The process designer’s task is to lay out the process unit operations in a Block Flow Process Diagram (BFPD), in which the process unit operations are connected by the continuous process stream flows. A process is the transformation of raw materials, into one or more products of commercial value. The process development aims for commercial scale operation of the process, for maximum product sales volume, revenue and profit. The transformation of the raw materials to products is conducted in a series of steps, usually and desirably continuously, in which specific chemical and physical changes are made to the process material. These individual steps are called unit operations, examples being particle size reduction, mixing, reaction, decantation, distillation and drying. The transformations all fall under the categories of reaction, separation and physical conversion. These steps are conducted under known, controlled conditions in process equipment.
The process designer is usually a chemical or biochemical engineer, conversant with industrial chemistry and process equipment, and he is guided by training, experience and experimental R&D information from the project development program. He must develop a process design which is physically feasible, safe, and which can be scaled to and conducted on the commercial scale. His process design must also ultimately be sufficiently profitable to meet the financial criteria of the investors. Skilled process designers minimize the number of unit operations, minimize the number and relative magnitude of recycle streams, simplify designs and exploit the financial economies of larger scale. They adopt moderate process conditions, especially temperature, pressure and pH. They also seek chemical reactions which are high in product selectivity, conversion and yield and commission R&D, if feasible, to correct such deficiencies. Good process designs consciously minimize solvent and additive use.
Later in the process design, the designer identifies the specific process equipment which is required for each unit operation and develops the mass and energy balances. This yields the Process Flow Diagram (PFD), which is based on the BFPD above, but contains much more detail. This is the basis for computing the process economics.
At Lee Enterprises Consulting, we have a number of highly qualified process design experts available to assist you with any biodiesel related matter. Feel free to call or email us for more information.