Process Heat Recovery Targeting Assessment

Identifying savings opportunities for process heat recovery is an important step for process energy optimization. If the opportunity is large enough, it will warrant a more detailed study to determine what modifications are required at what capital investment. The benefit and cost will form the central part of the business case to be presented to management for approval of the capital budget. 

Energy and Process Optimization for the Process Industries, First Edition. Frank (Xin X.) Zhu. 

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PROCESS HEAT RECOVERY TARGETING ASSESSMENT Recycle gas... 

A heat recovery targeting assessment starts with data collection for process streams based on existing process design and operation conditions. When extracting operating data, the questions are as follows What time periods of data should be extracted What feed rate and compositions should be used as the basis The idea is to select the operating conditions that reflect the most common operation in terms of feed rate and product yields. On this basis alone, the benefit calculation has meaningful representation. Therefore, two criteria could be satisfied for data extractions ... 

Composite curves were developed for heat recovery targeting (Linnhoff et al., 1982). The word composite reveals the basic concept behind the composite curves method A system view of the overall heat recovery system. One hot composite stream represents all the hot process streams, while one cold composite stream represents all the cold process streams. In this manner, the problem of assessing a complex heat recovery system involving multiple hot and cold streams is simplified as a problem of two composite streams. In essence, the hot composite stream represents a single process heat source, while the cold composite stream represents a single process heat sink. 

Assessment methods (Chapters 5-7 for energy operation Chapters 9-10 for heat recovery system Chapters 12-14 for process operation and Chapters 16-19 for utility system operation) are then applied to identify root causes— potential causes include inefficient process operation, insufficient maintenance, inadequate or lack of operating practices, procedures and control, inefficient energy system design, and outdated technology. Assessment results are translated into specific corrective actions to achieve targets via either manual adjustments, the best practices, or by automatic control systems. Finally, the results are tracked to measure the improvements and benefits achieved. 

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