International Journal of ChemTech Research CODEN (USA): IJCRGG, ISSN: 0974-4290, ISSN(Online):2455-9555 Vol.9, No.12, pp 833-843, 2016
Abstract: The environmental assessment of a process allows detection of improvement areas from this point of view, serving as a tool for making decision and quantification of environmental benefits for a raw material transformation into a final product. In this work, a real crude palm oil extraction process found in North Colombian region was analyzed using WAR algorithm to evaluate 8 impact categories. Results show that in general terms, the process is environmentally beneficial. The total generated PEI is negative and 10-4 order, in addition, although output impacts occur, these are low compared to the PEI output of an oil extraction process with chemical solvents. Moreover, high emissions of greenhouse gases do not occur, however, if energy improvements in the process are carried out by changing the type of fuel, values for PEI output for atmospheric environmental impacts categories could be reduced considerable. Keywords : WAR algorithm, Environmental evaluation, crude palm oil.
The palm oil is a vegetable oil obtained by pressing the mesocarp of Elaeis guineensis palm fruit1. The yield of oil palm cultivation is six to ten times higher than the aforementioned cultures, producing 39% of vegetable oil in the world, which is used in the food industry, cosmetics and as a raw material for biofuel production2. In 2010, Colombia was the first Latin American country producer of palm oil and the fifth in the world after Indonesia, Malaysia, Thailand and Nigeria, with domestic production of 753,000 tonnes, and since 2012, has about 500,000 hectares of oil palm3. In addition, in Colombia there are plans to increase production to six times by 2020, which would require 3 million hectares for plantations4. This large production demand is leading palm growing countries to seek and implement optimal and efficient processes that can ensure a better use of raw materials, high oil yield, reducing environmental impacts. An environmental assessment provides an orderly, replicable and multidisciplinary analysis of possible environmental impacts that a process can have on the ecosystem, either causing an ecological imbalance or
Angel Darío González-Delgado et al /International Journal of ChemTech Research, 2016,9(12): 833-843. 834
exceeding the limits and conditions set forth in the applicable provisions to protect, preserve and restore the environment. Some of the methodologies and tools used to develop an analysis of the environmental impacts are the Waste Reduction (WAR) Algorithm5, Environmental Impact Minimization Method (MEIM), AHI methodology, EFRAT tool and Life-Cycle Assessment6. Regarding WAR algorithm, this is useful because allows quantifying the generation of potential environmental impacts based upon several different impact categories7. In this work, authors present an environmental assessment of a production process of crude palm oil in the northern Colombian region using the software WARGUI, which is based on WAR algorithm, in order to quantify eight impact categories that can lead to possible optimization thereof.
The process was evaluated using as references two extraction plants of crude palm oil located in North Colombia in Bolivar and Cesar departments; furthermore, this process is similar to that reported in the literature8. Figure 1 shows that extraction process simulation of crude palm oil starts with steam ingress (stream 4) by a boiler to sterilize the bunch of African Palm (stream 1), previously transported from a hopper to a horizontal cylinders closed by trucks. This sterilization is performed in order to prevent the effect of lipase enzyme on free fatty acids and hydrolyzing the palm rachis to soften the pulp tissues. From this step, the sterilized bunch (stream 5) and saturated steam (stream 2 and 3) out. The sterilized cluster passes through a rotating drum to separate the fruits (stream 7) of bunches (stream 6). The fruits pass to the digestion step, where the fruit is heated to facilitate the oil expulsion in the pressing and to release the nuts pulp by maceration that includes the entry of steam (stream 8) through a heat exchanger. Subsequently, the digested fruits (stream 9) are pressed by a horizontal perforated basket cylindrical shape, where a liquor (stream 11) containing large amount of oil is extracted. This liquor is generated through the mechanical action of two augers regressive step, which rotate parallel in the opposite direction, by outputting in the top the presscake (stream 10). Then, water (stream 12) is added to the liquor to dilute it, facilitating the oil separation and purification. In static clarification stage is separated by static clarification up to 90 % oil
(6.81 t/h), which it is collected by overflow and is pumped (stream 16) to a drying process. After this, the dynamic clarification by centrifugation is carry out, where 10 % recovery of oil is achieved.
At this stage enters the heavy fraction from decantation (stream 13), obtaining water and heavy sludge as outputs by nozzles (stream 14), oil and light sludge are concentrated in the center and discharged by a collector tube. This last outlet stream is recirculated (stream 15) to the static clarification with the press liquor. As last step, the oil is subjected to another drying in order to minimize the moisture and residual impurities (stream 17) still contain this. Due to high temperature of oil outlet, the drying is performed under vacuum, by reducing the pressure of the stream, causing evaporation of the remaining water. Dry Crude Palm oil (6.757 t/h) is pumped (stream 18) from this stage as final product to its respective storage.