Biocrude Production from Wheat Straw at Sub and Supercritical Hydrothermal Liquefaction

Tahir H Seehar,Thomas H Pedersen,Ayaz A Shah,Lasse A Rosendahl,Saqib S Toor

doi:10.3390/en13123114

Tahir H Seehar, Thomas H Pedersen + Show 3 more

Open Access

https://doi.org/10.3390/en13123114

Copy DOI

Abstract

In this study, hydrothermal liquefaction (HTL) of wheat straw (WS) in sub (350 °C) and supercritical (400 °C) water with and without alkali catalyst was performed to investigate the potential of WS for the production of biocrude. The influences of temperature and catalyst were studied for the HTL products. Results showed that maximum biocrude yield (32.34 wt. %) with least solid residue (4.34 wt. %) was obtained at subcritical catalytic condition, whereas the carbon content was slightly higher in biocrude at supercritical. The higher heating value (HHV) for biocrude is around 35 MJ/kg for all four conditions. The major compounds in biocrude were observed as ketones, alcohols, acids, and hydrocarbons. At 350 °C, 44–55% of the carbon recovered into biocrude. The products were characterized in terms of elemental composition, higher heating values, organics, and inorganic compounds in different phases. To keep in consideration the scale-up of HTL process for continuous plant, aqueous phase from HTL was also recirculated which showed the fruitful outcomes by increasing the biocrude yield at each cycle.

Highlights

The consumption and demand for energy are continuously increasing due to rapid growth in population and the global economy
The aim of this study is to provide the comparative information about the production and properties of the biocrude through hydrothermal liquefaction at sub- and supercritical conditions
Wheat straw was used as a feedstock along with distilled water and thermally liquefied at the sub and supercritical temperature with and without the alkali catalyst K2 CO3

Summary

Introduction

The consumption and demand for energy are continuously increasing due to rapid growth in population and the global economy. Depletion of fossil fuel reservoirs and increasing greenhouse gasses (GHG) emissions are harmful to the environment. As an alternative to fossil fuels, biomass has become a more attractive resource for years as a renewable source of energy. The utilization of biomass for the production of energy reduces GHG emission as well as dependency on fossil fuels [1]. Lignocellulosic biomass is non-edible and potentially available in the world in the form of forest, wood, and agricultural residue that can be adopted for the fuel production [2].

Objectives

Methods

Results

Conclusion