SBIR Phase I: Production of alkoxysilanes directly from biogenic silica

这个小企业创新研究第一阶段项目的更广泛的影响/商业潜力是，它为使用可持续的自然资源作为起始材料生产硅的新工艺技术提供了潜力。目前，用于太阳能电池和计算机芯片的所有硅，以及用于制造含硅化学品（包括硅橡胶、油、润滑剂和气相二氧化硅（油漆、纸张）等）的所有硅，都是在能源、设备和二氧化碳密集的过程中生产的。生物二氧化硅包括硅藻土和多种农业废弃物，包括稻壳灰、生物乙醇生产产生的无机废弃物、玉米秸秆和小麦糠。该项目的目标是通过使用绿色和可持续的技术，以比现有成本低得多的成本，从这些二氧化硅来源开发高纯度、高价值的二氧化硅产品。主要市场包括电子、光学和光子应用、特种化学品和消费品。该一期项目的技术目标是在Ü 200 <e:1>℃的温度下成功解聚生物硅，生产可蒸馏的烷氧基硅烷。二氧化硅的主要来源是稻壳灰（RHA），这是一种可持续的、不含重金属的、富含二氧化硅的农业废物。该工艺采用催化碱将RHA二氧化硅溶解于温度为Ö 200℃的防冻液中，然后与醇交换生成烷氧基硅烷。传统的烷氧基硅烷是在电弧炉中用碳在1900℃下对二氧化硅进行碳热还原制备的金属硅；这是一个高能耗、资本设备和二氧化碳密集的过程。该工艺的另一个优点是，二氧化硅耗尽的RHA可以直接获得高纯度（99.9999%）光伏级硅，产量为数公斤/天。如果成功，提议的项目将改变高纯度烷氧基硅烷、沉淀二氧化硅和气相二氧化硅的生产方式，因为全球有多种RHA来源。与由金属硅制成的相同产品相比，烷基氧基硅烷产品可以以非常低的成本蒸馏到非常高的纯度。最初的目标是生产与金属硅衍生产品竞争的四乙氧基硅烷，然后转向用于电子和光学产品应用的高纯度沉淀二氧化硅。

The broader impact/commercial potential of this Small Business Innovation Research Phase I project is that it offers the potential for a new process technology to produce silicon using a sustainable, natural resource as the starting material. Currently, all silicon used in solar cells and computer chips, and all silicon used in the manufacture of silicon containing chemicals including silicone rubbers, oils, lubricants and fumed silica (paints, paper) etc. is produced in an energy, equipment and CO2-intensive process. Biogenic silica includes diatomaceous earth and many kinds of agricultural waste including rice hull ash, inorganic waste from bioethanol production, corn stover, and wheat chaff. The objectives of this project are to develop economical routes from these silica sources to high purity, high value silica products at significantly lower cost than currently available by using a green and sustainable technology. Key markets include electronic, optical, and photonic applications, specialty chemicals, and consumer products. The technical objectives of this Phase I project are to successfully depolymerize biogenic silicas at temperatures ¡Ü 200¡ãC to produce distillable alkoxysilanes. The primary silica source is rice hull ash (RHA), a sustainable, heavy metal free, silica rich agricultural waste. This process uses catalytic base to dissolved RHA silica in antifreeze at ¡Ö 200¡ãC followed by exchange with alcohol to produce alkoxysilanes. In contrast, traditional alkoxysilanes are made from silicon metal produced by carbothermal reduction of silica with carbon at 1900 ¡ãC in an electric arc furnace; a high energy, capital equipment and CO2 intensive process. A further advantage to this process is that the silica depleted RHA offers direct access to high purity (99.9999 %) photovoltaic grade silicon at multi-kg/day scales. If successful, the proposed project could change how high purity alkoxysilanes, precipitated silica, and fumed silica are produced as multiple RHA sources are available worldwide. The alkoxysilane products can be distilled to very high purity at very low cost compared to the same product made from Silicon metal. The initial goal is to produce tetraethoxysilane to compete against Silicon metal derived product and move thereafter to high purity precipitated silica for electronic and optical products applications.