Valorization of algal waste via pyrolysis in a fixed-bed reactor: Production and characterization of bio-oil and bio-char

Abstract

The aim of the present work is to develop processes for the production of bio-oil and bio-char from algae waste using the pyrolysis at controlled conditions. The pyrolysis was carried out at different temperatures 400-600°C and different heating rates 5-50°C/min. The algal waste, bio-oil and bio-char were successfully characterized using Elemental analysis, Chemical composition, TGA, FTIR, H NMR, GC-MS and SEM. At a temperature of 500°C and a heating rate of 10°C/min, the maximum yield of bio-oil and bio-char was found to be 24.10 and 44.01wt%, respectively, which was found to be strongly influenced by the temperature variation, and weakly affected by the heating rate variation. Results show that the bio-oil cannot be used as bio-fuel, but can be used as a source of value-added chemicals. On the other hand, the bio-char is a promising candidate for solid fuel applications and for the production of carbon materials.

One-pot activation and pyrolysis of Moroccan Gelidium sesquipedale red macroalgae residue: production of an efficient adsorbent biochar

“…After 48 h of impregnation at room temperature, the chemically activated samples were dried at 105 °C for 24 h. Biochars from raw and chemically activated algae residues were produced in a labscale pyrolysis device developed in the laboratory (Fig. 2) under operating conditions adapted from (Francavilla et al 2014;Aboulkas et al 2017). All of the experiments were carried out using a horizontal stainless steel fixed-bed reactor.…”

“…In this study, an activation/pyrolysis process was developed and referred to a "one-pot activation and pyrolysis process". Moroccan Gelidium sesquipedale red macroalgae residue is abundant in Marine area of Morocco (3500 km of coastline) (Ainane and M'hammed 2011), which represents about 90% of the harvest of the marine algae treated locally and generated an important quantity of residues and by-products, which is estimated to be of 870 tons/years (Aboulkas et al 2017). The algal residue was impregnated using different chemical catalysts and then directly pyrolyzed without washing and without generation of waste effluents.…”

A comparative study of the behavior of Chlamydomonas reinhardtii and Spirulina platensis in solar catalytic pyrolysis

“…The NH stretches are weaker and narrow than those of OH. The absorption bands between 2960 and 2875 cm −1 correspond to CH bond vibrations bond associated with methyl or methylene groups such as alkanes and alkenes, confirming the presence of hydrocarbons . The peaks near 1870 and 1540 cm −1 confirm the occurrence of CO stretching related to aldehydes, acids, and esters groups.…”

“…Similar functional groups are observed in the bio‐oil samples. The strong absorption bands localized near the 3100 and 3500 cm −1 regions can be ascribed to ν(OH) vibrations, which indicate the presence of oxygenated compounds in the bio‐oil such as alcohols, phenols, and water . However, in this region there is another band generally attributed to NH groups, that can be overlapped by the OH absorption peak .…”

Hidropirólise solar da microalga Chlamydomonas reinhardtii combinada com o precursor catalítico tipo Hidrotalcita

“…As análises imediata e elementar e o poder calorífico (HHV) do bio-char obtido dos testes ABOULKAS et al, 2017). Os vários picos encontrados podem indicar a presença de materiais não carbonáceos como minerais (CHEN et al, 2016;SONIBARE et al, 2010).…”