Department of Environmental Engineering, Federal University of Espírito Santo, Full Address: Avenida Fernando Ferrari, 514, Goiabeiras, CEP 29075-910, Vitória, Espírito Santo, Brazil; Federal Institute of Education of Espírito Santo, Full Address: Avenida Min. Salgado Filho, 1000, Soteco, CEP 29106-010, Vila Velha, Espírito Santo, Brazil.
Laboratory of Combustion and Combustible Matter (LCC), PPGEM, Federal University of Espírito Santo, Full Address: Avenida Fernando Ferrari, 514, Goiabeiras, CEP 29075-910, Vitória, Espírito Santo, Brazil.
J Environ Manage. 2019 Dec 15;252:109639. doi: 10.1016/j.jenvman.2019.109639. Epub 2019 Oct 3.
Microalgae are a potential source of biomass for the production of energy, which is why the amount of research on this topic has increased in recent years. This work describes the state of the art of microalgae production from wastewater treatment plants (WWTP), its potential to generate electricity and the scale in which it is possible. The methodology used was a systematic review of the gasification of microalgae from 49 articles selected. Based on the review, a conceptual scenario for microgeneration in WWTP using as feedstock microalgae for thermal gasification was developed. The most consistent assumptions for a real scale microgeneration are microalgae production in open ponds using domestic sewage as a nutritional medium; the use of the flocculation process in process of harvesting; microalgae to energy through thermal gasification process using a downdraft gasifier. Considering a WWTP with a 3000 m/d flux capacity, 860 kg/d of dry microalgae biomass might be produced. For which, gasification has a production potential of 0.167 kWh/m of treated sewage, but the energy balance is compromised by the drying process. However, when the biogas produced in anaerobic treatment enter in the model, it is possible to add a surplus of electricity of 0.14 kWh/m of treated sewage. Finally, a cost estimate is made for the acquisition of drying and gasification-electricity generation systems. For this scenario, the results suggest that the investments may be financially returned after five years, with additional potential for further optimization.
微藻是生物量能源生产的潜在来源，这就是为什么近年来对该主题的研究有所增加的原因。这项工作描述了从废水处理厂（WWTP）生产微藻的最新技术，其发电潜力和可能的规模。所使用的方法是对 49 篇选定的微藻气化文章进行系统综述。基于综述，开发了一种使用作为原料的微藻进行热气化的 WWTP 微发电概念方案。在实际规模微发电中最一致的假设是，在开放池塘中使用生活污水作为营养介质生产微藻；在收获过程中使用絮凝过程；通过使用下吸式气化炉的热气化过程将微藻转化为能源。考虑到一个通量为 3000 立方米/天的 WWTP，可能会产生 860 公斤/天的干微藻生物质。对于这个规模，气化具有 0.167 千瓦时/立方米处理污水的生产潜力，但干燥过程会影响能量平衡。然而，当厌氧处理产生的沼气进入模型时，就有可能为处理后的污水增加 0.14 千瓦时/立方米的电力盈余。最后，对干燥和气化-发电系统的购置进行了成本估算。对于这种情况，结果表明，投资可能在五年后获得财务回报，并有进一步优化的潜力。
