Today the focus in the emerging biorefinery area is in second-generation biofuel for the transport sector; other end products will become interesting as the industry matures.
Bioethanol plants are operated in various forms, they can be anything from companies in the chemical and oil industries to forestry companies facing the fact that the demand for some of the traditional products is decreasing. The challenge is to find new revenue sources. Using e.g. residues from the forest to produce various forms of biofuels or other useful and marketable products has proven successful.
”Valmet’s focus is on second-generation biofuels, primarily ethanol. Green coal is also a priority as this product will reduce CO2 emissions significantly in the future. Green coal can primarily be used as a carbon-neutral and environment-friendly fuel in power plants to replace up to 45% of the fossil coal. During the past year, Valmet (until Dec. 31, 2013 Metso Paper) has been in contact with over 70 companies interested in building pilot, demonstration or commercial-scale biorefinery plants. This has already resulted in nineteen systems sold”, says Rickard Andersson, Vice President, Bio Business Development.
The demand for bio-based transportation fuels, like E85, is increasing.
“Valmet is developing processes and equipment in three main routes where the end products are second-generation bio-based transportation fuels, chemicals and materials via concentrated acid hydrolysis of biomass and green coal. Our technology is today mainly suitable for the initial steps of the process chain: pretreatment and feeding of biomass into pressurized reactors, separation of liquids and solid reaction products and separation and recovery of steam”, says Andersson. The solutions develop all the time to include more sub-processes in the biorefinery chain, through co-operation with customers and own development work.
The key driving force for producing transportation fuels from biomass and green coal is to reduce global warming through reduced emissions of fossil carbon dioxide. The production of chemicals and materials, e.g. polymers and plastics from biomass, contributes to making the society more sustainable. A finite resource – fossil oil – is replaced by renewable biomass. Moreover, several countries would like to reduce their dependence on fuel imports.
Most of the potential biorefinery projects are looking at agricultural and forest industry residues as feed stock. ”Valmet has experience and proven technology for annual fibers and forest products and can mainly supply equipment to the front end of a biorefinery”, says Andersson.
There are several process solutions, but the hydrolysis stage will be a key first process unit for all variants. C5 (xylose) och C6 (glucose) sugars will be the key intermediates. From these, not only ethanol can be produced, but also many chemicals that will be important as the industry develops.
Three different methods are available for refining of biomasses to green coal. Torrefaction is a process where biomass is heated without oxygen, breaking its fibrous structure, removing vapors and volatiles, and giving it coal-like physical properties. Hydro Thermal Carbonization (HTC) method is torrefaction in liquid phase and takes place in a pressurized reactor. Steam Explosion (SE) is a method where the biomass is heated with steam in a pressure vessel and then blown to atmospheric pressure breaking the material structure.
High-quality, water-resistant green coal pellets are produced with a high level of security.
Valmet primarily uses the steam explosion method as pellets produced by this method have many good physical properties. For example, the quality is high, it is water resistant and the manufacturing process maintains a high level of security. Valmet already has the technology required and successful pilot trials have been conducted.
In July 2012, Clariant, the Swiss speciality chemicals company, inaugurated Germany’s largest second-generation bioethanol plant. With an annual production of 1,000 tonnes, the plant will produce climate-friendly cellulosic ethanol from around 4,500 tonnes of agricultural waste, like wheat straw. The pretreatment system in the plant is supplied by Valmet. This project is a good example of Valmet breaking ground into a new market with proven and improved technology, while at the same time reducing the environmental impact. Tests were done in Valmet’s Sundsvall pilot plant and the result was a really good end product after the pretreatment stage. The biofuel produced at Clariant (second-generation bioethanol), cuts CO2 emissions by about 95% compared to fossil-based fuels without competing with food production. There is no “food or fuel” issue as plant waste is recycled. “This plant clearly demonstrates that products traditionally based on petroleum can be manufactured to the same standard using biomass. Thus this new plant serves as an important contribution to a sustainable Bio-Economy”, the Federal Minister of Research Annette Schavan said during the inauguration.
If the established national climate targets for the share of bio-based transportation fuels by 2020 would be met exclusively by second-generation bioethanol, it would require 130 billion liters. This volume will not be achieved. A more reasonable estimate, made by McKinsey, is 25 billion liters of bioethanol from lignocellulosic materials by 2020. The announced demand would require building more than 300 second-generation bioethanol plants based on cellulose within the next ten years. Building that many plants may not be possible, but the demand will grow, the market is there and the driving forces will increase. Emissions from power producers in the EU have been regulated by a directive which comes into force in 2016. The limit values for nitrogen and sulfur oxides and particulates are thereby tightened, making it beneficial for power plants to replace hard coal with biomass in the near future.
Valmet is investing in bio organization to cope with pressure from the market. The company has many products suitable for second-generation bioethanol and pellets plants. The possibilities are many and the demand is strong. Valmet will meet it with experience and new technologies.