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It has always been thought that the character \"zhong\" in \"pilot test\" is defined in terms of production capacity, referring to \"medium scale\", but in fact \"pilot test\" means \"intermediate test\". Pilot testing is short for intermediate testing, and by intermediate testing, it refers to tests that lie between laboratory tests and industrial production. Pilot testing is necessary when certain development projects cannot be scaled up using mathematical modeling methods, or when some of the research topics cannot be carried out on a small scale and data or experience can only be obtained through facilities of an appropriate size. Pilot testing is a scale-up experiment carried out on the basis of the conceptual design, after the laboratory tests have been completed and a technical-economic evaluation has been performed. Its scale lies between that of a laboratory and that of an industrial plant, but no specific scale has been defined. For fine chemical products, a pilot plant scale of several kilograms is sufficient to meet the demands, whereas the pilot plants built for many basic chemical products are quite large, with production capacities reaching several thousand tons per year. Pilot-scale testing must be carried out under industrial conditions, and its main tasks are as follows: 1. Establish a scale-up facility of appropriate size to conduct comprehensive simulations of the development process, determine the operating conditions as well as the methods of operation and control for the industrial plant, and address engineering issues related to long-term, continuous, and stable operation. This includes examining the methods for handling raw materials and products, necessary recycling processes, as well as the structure and material properties of equipment such as reactors. 2. Verify the pilot-scale conditions, collect more complete and reliable data of various types, address the scaling issues, and provide the technical information and data required for preparing process design packages and basic designs. 3. Evaluate the achievable production indicators, and calculate various economic indicators under conditions of high reliability, in order to provide a final assessment of the industrialized facility. 4. Study issues such as the treatment of waste gases, waste liquids, and waste solids, as well as production safety. 5. Conduct demonstration operations, train technical workers, develop start-up, shutdown, and accident handling plans, and acquire specialized production skills and experience. 6. Provide a certain quantity of products (samples) for market development purposes (the selection and scaling up of reactors, along with the subsequent study of reaction conditions, forms the basis for pilot-scale research). 7. Propose measures for the comprehensive utilization of materials and the treatment of \"three wastes\". 8. Propose a process flow diagram with control points, process parameters, data on material balance and energy balance, etc. Certain issues in chemical process development often cannot be fully identified during the pilot scale stage; they must be studied and resolved at the pilot plant scale. For example, in reactions carried out in tubular reactors, due to the limitations in equipment size, it is not possible to conduct detailed studies on aspects such as gas flow distribution on a pilot scale; therefore, these key issues must be carefully addressed when scaling up the equipment. For example, the screening of catalysts for gas-solid catalytic reactions is generally carried out in small fixed-bed reactors; only at the pilot scale can fluidized-bed reactors be investigated to further examine a range of issues such as reactor structure, material selection, and heat dissipation. For chemical plants that are technically complex, have low profit margins, operate on a large industrial scale, and utilize entirely new technologies, a semi-industrial testing phase can be added after the pilot testing stage.