WO2016204601A1 - A process and system for concentrating epoxidized natural rubber latex into epoxidized natural rubber latex concentrate - Google Patents

A process and system for concentrating epoxidized natural rubber latex into epoxidized natural rubber latex concentrate Download PDF

Info

Publication number
WO2016204601A1
WO2016204601A1 PCT/MY2016/000017 MY2016000017W WO2016204601A1 WO 2016204601 A1 WO2016204601 A1 WO 2016204601A1 MY 2016000017 W MY2016000017 W MY 2016000017W WO 2016204601 A1 WO2016204601 A1 WO 2016204601A1
Authority
WO
WIPO (PCT)
Prior art keywords
natural rubber
epoxidized natural
rubber latex
membrane
membranes
Prior art date
Application number
PCT/MY2016/000017
Other languages
French (fr)
Inventor
Jaya Kumar VEELLU
Khairul Muis MOHAMED YUSOF
Ahmad Jaril ASIS
Mohamed Kheireddine AROUA
Nik Meriam SULAIMAN
Original Assignee
Sime Darby Plantation Sdn. Bhd.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Sime Darby Plantation Sdn. Bhd. filed Critical Sime Darby Plantation Sdn. Bhd.
Publication of WO2016204601A1 publication Critical patent/WO2016204601A1/en

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08C—TREATMENT OR CHEMICAL MODIFICATION OF RUBBERS
    • C08C1/00—Treatment of rubber latex
    • C08C1/02—Chemical or physical treatment of rubber latex before or during concentration
    • C08C1/075—Concentrating
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D61/00—Processes of separation using semi-permeable membranes, e.g. dialysis, osmosis or ultrafiltration; Apparatus, accessories or auxiliary operations specially adapted therefor
    • B01D61/14—Ultrafiltration; Microfiltration
    • B01D61/145—Ultrafiltration
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2315/00—Details relating to the membrane module operation
    • B01D2315/14—Batch-systems
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2317/00—Membrane module arrangements within a plant or an apparatus
    • B01D2317/02—Elements in series
    • B01D2317/022—Reject series
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D63/00—Apparatus in general for separation processes using semi-permeable membranes
    • B01D63/06—Tubular membrane modules
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D71/00—Semi-permeable membranes for separation processes or apparatus characterised by the material; Manufacturing processes specially adapted therefor
    • B01D71/02—Inorganic material
    • B01D71/024—Oxides

Definitions

  • the present invention relates to a process and system for concentrating epoxidized natural rubber latex into epoxidized natural rubber latex concentrate. More particularly, the present invention relates to a process and system for concentrating epoxidized natural rubber latex into epoxidized natural rubber latex concentrate having a dry rubber content of more than 50% using ceramic ultrafiltration membrane system.
  • Epoxidized natural rubber is a modified natural rubber. It is produced via epoxidation process of natural rubber latex concentrate. Epoxidized natural rubber is conventionally produced and sold in the form of dry block rubber. The steps involved in producing epoxidized natural rubber block rubber using the conventional method are as shown in Figure 1. The process generally involves treating a latex concentrate (containing 60% latex) with reverse osmosis (RO) water, non-ionic surfactant and formic acid. The latex concentrate is then allowed to react with hydrogen peroxide to form epoxidized natural rubber latex. After epoxidation, the epoxidized natural rubber latex is treated with ammonia solution. Antioxidant may also be added.
  • RO reverse osmosis
  • the epoxidized natural rubber latex then undergoes coagulation using steam, and the coagulated rubber latex is granulated before the rubber latex is soaked in sodium carbonate.
  • the epoxidized natural rubber latex then undergoes further processing, such as extrusion, drying and baling to obtain the resultant product.
  • the epoxidized natural rubber latex produced by the conventional method generally contains about 30% dry rubber content (DRC). Dry rubber content of latex is defined as the quantity of rubber present in latex. It is the ratio of the weight of dry substance solidified by the acid to the weight of latex.
  • WO 2014/073947 A1 describes an ultrafiltration system and process for concentrating lattices using membrane filtration with ultrasonic transducers.
  • the epoxidized natural rubber latex concentrate produced by this method has a total solid content of 50%.
  • this system requires each membrane unit of the ultrafiltration system to be fitted with ultrasonic transducers. Such system is costly and thus not practical for large-scale production of epoxidized natural rubber latex concentrate.
  • a process for concentrating epoxidized natural rubber latex into epoxidized natural rubber latex concentrate comprises the steps of introducing an epoxidized natural rubber latex into a feed tank; adding 0.025% to 0.10% ammonium laureate to the epoxidized natural rubber latex in the feed tank to pre-treat the epoxidized natural rubber latex; and passing the pre-treated epoxidized natural rubber latex through a ceramic ultrafiltration membrane module repeatedly under a trans-membrane pressure of 3 to 4 bar (300 to 400 kPa), wherein the ceramic ultrafiltration membrane comprises a plurality of membrane skids, each membrane skid containing a plurality of membranes having pore size between 50 and 100 nm, to obtain an epoxidized natural rubber latex concentrate having a dry rubber content of more than 50%.
  • the plurality of membranes is multi-tubular membranes, each membrane having a channel diameter of 5.0 to 7.0 mm.
  • the method further comprises adding a further 0.025% to 0.10% ammonium laureate to the epoxidized natural rubber latex in the feed tank at every 10 to 30 minutes time intervals.
  • the process further comprises cleaning the membrane with a combination of chemicals to regenerate the membrane for subsequent concentration.
  • an ultrafiltration system for concentrating epoxidized natural rubber latex into epoxidized natural rubber latex concentrate having a dry rubber content of more than 50%.
  • the system comprises a feed tank for receiving epoxidized natural rubber latex as feedstock; a ceramic ultrafiltration membrane module comprising a plurality of membrane skids, each membrane skid containing a plurality of membranes having pore size between 50 and 100 nm; a feed pump for delivering epoxidized natural rubber latex from the feed tank to the membrane module under a trans-membrane pressure of 3 to 4 bar (300 to 400 kPa); a tank for collecting the epoxidized natural rubber latex concentrate having dry rubber content of more than 50%; and a cleaning tank.
  • the plurality of membrane skids are arranged and connected in series to allow effective flow of the feedstock from one skid to another skid.
  • the plurality of membranes is cross-flow multi-tubular ceramic membranes.
  • the cross-flow multi-tubular ceramic membranes in each membrane skid are arranged and connected in parallel.
  • FIG. 1 is a flowchart showing the steps involved in a conventional process for producing epoxidized natural rubber via epoxidation of natural rubber latex concentrate.
  • FIG. 2 is a schematic diagram of an ultrafiltration system for concentrating epoxidized natural rubber latex in a continuous manner in accordance with an exemplary embodiment of the present invention.
  • Figure 3 is a schematic diagram of an ultrafiltration system for concentrating epoxidized natural rubber latex in batches in accordance with another exemplary embodiment of the present invention.
  • FIG. 4 is a chart showing the flux profile of the epoxidized natural rubber latex concentration.
  • the present invention relates to a process and a system for concentrating epoxidized natural rubber (ENR) latex into epoxidized natural rubber latex concentrate. More particularly, the present invention relates to a process for concentrating epoxidized natural rubber latex into epoxidized natural rubber latex concentrate having a dry rubber content of more than 50% using ceramic ultrafiltration membrane system.
  • EMR epoxidized natural rubber
  • a simplified process is used in concentrating epoxidized natural rubber latex into epoxidized natural rubber latex concentrate.
  • the process comprises the steps of pre-treating epoxidized natural rubber latex having a low dry rubber content of 25% to 35% with ammonium laureate.
  • the epoxidized natural rubber latex is first pre-treated with ammonium laureate by adding 0.025% to 0.10% ammonium laureate based on the total amount of epoxidized natural rubber latex to be pre-treated in a feed tank.
  • the pre-treated epoxidized natural rubber latex or feedstock is then delivered to a ceramic ultrafiltration membrane module.
  • a further 0.025 to 0.10% ammonium laureate is added to the epoxidized natural rubber latex in the feed tank at every 10 to 30 minutes time intervals. This latter step is repeated until the concentration process is completed.
  • 0.10% ammonium laureate is added in the first step.
  • 0.025% ammonium laureate is added into the feed tank at every 10 to 30 minutes time intervals.
  • the feedstock passes through the ceramic ultrafiltration membrane module to form a retentate fraction and a permeate fraction.
  • the retentate collected is the final product, which is an epoxidized natural rubber latex concentrate having a dry rubber content of more than 50%.
  • the ultrafiltration membrane module comprises at least two membrane skids.
  • Each membrane skid comprises a plurality of multi-tubular ultrafiltration cartridges and each cartridge comprises a plurality of cross-flow multitubular ceramic membranes.
  • Each multi-tubular ceramic membrane has a pore size in the range between 50 nm and 100 nm.
  • each multi-tubular membrane has a channel diameter of 5.0 mm to 7.0 mm, preferably 6.0 mm.
  • the ultrafiltration membrane module comprises 2 to 3 membrane skids. Each skid comprises four ultrafiltration cartridges.
  • the feedstock from the feed tank first passes through the first membrane skid to form a first retentate fraction and a first permeate fraction.
  • the first retentate fraction is then channelled to a second skid.
  • the first retentate fraction passes through the second skid to form a second retentate fraction and a second permeate fraction.
  • the second retentate may then be channelled to a third skid. This process continues until the retentate from the last skid is collected.
  • the retentate collected from the last skid is the epoxidized natural rubber latex concentrate having a dry rubber content of more than 50%.
  • the epoxidized natural rubber passes through the membrane module at a linear velocity of 4.0 to 5.0 m/s.
  • the epoxidized natural rubber passes through the membrane module under a trans-membrane pressure (TMP) of 3.0 to 4.0 bar (300 to 400 kPa).
  • TMP trans-membrane pressure
  • ceramic membranes are used, as ceramic membranes are an operationally reliable filter medium - particularly under extreme conditions - with an excellent chemical, thermal and mechanical strength that is matched by almost no other materials.
  • the medium to be filtered flows through the channels of the membrane carrier. All particles whose size exceeds the pore radius of the membrane are retained. The particles / molecules build up in the concentrate.
  • the process of the present invention may further comprise cleaning the membrane with a combination of chemicals to regenerate the membrane for subsequent concentration.
  • the membrane is cleaned using a combination of chemicals including, but are not limited to, sodium hydroxide, nitric acid, and hydrogen peroxide.
  • the cleaning process involves rinsing the membranes with water followed by cleaning the membranes with chemicals.
  • the chemical cleaning may include the steps of cleaning the membranes with 1 % to 3% sodium hydroxide, followed by cleaning with 1 % to 3% nitric acid.
  • the membranes are cleaned with sodium hydroxide for 1 to 2 hours at a temperature of 60 °C to 70°C, followed by with nitric acid for 1 hour at 60°C to 70°C.
  • the process of the present invention may be a continuous process or a batch process. In a preferred embodiment, the process is a continuous process.
  • an ultrafiltration system for concentrating epoxidized natural rubber latex into epoxidized natural rubber latex concentrate having a dry rubber content of more than 50% is provided.
  • the system (10) comprises a feed tank (12) for receiving epoxidized natural rubber latex as a feedstock; a ceramic ultrafiltration membrane module (14); a feed pump (16) for delivering feedstock from the feed tank (12) to the membrane module (14) in a continuous manner and under a trans-membrane pressure of 3 to 4 bar (300 to 400 kPa); and a cleaning tank (not shown).
  • the ultrafiltration membrane module (14) comprises a plurality of membrane skids (18). Each membrane skid (18) is equipped with an individual circulation pump (20). Each skid contains a plurality of multi-tubular ultrafiltration cartridges. Each cartridge comprises a plurality of cross-flow tubular ceramic membranes. Any suitable number of multi-tubular ultrafiltration cartridges may be used without departing from the scope of this invention. The higher the number of multi-tubular ultrafiltration cartridges provided in the skid, the greater is the surface contact area of the membranes with the feedstock, the greater is the production rate. In one embodiment, the ultrafiltration membrane module (14) comprises 2 to 3 membrane skids (18). Each membrane skid (18) has a pore size between 50 and 100 nm.
  • each skid comprises four ultrafiltration cartridges.
  • each cartridge comprises 7 to 19 channel cross-flow tubular ceramic membranes.
  • Other number of channel cross-flow tubular ceramic membranes may be employed without departing from the scope of the invention.
  • the channel cross-flow tubular ceramic membranes are cylindrical in shape.
  • the channel cross-flow tubular ceramic membranes in each skid are arranged and connected in parallel. All the membrane skids are arranged and connected in series to allow effective flow of the feedstock from one skid to another skid.
  • Feed pump (16) is provided to deliver feedstock comprising epoxidized natural rubber latex having a dry rubber content of 25% to 35%, preferably 30%, from the feed tank (12) to the ultrafiltration membrane module (14) via conduits.
  • the feedstock first passes through a first membrane skid (18) provided within the membrane module to form a first retentate fraction and first permeate fraction.
  • the first retentate fraction from the first membrane skid (18) is then channelled to a second membrane skid (18') to form a second retentate fraction and a second permeate fraction.
  • the permeate fraction from the last skid (18") is removed and channelled into a permeate tank (24).
  • the retentate collected from the last skid (18") is the final product having a dry rubber content of more than 50%.
  • the cleaning tank (not shown) is provided to store cleaning chemicals. During a cleaning-in-place process, cleaning chemicals from the cleaning tank are channelled to the membrane skid (18). The cleaning chemicals circulate within the membrane skid (18) by means of a circulation pump (20) to clean the membrane. After the cleaning is completed, the cleaning chemicals are then channelled back to the cleaning tank.
  • the system (10) as shown in Figure 2 is configured in such a manner that it allows a continuous process for concentrating epoxidized natural rubber latex into epoxidized natural rubber latex concentrate to take place.
  • a system (30) for carrying out a batch process comprises a feed tank (31) for receiving epoxidized natural rubber latex as a feedstock; a ceramic ultrafiltration membrane module (32); a pump (33) for delivering feedstock from the feed tank (31) to the membrane module (32) under a transmembrane pressure of 3 to 4 bar (300 to 400 kPa) via conduits; and a cleaning tank (not shown).
  • the feedstock passes through the ceramic ultrafiltration membrane module (32) to form a retentate fraction and a permeate fraction.
  • the permeate fraction is collected in a permeate tank (34) and the retentate fraction is channelled back to the feed tank (31).
  • the process in accordance with the present invention has several advantages. The process is simple and it is suitable for large-scale production of epoxidized natural rubber latex concentrate having dry rubber content of more than 50% as the process does not require the use of any additional costly apparatus.
  • the following examples are provided to further illustrate and describe particular embodiments of the present invention, and are in no way to be construed to limit the invention to the specific procedures, conditions or compositions described therein.
  • Epoxidized natural rubber latex with about 30% dry rubber content was pre-treated with 0.1% of ammonium laureate in a feed tank.
  • the pre-treated epoxidized natural rubber latex was then delivered to a ceramic multi-tubular membrane module via a feed pump.
  • the ceramic multi-tubular membrane module used in this example has a pore size of about 50 nm, with a channel internal diameter of about 6.0 mm, with an overall length of 1.0 m.
  • the inlet pressure of the membrane module was set at about 2.6 bar (2.6 x 10 5 Pa).
  • the pre-treated epoxidized natural rubber latex passed through the ceramic multitubular membrane module in a continuous manner until about 40% to 50% by weight of a clear serum was obtained.
  • the clear serum was removed as permeate, leaving behind a retentate having a dry rubber content of more than 50%.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Engineering & Computer Science (AREA)
  • Water Supply & Treatment (AREA)
  • Inorganic Chemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Health & Medical Sciences (AREA)
  • Medicinal Chemistry (AREA)
  • Polymers & Plastics (AREA)
  • Organic Chemistry (AREA)
  • Separation Using Semi-Permeable Membranes (AREA)
  • Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)

Abstract

The present invention relates to a process of concentrating epoxidized natural rubber latex into epoxidized natural rubber latex concentrate. The process comprises the steps of pre-treating the epoxidized natural rubber latex with ammonium laureate; and passing the pre-treated epoxidized natural rubber latex through a ceramic ultrafiltration membrane module repeatedly under a trans-membrane pressure of 3 to 4 bar (300 to 400 kPa), wherein the ceramic ultrafiltration membrane comprises a plurality of membrane skids, each membrane skid containing a plurality of membranes having pore size between 50 nm and 100 nm, to obtain an epoxidized natural rubber latex concentrate having a dry rubber content of more than 50%. A system for concentrating epoxidized natural rubber latex into epoxidized natural rubber latex concentrate having a dry rubber content of more than 50% is also provided.

Description

A PROCESS AND SYSTEM FOR CONCENTRATING EPOXIDIZED NATURAL RUBBER LATEX INTO EPOXIDIZED NATURAL RUBBER LATEX CONCENTRATE
FIELD OF THE INVENTION
The present invention relates to a process and system for concentrating epoxidized natural rubber latex into epoxidized natural rubber latex concentrate. More particularly, the present invention relates to a process and system for concentrating epoxidized natural rubber latex into epoxidized natural rubber latex concentrate having a dry rubber content of more than 50% using ceramic ultrafiltration membrane system.
BACKGROUND OF THE INVENTION Epoxidized natural rubber (ENR) is a modified natural rubber. It is produced via epoxidation process of natural rubber latex concentrate. Epoxidized natural rubber is conventionally produced and sold in the form of dry block rubber. The steps involved in producing epoxidized natural rubber block rubber using the conventional method are as shown in Figure 1. The process generally involves treating a latex concentrate (containing 60% latex) with reverse osmosis (RO) water, non-ionic surfactant and formic acid. The latex concentrate is then allowed to react with hydrogen peroxide to form epoxidized natural rubber latex. After epoxidation, the epoxidized natural rubber latex is treated with ammonia solution. Antioxidant may also be added. The epoxidized natural rubber latex then undergoes coagulation using steam, and the coagulated rubber latex is granulated before the rubber latex is soaked in sodium carbonate. The epoxidized natural rubber latex then undergoes further processing, such as extrusion, drying and baling to obtain the resultant product. The epoxidized natural rubber latex produced by the conventional method generally contains about 30% dry rubber content (DRC). Dry rubber content of latex is defined as the quantity of rubber present in latex. It is the ratio of the weight of dry substance solidified by the acid to the weight of latex.
In recent years, there have been increasing demands for epoxidized natural rubber in latex concentrate form. However, most of the epoxidized natural rubber is produced and sold in dry block rubber form and for experimental purposes, the epoxidized natural rubber latex with about 30% dry rubber content is supplied to new potential customers. Such latex is not economical to transport due to its low dry rubber content. WO 2014/073947 A1 describes an ultrafiltration system and process for concentrating lattices using membrane filtration with ultrasonic transducers. The epoxidized natural rubber latex concentrate produced by this method has a total solid content of 50%. However, this system requires each membrane unit of the ultrafiltration system to be fitted with ultrasonic transducers. Such system is costly and thus not practical for large-scale production of epoxidized natural rubber latex concentrate.
Consequently, there is a need to provide a process for concentrating epoxidized natural rubber latex into an epoxidized natural rubber latex concentrate having a higher dry rubber content (DRC) that seeks to address at least some of the problems described hereinabove, or at least to provide an alternative.
SUMMARY OF THE INVENTION
In accordance with a first aspect of the invention, a process for concentrating epoxidized natural rubber latex into epoxidized natural rubber latex concentrate is provided. The process comprises the steps of introducing an epoxidized natural rubber latex into a feed tank; adding 0.025% to 0.10% ammonium laureate to the epoxidized natural rubber latex in the feed tank to pre-treat the epoxidized natural rubber latex; and passing the pre-treated epoxidized natural rubber latex through a ceramic ultrafiltration membrane module repeatedly under a trans-membrane pressure of 3 to 4 bar (300 to 400 kPa), wherein the ceramic ultrafiltration membrane comprises a plurality of membrane skids, each membrane skid containing a plurality of membranes having pore size between 50 and 100 nm, to obtain an epoxidized natural rubber latex concentrate having a dry rubber content of more than 50%.
In accordance with an embodiment of the invention, the plurality of membranes is multi-tubular membranes, each membrane having a channel diameter of 5.0 to 7.0 mm. In accordance with an embodiment of the invention, the method further comprises adding a further 0.025% to 0.10% ammonium laureate to the epoxidized natural rubber latex in the feed tank at every 10 to 30 minutes time intervals. In accordance with an embodiment of the invention, the process further comprises cleaning the membrane with a combination of chemicals to regenerate the membrane for subsequent concentration.
In accordance with a second aspect of the invention, an ultrafiltration system for concentrating epoxidized natural rubber latex into epoxidized natural rubber latex concentrate having a dry rubber content of more than 50% is provided. The system comprises a feed tank for receiving epoxidized natural rubber latex as feedstock; a ceramic ultrafiltration membrane module comprising a plurality of membrane skids, each membrane skid containing a plurality of membranes having pore size between 50 and 100 nm; a feed pump for delivering epoxidized natural rubber latex from the feed tank to the membrane module under a trans-membrane pressure of 3 to 4 bar (300 to 400 kPa); a tank for collecting the epoxidized natural rubber latex concentrate having dry rubber content of more than 50%; and a cleaning tank. In accordance with an embodiment of the invention, the plurality of membrane skids are arranged and connected in series to allow effective flow of the feedstock from one skid to another skid.
In accordance with an embodiment of the invention, the plurality of membranes is cross-flow multi-tubular ceramic membranes. In accordance with other embodiments of the invention, the cross-flow multi-tubular ceramic membranes in each membrane skid are arranged and connected in parallel.
Brief Description of the Drawings
The above and other features and advantages of the present invention will more clearly understood from the following detailed description taken in conjunction with the accompanying drawings: FIG. 1 is a flowchart showing the steps involved in a conventional process for producing epoxidized natural rubber via epoxidation of natural rubber latex concentrate. FIG. 2 is a schematic diagram of an ultrafiltration system for concentrating epoxidized natural rubber latex in a continuous manner in accordance with an exemplary embodiment of the present invention.
Figure 3 is a schematic diagram of an ultrafiltration system for concentrating epoxidized natural rubber latex in batches in accordance with another exemplary embodiment of the present invention.
FIG. 4 is a chart showing the flux profile of the epoxidized natural rubber latex concentration.
DETAILED DESCRIPTION OF THE INVENTION
The present invention relates to a process and a system for concentrating epoxidized natural rubber (ENR) latex into epoxidized natural rubber latex concentrate. More particularly, the present invention relates to a process for concentrating epoxidized natural rubber latex into epoxidized natural rubber latex concentrate having a dry rubber content of more than 50% using ceramic ultrafiltration membrane system.
In the present invention, a simplified process is used in concentrating epoxidized natural rubber latex into epoxidized natural rubber latex concentrate. The process comprises the steps of pre-treating epoxidized natural rubber latex having a low dry rubber content of 25% to 35% with ammonium laureate. The epoxidized natural rubber latex is first pre-treated with ammonium laureate by adding 0.025% to 0.10% ammonium laureate based on the total amount of epoxidized natural rubber latex to be pre-treated in a feed tank. The pre-treated epoxidized natural rubber latex or feedstock is then delivered to a ceramic ultrafiltration membrane module. At the same time, a further 0.025 to 0.10% ammonium laureate is added to the epoxidized natural rubber latex in the feed tank at every 10 to 30 minutes time intervals. This latter step is repeated until the concentration process is completed. In one embodiment, 0.10% ammonium laureate is added in the first step. In another embodiment, 0.025% ammonium laureate is added into the feed tank at every 10 to 30 minutes time intervals.
The feedstock passes through the ceramic ultrafiltration membrane module to form a retentate fraction and a permeate fraction. The retentate collected is the final product, which is an epoxidized natural rubber latex concentrate having a dry rubber content of more than 50%.
In one embodiment, the ultrafiltration membrane module comprises at least two membrane skids. Each membrane skid comprises a plurality of multi-tubular ultrafiltration cartridges and each cartridge comprises a plurality of cross-flow multitubular ceramic membranes. Each multi-tubular ceramic membrane has a pore size in the range between 50 nm and 100 nm. In one embodiment, each multi-tubular membrane has a channel diameter of 5.0 mm to 7.0 mm, preferably 6.0 mm.
In a preferred embodiment, the ultrafiltration membrane module comprises 2 to 3 membrane skids. Each skid comprises four ultrafiltration cartridges.
In an exemplary embodiment of the invention, the feedstock from the feed tank first passes through the first membrane skid to form a first retentate fraction and a first permeate fraction. The first retentate fraction is then channelled to a second skid. The first retentate fraction passes through the second skid to form a second retentate fraction and a second permeate fraction. The second retentate may then be channelled to a third skid. This process continues until the retentate from the last skid is collected. The retentate collected from the last skid is the epoxidized natural rubber latex concentrate having a dry rubber content of more than 50%.
In an embodiment of the invention, the epoxidized natural rubber passes through the membrane module at a linear velocity of 4.0 to 5.0 m/s. Preferably, the epoxidized natural rubber passes through the membrane module under a trans-membrane pressure (TMP) of 3.0 to 4.0 bar (300 to 400 kPa).
In the present invention, ceramic membranes are used, as ceramic membranes are an operationally reliable filter medium - particularly under extreme conditions - with an excellent chemical, thermal and mechanical strength that is matched by almost no other materials. During filtration by means of ceramic membranes, the medium to be filtered flows through the channels of the membrane carrier. All particles whose size exceeds the pore radius of the membrane are retained. The particles / molecules build up in the concentrate.
The process of the present invention may further comprise cleaning the membrane with a combination of chemicals to regenerate the membrane for subsequent concentration. In one embodiment, the membrane is cleaned using a combination of chemicals including, but are not limited to, sodium hydroxide, nitric acid, and hydrogen peroxide.
In an exemplary embodiment of the invention, the cleaning process involves rinsing the membranes with water followed by cleaning the membranes with chemicals. The chemical cleaning may include the steps of cleaning the membranes with 1 % to 3% sodium hydroxide, followed by cleaning with 1 % to 3% nitric acid. In one embodiment, the membranes are cleaned with sodium hydroxide for 1 to 2 hours at a temperature of 60 °C to 70°C, followed by with nitric acid for 1 hour at 60°C to 70°C.
The process of the present invention may be a continuous process or a batch process. In a preferred embodiment, the process is a continuous process.
In another aspect of the invention, an ultrafiltration system for concentrating epoxidized natural rubber latex into epoxidized natural rubber latex concentrate having a dry rubber content of more than 50% is provided.
An exemplary embodiment of the system of the present invention is shown in Figure 2. The system (10) comprises a feed tank (12) for receiving epoxidized natural rubber latex as a feedstock; a ceramic ultrafiltration membrane module (14); a feed pump (16) for delivering feedstock from the feed tank (12) to the membrane module (14) in a continuous manner and under a trans-membrane pressure of 3 to 4 bar (300 to 400 kPa); and a cleaning tank (not shown).
In one embodiment, the ultrafiltration membrane module (14) comprises a plurality of membrane skids (18). Each membrane skid (18) is equipped with an individual circulation pump (20). Each skid contains a plurality of multi-tubular ultrafiltration cartridges. Each cartridge comprises a plurality of cross-flow tubular ceramic membranes. Any suitable number of multi-tubular ultrafiltration cartridges may be used without departing from the scope of this invention. The higher the number of multi-tubular ultrafiltration cartridges provided in the skid, the greater is the surface contact area of the membranes with the feedstock, the greater is the production rate. In one embodiment, the ultrafiltration membrane module (14) comprises 2 to 3 membrane skids (18). Each membrane skid (18) has a pore size between 50 and 100 nm. In a preferred embodiment, each skid comprises four ultrafiltration cartridges. In one embodiment, each cartridge comprises 7 to 19 channel cross-flow tubular ceramic membranes. Other number of channel cross-flow tubular ceramic membranes may be employed without departing from the scope of the invention. The channel cross-flow tubular ceramic membranes are cylindrical in shape. In one embodiment of the invention, the channel cross-flow tubular ceramic membranes in each skid are arranged and connected in parallel. All the membrane skids are arranged and connected in series to allow effective flow of the feedstock from one skid to another skid. Feed pump (16) is provided to deliver feedstock comprising epoxidized natural rubber latex having a dry rubber content of 25% to 35%, preferably 30%, from the feed tank (12) to the ultrafiltration membrane module (14) via conduits. As described hereinabove and as shown in Figure 2, the feedstock first passes through a first membrane skid (18) provided within the membrane module to form a first retentate fraction and first permeate fraction. The first retentate fraction from the first membrane skid (18) is then channelled to a second membrane skid (18') to form a second retentate fraction and a second permeate fraction. This continues until the retentate fraction exiting the last skid (18") is collected and channelled into a retentate tank (22). The permeate fraction from the last skid (18") is removed and channelled into a permeate tank (24). The retentate collected from the last skid (18") is the final product having a dry rubber content of more than 50%.
The cleaning tank (not shown) is provided to store cleaning chemicals. During a cleaning-in-place process, cleaning chemicals from the cleaning tank are channelled to the membrane skid (18). The cleaning chemicals circulate within the membrane skid (18) by means of a circulation pump (20) to clean the membrane. After the cleaning is completed, the cleaning chemicals are then channelled back to the cleaning tank. The system (10) as shown in Figure 2 is configured in such a manner that it allows a continuous process for concentrating epoxidized natural rubber latex into epoxidized natural rubber latex concentrate to take place.
Another exemplary embodiment of the system is shown in Figure 3. In this embodiment, a system (30) for carrying out a batch process is provided. The system (30) comprises a feed tank (31) for receiving epoxidized natural rubber latex as a feedstock; a ceramic ultrafiltration membrane module (32); a pump (33) for delivering feedstock from the feed tank (31) to the membrane module (32) under a transmembrane pressure of 3 to 4 bar (300 to 400 kPa) via conduits; and a cleaning tank (not shown). In this embodiment, the feedstock passes through the ceramic ultrafiltration membrane module (32) to form a retentate fraction and a permeate fraction. The permeate fraction is collected in a permeate tank (34) and the retentate fraction is channelled back to the feed tank (31). The process in accordance with the present invention has several advantages. The process is simple and it is suitable for large-scale production of epoxidized natural rubber latex concentrate having dry rubber content of more than 50% as the process does not require the use of any additional costly apparatus. The following examples are provided to further illustrate and describe particular embodiments of the present invention, and are in no way to be construed to limit the invention to the specific procedures, conditions or compositions described therein.
EXAMPLES
Example 1
Epoxidized natural rubber latex with about 30% dry rubber content was pre-treated with 0.1% of ammonium laureate in a feed tank. The pre-treated epoxidized natural rubber latex was then delivered to a ceramic multi-tubular membrane module via a feed pump. The ceramic multi-tubular membrane module used in this example has a pore size of about 50 nm, with a channel internal diameter of about 6.0 mm, with an overall length of 1.0 m. The inlet pressure of the membrane module was set at about 2.6 bar (2.6 x 105 Pa).
The pre-treated epoxidized natural rubber latex passed through the ceramic multitubular membrane module in a continuous manner until about 40% to 50% by weight of a clear serum was obtained. The clear serum was removed as permeate, leaving behind a retentate having a dry rubber content of more than 50%.
In summary, the following conditions were used in this example.
Figure imgf000011_0001
The above data shows that the process of the present invention is able to produce an epoxidized natural rubber latex concentrate having a dry rubber content of more than 50%.
The above is a description of the subject matter the inventor regards as the invention and is believed that others can and will design alternative systems that include this invention based on the above disclosure.

Claims

Claims
1. A process of concentrating epoxidized natural rubber latex into epoxidized natural rubber latex concentrate, the process comprising:
introducing an epoxidized natural rubber latex into a feed tank;
adding 0.025% to 0.10% ammonium laureate to the epoxidized natural rubber latex in the feed tank to pre-treat the epoxidized natural rubber latex; and
passing the pre-treated epoxidized natural rubber latex through a ceramic ultrafiltration membrane module repeatedly under a trans-membrane pressure of 3 to 4 bar (300 to 400 kPa), wherein the ceramic ultrafiltration membrane comprises a plurality of membrane skids, each membrane skid containing a plurality of membranes having pore size between 50 nm and 100 nm, to obtain an epoxidized natural rubber latex concentrate having a dry rubber content of more than 50%.
2. The process according to claim 1 , wherein the plurality of membranes is multitubular membranes, each membrane having a channel diameter of 5.0 mm to 7.0 mm.
3. The process according to claim 2, wherein each membrane having a channel diameter of 6.0 mm.
4. The process according to claim 1 , further comprising:
adding a further 0.025% to 0.10% ammonium laureate to the epoxidized natural rubber latex in the feed tank at every 10 to 30 minutes time intervals.
5. The process according to claim 1 , wherein the process is a continuous process.
6. The process according to claim 1 , further comprising:
cleaning the membrane with a combination of chemicals to regenerate the membrane for subsequent concentration.
7. An ultrafiltration system for concentrating epoxidized natural rubber latex into epoxidized natural rubber latex concentrate having a dry rubber content of more than 50%, the system comprising: a feed tank for receiving epoxidized natural rubber latex as feedstock;
a ceramic ultrafiltration membrane module comprising a plurality of membrane skids, each membrane skid containing a plurality of membranes having pore size between 50 nm and 100 nm;
a feed pump for delivering the epoxidized natural rubber latex from the feed tank to the membrane module under a trans-membrane pressure of 3 to 4 bar (300 to 400 kPa);
a tank for collecting the epoxidized natural rubber latex concentrate having a dry rubber content of more than 50%; and
a cleaning tank.
8. The ultrafiltration system according to claim 7, wherein the plurality of membrane skids are arranged and connected in series to allow effective flow of the feedstock from one skid to another skid.
9. The ultrafiltration system according to claim 7, wherein the plurality of membranes is cross-flow multi-tubular ceramic membranes.
10. The ultrafiltration system according to claim 9, wherein the multi-tubular ceramic membranes each having a channel diameter of 5.0 mm to 7.0 mm.
11. The ultrafiltration system according to claim 9, wherein the multi-tubular ceramic membranes in each membrane skid are arranged and connected in parallel.
PCT/MY2016/000017 2015-06-18 2016-03-29 A process and system for concentrating epoxidized natural rubber latex into epoxidized natural rubber latex concentrate WO2016204601A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
MYPI2015702081 2015-06-18
MYPI2015702081A MY173398A (en) 2015-06-18 2015-06-18 A process and system for concentrating epoxidized natural rubber latex into epoxidized natural rubber latex concentrate

Publications (1)

Publication Number Publication Date
WO2016204601A1 true WO2016204601A1 (en) 2016-12-22

Family

ID=56148628

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/MY2016/000017 WO2016204601A1 (en) 2015-06-18 2016-03-29 A process and system for concentrating epoxidized natural rubber latex into epoxidized natural rubber latex concentrate

Country Status (2)

Country Link
MY (1) MY173398A (en)
WO (1) WO2016204601A1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115477711A (en) * 2022-09-13 2022-12-16 中国热带农业科学院农产品加工研究所 Method and device for improving solid content of epoxidized natural latex by using ceramic membrane

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4308380A1 (en) * 1992-03-18 1993-09-23 Eisenmann Kg Maschbau Micro-filtration assembly - has compressed air membrane pump and robust membranes in filtration module for processing highly abrasive media
WO2013055202A1 (en) * 2011-10-11 2013-04-18 Sime Darby Malaysia Berhad A method of recovering rubber from skim natural rubber latex
WO2014069979A1 (en) * 2012-10-29 2014-05-08 Sime Darby Malaysia Berhad An improved method of recovering rubber from skim natural rubber latex
WO2014073947A1 (en) 2012-11-07 2014-05-15 Lembaga Getah Malaysia An ultrafiltration system for concentration of latices
WO2015053609A1 (en) * 2013-10-08 2015-04-16 Sime Darby Malaysia Berhad A membrane pre-treatment system and process for producing refined oils and fats

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4308380A1 (en) * 1992-03-18 1993-09-23 Eisenmann Kg Maschbau Micro-filtration assembly - has compressed air membrane pump and robust membranes in filtration module for processing highly abrasive media
WO2013055202A1 (en) * 2011-10-11 2013-04-18 Sime Darby Malaysia Berhad A method of recovering rubber from skim natural rubber latex
WO2014069979A1 (en) * 2012-10-29 2014-05-08 Sime Darby Malaysia Berhad An improved method of recovering rubber from skim natural rubber latex
WO2014073947A1 (en) 2012-11-07 2014-05-15 Lembaga Getah Malaysia An ultrafiltration system for concentration of latices
WO2015053609A1 (en) * 2013-10-08 2015-04-16 Sime Darby Malaysia Berhad A membrane pre-treatment system and process for producing refined oils and fats

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115477711A (en) * 2022-09-13 2022-12-16 中国热带农业科学院农产品加工研究所 Method and device for improving solid content of epoxidized natural latex by using ceramic membrane
CN115477711B (en) * 2022-09-13 2024-05-14 中国热带农业科学院农产品加工研究所 Method and device for improving solid content of epoxidized natural latex by utilizing ceramic membrane

Also Published As

Publication number Publication date
MY173398A (en) 2020-01-22

Similar Documents

Publication Publication Date Title
JP5561346B2 (en) Method for producing sugar solution
JPS62502108A (en) Method and apparatus for concentrating fine solids in suspension
JP2018503514A (en) Brine concentration
JPH08295697A (en) Production of aqueous solution of silk fibroin at high concentration
JPH11309351A (en) Washing of hollow fiber membrane module
WO2016204601A1 (en) A process and system for concentrating epoxidized natural rubber latex into epoxidized natural rubber latex concentrate
JP3577992B2 (en) Membrane separation method
JP6303501B2 (en) Method for producing sugar solution
JP2019146514A (en) Continuous culture method and continuous culture apparatus
JP2018143970A (en) Concentration system and concentration method
JP6287210B2 (en) Method for producing sugar solution
JP6210034B2 (en) Water desalination method and apparatus
JP6210008B2 (en) Water treatment equipment
JP2013119042A (en) Water treatment method
JP6653154B2 (en) Cleaning method and filtration device for hollow fiber membrane module
JP2016215089A (en) Operation method of hollow fiber membrane module and filtration apparatus
JP2018058018A (en) Regeneration method for reverse osmosis membrane
CN104098112B (en) A kind of potassium fluoride filtrate embrane method desiliconizing and dephosphorizing method
JP2004130307A (en) Method for filtration of hollow fiber membrane
JP2008221178A (en) Cleaning method of hollow fiber membrane module
JP2005161179A (en) Method of cleaning hollow-fiber membrane module
JP5823761B2 (en) NF membrane and manufacturing method thereof
JP2001029755A (en) Washing method of hollow fiber membrane module
JPH05329339A (en) Filtering apparatus
JP6740843B2 (en) Water treatment method and water treatment device

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 16730915

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 16730915

Country of ref document: EP

Kind code of ref document: A1