Currently, there are mainly two pathways of the biodiesel production from wastewater sludge including 1) directly extracting the lipid in sludge and then converting the lipid to biodiesel through trans-esterification, and 2) employing sludge as medium to cultivate oleaginous microorganism to accumulate lipid and then transferring the lipid to biodiesel. So far, the study was still in research stage and its cost feasibility was not yet investigated. In this study, biodiesel production from wastewater sludge was designed and the cost was estimated with SuperPro Designer. With consideration of converting the lipid in raw sludge to biodiesel, the unit production cost was 0.67 US $/kg biodiesel (0.59 US $/L biodiesel). When the sludge was used as medium to grow oleaginous microorganism to accumulate lipid for producing biodiesel, the unit production cost was 1.08 US $/kg biodiesel (0.94 US $/L biodiesel). The study showed that sludge has great potential in biodiesel production.

目前，废水污泥生产生物柴油的途径主要有两种，一种是直接提取污泥中的脂质，然后通过酯交换反应将其转化为生物柴油，其二，以污泥为培养基，培养油脂性微生物，以积累脂质。然后将脂质转移到生物柴油中。到目前为止，该研究仍处于研究阶段，其成本可行性尚未得到研究。在这项研究中，设计了废水污泥生产生物柴油的成本，并通过SuperPro Designer估算了成本。考虑到将原污泥中的脂质转化为生物柴油，单位生产成本为0.67美元/千克生物柴油（0.59美元/升生物柴油）。当污泥用作培养油质微生物以积累脂质以生产生物柴油的介质时，单位生产成本为1.08美元/千克生物柴油（0.94美元/升生物柴油）。研究表明，污泥在生物柴油生产中具有巨大潜力。