Bioethanol, as a sustainable fuel or as a precursor for high-value chemicals, may be produced through a variety process technologies, depending on the feedstock available. Thus, these processes are comprehensively evaluated to identify the most cost-effective process for a given feedstock, as well as cost reduction measures. Process designs for first (1G), second (2G) and third (3G) generation ethanol production were simulated in Aspen Plus® for technical evaluations, followed by economic modelling to determine the minimum ethanol selling price (MESP). 1G-ethanol from A-molasses at sugar mills was most cost-effective (MESP = 0.52 US$/l). While the 1G-2G option (using sugarcane lignocelluloses) produced 98% more ethanol (MESP = 0.62 US$/l), costs of enzymes were inhibitive. For 2G-ethanol using invasive alien plants, hydrolysis-fermentation had the lower MESP (0.72 US$/l) compared to gasification-fermentation because the latter had comparatively high capital costs (i.e. 215 vs 135 million US$). Energy self-sufficiency for 3G ethanol from off-gas decreased the ethanol yield (178 to 114 l/tonne) and increased the MESPs (0.61 to 0.87 US$/l) compared to the buy-in of the required electricity. Similarly, for the gasification-fermentation scenario, a MESP of 1.58 US$/l was required to obtain energy self-sufficiency. Energy self-sufficiency therefore increases process costs, but simultaneously abates the potential use of fossil fuels. Thus, it is worth pursing renewable electricity to meet process energy needs to improve ethanol yields and lower production costs. Furthermore, fermentation processes should be tailored to tolerate lower water quality requirements.

生物乙醇作为一种可持续燃料或作为高价值化学品的前体，可以通过各种工艺技术生产，具体取决于可用的原料。因此，对这些工艺进行综合评估，以确定给定原料的最具成本效益的工艺，以及降低成本的措施。在 Aspen Plus® 中模拟第一代 (1G)、第二代 (2G) 和第三代 (3G) 乙醇生产的工艺设计以进行技术评估，然后进行经济建模以确定最低乙醇销售价格 (MESP)。来自糖厂 A-糖蜜的 1G-乙醇最具成本效益（MESP = 0.52 美元/升）。而 1G-2G 选项（使用甘蔗木质纤维素）生产的乙醇多 98%（MESP = 0.62 美元/升），酶的成本受到抑制。对于使用外来入侵植物的 2G-乙醇，与气化发酵相比，水解发酵具有较低的 MESP（0.72 美元/升），因为后者的资本成本相对较高（即 215美元 对 1.35 亿美元）。与所需电力的购买相比，来自废气的 3G 乙醇的能源自给自足降低了乙醇产量（178 至 114 升/吨）并增加了 MESP（0.61 至 0.87 美元/升）。同样，对于气化发酵方案，MESP 为 1.58 达到能源自给自足需要美元/升。因此，能源自给自足增加了工艺成本，但同时减少了化石燃料的潜在使用。因此，值得追求可再生电力以满足过程能源需求，以提高乙醇产量和降低生产成本。此外，发酵过程应该适应较低的水质要求。