Poplar is recognized as an excellent biorefinery feedstock because of year-round availability and ease of fractionation. Further, poplar is commonly used to provide ecosystem services such as for riparian buffers or phytoremediation. While biofuels offer many environmental and socioeconomic benefits, commercial scale biorefineries are not prominent in the U.S. in part because of feedstock availability and cost. To reduce feedstock cost, we investigated incorporation of hybrid poplar grown to receive treated municipal wastewater into our supply curves, using a Western Washington location as a case study. We first developed supply curves for purpose-grown hybrid poplar feedstock, a likely biorefinery feedstock for the Pacific Northwest, to supply a biorefinery in Washington State. It was found that there was abundant land within 100 km to grow enough poplar to supply a larger scale biorefinery – as much as 800 Gg per year - and that the plant gate cost of the poplar biomass is in the range of $75 - $85 per Mg feedstock. Most of this land was pastureland, mitigating fuel vs. food concerns. We then incorporated wastewater treatment poplar into the supply curves. The amount of feedstock that could be grown to receive wastewater was limited; approximately 54 Gg per year. However, for a modest sized biorefinery (150 Gg poplar per year) the wastewater treatment poplar provided 36% of the feedstock and reduced the plant gate feedstock cost by 14%. Expanding the use of ecosystem services poplar would enable even large scale biorefineries to see substantial benefits from this lower cost feedstock.

杨树因其全年可用性和易于分馏而被公认为是一种极好的生物炼制原料。此外，杨树通常用于提供生态系统服务，例如河岸缓冲区或植物修复。虽然生物燃料提供了许多环境和社会经济效益，但商业规模的生物精炼厂在美国并不突出，部分原因是原料的可用性和成本。为了降低原料成本，我们以华盛顿西部地区为例，研究了将接受处理过的市政废水的杂交杨树纳入我们的供应曲线。我们首先制定了专门种植的混合杨树原料的供应曲线，该原料可能是太平洋西北部的生物精炼原料，以供应华盛顿州的生物精炼厂。发现 100 公里范围内有丰富的土地可以种植足够的杨树来供应更大规模的生物精炼厂——每年高达 800 克——并且杨树生物质的工厂门成本在每毫克 75 到 85 美元的范围内原料。这片土地的大部分是牧场，缓解了燃料与食物的问题。然后我们将废水处理杨树纳入供应曲线。可用于接收废水的原料数量有限；每年约 54 Gg。然而，对于中等规模的生物精炼厂（每年 150 Gg 杨树），废水处理杨树提供了 36% 的原料，并将工厂门口的原料成本降低了 14%。扩大生态系统服务杨树的使用将使即使是大型生物精炼厂也能从这种低成本原料中获得巨大收益。