Separation of soap, glycerol and water from biodiesel produced in a continuous biodiesel production process

生物柴油是从可再生的油脂原料中生产的，如植物油和动物脂肪。通常情况下，石油和甲醇在催化剂存在下反应生成生物柴油和甘油作为副产品。从副产物中分离得到的生物柴油含有肥皂、水、甘油和游离钾离子等杂质，这些杂质会对生物柴油的性能产生不利影响。这些杂质需要从生物柴油中分离出来，以满足ASTM标准的要求。该公司名为Bio-LIQ Inc.，试图通过合成树脂去除杂质，但这些树脂在连续的过程中向生物柴油中注入H+离子(酸性)和水。具有负电荷磺酸基的离子交换树脂能够去除粗制生物柴油中带正电荷的杂质(H+、钾和钠离子、肥皂、游离甘油)，而具有较大比表面积的硅基树脂(SIPERNAT)能够吸附所有类型的杂质。为了满足公司对生物柴油连续提纯的需求，需要选择一种合适的树脂来去除杂质，使生物柴油符合ASTM标准。首先，将进行不同树脂处理粗生物柴油的批量研究。然后，选定的树脂将在连续的柱操作中进行测试，其中将连续监测工艺参数(流速、柱背压)和提纯生物柴油中的杂质。采用柱操作的生物柴油连续净化工艺是一种经济、有效和工业可行的工艺，不像湿式洗涤技术那样需要大量昂贵的溶剂，而且产生大量废水。根据拟议的研究开发的工艺将帮助BIOLIQ和加拿大其他行业以连续模式生产生物柴油，消除对大型储罐的使用。

Biodiesel is produced from renewable lipid feedstocks, such as vegetable oil and animal fats. Generally, oil andmethanol are reacted in the presence of a catalyst to yield biodiesel and glycerol as a by-product. Biodieselobtained after separation from the by-product contains impurities such as soap, water, glycerol and freepotassium ions that affect the performance of biodiesel adversely. These impurities need to be separated frombiodiesel to meet the requirements of ASTM standards. The company, BIO-LIQ INC, tried to eliminateimpurities by using synthetic resins, but the resins imparted H+ ions (acidity) and water into the biodiesel in acontinuous process. Ion-exchange resins having negatively charged sulphonate group are able to removepositively charged impurities (H+, potassium and sodium ions, soap, free glycerol) from the crude biodieselwhile silica-based resin (SIPERNAT) with large surface area for adsorption is capable of trapping all types ofimpurities. In order to respond to the need of the company to purify biodiesel in a continuous process, anappropriate resin needs to be selected which can remove impurities so that the biodiesel follows the ASTMstandards. First, a batch study will be conducted to treat crude biodiesel with different resins. Then, the selectedresin will be tested in a continuous column operation where process parameters (flow-rate, columnback-pressure) and impurities in the purified biodiesel will be continuously monitored. The continuous processof biodiesel purification using column operation is economical, effective and industrially feasible unlikewet-washing techniques requiring a large amount of expensive solvents and produce large amount ofwastewater. The process developed from the proposed research will help BIOLIQ and other industries ofCanada to produce biodiesel in a continuous mode, eliminating the use of large holding tanks.