Cellulosic Technology— Pulp and Paper Style

American Process applies forestry products know-how to cellulosic conversion.
By Chris Hanson | June 26, 2013

Though a relative newcomer to the ethanol world, Georgia-based American Process Inc. is no stranger in the forest products industry. The company has demonstrated its consulting expertise in 500-some projects, logging more than 2 million work hours of project experience in nearly two decades. Founded in 1995 by Theodora Retsina as an engineering consulting firm, API has been increasing its presence in the cellulosic ethanol market with its bolt-on and stand-alone technologies utilizing woody biomass and crop residues to produce cellulosic sugars. 

In 2006, API began investing its own funds into developing two technologies for cellulosic sugar production. Kim Nelson, vice president of governmental affairs at API, says the move was spearheaded by the need to keep the forest products industry thriving and viable. “We were consultants to the pulp and paper industry,” Nelson says, adding that it’s fairly unusual for consulting firms to develop their own processes. “Most of our employees at the time had advanced degrees in pulp and paper science engineering, biomass chemistry, wood chemistry, etc. If they did not have those advanced degrees, they had worked in the industry for many years. So we had this great understanding of the existing processes, and in handling, treating and extracting biomass. So it was kind of a unique resource that we had and took advantage of.” 

Bolt-on Conversion
API’s GreenPower Plus and AVAP (which was originally developed as American value-added pulping) technologies are utilized to extract sugars that may be used to produce biofuels and biobased chemicals from a variety of feedstocks. The GreenPower Plus technology first treats biomass, including hardwood, softwood or bagasse, through a hot water extraction process. The hemicelluloses are removed from the wood in this process and then treated with acid to form sugars. Last, the sugars are concentrated until it can be converted into biochemicals or fermented into cellulosic ethanol by organisms able to process C5 and C6 sugars.  Any residual solid material containing lignin and cellulose is then processed to create pellets, combusted in a boiler or used for pulp and paper applications. Retsina, CEO of API, describes GreenPower Plus as a bolt-on technology for plants that are already aggregating biomass, such as a first-generation sugar-to-ethanol plant.

Basil Karampelas, president of API, says one of the main benefits of using GreenPower Plus is it upgrades a portion of the biomass to a higher value product at a capital cost of less than $10 per annual gallon of capacity. “We are only taking the hemicellulose fraction of the biomass, which is typically 20 to 25 percent,” Karampelas adds. “Whatever we’re not using goes back to the original user. You have the possibility to generate cash flow from that 25 percent that could be approximately equal to the cash flow from the burning of the other 75 percent of the biomass in the boiler or pelletizer.”

Currently, API’s GreenPower Plus technology is being demonstrated at the Alpena Biorefinery in Alpena, Mich. Co-located at the Decorative Panels International hardboard facility, the refinery began operating in the second quarter last year utilizing a DPI waste stream of woody biomass extract. It has a nameplate capacity of 894,000 gallons of cellulosic ethanol and 696,000 gallons of potassium acetate per year. The project was named a Center of Energy Excellence and a Renewable Energy Renaissance Zone by the state, and awarded $22 million in 2010. 

Stand-alone Technology
AVAP is API’s stand-alone technology that converts biomass into sugars for cellulosic ethanol or biochemical production. It uses sulfur dioxide and ethanol pretreatment chemistry to extract hemicelluloses and lignin, Nelson explains. The lignin and hemicelluloses are processed by autohydrolysis. The hemicellulose is used to produce sugars while the lignin is transported to a boiler to generate energy for the facility. Meanwhile, the separated cellulose is either sold as a coproduct or is processed through enzymatic hydrolysis to produce cellulosic sugars, which can be converted along with the hemicellulose sugars into biochemicals or biofuels such as cellulosic ethanol.

On the AVAP technology, Retsina says it “takes any biomass, it is completely feedstock agnostic, and converts all the biomass to fungible intermediate feedstock, which is sugars. Those cellulosic sugars can be converted to chemicals and fuel on site or shipped to another site and dropped into another operation.”

API set up an affiliate in 2011, AVAP Co. LLC, to commercialize the AVAP technology it uses at its demonstration plant in Thomaston, Ga., which came online in May. “With any first-of-its-kind facility,” Karampelas says, “we’re anticipating there will be different things we’ll be doing to tweak and optimize as we start up, which is what we did with Alpena.” The plant can handle a variety of feedstocks at rates up to 10 tons per day, with an annual capacity of about 300,000 gallons per year. He mentions one way API is optimizing the site in Thomaston is by relocating API’s corporate R&D capabilities onsite.

“AVAP is a technology that will fractionate the entire biomass and in doing so it gives us a lot of optionality around what we can ultimately produce,” Karampelas says. He then clarifies that since the technology is fractionating the feedstock into cellulose, lignin and hemicelluloses, the plant can decide to skip the cellulose-to-glucose conversion stage and use the separated cellulose to produce coproducts, such as fluff pulp, while using the hemicellulose sugars for biochemical or biofuel production. 

“Our plan for both Thomaston and Alpena for the remainder of 2013 is to really perfect and optimize the two technologies at the demo facilities,” Karampelas says.  API was not prepared to share any specific yield estimates, since yield values are dependent on the feedstock and configuration, which can vary from site to site, he adds.

In addition to API’s sugar extracting technologies, it has developed two energy management software tools for the pulp and paper industry. Energy Targetter is used to identify energy consumption problems, track performance of projects and improve energy efficiency. The Performance Indicator Benchmarking program is a Web-based tool that utilizes data from mills in the pulp and paper industry to help users benchmark their steam, water, electricity and thermal energy consumption.

API’s newest software, apiMax, is a biorefinery simulator developed in 2009 for industries such as cellulosic biofuel and biochemical, pulp and paper and pellet production. API’s website notes 30 companies and 13 institutions are using or evaluating the program that can simulate biorefining and energy equipment. 

Brazilian Boost
API recently got a boost when the Brazil-based biotech company, GranBio acquired a 25 percent equity stake in API, giving the company access to API’s cellulosic sugar technologies. “The association with a demonstrated cleantech leader such as GranBio strengthens American Process and makes it possible to aggressively grow our business,” Retsina said in a press release about the agreement. “We believe that the production of low-cost clean sugars is key to unlocking the potential of biomass as a versatile feedstock for fuels, chemicals and products. We are actively partnering with ‘sugar converters’ to complete the supply chain and convert the sugars to high-value-added products. We are excited and very optimistic about the prospects of building the first commercial-scale plant with API technology in Brazil followed by one in the United States.” 

Karampelas views the deal as mutually beneficial for both API and GranBio. “The way it benefits API is we’ve got a partnership with a world-class company based in South America, specifically Brazil, where we see tremendous potential for both of our technologies,” he says. He adds that by working with GranBio, API may gain insight in attracting international customers interested in using cellulosic sugars to produce their products. He says the relationship will help GranBio gain more exposure and a better understanding of API’s home market of North America. 

Author: Chris Hanson
Staff Writer, Ethanol Producer Magazine