Sumwin Patented And Cost Effective Technology To Mitigate 3-Monochloropropanediol Ester And Glycidyl Ester

<p style="text-align: justify;">Sumwin&rsquo;s patented technology for 3-monochloropropanediol ester (3-MCPDE) and glycidyl ester (GE) mitigation for the vegetable oil consists of 3 steps viz Liquid-Liquid Extraction, REDGEM&reg; bleaching, and GE stripping. All these steps help achieve 3-MCPDE of less than 1.25 ppm and GE less than 0.5 ppm, which is 100% better than the current European Food Safety Authority (EFSA) Guidelines. All this is achieved at the &nbsp;lowest operational expenditure cost (OPEX) of less than USD 2 per metric tonne (MT) in an environmentally sustainable way and guaranteed oil loss in wash water in liquid-liquid extraction of less than 0.1%. For palm oil mills, only one step of the above technology, i.e., liquid-liquid extraction, is required to reduce the chlorides to less than 2 ppm with a guaranteed oil loss in wastewater of less than 0.1%.</p><p style="text-align: justify;"><strong>Keywords</strong> 3-monochloropropanendiol ester, glycidyl ester, chloride, adsorbent, liquid-liquid extraction, deodorizer, mitigation.</p><p style="text-align: center;"><strong>INTRODUCTION</strong></p><p style="text-align: justify;">As per the latest European Food Safety Authority (EFSA) Guidelines, 3-monochloropropanediol ester (3 MCPDE) and glycidyl ester (GE) levels in refined palm oil should meet limits of 2.5 ppm and 1 ppm max, respectively. 3-MCPDE levels will be lowered to 1.25 ppm for refined palm oil in line with other refined vegetable oils in the coming years.</p><p style="text-align: justify;">Various research organizations and companies have made several solutions to address this technological challenge. Crude palm oil (CPO) washing followed by centrifugal separation has been a popular method adopted for removing chlorine in CPO. While this method is effective, it results in higher oil loss in wash water due to emulsification, effluent treatment issues due to high chemical oxygen demand (COD) in the wash water, and high maintenance costs. Sumwin&rsquo;s Patented Extraction Technology overcomes all these problems by offering low capital expenditure (CAPEX) and low operational expenditure (OPEX) by avoiding emulsification and thereby virtually eliminating oil loss in the wash water.</p><p style="text-align: justify;">In addition, Sumwin has developed a proprietary adsorbent under the trademark REDGEM&reg; that reduces precursors to 3-MCPDE and GE in the bleaching process with no modification required in refineries and no additional OPEX. Further engineering modifications to the deodorizer system are tailor-made depending on individual refinery designs. It further reduces both 3-MCPDE and GE formation during deodorization and meets both 3-MCPDE of less than 1.25 ppm and GE of less than1 ppm.</p><p style="text-align: justify;">Sumwin&rsquo;s Patented Technology has been proven at the laboratory, pilot, and large-scale commercial plants. The result is an innovative low CAPEX solution without any significant increase in OPEX of the modified refining system and, most importantly, without compromising the plant throughput.</p><p style="text-align: center;"><br /><strong>MATERIALS AND METHODS</strong></p><p style="text-align: justify;"><strong>Materials</strong></p><p style="text-align: justify;">CPO &ndash; from palm oil mills based on Palm Oil Refiners Association of Malaysia (PORAM) Specifications REDGEM&reg; - Sumwin&rsquo;s propriety adsorbent formulation<br />Water &ndash; raw water</p><p style="text-align: justify;"><strong>Methods</strong></p><p style="text-align: justify;"><strong>Technology for Chloride Removal</strong><br />Liquid-liquid (L/L) extraction is a widely used process in the petrochemical industry for extracting a solute from a feed using a solvent to produce extract and raffinate. The choice of solvent is critical in effecting a liquid-liquid extraction. Solvent selection is influenced by many factors such as its ability to extract the preferred component, its distribution pattern, density, viscosity, volatility, toxicity, interfacial tension, corrosivity, food or non-food grade, cost, etc.</p><p style="text-align: justify;">In the study, laboratory experiments were conducted to test the chlorides extractive power of a few solvents, and water was found to be the most suitable and economical solvent. The target was to reduce chloride in palm oil from 10 ppm to less than 2 ppm. Laboratory experiments were conducted to decide on the number of stages required for a specific laboratory scale flow rate and extrapolated it for an industrial scale refinery of 1500 MT per day. Results obtained from laboratory scale were excellent, but when extrapolated a simple liquid-liquid extractor at industrial scale size, it was not very practical considering the enormous height required. A consultation was conducted with a few experts. Based on the discussions, it was decided to include some customized packing inside the column, thereby making the industrial scale feasible. The extractor was optimized by adding oil and water distributors to adjust the size of the oil bubbles. This should provide the maximum surface area for extraction, and at the same time, solvent (water) carries over with the palm oil should be minimal and minimal oil loss in the wastewater. Since it was a once-through system, the wastewater coming out is directly discharged to the effluent water treatment plant.</p><p style="text-align: justify;">Considering all these factors, the equipment was designed and installed in a 1500 MT per day palm oil refinery. Heat exchangers were used to regulate palm oil and water temperature to get the best extraction efficiency. The final scheme consists of a proprietary design of chlorine extractor, feed oil pumps, water feed pumps, wastewater removal pumps, CPO transfer pumps, intermediate tanks, and heat exchangers. Automation is an essential part of the industrial scale unit hence the inclusion of flow meters, temperature transmitters, pressure transmitters, level transmitters, programmable logic controller (PLC) panel, supervisory control, and data acquisition (SCADA) system to monitor all the essential parameters and control them by using state of the art PLC and SCADA systems remotely controlled. Figure 1 shows the schematic diagram of the whole setup. The whole system was commissioned, and the process parameters were rigorously optimized to obtain the desired results.</p><p style="text-align: justify;"><strong>Process Description: Chloride Extraction</strong></p><ul><li style="text-align: justify;">The raw material is CPO before drier</li><li style="text-align: justify;">A patented liquid-liquid (L/L) extraction column for chloride removal in CPO</li><li style="text-align: justify;">No additives are used for L/L extraction</li><li style="text-align: justify;">No emulsion is observed in the extractor column</li><li style="text-align: justify;">Fully integrated with existing SCADA or as a stand-alone system</li><li style="text-align: justify;">Moisture in CPO after chloride extraction and drying is &lt; 0.15%</li><li style="text-align: justify;">Unique extractor design guarantees oil in wastewater &lt; 0.1% (commercial plant showed nil)</li><li style="text-align: justify;">Very low COD in wastewater, &lt; 2000 ppm (no up-gradation of wastewater treatment plant (WWTP) in most cases)</li><li style="text-align: justify;">Practically maintenance-free (no moving parts in extractor)</li><li style="text-align: justify;">No reduction in CPO throughput</li><li style="text-align: justify;">Guaranteed chloride in CPO &lt; 2 ppm (&gt;80% removal of inorganic chlorides)</li></ul><p style="text-align: justify;">SUMWIN&rsquo;s Patented Liquid-Liquid Extraction Technology offers low CAPEX, very low OPEX, avoiding emulsification and thereby virtually eliminating oil loss in wash water and meets 3-MCPDE &lt; 1.25 ppm</p><p style="text-align: justify;"><img src="" /></p><p style="text-align: justify;">Figure 1. CPO Chloride Extractor System&nbsp;</p><p style="text-align: justify;"><strong>Technology for Post Stripping of GE</strong></p><p style="text-align: justify;">GE post stripper design is based on a fundamental distillation/fractionation process. Distillation is a process by which components in a chemical mixture are separated into fractions according to their different boiling points. Vapors from a boiling solution are passed along a tall column. The column is packed with distillation packings to improve the separation by providing more surface area for condensation and evaporation. The temperature of the column gradually decreases along its length. Components with a lower boiling point (more volatile) pass through the column and are collected near the top and removed.</p><p style="text-align: justify;">In the GE post stripping column, the column vacuum and temperature were optimized to let the GE component boil and vaporize and rise up in the column and is collected at the top and removed. Since the GE concentration in the feed is around 6-8 ppm, the aim is to reduce it to less than 0.5 ppm. The process was optimized to achieve the targeted concentration of GE less than 0.5 ppm. Figure 2 shows the schematic scheme of the process.</p><p style="text-align: justify;">Sumwin had also formulated an adsorbent used in the early stage during bleaching of the oil before it was fed to the deodorizer and GE stripper. REDGEM&reg; is a specially formulated proprietary adsorbent developed by Sumwin for the bleaching process. The bleaching process removes most of the pigments, traces of gums, soaps, oxidized products, polycyclic compounds, precursors of 3-MCPDE and GE, and other impurities remaining in the oil. These unwanted components are removed by mixing the oil with REDGEM&reg; and at a temperature of approximately 105&deg;C.</p><p style="text-align: justify;"><br /><strong>Process Description: GE Mitigation</strong></p><ul><li style="text-align: justify;">Use of Sumwin formulated adsorbent REDGEM&reg; to replace the bleaching earth</li><li style="text-align: justify;">Install a GE post-stripper operating pressure at &lt; 1.5 mbar and temperature to less than 240oC to strip out GE and achieve GE &lt; 0.5 ppm and free fatty acid (FFA) &lt; 0.05% in refined bleached deodorized palm oil (RBDPO).</li><li style="text-align: justify;">Sumwin&rsquo;s proprietary design optimizes the process to achieve GE &lt; 0.5 ppm at &lt; USD 2/MT</li><li style="text-align: justify;">Combination of all above steps based on site conditions guarantee GE &lt; 0.5 ppm</li><li style="text-align: justify;">No compromise on throughput is a key factor</li><li style="text-align: justify;">Commercial plant results show some reduction in oil loss in REDGEM&reg; as compared to other bleaching earth. Typical oil loss for other bleaching earth is around 20%.</li></ul><p style="text-align: justify;"><img src="" /></p><p style="text-align: justify;">Figure 2. GE Post-Stripper</p><p style="text-align: justify;"><strong>RESULTS AND DISCUSSION</strong></p><p style="text-align: justify;"><strong>Chloride Mitigation Results</strong></p><p style="text-align: justify;">A one-year data from commercial plant trials using Sumwin&rsquo;s patented L/L extraction technology is shown in Table 1. The chloride level in the extractor water-washed CPO samples has significantly reduced. However, high levels of chloride (&gt;11 ppm) could not be fully reduced to &lt; 2 ppm. Levels higher than 2 ppm in washed CPO were only observed when chloride in CPO was higher than 10 ppm (the design basis for the extractor).</p><p style="text-align: justify;">Table 1. Chloride removal from CPO with water-washing using Sumwin L/L extractor</p><table><tbody><tr><td width="144"><p><strong>CPO Feed Rate</strong></p></td><td width="153"><p><strong>Water Feed Rate</strong></p></td><td width="89"><p><strong>Water</strong></p></td><td width="95"><p><strong>Cl in CPO</strong></p></td><td width="101"><p><strong>Cl in WCPO</strong></p></td><td width="90"><p><strong>Oil in Water</strong></p></td></tr><tr><td width="144"><p>Kg/Hr</p></td><td width="153"><p>Kg/Hr</p></td><td width="89"><p>%</p></td><td width="95"><p>ppm</p></td><td width="101"><p>ppm</p></td><td width="90"><p>%</p></td></tr><tr><td width="144"><p>63,137</p></td><td width="153"><p>5,289</p></td><td width="89"><p>8.38</p></td><td width="95"><p>8.99</p></td><td width="101"><p>1.35</p></td><td width="90"><p>ND</p></td></tr><tr><td width="144"><p>61,516</p></td><td width="153"><p>5,583</p></td><td width="89"><p>9.08</p></td><td width="95"><p>11.97</p></td><td width="101"><p>3.48</p></td><td width="90"><p>ND</p></td></tr><tr><td width="144"><p>63,187</p></td><td width="153"><p>5,295</p></td><td width="89"><p>8.38</p></td><td width="95"><p>8.9</p></td><td width="101"><p>0.97</p></td><td width="90"><p>ND</p></td></tr><tr><td width="144"><p>56,224</p></td><td width="153"><p>5,342</p></td><td width="89"><p>9.50</p></td><td width="95"><p>13.28</p></td><td width="101"><p>3.8</p></td><td width="90"><p>ND</p></td></tr></tbody></table><p style="text-align: justify;">3-MCPDE Results</p><p style="text-align: justify;">The data on 3-MCPDE mitigation using counter-current L/L extraction followed by phosphoric acid degumming and bleaching with REDGEM&reg; is shown in Table 2. The removal of chloride to below 2 ppm in CPO should be effective in mitigating 3-MCPDE in physically refined oils. The actual data where water-washed CPO with less than 2 ppm had RBD palm oils well in the desired limits of 1.25 ppm (The 2020 &ldquo;EU Guideline&rdquo; being 2.5 ppm). CPO is not known to have 3-MCPDE, while the higher levels found in RBD palm olein are due to the ester's partitioning according to the liquid phase. In contrast, the solid RBD stearin has less. Monitoring chloride is important because it correlates with the amount of 3-MCPDE, and hence it is useful to analyze the content in CPO. Commercial plant results having washed CPO with higher chloride in the range of 3.5 - 3.8 ppm can still result in less than 1.25 ppm 3-MCPDE in RBDPO as REDGEM&reg; adsorbent was able to reduce chlorine further during the bleaching step.</p><p style="text-align: justify;">&nbsp;</p><p style="text-align: justify;">Table 2. Mitigation of 3-MCPDE with counter-current water-washing of CPO</p><table><tbody><tr><td rowspan="2" width="150"><p>&nbsp;</p></td><td width="150"><p>Chloride</p></td><td width="150"><p>3-MCPDE</p></td><td width="150"><p>Oil Loss</p></td></tr><tr><td width="150"><p>ppm</p></td><td width="150"><p>ppm</p></td><td width="150"><p>%</p></td></tr><tr><td width="150"><p>WCPO</p></td><td width="150"><p>1.06</p></td><td width="150"><p>NA</p></td><td width="150"><p>ND</p></td></tr><tr><td width="150"><p>RBDPO</p></td><td width="150"><p>1.16</p></td><td width="150"><p>1.03</p></td><td width="150"><p>NA</p></td></tr><tr><td width="150"><p>RBDOL</p></td><td width="150"><p>1.41</p></td><td width="150"><p>1.23</p></td><td width="150"><p>NA</p></td></tr><tr><td width="150"><p>RBDST</p></td><td width="150"><p>0.54</p></td><td width="150"><p>0.6</p></td><td width="150"><p>NA</p></td></tr></tbody></table><p style="text-align: justify;"><br />&nbsp; &nbsp;&nbsp;<br />NA = not available; ND = not detected or determined; WCPO = washed CPO.</p><p style="text-align: justify;">Table 4. Typical plant results for 3-MCPDE mitigation in RBD PO and RBD Olein</p><table><tbody><tr><td width="104"><p>Flow Rate</p></td><td width="96"><p>TC IN CPO</p></td><td width="102"><p>TC IN WCPO</p></td><td width="150"><p>3-MCPDE RBDPO</p></td><td width="150"><p>3-MCPDE RBDOL</p></td></tr><tr><td width="104"><p>MT/Hr</p></td><td width="96"><p>Ppm</p></td><td width="102"><p>ppm</p></td><td width="150"><p>ppm</p></td><td width="150"><p>ppm</p></td></tr><tr><td width="104"><p>60</p></td><td width="96"><p>10.3</p></td><td width="102"><p>1.27</p></td><td width="150"><p>0.97</p></td><td width="150"><p>1.23</p></td></tr><tr><td width="104"><p>58</p></td><td width="96"><p>6.65</p></td><td width="102"><p>1.02</p></td><td width="150"><p>0.8</p></td><td width="150"><p>1.14</p></td></tr><tr><td width="104"><p>60</p></td><td width="96"><p>7.73</p></td><td width="102"><p>1.3</p></td><td width="150"><p>0.86</p></td><td width="150"><p>1.29</p></td></tr><tr><td width="104"><p>63</p></td><td width="96"><p>8.99</p></td><td width="102"><p>1.35</p></td><td width="150"><p>1.1</p></td><td width="150"><p>1.38</p></td></tr></tbody></table><p style="text-align: justify;"><br />TC = Total Chlorides; RBDPO = Refined, Bleached, Deodorized Palm Oil ; RBDOL = Refined , Bleached, Deodorized Palm Olein;</p><p style="text-align: justify;"><strong>GE Mitigation Results</strong></p><p style="text-align: justify;">Limited data of Glycidyl Esters (GE) are given in Table 3 below. The EU Guideline for GE has already been in place for some time at 1 ppm max. GE is mainly formed at high-temperature deodorization (&gt; 260oC) but is also removed by low-pressure stripping during deodorization. The present method uses efficient bleaching earth and below 260oC bleaching and at the same time strips GE with deodorization at low pressure (1.5 mbar) and at slightly lower temperature 240oC.</p><p style="text-align: justify;"><br />Table 3. Typical results for GE mitigation</p><table><tbody><tr><td width="192"><p><strong>&nbsp;</strong></p><p><strong>Type of Oil</strong></p></td><td width="192"><p><strong>GE ppm</strong></p></td></tr><tr><td width="192"><p>Degummed CPO</p></td><td width="192"><p>0.00</p></td></tr><tr><td width="192"><p>REDGEM&reg; BPO</p></td><td width="192"><p>0.03 &ndash; 0.09</p></td></tr><tr><td width="192"><p>RBDPO</p></td><td width="192"><p>0.25 &ndash; 0.90</p></td></tr></tbody></table><p style="text-align: justify;"><strong>CONCLUSIONS</strong></p><p style="text-align: justify;">Based on the work done and results obtained, the following points are the summary of this technology:</p><ul><li style="text-align: justify;">Sumwin&rsquo;s patented process enables the production of 3- MCPDE of less than 1.25 ppm and GE of less than 0.5 ppm in RBDPO at lowest CAPEX and OPEX (&lt; USD 2/MT)</li><li style="text-align: justify;">The process has practically no oil loss (guaranteed less than 0.1% in wash water) and might not require up-gradation or expansion of WWTP at a refinery</li><li style="text-align: justify;">Unique L/L extraction design requires very low maintenance</li><li style="text-align: justify;">No additives are used in the entire mitigation process and therefore does not impact existing certifications such as Halal or Kosher</li><li style="text-align: justify;">Use of proprietary REDGEM&reg; adsorbent reduces oil loss in spent earth while simultaneously removing precursors of 3-MCPDE and GE during bleaching and still achieves the desired color and oxidative stability in RBDPO</li><li style="text-align: justify;">The mitigation process does not reduce plant throughput thereby avoiding an increase in OPEX per MT</li><li style="text-align: justify;">Seamless integration with existing SCADA.</li><li style="text-align: justify;">Customized and tailor-made configuration for individual plants that optimizes both CAPEX and OPEX</li></ul><p style="text-align: justify;">&nbsp;</p>
KR Expert - Unnikrishnan Unnithan