Analysis on Storage Off-Gas Emissions from Woody, Herbaceous, and Torrefied Biomass

Abstract

Wood chips, torrefied wood chips, ground switchgrass, and wood pellets were tested for off-gas emissions during storage. Storage canisters with gas-collection ports were used to conduct experiments at room temperature of 20 °C and in a laboratory oven set at 40 °C . Commercially-produced wood pellets yielded the highest carbon monoxide (CO) emissions at both 20 and 40 °C (1600 and 13,000 ppmv), whereas torrefied wood chips emitted the lowest of about <200 and <2000 ppmv. Carbon dioxide (CO2) emissions from wood pellets were 3000 ppmv and 42,000 ppmv, whereas torrefied wood chips registered at about 2000 and 25,000 ppmv, at 20 and 40 °C at the end of 11 days of storage. CO emission factors (milligrams per kilogram of biomass) calculated were lowest for ground switchgrass and torrefied wood chips (2.68 and 4.86 mg/kg) whereas wood pellets had the highest CO of OPEN ACCESSEnergies 2015, 8 1746 about 10.60 mg/kg, respectively, at 40 °C after 11 days of storage. In the case of CO2, wood pellets recorded the lowest value of 55.46 mg/kg, whereas switchgrass recorded the highest value of 318.72 mg/kg. This study concludes that CO emission factor is highest for wood pellets, CO2 is highest for switchgrass and CH4 is negligible for all feedstocks except for wood pellets, which is about 0.374 mg/kg at the end of 11-day storage at 40 °C.

Pelleting of Pine and Switchgrass Blends: Effect of Process Variables and Blend Ratio on the Pellet Quality and Energy Consumption

“…According to Ray et al [10], the use of blended and densified feedstocks in conversion pathways instead of conventionally ground biomass from a single source addresses several challenges in the current biomass supply chain, such as transportation, storage, cost, quality, and supply variability. Edmunds et al [11], Sahoo and Mani [50], and Tumuluru et al [51] reported that herbaceous biomass, such as switchgrass, has a bulk density in the range of 150-160 kg/m 3 . Based on the present study, pelleting blends of switchgrass + 2-inch top pine residue increased bulk density values to about 540-580 kg/m 3 .…”

Effect of Moisture Content and Hammer Mill Screen Size on the Briquetting Characteristics of Woody and Herbaceous Biomass

“…Variable moisture content, low bulk density, and irregular size and shape create feeding, handling, and transportation issues that limit the biomass application at commercial scale for biofuels and biopower generation. Typically, herbaceous biomass after harvesting has a bulk density of 112 to 160 kg/m 3 (Atchison and Hettenhaus, 2004), whereas woody biomass has a bulk density of 220 to 265 kg/m 3 (Tumuluru et al, 2015a). Tumuluru et al (2016) indicated that densification helps to convert the raw biomass resources into an aerobically stable, high-density, tradable, and aggregatable commodity-like product.…”

Emission Factors and Energy Properties of Agro and Forest Biomass in Aspect of Sustainability of Energy Sector

“…This energy can be used for very different purposes, including the production of heat by burning. Of course, when burning biomass, carbon dioxide and other pollutants are released, but it is a gas that has been absorbed into the primary growth of combusted biomass and that will be absorbed during the photosynthesis processes carried out by new plants [3][4][5]. Surely, the assumption that the total emission is zero would be a mistake, because the cultivation of plants used for biomass requires some energy expenditure.…”