Grantee Research Project Results
Final Report: Industrial Process Pollution Reduction by Development of Amorphous Biogenic Silica to Replace Fumed Silica
EPA Contract Number: EPD17023Title: Industrial Process Pollution Reduction by Development of Amorphous Biogenic Silica to Replace Fumed Silica
Investigators: Gross, Marcus J
Small Business: SioTeX Corporation
EPA Contact: Richards, April
Phase: II
Project Period: March 1, 2017 through February 28, 2019
Project Amount: $299,955
RFA: Small Business Innovation Research (SBIR) - Phase II (2016) Recipients Lists
Research Category: Small Business Innovation Research (SBIR) , SBIR - Air and Climate
Description:
SioTeX has developed a novel method to produce silica that can meet performance specifications of fumed silica derived from a natural source, rice hulls, a byproduct of rice milling. In this Phase II program SioTeX demonstrated pilot plant production of silica from rice hulls and developed a viable market for this product. The Phase II research was focused on transferring the Phase I laboratory scale production to the pilot scale and ultimately to full scale production. The bulk of the work in Phase II was optimization of the manufacturing process, improving yield and demonstration of production of quality silica at the pilot scale. SioTeX demonstrated that there was a strong demand for their product, Grow Sil, in the agriculture market.
The initial Phase II research program was divided into three broad classes; raw materials characterization, process optimization, and final product characterization and applications. Rice hull varieties underwent testing to identify some of the differences in the varieties that might lead to significantly different end product. The feed and handling of rice hull varietals was also studied to determine if any varietals would pose complications to the Phase II process. Research on the pretreatment focused on optimizing the acid reuse, rinse water type and recycle, drying methods for kiln feed, and potential for waste utilization. The pilot scale kiln was constructed and used to optimize the air/fuel mixture, kiln temperature and temperature profile, rotational speed, and residence time in the kiln to fabricate optimal silica. The last step in the SioTeX process is ball milling, which was optimized to produce uniformly sized silica particles.
Summary/Accomplishments (Outputs/Outcomes):
All Phase II technical goals were met. SioTeX successfully transitioned from a 2" to an 8" Kiln and optimized the silica production process. This included pretreatment of the rice hulls, calcination of the treated hulls and milling of the resultant product. Optimization of these processes increased yields of high quality silica from 1.5 lbs / hr to >4 lbs per hr. In addition to improved yields SioTeX demonstrated that there is a large agricultural market for their Grow-Sil product.
SioTeX organized the work plan to accommodate operational priorities that overlap with operational milestones. The pilot plant was relocated to Canyon Lake, Texas. Duct work and a cyclone were installed and the kiln was operated 40 hours per week producing silica for sales into the agriculture market. Rice hull varietal studies were conducted, and findings indicate that all varietals are acceptable for producing high purity amorphous silica. The pre-treatment process was studies and SioTeX discovered that high residual moisture content of the rice hulls directly impacts the throughput of the pyroporcessing step and increases the overall weight of the pretreated material. SioTeX also designed and implemented a small scale modular drying system for rice hulls to keep the moisture content below5%. A cyclone was installed on the exhaust system to capture particulates reducing emission of this material in to the atmosphere. The rotary kiln was optimized for whiteness and throughput. This included: installing temperature sensors/controllers along the production kiln zones, controlling the air flow into the kiln, designing and installing mechanical structures such as Auger screws to improve the movement of material along the combustion zones. SioTeX sold every pound of material produced at Canyon Lake, with the exception of a few samples for future customers and third party testing, to the agriculture market. The demand for material in this market far exceeds current production capabilities. SioTeX is in the process of purchasing additional kilns and scaling the process to fulfill orders.
Conclusions:
During the Phase II program SioTeX successfully transitioned from a 2" to an 8" Kiln, optimized the production process and identified a large and growing market for our product. To date, SioTeX has received and filled around $15,000 in orders and has identified a potential $554MM market in agricultural silica production. SioTeX has also just closed on a $1,000,000 round of funding to scale the process to low volume production using a 12" diameter kiln. SioTeX believes that this was an extremely successful SBIR program that resulted in commercial sales of a product and successfully transitioned to Phase III production.
Commercialization:
To date, SioTeX has received around $15,000 in filled orders and has identified a potential $554MM market in agricultural silica production. SioTeX has also just closed on a $1,000,000 round of funding to scale the process to low volume production using a 12" diameter kiln. SioTeX believes that this was an extremely successful SBIR program that resulted in commercial sales of a product and successfully transitioned to Phase III production.
SBIR Phase I:
Industrial Process Pollution Reduction by Development of Amorphous Biogenic Silica to Replace Fumed Silica | Final ReportThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.