Bio-SNG (Synthetic Natural Gas) and Gasification Technologies
Bio-SNG is produced by gasification of cellulosic materials (e.g. forestry residues, energy crops), whereas "biogas" is produced by a biological process - anaerobic digestion of organic materials (e.g. manure, organic waste).
Bio-SNG is typically produced via an initial gasification step followed by gas conditioning, SNG synthesis and gas upgrading. Bio-SNG can be used in a similar way to biomethane (biogas) generated via anaerobic digestion. Syngas may also be converted into liquid advanced biofuels. Syngas may be converted to diesel, ethanol (e.g. Fulcrum Bioenergy) or other fuel molecules (e.g. via Methanol To Gasoline technology).
Biomass Gasification Technology Assessment (US 2012)
In November 2012 an extensive Biomass Gasification Technology Assessment was produced by M. Worley and J. Yale, Harris Group Inc. on behalf of NREL. The goal was to solicit and review the technical and performance data of gasifier systems and develop preliminary capital cost estimates for the core equipment. Specifically, the assessments focused on gasification and tar reforming technologies that are capable of producing a syngas suitable for further treatment and conversion to liquid fuels.
Bio-SNG Projects in Europe
SNG Demonstration in Güssing
The Biomass CHP Plant Güssing, which started operation in 2002, has a fuel capacity of 8 MW and an electrical output of about 2 MWel with an electrical efficiency of about 25 %. Wood chips with a water content of 20 – 30 % are used as fuel. The plant consists of a dual fluidized bed steam gasifier, a two-stage gas cleaning system, a gas engine with an electricity generator, and a heat utilization system, offering a complete value chain demonstration from woody biomass to SNG.
Commercial bio-sng plants are expected to be in the scale of 20 to 200 MW. In the initial conversion step i.e. in the biomass gasification process wood chips are converted into a syngas or more general into a product gas. The FICFB gasification process has operated in Güssing since 2002 for a combined heat and power (CHP) plant and in this time has been in operations for many 10000s of hours. The product gas is delivered at ambient pressure, has a high content of CH4, higher hydrocarbons and tars. This product gas is suitable for SNG production.
The final conversion step consists of three individual steps, i.e. gas conditioning, SNG synthesis and gas upgrading. R&D work over the first 8 years at Güssing focused on gas conditioning and SNG synthesis. The pilot scale showed that fluidized bed SNG synthesis is possible. The whole process chain reaches high conversion efficiencies and has the potential for lower investment and lower operation costs than conventional SNG synthesis technology.
The GoBiGas facility was inaugurated on 12 March 2014. On 18 December 2012 it was announced that GoBiGas Phase 2, Sweden, had been selected to receive counterpart funding of €58.8m under the first call for proposals of the NER300 funding programme for innovative low-carbon technologies. The Project will demonstrate the large-scale conversion of low-quality wood into high quality synthetic natural gas (SNG) by indirect gasification at atmospheric pressure, gas cleaning, methane production (via nickel catalyst), pressurization and injecting the product into the regional gas network. The Project will make use of forestry feedstock, which consists of pulpwood and forest residues harvested from the surrounding areas of Gothenburg, the Lake Vänern and Baltic region. The volume of ~0.5 Mt/year of wet biomass will be used in the Project, which has an installed capacity of ~100 MWth to produce 800 GWh/year of gas (SNG).
Gaya Demonstration Project
The Gaya Demonstration project, supported by the EC, aims to demonstrate a commercial pathway for gasification and methanation of residues (e.g. wood, straw) to produce synthetic biomethane at the industrial scale.
Dong Pyroneer Plant, Denmark
DONG Energy has developed a new technology 'Pyroneer' that converts biomass to gas at low temperature. In 2011, it established a 6MW demonstration plant adjoining Asnæs Power Station near Kalundborg.
Birmingham Bio Power Plant, Tyseley, UK
In December 2013 it was announced that work will begin on a 10.3 MW biomass gasification plant in Tyseley, UK. The plant will be developed by Carbonarius, a joint venture of O-Gen UK and UNA Group, with a £47.8m investment by the UK Green Investment Bank and Foresight Group. The plant will be built and operated by MWH, based in Broomfield, US, and will use the biomass gasification process of the Canadian firm Nexterra Systems to convert 67,000 metric tons of locally-sourced woodwaste into power. The feedstock will be supplied by JM Envirofuels Ltd.
Waste-to-energy gasifier Lahti, Finland
160 MW thermal waste gasifier in Lahti, Finland, uses Solid Recovered Fuel SRF (the fraction of MSW that cannot be recllced) as a feedstock. This mainly consists of shredded textiles, wood, paper, card and plastics, etc. that would otherwise be destined for landfill. The gas is cooled and cleaned before being passed to the boiler.
Cortus WoodRoll® Technology Sweden
Cortus has built an integrated production flow plant where the drying, pyrolysis and gasification of different biofuels is run at the scale of 500 kW. In February 2012, it was announced that the plant had succeeded to produce synthesis gas from biomass without traces of hydrocarbons. This 'breakthrough' facilitates the use of the synthesis gas for more cost-effective fuel production.
Following the success of these trials, the aim is to construct a ten times larger demonstration plant in Köping. The plant is constructed in cooperation with Torkapparater AB, Concordance AB, AGA Gas AB, ÅF and Sandvik Heating Technology, among others. Funding comes from the Swedish Energy Agency, Triple Steelix, Movexum and Cortus.
Bio-SNG project (FP6)
Demonstration of the Production and Utilization of Synthetic Natural Gas (SNG) from Solid Biofuels (Bio-SNG) (TREN/05/FP6EN/S07.56632/019895)
The objective of the Bio-SNG project (2006-2009) was to demonstrate SNG (Synthetic Natural Gas) production from solid biofuels and to integrate this Bio-SNG into the existing energy infrastructure (i.e. fuel station for vehicles, natural gas grid).
It has been demonstrated, that the entire process chain (wood to Bio-SNG) is feasible and fulfils the expectations in terms of efficiency. Such technology can be applied in the energy industry for the production of sustainable fuel as a replacement of fossil fuel. The interested potential user of such technology is the energy sector, particularly the natural gas industry (distributors). Since the EU decided to replace fossil fuels partially, this technology can fill part of the gap. The technology is not yet fully mature, but a first small industrial scale project will allow the technology to achieve maturity. Such a project is being planned. The project was started upon a granted base patent which has been extended. Patent rights have not yet been granted.
In order to run the catalyst of the process, the synthesis gas needs to be purified from sulphur to a very large extent. A process stage has been developed in order to remove sulphur containing tars to an extent not yet known using biogenic solvents which can be regenerated. Such a process cannot only be applied for Bio-SNG production but also for other synthesis gases (e.g. from coal) or for other downstream processes (e.g. Fischer Tropsch). Patent protection has been applied for.
E.ON Bio2G Project
The E.ON Bio2G project in Sweden involves the design, erection and commissioning of a gasification plant with 200MW output, with construction planned to start in 2013.
Concord Blue / Blue Tower Gasification Technology
In Germany, Blue Tower (Concord Blue) is developing gasification technology to convert a wide range of wastes to energy via gasification system with up to 80% efficiency.
The ECN/HVC Project for BioSNG
ECN has been developing a system for the conversion of dry lignocellulosic biomass into natural gas quality gas: BioSNG or Substitute Natural Gas from biomass. Technology choices have been based on the desire to have large-scale BioSNG plants with high overall efficiency. The ECN concept is based on so-called MILENA indirect gasification and OLGA tar removal.
The ECN concept offers 70% efficiency from biomass to BioSNG. A lab-scale system is available at ECN. A 1 MW pilot system at ECN is under commissioning for the two main parts of the system: the MILENA gasifier and the OLGA tar removal. HVC is a waste company, which is expanding its activities towards renewable energy. Joining the development of the BioSNG-concept perfectly fits in with HVC’s ambitions in the medium and long term. HVC intends to realize two demonstration plants to demonstrate the ECN-concept.
The first demo plant will be a ~10 MW CHP plant to demonstrate the combination of the MILENA and OLGA-processes. The second demo plant will be a ~50 MW SNG plant in which the MILENA and OLGA are up-scaled and further gas cleaning and methanation will be added. These additional units will be supplied by a large EPC, which will soon be involved in the development.
Bio-SNG Demonstrations in the United States
Gasification for production of cellulosic ethanol
Sundrop Fuels has announced a partnership with ThyssenKrupp Uhde (Germany) to produce 50mgy of drop in biofuels (renewable gasoline) at a plant near Alexandria, Louisiana. The plant will combine natural gas and biomass (forest residues) using a commercial XTL process that integrates ThyssenKrupp Uhde’s High Temperature Winkler gasification process and gas cleaning, followed by methanol synthesis and methanol-to-gasoline (MTG) technology (licensed from Exonn Mobil).
In July 2013 IHI E&C International Corporation, a US subsidiary of Tokyo - based IHI Corporation, was announed as contractor of choice for Sundrop's Alexandria facility. The combined commercial and demonstration plant will annually produce about 60 million gallons of finished gasoline from natural gas while providing the platform for Sundrop Fuels to prove its proprietary gasification technology for production of 'green gasoline'.
The Rentech Inc. Port St. Joe Renewable Energy Project (Port St. Joe Project), in Florida, is an advanced-stage renewable power project that would employ a Rentech-SilvaGas biomass gasifier to provide synthesis gas to a combined–cycle power plant. The project is designed to produce approximately 55 megawatts net of renewable low-carbon base load electric power (RenPower™) from approximately 930 dry tons per day of woody biomass.