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Alkali (NaOH) pretreatment of switchgrass by radio frequency-based dielectric heating.

Applied biochemistry and biotechnology · 2008 · Benefit · Insufficient evidence

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BenefitInsufficient evidencePaper 3393

RF-based dielectric heating was used to assist NaOH pretreatment of switchgrass and was reported to improve sugar yields compared with conventional heating under several conditions. At 20% solid content (0.1 g NaOH/g biomass, 90°C), RF-assisted pretreatment p…

Study snapshot

PublicationApplied biochemistry and biotechnology · 2008
Study typeengineering
Reported directionBenefit
Evidence ratingInsufficient

Abstract

Radio-frequency (RF)-based dielectric heating was used in the alkali (NaOH) pretreatment of switchgrass to enhance its enzymatic digestibility. Due to the unique features of RF heating (i.e., volumetric heat transfer, deep heat penetration of the samples, etc.), switchgrass could be treated on a large scale, high solid content, and uniform temperature profile. At 20% solid content, RF-assisted alkali pretreatment (at 0.1 g NaOH/g biomass loading and 90 degrees C) resulted in a higher xylose yield than the conventional heating pretreatment. The enzymatic hydrolysis of RF-treated solids led to a higher glucose yield than the corresponding value obtained from conventional heating treatment. When the solid content exceeded 25%, conventional heating could not handle this high-solid sample due to the loss of fluidity, poor mixing, and heating transfer of the samples. As a result, there was a significantly lower sugar yield, but the sugar yield of the RF-based pretreatment process was still maintained at high levels. Furthermore, the optimal particle size and alkali loading in the RF pretreatment was determined as 0.25-0.50 mm and 0.25 g NaOH/g biomass, respectively. At alkali loading of 0.20-0.25 g NaOH/g biomass, heating temperature of 90(o)C, and solid content of 20%, the glucose, xylose, and total sugar yield from the combined RF pretreatment and the enzymatic hydrolysis were 25.3, 21.2, and 46.5 g/g biomass, respectively.

Machine Enhanced Logic

AI evidence extraction

Structured fields below were generated from the paper’s abstract and metadata to make the evidence easier to inspect. Automated extraction may be incomplete or incorrect; verify important details against the original paper.

Study typeengineering
Effect directionbenefit
PopulationNot supplied
Sample sizeNot supplied
ExposureRF
Evidence strengthInsufficientConfidence: 74% · Peer reviewed: yes

Main findings

RF-based dielectric heating was used to assist NaOH pretreatment of switchgrass and was reported to improve sugar yields compared with conventional heating under several conditions. At 20% solid content (0.1 g NaOH/g biomass, 90°C), RF-assisted pretreatment produced higher xylose yield than conventional heating, and enzymatic hydrolysis of RF-treated solids produced higher glucose yield than conventional heating. When solid content exceeded 25%, conventional heating produced significantly lower sugar yield, while RF-based pretreatment maintained high sugar yields; optimal particle size and alkali loading for RF pretreatment were reported as 0.25–0.50 mm and 0.25 g NaOH/g biomass.

Outcomes measured

  • xylose yield
  • glucose yield
  • total sugar yield
  • enzymatic digestibility
  • process performance at high solid content
  • optimal particle size
  • optimal alkali (NaOH) loading
View raw extracted JSON
{
  "study_type": "engineering",
  "exposure": {
    "band": "RF",
    "source": "radio frequency-based dielectric heating",
    "frequency_mhz": null,
    "sar_wkg": null,
    "duration": null
  },
  "population": null,
  "sample_size": null,
  "outcomes": [
    "xylose yield",
    "glucose yield",
    "total sugar yield",
    "enzymatic digestibility",
    "process performance at high solid content",
    "optimal particle size",
    "optimal alkali (NaOH) loading"
  ],
  "main_findings": "RF-based dielectric heating was used to assist NaOH pretreatment of switchgrass and was reported to improve sugar yields compared with conventional heating under several conditions. At 20% solid content (0.1 g NaOH/g biomass, 90°C), RF-assisted pretreatment produced higher xylose yield than conventional heating, and enzymatic hydrolysis of RF-treated solids produced higher glucose yield than conventional heating. When solid content exceeded 25%, conventional heating produced significantly lower sugar yield, while RF-based pretreatment maintained high sugar yields; optimal particle size and alkali loading for RF pretreatment were reported as 0.25–0.50 mm and 0.25 g NaOH/g biomass.",
  "effect_direction": "benefit",
  "limitations": [],
  "evidence_strength": "insufficient",
  "confidence": 0.74,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "radio frequency",
    "RF-based dielectric heating",
    "alkali pretreatment",
    "NaOH",
    "switchgrass",
    "enzymatic hydrolysis",
    "glucose yield",
    "xylose yield",
    "high-solids processing"
  ],
  "suggested_hubs": []
}
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AI-extracted fields are generated from the abstract and metadata and may be incomplete or incorrect. This material is for informational purposes and is not medical advice.

Identifiers and source

DOI: 10.1007/s12010-007-8083-1
PubMed: 18418741

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