Fast Pyrolysis of Opuntia ficus-indica (Prickly Pear) and Grindelia squarrosa (Gumweed)

Abstract

Opuntia ficus-indica (prickly pear) and Grindelia squarrosa (gumweed) are two exceptionally drought tolerant plant species capable of growing in arid and semiarid environments. Additionally, they have unique cell wall structures. Prickly pear contains pectin and high levels of ash (16.1%) that is predominantly Ca and K. Gumweed has high levels of extractives that contain grindelic acid and monoterpenoids. The objective of this paper was to evaluate how these unique cell wall components alter the pyrolysis performance of prickly pear and gumweed. Using a tandem micropyrolyzer with GC-MS/FID/TCD, a detailed account of the product slate is given for products generated between 450 and 650 °C. Pyrolysis of prickly pear showed that the high levels of ash increase the amount of organics volatilized and shifted product pools, making it possible to generate up to 7.3% carbonyls vs 3.8% for Pinus taeda (loblolly pine) and 10.5% hydrocarbons vs 1.8% for pine depending on reaction conditions. Pyrolysis of gumweed showed that the extractives were volatilized at low temperatures and led to 17.7% grindelic acid and monoterpenoids derivatives in the condensed vapor phase. At high temperatures, the extractives and other biomass components are converted to aromatics and C5–C10 hydrocarbons, giving a total yield of 16.6%, and also generate large amounts of C2–C4 hydrocarbons, 11.3%.

Biomass Fast Pyrolysis Using a Novel Microparticle Microreactor Approach: Effect of Particles Size, Biomass Type, and Temperature

“…On the laboratory scale, research has focused on characterization of both weight losses, condensable and noncondensable volatiles. Various laboratory techniques, such as radiant flash pyrolysis, wire-mesh heating, drop tube processing, micropyrolyzers, − pyroprobes, − pyrolysis gas chromatography/mass spectrometry (Py-GC/MS), − and most recently the pulse-heated analysis of solid reactions (PHASRs) technique, , have all been used to achieve high heating rates.…”

Multiscale Catalytic Fast Pyrolysis of Grindelia Reveals Opportunities for Generating Low Oxygen Content Bio-Oils from Drought Tolerant Biomass

“…In addition, the results were compared to those for noncatalytic fast pyrolysis with the same amount of biomass but no catalyst. 2 The carbon yields (g of C in product/g of C in feed) of products by compound type and carbon number are illustrated in Figure 1 and Figure S1 in the SI. Oxygenates were the largest compound group during the noncatalytic fast pyrolysis of Grindelia (with phenols, carbonyls, acids, and alcohols major oxygenate groups, Table S1 in the SI), but with contributions from hydrocarbons (5% carbon yield), including those with carbon numbers ≥5, as was reported earlier.…”

“…Oxygenates were the largest compound group during the noncatalytic fast pyrolysis of Grindelia (with phenols, carbonyls, acids, and alcohols major oxygenate groups, Table S1 in the SI), but with contributions from hydrocarbons (5% carbon yield), including those with carbon numbers ≥5, as was reported earlier. 2 Aromatic hydrocarbons and low-carbon number aliphatics (mainly alkenes) were the largest product pools during CFP and can be selectively formed by altering catalyst placement. In situ CFP generated the highest yields of aromatic hydrocarbons (30% carbon yield, Figure S1), whereas ex situ CFP favored aliphatics (25% carbon yield, Figure S1); higher aromatic hydrocarbons and lower alkenes for the in situ configuration have been found for other feedstocks as well.…”

“…In the 21st century, we will see increased drought severity and duration through decreased precipitation/increased evaporation. 1,2 Therefore, drought-tolerant plants must be included in the biofuel economy. The benefits of drought-tolerant plants as feedstocks for biofuels and biochemicals have been identified by other groups 3,4 who stressed that increasing global temperature, drought, and soil-drying conditions caused by climate change will increase competition for agricultural freshwater and cultivated soils.…”

“…Previous work conducted with Grindelia using noncatalytic fast pyrolysis at different temperatures determined several interesting characteristics of the fast pyrolysis vapors. 2 Most notable was the observation that the extractives were successfully volatilized at 450 °C and partially deoxygenated through thermal cracking at 550 °C, leading to the formation of aromatics and aliphatic hydrocarbons. The vapors produced from Grindelia during fast pyrolysis showed significant potential for application in the production of fuels due to the high fraction of hydrocarbons in the product and the consequent high H/C eff value.…”