Pyrolysis has been considered as a promising thermochemical process that can convert biomass in nonoxidizing atmospheres to value-added liquid bio-oil, solid biochar, and noncondensable gas products. Fast pyrolysis has a better economic return because of the valuable biofuel production (e.g. bio-oil, syngas). Because of the complexity and heterogeneity of the feedstocks, the one-step pyrolysis often leads to the mixed, acidic, and highly oxygenated liquid products. Moreover, the downstream processes (e.g. deoxygenation) for the desired fuels require high costs on energy and catalysts consumption. Stepwise pyrolysis is defined as a temperature-programmed pyrolysis that can separately obtain the products from each temperature step. It is a feasible approach to accomplish the fractionation by optimizing the pyrolysis process based on the decomposition temperature ranges and products among the biomass constituents. In recent years, the stepwise pyrolysis technology has gained attentions in thermochemical conversion of complex organic solid wastes. Through the stepwise pyrolysis of a real waste, oxygenated and acidic products were concentrated in the first-step liquid product, whereas the second-step product normally contained a high portion of hydrocarbon with low acidity. The stepwise pyrolysis of biomass, plastics, and their mixtures is comprehensively reviewed with the objective of fully understanding the related mechanisms, influence factors, and challenges.

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通过逐步热解将生物质和塑料废物分馏为增值产品：最先进的审查

热解被认为是一种很有前途的热化学过程，可以将非氧化气氛中的生物质转化为具有附加值的液体生物油、固体生物炭和不可冷凝的气体产品。由于生产有价值的生物燃料（例如生物油、合成气），快速热解具有更好的经济回报。由于原料的复杂性和异质性，一步热解往往会导致混合、酸性和高度氧化的液体产品。此外，所需燃料的下游过程（例如脱氧）需要高成本的能源和催化剂消耗。逐步热解定义为程序升温的热解，可以分别从每个温度步骤中获得产品。根据生物质成分中的分解温度范围和产物，通过优化热解过程来完成分馏是一种可行的方法。近年来，逐步热解技术在复杂有机固体废物的热化学转化中受到关注。通过真正废物的逐步热解，氧化和酸性产物被浓缩在第一步液体产物中，而第二步产物通常含有高比例的低酸烃。全面回顾了生物质、塑料及其混合物的逐步热解，目的是充分了解相关机制、影响因素和挑战。逐步热解技术在复杂有机固体废物的热化学转化中受到关注。通过真正废物的逐步热解，氧化和酸性产物被浓缩在第一步液体产物中，而第二步产物通常含有高比例的低酸烃。全面回顾了生物质、塑料及其混合物的逐步热解，目的是充分了解相关机制、影响因素和挑战。逐步热解技术在复杂有机固体废物的热化学转化中受到关注。通过真正废物的逐步热解，氧化和酸性产物被浓缩在第一步液体产物中，而第二步产物通常含有高比例的低酸烃。全面回顾了生物质、塑料及其混合物的逐步热解，目的是充分了解相关机制、影响因素和挑战。