Biomass collection efficiency

Increasing Biomass Collection Efficiency by Responding to In-Field Variability... 

This research is being performed in two phases evaluation of pressure drop and flow characteristics of cold flow models of the filter and collection efficiency tests with a pilot-scale filter coupled to a 4.S tonne per day biomass gasifier. In this paper we describe three fluid dynamic design features developed in the cold flow model that improve performance of the Alter. 

Biomass yield variables—those that affect the mass per acre delivered to the biorefinery—are particularly important since they reside at the front end of the feedstock supply chain and thus have broad impacts that extend through the entire supply chain. In fact, biomass yield affects many of the other variable categories identified in the analysis, including machinery performance and system variables (harvest window and transportation distance). Accordingly, uncertainties of biomass yield variables—particularly collection efficiency and storage dry matter losses—are the focus of the discussion that follows. 

Collection efficiency (the ratio of biomass colleeted to the total amount available in the field) ranked second in sensitivity, fifth in uncertainty, seeond in influence, and highest in overall combined ranking. The probability distribution for collection efficiency used in this analysis was based on a review of reported com stover collection efficiencies (Richey et al., 1982 Shinners et al., 2003 Schechninger and Hettenhaus, 2004 Shinners and Binversie, 2004 Prewitt et al., 2007) from which we chose a most likely value of 43%, a minimum of 19%, and a maximum of 65%. The wide range of reported results show that current machinery itself is capable of high removal... 

In 2002, a prominent collection of scientists wrote, Biomass plantations can produce carbon-neutral fuels for power plants or transportation, but photosynthesis has too low a power density ( 6 W/m2) for biofuels to contribute significantly to climate stabilization. These researchers find the scale of our growing energy demand so daunting that they conclude that none of today s current options for renewable energy or energy efficiency are up to the... 

The conversion efficiency of the synthesis gas-to-methanol step is about 85%, and it is usually assumed that improved catalytic gasification techniques are required to raise the overall conversion efficiency above the 51% mentioned above (Faaij and Hamelinck, 2002). The total efficiency will become lower if all life-cycle contributions involving energy inputs, e.g. for collecting and transporting biomass, are included (EC, 1994). 

The boilers are of water-wall construction with the walls in the bed region lined with refractory to protect against erosion and abrasion damage. The heat released in the bed is removed from the flue gas by the exposed water walls and by convection pass tubing set in the gas path after the boiler. The coal boilers included multiclones to collect elutriated carbon and recycle it back to the boiler to increase combustion efficiency. However, because biomass is more reactive, recycle is not required. 

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