Batch Reactors Individuals who independently make biodiesel for personal use most commonly use batch reactors. They are easy to build a small, garagescale and have a low capital cost. Batch reactors can convert a wide variety of feedstocks into methyl esters, which is favorable when restaurant grease that by nature has a variable composition is used. The downsides to reactors are low conversion, high energy requirements, and long total reaction time. Batch reactions typically take place with either sodium or potassium hydroxide as a catalyst for transesterification, which is inefficient and leads to low yields. shows that adding an agitator or series of agitators increases conversion up to 99% while decreasing reaction time Agitator speeds typically range from 200-900 rpm, with higher speeds promoting greater conversion. Despite lowering reaction time, the combined time of heating, reacting, cooling, and preparing for subsequent runs makes the batch reactor time inefficient. Waste cooking oil must pass through a pretreatment step to lower FFA content in order to decrease the amount of glycerol formed as a side reaction during transesterification. This side reaction lowers methyl ester selectivity, and glycerol must be later separated from the methyl esters in order to meet production standards. Continuous Reactors
Batch Reactors Individuals who independently make biodiesel for personal use most commonly use batch reactors. They are easy to build a small, garagescale and have a low capital cost. Batch reactors can convert a wide variety of feedstocks into methyl esters, which is favorable when restaurant grease that by nature has a variable composition is used. The downsides to reactors are low conversion, high energy requirements, and long total reaction time. Batch reactions typically take place with either sodium or potassium hydroxide as a catalyst for transesterification, which is inefficient and leads to low yields. shows that adding an agitator or series of agitators increases conversion up to 99% while decreasing reaction time Agitator speeds typically range from 200-900 rpm, with higher speeds promoting greater conversion. Despite lowering reaction time, the combined time of heating, reacting, cooling, and preparing for subsequent runs makes the batch reactor time inefficient. Waste cooking oil must pass through a pretreatment step to lower FFA content in order to decrease the amount of glycerol formed as a side reaction during transesterification. This side reaction lowers methyl ester selectivity, and glycerol must be later separated from the methyl esters in order to meet production standards. Continuous Reactors
Team_14_PPFS.docx