WO2025193088A1

WO2025193088A1 - A system and method for processing palm oil wastewater

Info

Publication number: WO2025193088A1
Application number: PCT/MY2024/050025
Authority: WO
Inventors: Yi Sheng WAN
Original assignee: Agricode Green Sdn Bhd
Current assignee: Agricode Green Sdn Bhd
Priority date: 2024-03-14
Filing date: 2024-03-14
Publication date: 2025-09-18
Anticipated expiration: 2026-09-14

Abstract

The present invention relates to the field of wastewater treatment. More particularly, the present invention relates to a system (100) and method for processing palm oil wastewater. Preferably, the system (100) comprising (a) a reservoir (101) for collecting and settling the wastewater into an oil layer, a water layer, and a sludge layer; (b) a density probe (102) arranged along a depth of the reservoir (101) for sensing and collecting density information from the wastewater; and (c) a processing unit (103) in communication with the density probe (102) to determine the position and condition of each of the layers based on the density information, thereby providing a reference for subsequent extraction of each of the layers.

Description

A SYSTEM AND METHOD FOR PROCESSING PALM OIL WASTEWATER

FIELD OF INVENTION

The present invention relates to the field of wastewater treatment. More particularly, the present invention relates to a system and method for processing palm oil wastewater.

BACKGROUND OF THE INVENTION

Palm oil wastewater, such as palm oil mill effluent, is considered as an environmental hazard when being discharged without proper treatment. This is due to the presence of suspended solids, oil, organic matter, and nutrients in the palm oil wastewater. For example, the suspended solids, oil, and nutrients, such as nitrogen and phosphorus, can cause soil contamination and water pollution. On the other hand, the organic matter can undergo anaerobic decomposition to produce greenhouse gases, such as methane gas.

In view of this, there is a need to process and treat palm oil mill effluent to achieve zero waste discharge in oil palm industry. For example, palm oil wastewater can be separated into oil, water, and sludge. The oil can be processed into valuable fuels, such as aviation fuel. On the other hand, the water can be treated to irrigate oil palm plantation, whereas the sludge can be fermented to produce biofertilizer for use in oil palm plantation.

Conventionally, palm oil wastewater is treated through a series of processes prior to discharge. For example, International Patent Application Publication Number WO2016129986A2 disclosed a method for treating an effluent produced from palm oil milling process. Firstly, solid is removed from the effluent by filtration, pressing, centrifugation, or any combination thereof. Then, water is removed from the effluent by evaporation. Subsequently, oil is removed from the effluent by heating the effluent, centrifuging the effluent, feeding the effluent to a buffer tank to form an oil layer, and mechanically separating the oil layer in the buffer tank. The removal of solid, liquid, and oil is performed in a sequential manner.

However, the method as mentioned in WO2016129986A2 requires a complicated system for separating the solid, water, and oil from the effluent. Besides, the removal of solid prior to the removal of water from the effluent may not be efficient as the content of water in the effluent is significantly higher than the content of solid. Consequently, the method requires a system with a larger footprint. Therefore, it is desirable to provide a solution for processing palm oil wastewater that overcomes the aforementioned problems.

SUMMARY OF INVENTION

One aspect of the present invention is to provide a system to solve the problem of palm oil wastewater generated from oil palm industry, whereby the system is able to identify gravitationally settled layers formed from the palm oil wastewater, thereby allowing individual extraction of the identified layers.

Another aspect of the present invention is to provide a system for processing palm oil wastewater that requires a simpler setup or lesser infrastructure. For example, the system can be modified from existing palm oil mill effluent pond.

Still, another aspect of the present invention is to provide a system with a density probe being adjusted accordingly based on level of the wastewater, thereby allowing the sensing and determination of the density information from the wastewater.

Advantageously, the system of the present invention provides an effective processing of wastewater by settling the wastewater into different layers, obtaining density information of the wastewater, and processing the density information to determine the position and condition of each of the layers, which serves as a reference for subsequent extraction of each of the layers.

Further aspect of the present invention is to provide a method of operating the system, whereby each layer can be extracted individually for use in downstream processes. For example, the water can be extracted to be further processed by a biogas processing plant, the oil can be extracted to be further processed by to a fuel processing plant, and the sludge can be extracted to be further processed by a fertilizer processing plant.

At least one of the preceding aspects is met, in whole or in part, in which the embodiment of the present invention describes a system (100) for processing wastewater comprising (a) a reservoir (101) for collecting and settling the wastewater into an oil layer, a water layer, and a sludge layer; (b) a density probe (102) arranged along a depth of the reservoir (101) for sensing and collecting density information from the wastewater; and (c) a processing unit (103) in communication with the density probe (102) to determine the position and condition of each of the layers based on the density information, thereby providing a reference for subsequent extraction of each of the layers.

Preferably, the density probe (102) comprises a plurality of sensors, each positioned at a predetermined height interval corresponding to the depth of the reservoir (101), whereby the sensors are interconnected for facilitating real-time transmission of the density information to the processing unit (103), thereby enabling continuous monitoring and determination of the position and condition of each of the layers within the reservoir (101).

Preferably, the wastewater is derived from palm oil mill.

Preferably, the reservoir (101) is a settling pond configured with cement mortal walls to prevent leakage of the wastewater to surrounding soil.

The present invention further describes a method for processing wastewater comprising the steps of (a) collecting the wastewater in a reservoir (101); (b) gravitationally settling the wastewater to obtain an oil layer, a water layer, and a sludge layer; (c) obtaining density information from the wastewater; and (d) processing the obtained density information to determine the position and condition of each of the layers, thereby providing a reference for subsequent extraction of each of the layers.

In a preferred embodiment of the present invention, the subsequent extraction is conducted at a predetermined depth within the reservoir (101) based on the position and condition of each of the layers.

Preferably, the condition includes thickness or volume of each of the layers.

In the preferred embodiment of the present invention, the subsequent extraction comprises the steps of extracting water from the water layer; refilling the reservoir (101) with the wastewater after the step of extracting the water; gravitationally settling the refilled wastewater to obtain another oil layer, water layer, and sludge layer; and further extracting the water from the other water layer.

Still, in the preferred embodiment of the present invention, the subsequent extraction further comprises a step of extracting oil from the oil layer when it reaches a predetermined condition.

Further, in the preferred embodiment of the present invention, the subsequent extraction further comprises a step of extracting sludge from the sludge layer when it reaches another predetermined condition. BRIEF DESCRIPTION OF THE DRAWING

For the purpose of facilitating an understanding of the present invention, there is illustrated in the accompanying drawing the preferred embodiments from an inspection of which when considered in connection with the following description, the present invention, its construction and operation and many of its advantages would be readily understood and appreciated.

Figure 1 shows a system (100) for processing wastewater according to a preferred embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, the present invention shall be described according to the preferred embodiments of the present invention and by referring to the accompanying description and drawings. However, it is to be understood that limiting the description to the preferred embodiments of the present invention is merely to facilitate discussion of the present invention and it is envisioned that those skilled in the art may devise various modifications without departing from the scope of the appended claim.

The present invention relates to a system (100) for processing wastewater. The wastewater may contain oil, water, and solids. Preferably, the wastewater is derived from palm oil mill. For example, the wastewater is palm oil mill effluent. This is a crucial step of converting the palm oil mill effluent into usable raw materials for downstream processes. For example, the water can be extracted to be further processed by a biogas processing plant, the oil can be extracted to be further processed by to a fuel processing plant, and the sludge can be extracted to be further processed by a fertilizer processing plant. Figure 1 shows a preferred embodiment of the system (100). Accordingly, the system (100) comprises a reservoir (101) for collecting and settling the wastewater into an oil layer, a water layer, and a sludge layer. Preferably, the reservoir (101) is a settling pond or settling tank configured to contain the wastewater. For example, the settling pond is provided with cement mortal walls to prevent leakage of the wastewater to surrounding soil. More than one of the reservoir (101) can be provided to process a larger amount of wastewater.

According to the preferred embodiment of the present invention, the system (100) comprises a density probe (102) for sensing and collecting density information from the wastewater. Preferably, the density probe (102) is arranged along a depth of the reservoir (101). More preferably, the density probe (102) comprises a plurality of sensors, each positioned at a predetermined height interval corresponding to the depth of the reservoir (101). The sensors are responsible for sensing and collecting the density information from the wastewater at the positioned depth within the reservoir (101). For example, the sensors are density sensors, more preferably, liquid density sensors. Each of the sensors may be interconnected for facilitating real-time transmission of the density information.

When more than one of the reservoir (101) is provided, each reservoir (101) can be provided with the density probe (102) for sensing and collecting the density information in the respective reservoir (101). Alternatively, only one of the reservoir (101) can be provided with the density probe (101), in which the density information obtained from the reservoir (101) is considered to be same for the remaining reservoirs (101).

Further, according to the preferred embodiment of the present invention, the system (100) comprises a processing unit (103) in communication with the density probe (102). The processing unit (103) may be installed in a local server connected to the density probe (102) via data transmission cable. Alternatively, the processing unit (103) may be installed in a cloud server that is in communication with the density probe (102) via wireless transmission, such as Wi-Fi or Bluetooth.

Preferably, the processing unit (103) is configured to determine the position and condition of each of the layers based on the density information provided by the density probe (102). For example, the processing unit (103) collects the density information provided by the density probe (120). Then, the processing unit (103) processes the collected density information by sorting the collected density information with respect to the depth of the density probe (102) to determine a first cut-off depth, which is between the oil layer and the water layer, and a second cut-off dept, which is between the water layer and the sludge layer. It is known that the oil layer and sludge layer correspond to the layer with lowest density and highest density, respectively, whereas the water layer correspond to the layer with density in between the oil layer and sludge layer. Therefore, the first cut-off depth is the depth where the density changes from the highest density to a medium density. On the other hand, the second cut-off depth is the depth where the density changes from the medium density to the lowest density. Then, the processing unit (103) determines the position and condition of each of the layers based on the cut-off depths. Particularly, the oil layer is located above the first cut-off depth, the water layer is located between the first cut-off depth and the second cut-off depth, and the sludge layer is located below the second cut-off depth. Alternatively, the processing unit (103) processes the collected density information by referring to a density database that contains reference density of oil, water, and sludge to determine the position and condition of each layer in the reservoir (101). The position and condition of each of the layers serve as a reference for subsequent extraction of each of the layers.

Preferably, the processing unit (103) is further configured to continuously monitor and determine the position and condition of each of the layers within the reservoir (101) based on the real-time transmission data received from the density probe (102). This allows an operator to determine whether the processed wastewater in the reservoir (101) achieves equilibrium. For example, when the processed wastewater achieves equilibrium, the position and condition of each of the layers remain unchanged, thereby indicating that they are ready to be extracted.

Advantageously, the system (101) of the present invention provides an effective processing of wastewater by settling the wastewater into different layers, obtaining density information of the wastewater, and processing the density information to determine the position and condition of each of the layers, which serves as a reference for subsequent extraction of each of the layers.

The present invention further provides a method for processing the wastewater using the aforementioned system (100). Firstly, the method of the present invention provides a step of collecting the wastewater in the reservoir (101). The wastewater may be collected directly from palm oil mill. Subsequently, the method of the present invention provides a step of gravitationally settling the wastewater to obtain the oil layer, water layer, and sludge layer. Preferably, the gravitational settling is performed in the reservoir (101), such as the settling pond or settling tank. Additionally, the method of the present invention provides a step of obtaining the density information from the wastewater. Preferably, the density information is obtained by the density probe (102) arranged along a depth of the reservoir (101). Then, the method of the present invention provides a step of processing the obtained density information to determine the position and condition of each of the layers. Preferably, the density information is processed by the processing unit (103), thereby providing a reference for subsequent extraction of each of the layers.

Thereafter, the subsequent extraction is preferably conducted at a predetermined depth within the reservoir (101) based on the position and condition of each of the layers. In one embodiment, the subsequent extraction is conducted by extracting the water from the water layer. This can be performed by inserting a pipe connected to a pump into the water layer to extract water therefrom.

The system (100) can be used to carry out multiple extractions from each layer, thereby optimizing recovery thereof. In a further water extraction step, the reservoir (101) is refilled with the wastewater and subsequently gravitationally settled to obtain another oil layer, water layer, and sludge layer. Next, the water from the other water layer is extracted. The step of refilling the reservoir (101) with the wastewater, gravitationally settling the refilled wastewater, and extraction of the water from the other water layer can be repeated to achieve the aforementioned multiple extractions to enable fast processing of the wastewater. Particularly, only the water is extracted while the oil and sludge are remained in the reservoir (101) for the time being. Advantageously, this allows the system (100) to process a large amount of the wastewater within a relatively short period of time while recovering a large amount of the water therefrom. The extracted water can be further collected and subjected to a downstream process, such as to be used in biogas conversion.

In accordance to preceding description, a subsequent oil extraction step includes the step of extracting oil from the oil layer when it reaches a predetermined condition. For example, when the oil layer reaches a thickness of 10% of the depth of the reservoir (101), the oil is extracted from the oil layer after the extraction of water. This can be performed by inserting another pipe connecting to another pump into the oil layer to pump out the oil therefrom. The extracted oil can be further collected and subjected to another downstream process, such as to be processed into fuel.

In accordance to preceding description, a subsequent sludge extraction step includes the step of extracting the sludge when it reaches another predetermined condition. For example, when the sludge layer reaches a thickness of 10% of the depth of the reservoir (101), the sludge is extracted from the sludge layer after the extraction of oil or water. This can be performed by inserting another pipe connecting to another pump into the sludge layer to pump out the sludge therefrom. Alternatively, the extraction of the sludge can be performed after the extraction of the oil by means of excavation. The extracted sludge can be further collected and subjected to another downstream process, such as to be processed into a biofertilizer.

One skilled in the art will readily appreciate that the present invention is well adapted to carry out the objects and obtain the ends and advantages mentioned, as well as those inherent therein. The embodiment described herein is not intended as limitations on the scope of the present invention.

Claims

1. A system (100) for processing wastewater comprising:

(a) a reservoir (101) for collecting and settling the wastewater into an oil layer, a water layer, and a sludge layer;

(b) a density probe (102) arranged along a depth of the reservoir (101) for sensing and collecting density information from the wastewater; and

(c) a processing unit (103) in communication with the density probe (102) to determine the position and condition of each of the layers based on the density information, thereby providing a reference for subsequent extraction of each of the layers.

2. The system (100) according to claim 1, wherein the density probe (102) comprises a plurality of sensors, each positioned at a predetermined height interval corresponding to the depth of the reservoir (101), whereby the sensors are interconnected for facilitating real-time transmission of the density information to the processing unit (103), thereby enabling continuous monitoring and determination of the position and condition of each of the layers within the reservoir (101).

3. The system (100) according to claim 1, wherein the wastewater is derived from palm oil mill.

4. The system (100) according to claim 1, wherein the reservoir (101) is a settling pond configured with cement mortal walls to prevent leakage of the wastewater to surrounding soil.

5. A method for processing wastewater comprising the steps of:

(a) collecting the wastewater in a reservoir (101);

(b) gravitationally settling the wastewater to obtain an oil layer, a water layer, and a sludge layer; (c) obtaining density information from the wastewater; and

(d) processing the obtained density information to determine the position and condition of each of the layers, thereby providing a reference for subsequent extraction of each of the layers.

6. The method according to claim 5, wherein the subsequent extraction is conducted at a predetermined depth within the reservoir (101) based on the position and condition of each of the layers.

7. The method according to claim 5, wherein the condition includes thickness or volume of each of the layers.

8. The method according to any one of claims 5 to 7, wherein the subsequent extraction comprises the steps of: extracting water from the water layer; refilling the reservoir (101) with the wastewater after the step of extracting the water; gravitationally settling the refilled wastewater to obtain another oil layer, water layer, and sludge layer; and further extracting the water from the other water layer.

9. The method according to claim 8, wherein the subsequent extraction further comprises a step of extracting oil from the oil layer when it reaches a predetermined condition.

10. The method according to claim 8 or 9, wherein the subsequent extraction further comprises a step of extracting sludge from the sludge layer when it reaches another predetermined condition.

11. The method according to claim 5, wherein the wastewater is derived from palm oil mill.