Process integration in sugarcane biorefineries allows reducing steam consumption. As a consequence, the bagasse surplus can be diverted to second generation ethanol production. Furthermore, sugarcane plants can vary the production of ethanol and electricity, depending on the demand. For those reasons, equipment present in the plant might be required to operate under different conditions. This study presents the energy integration of a sugarcane biorefinery. A Mixed Integer Nonlinear Programming (MINLP) optimization model is proposed to solve the problem of synthesizing a Heat Exchanger Network (HEN) able to periodically operate under the distinct conditions required in the biorefinery, i.e., a multiperiod HEN. For solving the MINLP problem, a hybrid metaheuristic approach was used, which combines Simulated Annealing and Rocket Fireworks Optimization. The proposed strategy achieved lower HEN total annualized cost (TAC) when compared with the project energy integration that is commonly found in Brazilian plants. This reduction in TAC, in particular in utilities demand, allows the surplus bagasse to be available for the most suitable application: produce 2G ethanol or more electricity.

甘蔗生物精炼厂的过程集成可减少蒸汽消耗。结果，甘蔗渣过剩可以转移到第二代乙醇生产中。此外，甘蔗厂可以根据需求改变乙醇和电力的生产。由于这些原因，工厂中存在的设备可能需要在不同的条件下运行。这项研究提出了甘蔗生物精炼厂的能源整合。提出了混合整数非线性规划（MINLP）优化模型，以解决合成热交换器网络（HEN）的问题，该热交换器网络可以在生物炼油厂所需的不同条件下定期运行，即，一个多时期的母鸡。为了解决MINLP问题，使用了一种混合元启发式方法，该方法结合了模拟退火和火箭烟花优化。与巴西工厂中常见的项目能源整合相比，拟议的策略实现了较低的HEN总年度成本（TAC）。TAC的减少，尤其是公用事业需求的减少，使得剩余的蔗渣可用于最合适的应用：生产2G乙醇或更多的电力。