SynGest Bioammonia Plant, United States of America

There is an increasing movement in parts of the chemical industry towards sustainable processes. An important example is the use of waste biomass in the production of sustainable fuels such as bioethanol and biobutanol by fermentation processes. However, energy and carbon-rich biomass may be treated using more fundamental process chemistry to produce synthesis or syn gas, which can be the starting point for the production of a number of valuable chemical feedstocks.

In this instance SynGest Inc, a US company based in San Francisco, will use corn cobs and other related biomass in a gasification process to produce syn gas. The syn gas will be used as a source of hydrogen and the quantity of this gas will be optimised by use of the water gas shift reaction. The hydrogen will be used in a version of the Haber process to produce ammonia.

The ammonia will primarily be used for the production of nitrogenous fertiliser for the domestic US market, which is a net importer of fertiliser (55–65% imported of a total requirement of 18 million tons per year). There is also a possibility that the ammonia could be used as a power source when used to power alkaline fuel cells. SynGest will initially focus on the fertiliser market.

"The ammonia will primarily be used for the production of nitrogenous fertiliser for the domestic US market."

New bioammonia production plant

SynGest has already chosen a 75-acre site near Menlo, Guthrie County, Iowa, for the construction of the first bioammonia production facility. Iowa is an ideal choice for the site as it is in the heart of a major US grain-producing area and has a surfeit of waste biomass, which can be used as a source of raw material.

$7m per year will be used to purchase corncobs for the plant. The site is also close to major road and rail routes for the transportation of raw material and product.

The new SynGest facility will be capable of processing 130,000t of corn cobs per year to manufacture 50,000t of bio-ammonia (150t per day), which is sufficient to fertilise 500,000 acres of farmland. Pre-construction design, engineering and environmental assessment for the plant are in the final stages. The front-end engineering and design (FEED) for the project has been headed by Dr Ravi Randhava, chief technology officer of SynGest.

Randhava has been involved in the 'mini-plant' industry for a number of years and has based the design of the Menlo facility on an ammonia mini-plant concept he was involved in producing for Xytel-Bechtel, Inc (XBI) in the 1980s–1990s. He is president of Unitel Technologies and was a co-founder of the Xytel Group and the subsequent joint venture with the engineering company Bechtel, known as XBI.

The engineering, procurement and construction contract was awarded to the Weitz Company. The SynGest/Weitz team is targeting site preparation in autumn 2009 with construction beginning in spring 2010. The new plant is expected to be fully operational by autumn 2011.

Business model for biomass

According to Jack Oswald, the CEO of SynGest Inc, the new plant is not a pilot plant but is a mini-plant, which forms the basis of a business model designed to take advantage of areas in the world where there is waste biomass in abundance. Examples of this are sugar production in Brazil where the pulp can be used and also waste from rice production.

"The new SynGest facility will be capable of processing 130,000t of corn cobs per year to manufacture 50,000t of bio-ammonia."

SynGest will only be using 10% of the biomass that is available in the surrounding area. It plans to have a 75-acre site that can be used to stockpile corncobs following the harvest and give enough material to run the plant all year round.

The company is primarily focused on fertilisers but ammonia is a hydrogen source and could be used in alkaline fuel cells to power all sorts of equipment. There is already some movement towards establishing an ammonia infrastructure for powering agricultural machinery and the plant will not only return ammonia but also several other products such as biochar (20t produced per day), which can be used to enrich the soil. There will be excess heat from the plant that can be channelled off and used for other processes.

SynGest cannot generate enough power to run the whole thing but it can call on wind power in Iowa. There is also the stability of supply of natural gas to be taken into consideration, whereas corncobs and other biomass sources are plentiful.

Within the US, the stability of supply of nitrogen fertiliser is important. There are only a few large ammonia plants remaining in the US, which are coming to the end of their lifecycle. If biomass is not used as a source of ammonia then the US will be totally reliant on imports.

The SynGest plant at Menlow will be the first new ammonia production facility constructed in the US for five years. "We hope there will be around 20 plants across Iowa and we are in negotiations in seven other agriculture-based states," says Oswald.

"The new plant is expected to be fully operational by autumn 2011."

Financing the project

The facility is expected to cost between $102m and $105m to construct. So far support has been forthcoming from several US sources with one of the latest being an investment from Heartland Co-op, an Iowa grain production cooperative with 48 grain elevators which will also provide corncob material.

SynGest has a $3m loan from the Iowa Department of Economic Development, and has asked the Iowa Power Fund for a $2.5m grant. It also plans to ask the US Department of Energy for a $50m grant.

The project is expected to create 40 permanent jobs, alongside construction employing around 200 workers. SynGest will be able to apply for tax credits from the state worth around $805,472, based on capital investment. The latest estimates, based on current pricing, suggest that the Menlow plant will generate revenue of between $25m and £35m per year.