266, 2003. 

Ho, C.C. and Chan, C.Y. (1986) The application of lead dioxide-coated titanium anode in the electro flotation of palm oil mill effluent. Water Res. 20,1523-1527. 

Vijayaraghavan, K., and Ahmad, D. 2006. Biohydrogen generation from palm oil mill effluent using anaerobic contact filter. Int. J. Hydrogen Energy, 31, 1284-1291. 

Ho and Chan used a Pb02-coated titanium anode for the electroflotation of palm oil mill effluent [141]. The electroflotation of suspended particles and anodic destruction of soluble substances such as sugars and phenolics occurred simultaneously. At 0.5 A and after 20 hours of operation, 86% of the suspended matter was found to be removed by flotation while 50% of the dissolved substances were destroyed. The lead dioxide anode was not corroded during the course of operation. 

Milling Cost. After the fresh fruit bunches are harvested they are sent to palm oil mills where the oil is extracted and the nuts separated. The amount of crude palm oil (CPO) obtained from the bunch is in the ratio of 18-24% depending on the planting materials. 

A typical layout of a palm oil mill is shown in Figure 7 where the main stations of the process are also indicated. The equipment selected has to be carried out with care in order to obtain the correct balance for throughput, steam consumption, energy demands, and economics of the supply of stand-by equipment. Standardization of equipment is an important point to consider when selecting machinery on the basis of within mill and between mills when applicable. When a set range and/or make of equipment can be chosen (e.g., valves, gearboxes, electric motors and starts, etc.), considerable benefits can accrue by way of a reduction in the amount of spare parts to be carried. 

Sources of Wastewater Production. Large quantities of water are required in the palm oil milling operations. It is estimated that about 1 ton of water (including boiler feedwater) is required to process 1 ton of fresh fruit bunches. Obviously, a great... 

The sterilizer condensate and separator sludge are segregated into separate oil pits for residual oil recovery before they are mixed again for treatment. The hydrocyclone waste contains very little residual oil and is discharged directly into the treatment plant. The final mixed wastewaters are commonly known as palm oil mill effluent. 

TABLE 25. Metal Content in Palm Oil Mill Effluent (26). 

There are several options available to reduce the pollution problem created by palm oil mills. These include complete treatment and disposal of POME or systematic utilization of POME for beneficial purposes. The choice depends very much on the local environment. 

Ungazetted. POME, palm oil mill effluent PORE, palm oil refinery effluent OIE, oleochemical industrial effluent. Standard A or B depends on locations. 

Due to inadequate mixing by biogas, solid buildup at the bottom of the anaerobic pond poses another maintenance problem to the palm oil mills. Excessive solid buildup at the bottom of the ponds will reduce the effective digester capacity and consequently shorten the hydraulic retention time. Thus the treatment efficiency will be adversely affected. 

At the palm oil mills, about 20% CPO and 1.6% of PKO are recovered from the FFB thus leaving about 78.4% biomass, including pahn kernel meal. 

Empty Fruit Bunches and Fibers and Shells. Traditionally, the empty fruit bunches generated at the palm oil mill are mostly incinerated to produce bunch ash. Bunch ash is considered a good source of potassic fertilizer and is also useful as liming materials because of its high alkalinity (pH 12). However, incineration of EFB could cause air pollution, and this practice is not encouraged by the Department of Environment. 

Palm Oil Mill Effluent (POME). Palm oil mill effluent is essentially organic in nature and nontoxic but has a high polluting potential. In its raw state, POME has an extremely high concentration of biochemical and chemical oxygen demand (BOD and COD) and high in plant nutrient contents, particularly in nitrogen and potassium. After treatment processes various types of POME are available, and their chemical composition are shown in Table 28. 

Energy Potential from Oil Palm By-products. Apart from cmde palm oil and pahn kernel, a palm oil mill also produces a large quantity of biomass as byproducts. In general, an EFB contains about 20% palm oil, 6-7% palm kernel,... 

Fiber and Shell. The palm oil mill uses fiber and shell as boiler fuel to produce steam for electricity generation and palm oil and kernel production processes. The fiber and shell alone can supply more than enough electricity to meet the energy demand of a palm oil mill. It is estimated that about 20 kWh (lower for higher-capacity mill) of electrical energy is required to process 1 ton of FFB. 

The main by-products and wastes produced from the processing of palm oil are the empty fruit bunches (EFB), palm oil mill effluent (POME), palm fiber, and pahn kernel shell. EFB and POME have been used extensively as mutch and organic fertilizers in oil palm plantations while palm fiber and shell are used as fuel, making the palm oil mill self-sufficient in energy (Figure 23). Excess shell has been used for road surfacing in estates. 

N. S. Chua and H. L. Giam, paper presented at National Workshop on Recent Development in Palm Oil Milling and Pollution Control Aug. 5-6, 1986. 

N. S. Chua, paper presented at Seminar on Developments in Palm Oil Milling Technology and on Developments in Palm Oil Milling and Technology and Environment Management, May 16-17, 1981. 

A. L. Ahmad, S. Ismail, and S. Bhatia, Water Recycling from palm oil mill efflnent (POME) using membrane technology. Desalination 157, 87-95 (2003). 

Successful large-scale production of PHA is largely determined by the availability and constant supply of cheap fermentative substrates. At the same time, the overall cost involved in the production of this biodegradable polymeric material needs to be controlled and reduced in order to penetrate and compete in the world s commodity market. Palm oil has been identified as suitable carbon feedstock and potential strains capable of utilizing this raw material have been discussed in the above sections. However, waste disposals from palm oil mill and the amount of energy needed for PHA production are other issues that require equivalent attention when PHA is produced in large scale. 

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