Plant biomass refineries

Depletion of fossil oil resources and concern about environmental pollution, especially heavy metals and greenhouse gases, have brought biomass into focus as a renewable source of raw materials for large-scale chemicals and energy production (1). The biomass refinery of the future will require a powerful toolbox of processes for converting complex plant matter into useful commodity and specialty products. 

European refinery gasification projects include the API project in Falconara, Italy Sarlux project in Sardinia, Italy ISAB project in Sicily, Italy and Shell project in Pemis, Netherlands. Several plants are also reported to gasify biomass to produce gaseous fuels or electric power. 

Chemical intermediates are produced at a scale that is close to that of biomass conversion plants, e.g., between 100 kt a-1 (e.g., for acrylic acid) to 800 kt a-1 (e.g., for ethene diol). This has to be compared with the 20 Mt a-1 scale of a major oil refinery. 

The valorization of by-products in biomass conversion is a key factor for introducing a biomass based energy and chemistry. There is the need to develop new (catalytic) solutions for the utilization of plant and biomass fractions that are residual after the production of bioethanol and other biofuels or production chains. Valorization, retreatment or disposal of co-products and wastes from a biorefinery is also an important consideration in the overall bioreftnery system, because, for example, the production of waste water will be much larger than in oil-based refineries. A typical oil-based refinery treats about 25 000 t d-1 and produces about 15 000 t d 1 of waste water. The relative amount of waste water may increase by a factor 10 or more, depending on the type of feed and production, in a biorefinery. Evidently, new solutions are needed, including improved catalytic methods to eliminate some of the toxic chemicals present in the waste water (e.g., phenols). 

IGCC plants can use various coal types, biomass, and other refinery byproducts. 

Biorefinery A refinery that produces fuels from biomass. These fuels may include bioethanol (produced from com or other plant matter) or biodiesel (produced from plant or animal matter). 

Although still limited, there is also some interest in using biomass-derived raw materials (bio-ethanol, glycerine) in ammoxidation processes. These processes could be of value only in the context of valorization of side streams in bio-refinery plants. However, owing to the growing interest in the latter, it may be expected that some opportunities will arise for the ammoxidation of biomass-derived side-products in the near future. 

It is important to realize the general characteristics of IBPCSs and what is required to sustain their operation. As an example, consider an IBPCS that produces salable energy products at a rate of 10,000 BOE/day from virgin biomass. This is a small output relative to most petroleum refineries, but it is not small for an IBPCS. Assume that the conversion plant operates at an availability of 330 day/year and an overall thermal efficiency of feedstock to salable energy products of 60%, a reasonable value for established thermochem-... 

The first example (Fig. 10) shows the evolution of UV spectra of raw and treated wastewater for one refinery and one petrochemical site, with two different biological treatment plants, one with fixed biomass, and the other with activated sludge. For both cases, the treatment efficiency is good, with a TOC removal of around 90% (either measured or UV-estimated) and the presence of nitrate in the treated effluent. 

For the feedstock, there are logistical and sustainability concerns. Each potential biorefinery concept has specific coproduct and waste issues to consider. Transport is a general issue in this discussion. The biomass resource has to be transported to the refinery subsequently the products have to be transported to the downsdeam industry and/or the consumer. Of interest is the approach of the company Nature-Works LLC that currently operates the largest biorefinery in the United States in Blair, Nebraska. The nameplate capacity of the polymer production plant is 140,000 tons of polymer per year. Corn is the basis for the production of the bioplastic polylactic acid (PLA) in a complex multistage process. Sixty percent of its com feedstock is obtained from the local area (producers, located less than 40 kilometers from the plant). Several companies in an emergent network are now active on the Blair biorefinery campus (Wells and Zapata, 2012) reducing transportation from one industrial branch to the next one. 

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