(311e) Pre Feasibility Analysis of Alpha-Sulphonated Methyl Ester (MES) Production Process in Colombia

ABSTRACT Alpha sulphonated methyl esters (MES) are anionic surfactants derived from biorenewable resources as Palm oil and whose environmental (fast biodegradability (Ghazali et al, 2004) and water hardness tolerance (Satsuki et al, 1992)) and chemical properties (detergency and foam properties (Kapur et al,1994)) are really interesting for its application in detergents industry. As Colombia is the principal palm oil producer in Latin America and the fourth in the world, some investigations about sulphonated methyl ester's production and properties have been done. This work is about the pre-feasibility analysis of the sulfonated methyl esters (MES) production in Colombia using Palm Oil. For this analysis, it was necessary to determinate a base process for its production (sulfonation of palm oil methyl esters with gaseous SO3), the development of the process simulation using Aspen One 2006 tools, the economic analysis using Aspen Icarus (IPE) based on the results of the simulation and the methyl ester feedstock price, and the approach to the production system based on actual technology of the country. The national production of palm oil was 732.478 tons for 2007 from 316.402 hectares of palm. The production of palm oil has been growing so 478.771 tons of palm oil were consumed in 2008 where 39.736 tons were used for biodiesel and 413.687 tons for soap and food industry. In consequence, it was estimated that 400.000 tons of palm oil will be used for traditional uses in 2010, while 200.000 tons will be used for biodiesel and 400.000 tons for other business (Cenipalma, 2009). The process developed considers the Methyl esters from palm oil obtained from basic transesterification process. Next, a pre treatment process (Crystallization) for methyl ester feedstock was considered in order to separate saturated from unsaturated chain methyl esters. All saturated methyl esters (Methyl palmitate principally) were sulfonated in a FFR (Falling Film Reactor) using a 6% SO3 air stream and heat regulation. The air stream is previously deshumidified (two processes were evaluated: drying with ethylene glycol or cooling to condensate the water) and is used to generate the SO3 from sulfur combustion and SO2 conversion in a catalyzed conversion tower. The products from FFR go to a digestor (tubular reactor) where sulfonated intermediates are transformed into acid sulfonated methyl esters. Acid sulfonated methyl esters go to a bleacher with methanol and 50% Hydrogen Peroxide where the biggest parts of impurities (double bonded chains and OH groups) are eliminated. Next, the product is neutralized with NaOH and finally it is dryed. A stage for methanol recovery and other for gas treatment (electroprecipitation, scrubber and oxidation of sulfites) was considered. Also, the reactions for methyl ester sulfonation, disalt formation, MES hydrolysis by acid and basic pH were considered. As a outcome, a MES stream was obtained with the properties included in the next table. Tabla 1: Properties of Sulphonated methyl ester stream obtained from the simulated process. MES Temperature C 110 Pressure bar 1,01 Mole Flow kmol/hr 21,021 Mass Flow kg/hr 6126,103 Mass Frac MES 0,942 Methanol 0,003 Disalts 0,02 Water 0,004 Methyl sulfonic salt 0,005 Impurities 0,026 The methyl ester and sulfonated methyl ester production process from palm oil were simulated using Aspen One 2006 tools. Using UNIFAC and NRTL properties methods, the properties of involved substances were compared with experimental values (Castañeda et al., 2005) finding errors between 0,6 ? 5% in properties as viscosity and heat capacity. Using the information obtained from the process simulation and Aspen Icarus Process Evaluator tools (IPE) it was possible to evaluate the actual price of the methyl ester and the total capital cost of sulfonated methyl ester production process. It was found that the Colombian national price of methyl ester (0,7127 U$/kg) is better than the best price found using IPE. The best air drying system was evaluated using the capital cost and IRR (Internal return rate) variation with feedstock prices. It was found that the best alternative is air deshumidification with a water condensation system and absorption tower based on the lower final MES price and principal influence of methyl ester price in project IRR (IRR variation of 12,5% with 0,1U$ variation/kg methyl ester). Also, it was found that increasing methyl ester price in 20%, 50% and the equivalent to LAS raw material prices (1,4 U$/kg (Aparicio, 2008)), the final price of MES is lower than LAS actual price (2,1 U$/kg (Aparicio, 2008)). At the same time, it was found that a U$ 10.919.025,33 capital cost is necessary in order to develop the process with a production of 49.000 tons/year of MES. The P.O. Period found was 5 years for ME price of U$ 0,855/kg and MES price of U$ 1,47/kg. With that it was possible to determinate that it is feasible to produce MES in Colombia based in Palm oil. Fig. 1: Sulphonated methyl ester production process diagram. Keywords: Palm Oil; Methyl Ester (ME); Sulphonated Methyl Ester (MES); Transesterification; Sulphonation; Economics; Aspen One 2006.